Non-invasive method of demonstrating internal anatomy based on the principle that atomic nuclei in a strong magnetic field absorb pulses of radiofrequency energy and emit them as radiowaves which can be reconstructed into computerized images. The concept includes proton spin tomographic techniques.
Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).
Non-invasive method of vascular imaging and determination of internal anatomy without injection of contrast media or radiation exposure. The technique is used especially in CEREBRAL ANGIOGRAPHY as well as for studies of other vascular structures.
A type of imaging technique used primarily in the field of cardiology. By coordinating the fast gradient-echo MRI sequence with retrospective ECG-gating, numerous short time frames evenly spaced in the cardiac cycle are produced. These images are laced together in a cinematic display so that wall motion of the ventricles, valve motion, and blood flow patterns in the heart and great vessels can be visualized.
Substances used to allow enhanced visualization of tissues.
A diagnostic technique that incorporates the measurement of molecular diffusion (such as water or metabolites) for tissue assessment by MRI. The degree of molecular movement can be measured by changes of apparent diffusion coefficient (ADC) with time, as reflected by tissue microstructure. Diffusion MRI has been used to study BRAIN ISCHEMIA and tumor response to treatment.
The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.
A complex of gadolinium with a chelating agent, diethylenetriamine penta-acetic acid (DTPA see PENTETIC ACID), that is given to enhance the image in cranial and spinal MRIs. (From Martindale, The Extra Pharmacopoeia, 30th ed, p706)
NMR spectroscopy on small- to medium-size biological macromolecules. This is often used for structural investigation of proteins and nucleic acids, and often involves more than one isotope.
Gadolinium. An element of the rare earth family of metals. It has the atomic symbol Gd, atomic number 64, and atomic weight 157.25. Its oxide is used in the control rods of some nuclear reactors.
Imaging techniques used to colocalize sites of brain functions or physiological activity with brain structures.
A technique of inputting two-dimensional images into a computer and then enhancing or analyzing the imagery into a form that is more useful to the human observer.
A biosensing technique in which biomolecules capable of binding to specific analytes or ligands are first immobilized on one side of a metallic film. Light is then focused on the opposite side of the film to excite the surface plasmons, that is, the oscillations of free electrons propagating along the film's surface. The refractive index of light reflecting off this surface is measured. When the immobilized biomolecules are bound by their ligands, an alteration in surface plasmons on the opposite side of the film is created which is directly proportional to the change in bound, or adsorbed, mass. Binding is measured by changes in the refractive index. The technique is used to study biomolecular interactions, such as antigen-antibody binding.
Methods developed to aid in the interpretation of ultrasound, radiographic images, etc., for diagnosis of disease.
Improvement of the quality of a picture by various techniques, including computer processing, digital filtering, echocardiographic techniques, light and ultrastructural MICROSCOPY, fluorescence spectrometry and microscopy, scintigraphy, and in vitro image processing at the molecular level.
A technique applicable to the wide variety of substances which exhibit paramagnetism because of the magnetic moments of unpaired electrons. The spectra are useful for detection and identification, for determination of electron structure, for study of interactions between molecules, and for measurement of nuclear spins and moments. (From McGraw-Hill Encyclopedia of Science and Technology, 7th edition) Electron nuclear double resonance (ENDOR) spectroscopy is a variant of the technique which can give enhanced resolution. Electron spin resonance analysis can now be used in vivo, including imaging applications such as MAGNETIC RESONANCE IMAGING.
The process of generating three-dimensional images by electronic, photographic, or other methods. For example, three-dimensional images can be generated by assembling multiple tomographic images with the aid of a computer, while photographic 3-D images (HOLOGRAPHY) can be made by exposing film to the interference pattern created when two laser light sources shine on an object.
Minimally invasive procedures guided with the aid of magnetic resonance imaging to visualize tissue structures.
The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.
A type of FLUORESCENCE SPECTROSCOPY using two FLUORESCENT DYES with overlapping emission and absorption spectra, which is used to indicate proximity of labeled molecules. This technique is useful for studying interactions of molecules and PROTEIN FOLDING.
Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)
Tomography using x-ray transmission and a computer algorithm to reconstruct the image.
Non-invasive diagnostic technique for visualizing the PANCREATIC DUCTS and BILE DUCTS without the use of injected CONTRAST MEDIA or x-ray. MRI scans provide excellent sensitivity for duct dilatation, biliary stricture, and intraductal abnormalities.
Stable elementary particles having the smallest known positive charge, found in the nuclei of all elements. The proton mass is less than that of a neutron. A proton is the nucleus of the light hydrogen atom, i.e., the hydrogen ion.
An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.
In screening and diagnostic tests, the probability that a person with a positive test is a true positive (i.e., has the disease), is referred to as the predictive value of a positive test; whereas, the predictive value of a negative test is the probability that the person with a negative test does not have the disease. Predictive value is related to the sensitivity and specificity of the test.
An amino acid that occurs in vertebrate tissues and in urine. In muscle tissue, creatine generally occurs as phosphocreatine. Creatine is excreted as CREATININE in the urine.
An endogenous substance found mainly in skeletal muscle of vertebrates. It has been tried in the treatment of cardiac disorders and has been added to cardioplegic solutions. (Reynolds JEF(Ed): Martindale: The Extra Pharmacopoeia (electronic version). Micromedex, Inc, Englewood, CO, 1996)
Behavioral manifestations of cerebral dominance in which there is preferential use and superior functioning of either the left or the right side, as in the preferred use of the right hand or right foot.
Elements of limited time intervals, contributing to particular results or situations.
Pathologic conditions affecting the BRAIN, which is composed of the intracranial components of the CENTRAL NERVOUS SYSTEM. This includes (but is not limited to) the CEREBRAL CORTEX; intracranial white matter; BASAL GANGLIA; THALAMUS; HYPOTHALAMUS; BRAIN STEM; and CEREBELLUM.
A class of compounds of the type R-M, where a C atom is joined directly to any other element except H, C, N, O, F, Cl, Br, I, or At. (Grant & Hackh's Chemical Dictionary, 5th ed)
A type of MAGNETIC RESONANCE IMAGING that uses only one nuclear spin excitation per image and therefore can obtain images in a fraction of a second rather than the minutes required in traditional MRI techniques. It is used in a variety of medical and scientific applications.
The thin layer of GRAY MATTER on the surface of the CEREBRAL HEMISPHERES that develops from the TELENCEPHALON and folds into gyri and sulchi. It reaches its highest development in humans and is responsible for intellectual faculties and higher mental functions.
Synthesized magnetic particles under 100 nanometers possessing many biomedical applications including DRUG DELIVERY SYSTEMS and CONTRAST AGENTS. The particles are usually coated with a variety of polymeric compounds.
Any visual display of structural or functional patterns of organs or tissues for diagnostic evaluation. It includes measuring physiologic and metabolic responses to physical and chemical stimuli, as well as ultramicroscopy.
A basic constituent of lecithin that is found in many plants and animal organs. It is important as a precursor of acetylcholine, as a methyl donor in various metabolic processes, and in lipid metabolism.
One of the non-essential amino acids commonly occurring in the L-form. It is found in animals and plants, especially in sugar cane and sugar beets. It may be a neurotransmitter.
A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.
Decrease in the size of a cell, tissue, organ, or multiple organs, associated with a variety of pathological conditions such as abnormal cellular changes, ischemia, malnutrition, or hormonal changes.
The part of the cerebral hemisphere anterior to the central sulcus, and anterior and superior to the lateral sulcus.
Iron (II,III) oxide (Fe3O4). It is a black ore of IRON that forms opaque crystals and exerts strong magnetism.
Lower lateral part of the cerebral hemisphere responsible for auditory, olfactory, and semantic processing. It is located inferior to the lateral fissure and anterior to the OCCIPITAL LOBE.
Neoplasms of the intracranial components of the central nervous system, including the cerebral hemispheres, basal ganglia, hypothalamus, thalamus, brain stem, and cerebellum. Brain neoplasms are subdivided into primary (originating from brain tissue) and secondary (i.e., metastatic) forms. Primary neoplasms are subdivided into benign and malignant forms. In general, brain tumors may also be classified by age of onset, histologic type, or presenting location in the brain.
One of the convolutions on the medial surface of the CEREBRAL HEMISPHERES. It surrounds the rostral part of the brain and CORPUS CALLOSUM and forms part of the LIMBIC SYSTEM.
Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.
Any visible result of a procedure which is caused by the procedure itself and not by the entity being analyzed. Common examples include histological structures introduced by tissue processing, radiographic images of structures that are not naturally present in living tissue, and products of chemical reactions that occur during analysis.
Investigative technique commonly used during ELECTROENCEPHALOGRAPHY in which a series of bright light flashes or visual patterns are used to elicit brain activity.
The failure by the observer to measure or identify a phenomenon accurately, which results in an error. Sources for this may be due to the observer's missing an abnormality, or to faulty technique resulting in incorrect test measurement, or to misinterpretation of the data. Two varieties are inter-observer variation (the amount observers vary from one another when reporting on the same material) and intra-observer variation (the amount one observer varies between observations when reporting more than once on the same material).
Tests designed to assess neurological function associated with certain behaviors. They are used in diagnosing brain dysfunction or damage and central nervous system disorders or injury.
Stable carbon atoms that have the same atomic number as the element carbon, but differ in atomic weight. C-13 is a stable carbon isotope.
Devices or objects in various imaging techniques used to visualize or enhance visualization by simulating conditions encountered in the procedure. Phantoms are used very often in procedures employing or measuring x-irradiation or radioactive material to evaluate performance. Phantoms often have properties similar to human tissue. Water demonstrates absorbing properties similar to normal tissue, hence water-filled phantoms are used to map radiation levels. Phantoms are used also as teaching aids to simulate real conditions with x-ray or ultrasonic machines. (From Iturralde, Dictionary and Handbook of Nuclear Medicine and Clinical Imaging, 1990)
A nonmetallic, diatomic gas that is a trace element and member of the halogen family. It is used in dentistry as flouride (FLUORIDES) to prevent dental caries.
A non-metal element that has the atomic symbol P, atomic number 15, and atomic weight 31. It is an essential element that takes part in a broad variety of biochemical reactions.
Molecules which contain an atom or a group of atoms exhibiting an unpaired electron spin that can be detected by electron spin resonance spectroscopy and can be bonded to another molecule. (McGraw-Hill Dictionary of Chemical and Technical Terms, 4th ed)
Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.
Upper central part of the cerebral hemisphere. It is located posterior to central sulcus, anterior to the OCCIPITAL LOBE, and superior to the TEMPORAL LOBES.
The rostral part of the frontal lobe, bounded by the inferior precentral fissure in humans, which receives projection fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from numerous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical afferents of visual, auditory, and somatic origin.
The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).
Studies to determine the advantages or disadvantages, practicability, or capability of accomplishing a projected plan, study, or project.
Levels within a diagnostic group which are established by various measurement criteria applied to the seriousness of a patient's disorder.
The circulation of blood through the BLOOD VESSELS of the BRAIN.
Analysis of the intensity of Raman scattering of monochromatic light as a function of frequency of the scattered light.
Inorganic or organic compounds containing trivalent iron.
A meshlike structure composed of interconnecting nerve cells that are separated at the synaptic junction or joined to one another by cytoplasmic processes. In invertebrates, for example, the nerve net allows nerve impulses to spread over a wide area of the net because synapses can pass information in any direction.
Posterior portion of the CEREBRAL HEMISPHERES responsible for processing visual sensory information. It is located posterior to the parieto-occipital sulcus and extends to the preoccipital notch.
Neural tracts connecting one part of the nervous system with another.
Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.
The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.
The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.
Methods for visualizing REGIONAL BLOOD FLOW, metabolic, electrical, or other physiological activities in the CENTRAL NERVOUS SYSTEM using various imaging modalities.
The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.
An imaging technique using compounds labelled with short-lived positron-emitting radionuclides (such as carbon-11, nitrogen-13, oxygen-15 and fluorine-18) to measure cell metabolism. It has been useful in study of soft tissues such as CANCER; CARDIOVASCULAR SYSTEM; and brain. SINGLE-PHOTON EMISSION-COMPUTED TOMOGRAPHY is closely related to positron emission tomography, but uses isotopes with longer half-lives and resolution is lower.
A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Non-invasive methods of visualizing the CENTRAL NERVOUS SYSTEM, especially the brain, by various imaging modalities.
Studies in which individuals or populations are followed to assess the outcome of exposures, procedures, or effects of a characteristic, e.g., occurrence of disease.
A synovial hinge connection formed between the bones of the FEMUR; TIBIA; and PATELLA.
Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.
Deuterium. The stable isotope of hydrogen. It has one neutron and one proton in the nucleus.
Descriptive anatomy based on three-dimensional imaging (IMAGING, THREE-DIMENSIONAL) of the body, organs, and structures using a series of computer multiplane sections, displayed by transverse, coronal, and sagittal analyses. It is essential to accurate interpretation by the radiologist of such techniques as ultrasonic diagnosis, MAGNETIC RESONANCE IMAGING, and computed tomography (TOMOGRAPHY, X-RAY COMPUTED). (From Lane & Sharfaei, Modern Sectional Anatomy, 1992, Preface)
Dominance of one cerebral hemisphere over the other in cerebral functions.
Studies which start with the identification of persons with a disease of interest and a control (comparison, referent) group without the disease. The relationship of an attribute to the disease is examined by comparing diseased and non-diseased persons with regard to the frequency or levels of the attribute in each group.
The characteristic three-dimensional shape of a molecule.
A physical property showing different values in relation to the direction in or along which the measurement is made. The physical property may be with regard to thermal or electric conductivity or light refraction. In crystallography, it describes crystals whose index of refraction varies with the direction of the incident light. It is also called acolotropy and colotropy. The opposite of anisotropy is isotropy wherein the same values characterize the object when measured along axes in all directions.
The time from the onset of a stimulus until a response is observed.
1-Deoxy-1-(methylamino)-D-glucitol. A derivative of sorbitol in which the hydroxyl group in position 1 is replaced by a methylamino group. Often used in conjunction with iodinated organic compounds as contrast medium.
Abnormal fluid retention by the body due to impaired cardiac function or heart failure. It is usually characterized by increase in venous and capillary pressure, and swollen legs when standing. It is different from the generalized edema caused by renal dysfunction (NEPHROTIC SYNDROME).
The hemodynamic and electrophysiological action of the left HEART VENTRICLE. Its measurement is an important aspect of the clinical evaluation of patients with heart disease to determine the effects of the disease on cardiac performance.
The creation of a visual display of the inside of the entire body of a human or animal for the purposes of diagnostic evaluation. This is most commonly achieved by using MAGNETIC RESONANCE IMAGING; or POSITRON EMISSION TOMOGRAPHY.
The homogeneous mixtures formed by the mixing of a solid, liquid, or gaseous substance (solute) with a liquid (the solvent), from which the dissolved substances can be recovered by physical processes. (From Grant & Hackh's Chemical Dictionary, 5th ed)
An iron chelating agent with properties like EDETIC ACID. DTPA has also been used as a chelator for other metals, such as plutonium.
The amount of BLOOD pumped out of the HEART per beat, not to be confused with cardiac output (volume/time). It is calculated as the difference between the end-diastolic volume and the end-systolic volume.
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
Surgery performed on the nervous system or its parts.
The lower right and left chambers of the heart. The right ventricle pumps venous BLOOD into the LUNGS and the left ventricle pumps oxygenated blood into the systemic arterial circulation.
Pathologic conditions which feature SPINAL CORD damage or dysfunction, including disorders involving the meninges and perimeningeal spaces surrounding the spinal cord. Traumatic injuries, vascular diseases, infections, and inflammatory/autoimmune processes may affect the spinal cord.
Almond-shaped group of basal nuclei anterior to the INFERIOR HORN OF THE LATERAL VENTRICLE of the TEMPORAL LOBE. The amygdala is part of the limbic system.
Stable nitrogen atoms that have the same atomic number as the element nitrogen, but differ in atomic weight. N-15 is a stable nitrogen isotope.
The use of diffusion ANISOTROPY data from diffusion magnetic resonance imaging results to construct images based on the direction of the faster diffusing molecules.
A class of nerve fibers as defined by their structure, specifically the nerve sheath arrangement. The AXONS of the myelinated nerve fibers are completely encased in a MYELIN SHEATH. They are fibers of relatively large and varied diameters. Their NEURAL CONDUCTION rates are faster than those of the unmyelinated nerve fibers (NERVE FIBERS, UNMYELINATED). Myelinated nerve fibers are present in somatic and autonomic nerves.
The first chemical element in the periodic table. It has the atomic symbol H, atomic number 1, and atomic weight [1.00784; 1.00811]. It exists, under normal conditions, as a colorless, odorless, tasteless, diatomic gas. Hydrogen ions are PROTONS. Besides the common H1 isotope, hydrogen exists as the stable isotope DEUTERIUM and the unstable, radioactive isotope TRITIUM.
Analysis based on the mathematical function first formulated by Jean-Baptiste-Joseph Fourier in 1807. The function, known as the Fourier transform, describes the sinusoidal pattern of any fluctuating pattern in the physical world in terms of its amplitude and its phase. It has broad applications in biomedicine, e.g., analysis of the x-ray crystallography data pivotal in identifying the double helical nature of DNA and in analysis of other molecules, including viruses, and the modified back-projection algorithm universally used in computerized tomography imaging, etc. (From Segen, The Dictionary of Modern Medicine, 1992)
The formation of an area of NECROSIS in the CEREBRUM caused by an insufficiency of arterial or venous blood flow. Infarcts of the cerebrum are generally classified by hemisphere (i.e., left vs. right), lobe (e.g., frontal lobe infarction), arterial distribution (e.g., INFARCTION, ANTERIOR CEREBRAL ARTERY), and etiology (e.g., embolic infarction).
Non-invasive imaging methods based on the mechanical response of an object to a vibrational or impulsive force. It is used for determining the viscoelastic properties of tissue, and thereby differentiating soft from hard inclusions in tissue such as microcalcifications, and some cancer lesions. Most techniques use ultrasound to create the images - eliciting the response with an ultrasonic radiation force and/or recording displacements of the tissue by Doppler ultrasonography.
The comparison of the quantity of meaningful data to the irrelevant or incorrect data.
Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.
Intellectual or mental process whereby an organism obtains knowledge.
Large subcortical nuclear masses derived from the telencephalon and located in the basal regions of the cerebral hemispheres.
The worsening of a disease over time. This concept is most often used for chronic and incurable diseases where the stage of the disease is an important determinant of therapy and prognosis.
The rate dynamics in chemical or physical systems.
Statistical models in which the value of a parameter for a given value of a factor is assumed to be equal to a + bx, where a and b are constants. The models predict a linear regression.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
The creation and display of functional images showing where the blood is flowing into the MYOCARDIUM by following over time the distribution of tracers injected into the blood stream.
Area of the OCCIPITAL LOBE concerned with the processing of visual information relayed via VISUAL PATHWAYS.
A group of diseases in which the dominant feature is the involvement of the CARDIAC MUSCLE itself. Cardiomyopathies are classified according to their predominant pathophysiological features (DILATED CARDIOMYOPATHY; HYPERTROPHIC CARDIOMYOPATHY; RESTRICTIVE CARDIOMYOPATHY) or their etiological/pathological factors (CARDIOMYOPATHY, ALCOHOLIC; ENDOCARDIAL FIBROELASTOSIS).
Computer-based representation of physical systems and phenomena such as chemical processes.
Benign and malignant neoplastic processes that arise from or secondarily involve the meningeal coverings of the brain and spinal cord.
A relatively common neoplasm of the CENTRAL NERVOUS SYSTEM that arises from arachnoidal cells. The majority are well differentiated vascular tumors which grow slowly and have a low potential to be invasive, although malignant subtypes occur. Meningiomas have a predilection to arise from the parasagittal region, cerebral convexity, sphenoidal ridge, olfactory groove, and SPINAL CANAL. (From DeVita et al., Cancer: Principles and Practice of Oncology, 5th ed, pp2056-7)
A protective layer of firm, flexible cartilage over the articulating ends of bones. It provides a smooth surface for joint movement, protecting the ends of long bones from wear at points of contact.
The visualization of deep structures of the body by recording the reflections or echoes of ultrasonic pulses directed into the tissues. Use of ultrasound for imaging or diagnostic purposes employs frequencies ranging from 1.6 to 10 megahertz.
Benign and malignant central nervous system neoplasms derived from glial cells (i.e., astrocytes, oligodendrocytes, and ependymocytes). Astrocytes may give rise to astrocytomas (ASTROCYTOMA) or glioblastoma multiforme (see GLIOBLASTOMA). Oligodendrocytes give rise to oligodendrogliomas (OLIGODENDROGLIOMA) and ependymocytes may undergo transformation to become EPENDYMOMA; CHOROID PLEXUS NEOPLASMS; or colloid cysts of the third ventricle. (From Escourolle et al., Manual of Basic Neuropathology, 2nd ed, p21)
Broad plate of dense myelinated fibers that reciprocally interconnect regions of the cortex in all lobes with corresponding regions of the opposite hemisphere. The corpus callosum is located deep in the longitudinal fissure.
The measurement of an organ in volume, mass, or heaviness.
An isomer of glucose that has traditionally been considered to be a B vitamin although it has an uncertain status as a vitamin and a deficiency syndrome has not been identified in man. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1379) Inositol phospholipids are important in signal transduction.
Inorganic salts of phosphoric acid.
The use of molecularly targeted imaging probes to localize and/or monitor biochemical and cellular processes via various imaging modalities that include RADIONUCLIDE IMAGING; ULTRASONOGRAPHY; MAGNETIC RESONANCE IMAGING; FLUORESCENCE IMAGING; and MICROSCOPY.
The parts of a macromolecule that directly participate in its specific combination with another molecule.
The coordination of a sensory or ideational (cognitive) process and a motor activity.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
The tendency of a gas or solute to pass from a point of higher pressure or concentration to a point of lower pressure or concentration and to distribute itself throughout the available space. Diffusion, especially FACILITATED DIFFUSION, is a major mechanism of BIOLOGICAL TRANSPORT.
Non-invasive imaging of cells that have been labeled non-destructively, such as with nanoemulsions or reporter genes that can be detected by molecular imaging, to monitor their location, viability, cell lineage expansion, response to drugs, movement, or other behaviors in vivo.
Care given during the period prior to undergoing surgery when psychological and physical preparations are made according to the special needs of the individual patient. This period spans the time between admission to the hospital to the time the surgery begins. (From Dictionary of Health Services Management, 2d ed)
VERTEBRAE in the region of the lower BACK below the THORACIC VERTEBRAE and above the SACRAL VERTEBRAE.
Disturbances in mental processes related to learning, thinking, reasoning, and judgment.
Those affective states which can be experienced and have arousing and motivational properties.
Ring compounds having atoms other than carbon in their nuclei. (Grant & Hackh's Chemical Dictionary, 5th ed)
Methods of creating machines and devices.
Nanometer-sized particles that are nanoscale in three dimensions. They include nanocrystaline materials; NANOCAPSULES; METAL NANOPARTICLES; DENDRIMERS, and QUANTUM DOTS. The uses of nanoparticles include DRUG DELIVERY SYSTEMS and cancer targeting and imaging.
The chemical reactions involved in the production and utilization of various forms of energy in cells.
A subtype of striated muscle, attached by TENDONS to the SKELETON. Skeletal muscles are innervated and their movement can be consciously controlled. They are also called voluntary muscles.
Helium. A noble gas with the atomic symbol He, atomic number 2, and atomic weight 4.003. It is a colorless, odorless, tasteless gas that is not combustible and does not support combustion. It was first detected in the sun and is now obtained from natural gas. Medically it is used as a diluent for other gases, being especially useful with oxygen in the treatment of certain cases of respiratory obstruction, and as a vehicle for general anesthetics. (Dorland, 27th ed)
The part of brain that lies behind the BRAIN STEM in the posterior base of skull (CRANIAL FOSSA, POSTERIOR). It is also known as the "little brain" with convolutions similar to those of CEREBRAL CORTEX, inner white matter, and deep cerebellar nuclei. Its function is to coordinate voluntary movements, maintain balance, and learn motor skills.
An autoimmune disorder mainly affecting young adults and characterized by destruction of myelin in the central nervous system. Pathologic findings include multiple sharply demarcated areas of demyelination throughout the white matter of the central nervous system. Clinical manifestations include visual loss, extra-ocular movement disorders, paresthesias, loss of sensation, weakness, dysarthria, spasticity, ataxia, and bladder dysfunction. The usual pattern is one of recurrent attacks followed by partial recovery (see MULTIPLE SCLEROSIS, RELAPSING-REMITTING), but acute fulminating and chronic progressive forms (see MULTIPLE SCLEROSIS, CHRONIC PROGRESSIVE) also occur. (Adams et al., Principles of Neurology, 6th ed, p903)
A metallic element with atomic symbol Fe, atomic number 26, and atomic weight 55.85. It is an essential constituent of HEMOGLOBINS; CYTOCHROMES; and IRON-BINDING PROTEINS. It plays a role in cellular redox reactions and in the transport of OXYGEN.
A group of glucose polymers made by certain bacteria. Dextrans are used therapeutically as plasma volume expanders and anticoagulants. They are also commonly used in biological experimentation and in industry for a wide variety of purposes.
Localized reduction of blood flow to brain tissue due to arterial obstruction or systemic hypoperfusion. This frequently occurs in conjunction with brain hypoxia (HYPOXIA, BRAIN). Prolonged ischemia is associated with BRAIN INFARCTION.
Changes in the amounts of various chemicals (neurotransmitters, receptors, enzymes, and other metabolites) specific to the area of the central nervous system contained within the head. These are monitored over time, during sensory stimulation, or under different disease states.
Abnormal fluid accumulation in TISSUES or body cavities. Most cases of edema are present under the SKIN in SUBCUTANEOUS TISSUE.
Noninflammatory degenerative disease of the knee joint consisting of three large categories: conditions that block normal synchronous movement, conditions that produce abnormal pathways of motion, and conditions that cause stress concentration resulting in changes to articular cartilage. (Crenshaw, Campbell's Operative Orthopaedics, 8th ed, p2019)
A method of computed tomography that uses radionuclides which emit a single photon of a given energy. The camera is rotated 180 or 360 degrees around the patient to capture images at multiple positions along the arc. The computer is then used to reconstruct the transaxial, sagittal, and coronal images from the 3-dimensional distribution of radionuclides in the organ. The advantages of SPECT are that it can be used to observe biochemical and physiological processes as well as size and volume of the organ. The disadvantage is that, unlike positron-emission tomography where the positron-electron annihilation results in the emission of 2 photons at 180 degrees from each other, SPECT requires physical collimation to line up the photons, which results in the loss of many available photons and hence degrades the image.
The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.
The level of protein structure in which regular hydrogen-bond interactions within contiguous stretches of polypeptide chain give rise to alpha helices, beta strands (which align to form beta sheets) or other types of coils. This is the first folding level of protein conformation.
A normal intermediate in the fermentation (oxidation, metabolism) of sugar. The concentrated form is used internally to prevent gastrointestinal fermentation. (From Stedman, 26th ed)
The science and art of collecting, summarizing, and analyzing data that are subject to random variation. The term is also applied to the data themselves and to the summarization of the data.
A curved elevation of GRAY MATTER extending the entire length of the floor of the TEMPORAL HORN of the LATERAL VENTRICLE (see also TEMPORAL LOBE). The hippocampus proper, subiculum, and DENTATE GYRUS constitute the hippocampal formation. Sometimes authors include the ENTORHINAL CORTEX in the hippocampal formation.
Any fluid-filled closed cavity or sac that is lined by an EPITHELIUM. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues.
Inflammation of a synovial membrane. It is usually painful, particularly on motion, and is characterized by a fluctuating swelling due to effusion within a synovial sac. (Dorland, 27th ed)
Timing the acquisition of imaging data to specific points in the cardiac cycle to minimize image blurring and other motion artifacts.
The outermost of the three MENINGES, a fibrous membrane of connective tissue that covers the brain and the spinal cord.
Focusing on certain aspects of current experience to the exclusion of others. It is the act of heeding or taking notice or concentrating.
Removal and pathologic examination of specimens in the form of small pieces of tissue from the living body.
Derived from TELENCEPHALON, cerebrum is composed of a right and a left hemisphere. Each contains an outer cerebral cortex and a subcortical basal ganglia. The cerebrum includes all parts within the skull except the MEDULLA OBLONGATA, the PONS, and the CEREBELLUM. Cerebral functions include sensorimotor, emotional, and intellectual activities.
An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.
Visualization of the heart structure and cardiac blood flow for diagnostic evaluation or to guide cardiac procedures via techniques including ENDOSCOPY (cardiac endoscopy, sometimes refered to as cardioscopy), RADIONUCLIDE IMAGING; MAGNETIC RESONANCE IMAGING; TOMOGRAPHY; or ULTRASONOGRAPHY.
Paired bodies containing mostly GRAY MATTER and forming part of the lateral wall of the THIRD VENTRICLE of the brain.
A prediction of the probable outcome of a disease based on a individual's condition and the usual course of the disease as seen in similar situations.
The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.
Mental process to visually perceive a critical number of facts (the pattern), such as characters, shapes, displays, or designs.
The transfer of energy of a given form among different scales of motion. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed). It includes the transfer of kinetic energy and the transfer of chemical energy. The transfer of chemical energy from one molecule to another depends on proximity of molecules so it is often used as in techniques to measure distance such as the use of FORSTER RESONANCE ENERGY TRANSFER.
The first seven VERTEBRAE of the SPINAL COLUMN, which correspond to the VERTEBRAE of the NECK.
Longitudinal cavities in the spinal cord, most often in the cervical region, which may extend for multiple spinal levels. The cavities are lined by dense, gliogenous tissue and may be associated with SPINAL CORD NEOPLASMS; spinal cord traumatic injuries; and vascular malformations. Syringomyelia is marked clinically by pain and PARESTHESIA, muscular atrophy of the hands, and analgesia with thermoanesthesia of the hands and arms, but with the tactile sense preserved (sensory dissociation). Lower extremity spasticity and incontinence may also develop. (From Adams et al., Principles of Neurology, 6th ed, p1269)
Stable phosphorus atoms that have the same atomic number as the element phosphorus, but differ in atomic weight. P-31 is a stable phosphorus isotope.
NECROSIS of the MYOCARDIUM caused by an obstruction of the blood supply to the heart (CORONARY CIRCULATION).
Recording of electric currents developed in the brain by means of electrodes applied to the scalp, to the surface of the brain, or placed within the substance of the brain.
The selecting and organizing of visual stimuli based on the individual's past experience.
A group of pathological conditions characterized by sudden, non-convulsive loss of neurological function due to BRAIN ISCHEMIA or INTRACRANIAL HEMORRHAGES. Stroke is classified by the type of tissue NECROSIS, such as the anatomic location, vasculature involved, etiology, age of the affected individual, and hemorrhagic vs. non-hemorrhagic nature. (From Adams et al., Principles of Neurology, 6th ed, pp777-810)
Acute and chronic conditions characterized by external mechanical compression of the SPINAL CORD due to extramedullary neoplasm; EPIDURAL ABSCESS; SPINAL FRACTURES; bony deformities of the vertebral bodies; and other conditions. Clinical manifestations vary with the anatomic site of the lesion and may include localized pain, weakness, sensory loss, incontinence, and impotence.
Freedom from activity.
A method of delineating blood vessels by subtracting a tissue background image from an image of tissue plus intravascular contrast material that attenuates the X-ray photons. The background image is determined from a digitized image taken a few moments before injection of the contrast material. The resulting angiogram is a high-contrast image of the vessel. This subtraction technique allows extraction of a high-intensity signal from the superimposed background information. The image is thus the result of the differential absorption of X-rays by different tissues.
Areas of attractive or repulsive force surrounding MAGNETS.
The hemodynamic and electrophysiological action of the right HEART VENTRICLE.
Computer-assisted processing of electric, ultrasonic, or electronic signals to interpret function and activity.
Any of various diseases affecting the white matter of the central nervous system.
A condition in which the LEFT VENTRICLE of the heart was functionally impaired. This condition usually leads to HEART FAILURE; MYOCARDIAL INFARCTION; and other cardiovascular complications. Diagnosis is made by measuring the diminished ejection fraction and a depressed level of motility of the left ventricular wall.
Observable changes of expression in the face in response to emotional stimuli.
A severe emotional disorder of psychotic depth characteristically marked by a retreat from reality with delusion formation, HALLUCINATIONS, emotional disharmony, and regressive behavior.
A convolution on the inferior surface of each cerebral hemisphere, lying between the hippocampal and collateral sulci.
Any operation on the cranium or incision into the cranium. (Dorland, 28th ed)
Three-dimensional representation to show anatomic structures. Models may be used in place of intact animals or organisms for teaching, practice, and study.
A class of statistical methods applicable to a large set of probability distributions used to test for correlation, location, independence, etc. In most nonparametric statistical tests, the original scores or observations are replaced by another variable containing less information. An important class of nonparametric tests employs the ordinal properties of the data. Another class of tests uses information about whether an observation is above or below some fixed value such as the median, and a third class is based on the frequency of the occurrence of runs in the data. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1284; Corsini, Concise Encyclopedia of Psychology, 1987, p764-5)
A value equal to the total volume flow divided by the cross-sectional area of the vascular bed.
The interarticular fibrocartilages of the superior surface of the tibia.
Inorganic chemicals that contain manganese as an integral part of the molecule.
Radiography of the vascular system of the brain after injection of a contrast medium.
Complex mental function having four distinct phases: (1) memorizing or learning, (2) retention, (3) recall, and (4) recognition. Clinically, it is usually subdivided into immediate, recent, and remote memory.
Small-scale tests of methods and procedures to be used on a larger scale if the pilot study demonstrates that these methods and procedures can work.
A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.
The measurement of the amplitude of the components of a complex waveform throughout the frequency range of the waveform. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
A partial or complete return to the normal or proper physiologic activity of an organ or part following disease or trauma.
The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.

Visual perception: mind and brain see eye to eye. (1/44946)

Recent functional imaging studies have identified neural activity that is closely associated with the perception of illusory motion. The mapping of the mind onto the bin appears to be one-to-one: activity in visual 'motion area' MT is highly correlated with perceptual experience.  (+info)

Physiological characteristics of capacity constraints in working memory as revealed by functional MRI. (2/44946)

A fundamental characteristic of working memory is that its capacity to handle information is limited. While there have been many brain mapping studies of working memory, the physiological basis of its capacity limitation has not been explained. We identified characteristics of working memory capacity using functional magnetic resonance imaging (fMRI) in healthy subjects. Working memory capacity was studied using a parametric 'n-back' working memory task involving increasing cognitive load and ultimately decreasing task performance. Loci within dorsolateral prefrontal cortex (DLPFC) evinced exclusively an 'inverted-U' shaped neurophysiological response from lowest to highest load, consistent with a capacity-constrained response. Regions outside of DLPFC, in contrast, were more heterogeneous in response and often showed early plateau or continuously increasing responses, which did not reflect capacity constraints. However, sporadic loci, including in the premotor cortex, thalamus and superior parietal lobule, also demonstrated putative capacity-constrained responses, perhaps arising as an upstream effect of DLPFC limitations or as part of a broader network-wide capacity limitation. These results demonstrate that regionally specific nodes within the working memory network are capacity-constrained in the physiological domain, providing a missing link in current explorations of the capacity characteristics of working memory.  (+info)

Signal-, set- and movement-related activity in the human brain: an event-related fMRI study. (3/44946)

Electrophysiological studies on monkeys have been able to distinguish sensory and motor signals close in time by pseudorandomly delaying the cue that instructs the movement from the stimulus that triggers the movement. We have used a similar experimental design in functional magnetic resonance imaging (fMRI), scanning subjects while they performed a visuomotor conditional task with instructed delays. One of four shapes was presented briefly. Two shapes instructed the subjects to flex the index finger; the other two shapes coded the flexion of the middle finger. The subjects were told to perform the movement after a tone. We have exploited a novel use of event-related fMRI. By systematically varying the interval between the visual and acoustic stimuli, it has been possible to estimate the significance of the evoked haemodynamic response (EHR) to each of the stimuli, despite their temporal proximity in relation to the time constant of the EHR. Furthermore, by varying the phase between events and image acquisition, we have been able to achieve high temporal resolution while scanning the whole brain. We dissociated sensory and motor components of the sensorimotor transformations elicited by the task, and assessed sustained activity during the instructed delays. In calcarine and occipitotemporal cortex, the responses were exclusively associated with the visual instruction cues. In temporal auditory cortex and in primary motor cortex, they were exclusively associated with the auditory trigger stimulus. In ventral prefrontal cortex there were movement-related responses preceded by preparatory activity and by signal-related activity. Finally, responses associated with the instruction cue and with sustained activity during the delay period were observed in the dorsal premotor cortex and in the dorsal posterior parietal cortex. Where the association between a visual cue and the appropriate movement is arbitrary, the underlying visuomotor transformations are not achieved exclusively through frontoparietal interactions. Rather, these processes seem to rely on the ventral visual stream, the ventral prefrontal cortex and the anterior part of the dorsal premotor cortex.  (+info)

Transient and permanent deficits in motion perception after lesions of cortical areas MT and MST in the macaque monkey. (4/44946)

We examined the nature and the selectivity of the motion deficits produced by lesions of extrastriate areas MT and MST. Lesions were made by injecting ibotenic acid into the representation of the left visual field in two macaque monkeys. The monkeys discriminated two stimuli that differed either in stimulus direction or orientation. Direction and orientation discrimination were assessed by measuring thresholds with gratings and random-dots placed in the intact or lesioned visual fields. At the start of behavioral testing, we found pronounced, motion-specific deficits in thresholds for all types of moving stimuli, including pronounced elevations in contrast thresholds and in signal-to-noise thresholds measured with moving gratings, as well as deficits in direction range thresholds and motion coherence measured with random-dot stimuli. In addition, the accuracy of direction discrimination was reduced at smaller spatial displacements (i.e. step sizes), suggesting an increase in spatial scale of the residual directional mechanism. Subsequent improvements in thresholds were seen with all motion stimuli, as behavioral training progressed, and these improvements occurred only with extensive behavioral testing in the lesioned visual field. These improvements were particularly pronounced for stimuli not masked by noise. On the other hand, deficits in the ability to extract motion from noisy stimuli and in the accuracy of direction discrimination persisted despite extensive behavioral training. These results demonstrate the importance of areas MT and MST for the perception of motion direction, particularly in the presence of noise. In addition, they provide evidence for the importance of behavioral training for functional recovery after cortical lesions. The data also strongly support the idea of functional specialization of areas MT and MST for motion processing.  (+info)

Integrated visualization of functional and anatomic brain data: a validation study. (5/44946)

Two-dimensional SPECT display and three methods for integrated visualization of SPECT and MRI patient data are evaluated in a multiobserver study to determine whether localization of functional data can be improved by adding anatomical information to the display. METHODS: SPECT and MRI data of 30 patients were gathered and presented using four types of display: one of SPECT in isolation, two integrated two-dimensional displays and one integrated three-dimensional display. Cold and hot spots in the peripheral cortex were preselected and indicated on black-and-white hard copies of the image data. Nuclear medicine physicians were asked to assign the corresponding spots in the image data on the computer screen to a lobe and a gyrus and give a confidence rating for both localizations. Interobserver agreement using kappa statistics and average confidence ratings were assessed to interpret the reported observations. RESULTS: Both the interobserver agreement and the confidence of the observers were greater for the integrated two-dimensional displays than for the two-dimensional SPECT display. An additional increase in agreement and confidence was seen with the integrated three-dimensional display. CONCLUSION: Integrated display of SPECT and MR brain images provides better localization of cerebral blood perfusion abnormalities in the peripheral cortex in relation to the anatomy of the brain than single-modality display and increases the confidence of the observer.  (+info)

Anatomic validation of spatial normalization methods for PET. (6/44946)

Spatial normalization methods, which are indispensable for intersubject analysis in current PET studies, have been improved in many aspects. These methods have not necessarily been evaluated as anatomic normalization methods because PET images are functional images. However, in view of the close relation between brain function and morphology, it is very intriguing how precisely normalized brains coincide with each other. In this report, the anatomic precision of spatial normalization is validated with three different methods. METHODS: Four PET centers in Japan participated in this study. In each center, six normal subjects were recruited for both H2(15)O-PET and high-resolution MRI studies. Variations in the location of the anterior commissure (AC) and size and contours of the brain and the courses of major sulci were measured in spatially normalized MR images for each method. Spatial normalization was performed as follows. (a) Linear: The AC-posterior commissure and midsagittal plane were identified on MRI and the size of the brain was adjusted to the Talairach space in each axis using linear parameters. (b) Human brain atlas (HBA): Atlas structures were manually adjusted to MRI to determine linear and nonlinear transformation parameters and then MRI was transformed with the inverse of these parameters. (c) Statistical parametric mapping (SPM) 95: PET images were transformed into the template PET image with linear and nonlinear parameters in a least-squares manner. Then, coregistered MR images were transformed with the same parameters used for the PET transformation. RESULTS: The AC was well registered in all methods. The size of the brain normalized with SPM95 varied to a greater extent than with other approaches. Larger variance in contours was observed with the linear method. Only SPM95 showed significant superiority to the linear method when the courses of major sulci were compared. CONCLUSION: The results of this study indicate that SPM95 is as effective a spatial normalization as HBA, although it does not use anatomic images. Large variance in structures other than the AC and size of the brain in the linear method suggests the necessity of nonlinear transformations for effective spatial normalization. Operator dependency of HBA also must be considered.  (+info)

Genetic influences on cervical and lumbar disc degeneration: a magnetic resonance imaging study in twins. (7/44946)

OBJECTIVE: Degenerative intervertebral disc disease is common; however, the importance of genetic factors is unknown. This study sought to determine the extent of genetic influences on disc degeneration by classic twin study methods using magnetic resonance imaging (MRI). METHODS: We compared MRI features of degenerative disc disease in the cervical and lumbar spine of 172 monozygotic and 154 dizygotic twins (mean age 51.7 and 54.4, respectively) who were unselected for back pain or disc disease. An overall score for disc degeneration was calculated as the sum of the grades for disc height, bulge, osteophytosis, and signal intensity at each level. A "severe disease" score (excluding minor grades) and an "extent of disease" score (number of levels affected) were also calculated. RESULTS: For the overall score, heritability was 74% (95% confidence interval [95% CI] 64-81%) at the lumbar spine and 73% (95% CI 64-80%) at the cervical spine. For "severe disease," heritability was 64% and 79% at the lumbar and cervical spine, respectively, and for "extent of disease," heritability was 63% and 63%, respectively. These results were adjusted for age, weight, height, smoking, occupational manual work, and exercise. Examination of individual features revealed that disc height and bulge were highly heritable at both sites, and osteophytes were heritable in the lumbar spine. CONCLUSION: These results suggest an important genetic influence on variation in intervertebral disc degeneration. However, variation in disc signal is largely influenced by environmental factors shared by twins. The use of MRI scans to determine the phenotype in family and population studies should allow a better understanding of disease mechanisms and the identification of the genes involved.  (+info)

The effect of face inversion on activity in human neural systems for face and object perception. (8/44946)

The differential effect of stimulus inversion on face and object recognition suggests that inverted faces are processed by mechanisms for the perception of other objects rather than by face perception mechanisms. We investigated the face inversion using functional magnetic resonance imaging (fMRI). The principal effect of face inversion on was an increased response in ventral extrastriate regions that respond preferentially to another class of objects (houses). In contrast, house inversion did not produce a similar change in face-selective regions. Moreover, stimulus inversion had equivalent, minimal effects for faces in in face-selective regions and for houses in house-selective regions. The results suggest that the failure of face perception systems with inverted faces leads to the recruitment of processing resources in object perception systems, but this failure is not reflected by altered activity in face perception systems.  (+info)

TY - JOUR. T1 - Signal polarity restoration in a 3D inversion recovery sequence used with delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC). AU - Szumowski, Jerzy. AU - Durkan, Michael G.. AU - Foss, Erik W.. AU - Brown, Dawson S.. AU - Schwarz, Erwin. AU - Crawford, Dennis C.. PY - 2012/11/1. Y1 - 2012/11/1. N2 - Purpose: To develop an image reconstruction algorithm that restores the signal polarity in a three-dimensional inversion-recovery (3D-IR) sequence used in delayed gadolinium-enhanced MRI of cartilage (dGEMRIC). This approach effectively doubles the dynamic range of data used for T1 curve fitting. Materials and Methods: We applied this reconstruction algorithm to a 3D-IR TFE sequence used for T1 mapping, validated the technique in a phantom study, and performed T1-map calculations in postosteochondral allograft transplant (OAT) patients. In addition, we performed a signal simulation study to assess the algorithms capability to reduce the number of inversion ...
Differential diagnosis of ovarian cystadenofibromas should include stromal ovarian tumors with fibrous component, struma ovarri, ovarian metastases and endometriomas. Ovarian tumors with fibrous parts, including fibroma, fibrothecoma and Brenner tumor often present with a predominantly solid component of low signal intensity on T2-weighted images [7, 11, 12]. Struma ovarri has been described as multilocular ovarian mass, with variable signal intensity of the cystic parts and coexistence of hypointense areas on T2-weighted images, due to the presence of viscous colloid material [15, 16]. Ovarian metastases with a rich fibrous component, usually originating from the gastrointestinal tract often have areas of low signal intensity on T2-weighted images and display strong enhancement after contrast material administration [17 ...
Prostate cancer (PCa) patients receive androgen-deprivation therapy (ADT) to reduce tumor burden. However, complete eradication of PCa is unusual, and recurrent disease is evident within approximately 2 years in high-risk patients. Clinical evidence suggests that combining ADT with radiotherapy improves local control and disease-free survival in these patients compared with radiotherapy alone. We investigated whether vascularization of androgen-sensitive PCa xenografts changed after ADT and whether such therapy affected radiation response. CWR22 xenografts received combinations of ADT by castration (CWR22-cas) and 15 Gy of single-dose irradiation. At a shortest tumor diameter of 8 mm, vascularization was visualized by dynamic contrast-enhanced magnetic resonance imaging before radiation and 1 and 9 days after radiation. Voxel-wise quantitative modeling of contrast enhancement curves extracted the hemodynamic parameter Ktrans, reflecting a combination of permeability, density, and blood flow. ...
Examples of coronal cUS and axial MR images performed during the first week after birth in infants presenting with neonatal seizures. (A) HIE: hyperechogenicity in both thalami on cUS and low signal intensity on the ADC map in thalami, optic radiation and splenium of the corpus callosum (D); (B) PAIS of main branch of the left-middle cerebral artery: wedge-shaped hyperechogenicity with a linear demarcation line in the left hemisphere on cUS and low signal intensity on the ADC map in territory of the left-middle cerebral artery, as well as optic radiation and splenium of the corpus callosum (E); (C) haemorrhage in the right temporal lobe recognised on cUS as a round area of hyperechogenicity and on T2WI as an area of low signal intensity surrounded by high signal intensity due to oedema (F).. ...
White matter hyperintensities (WMH) of presumed vascular origin, as seen on T2-weighted fluid attenuated inversion recovery magnetic resonance imaging, are known to increase with age and are elevated in Alzheimers disease (AD). The cognitive implications of these common markers are not well understood. Previous research has primarily focused on global measures of WMH burden and broad localizations that contain multiple white matter tracts. The aims of this study were to determine the pattern of WMH accumulation with age, risk for AD, and the relationship with cognitive function utilizing a voxel-wise analysis capable of identifying specific white matter regions. A total of 349 participants underwent T1-weighted and high-resolution T2-weighted fluid attenuated inversion recovery magnetic resonance imaging and neuropsychological testing. Increasing age and lower cognitive speed and flexibility (a component of executive function), were both significantly associated with regional WMH throughout the ...
By EDWARD F. JACKSON, PhD. One key advantage of MR is the wide range of intrinsic tissue properties that can be assessed by the appropriate choice of parameters defining the associated measurement technique.. In neuroimaging applications, for example, routine MR imaging provides a qualitative means of assessing the breakdown of the blood brain barrier as reflected by the extent of gadolinium contrast agent extravasation (T1-weighted sequences), the extent of vasogenic edema (T2-weighted and T2-weighted fluid attenuated inversion recovery sequences), the presence of blood products such as hemosiderin, methemoglobin (T1-weighted and T2* susceptibility-weighted images), and the ability to assess brain atrophy and regional white/gray matter abnormalities (using proton density-weighted and/or magnetization prepared gradient-echo sequences).. Neurovascular anatomy can be evaluated with or without the injection of exogenous contrast agents (using time-of-flight and/or phase-contrast MR angiography ...
We hypothesized that pediatric patients with type 1 diabetes have cardiac magnetic resonance (CMR) detectable differences in thoracic aortic wall properties and hemodynamics leading to significant local differences in indices of wall shear stress, when compared with age-matched control subjects without diabetes. Pediatric patients with type 1 diabetes were recruited from Childrens Hospital of Wisconsin and compared with controls. All underwent morning CMR scanning, 4-limb blood pressure, brachial artery reactivity testing, and venipuncture. Patient-specific computational fluid dynamics modeling with fluid-structure interaction, based on CMR data, determined regional time-averaged wall shear stress (TAWSS) and oscillatory shear index (OSI). Twenty type 1 diabetic subjects, median age 15.8 years (11.6-18.4) and 8 controls 15.4 years (10.3-18.2) were similar except for higher glucose, hemoglobin A1c, and triglycerides for type 1 diabetic subjects. Lower flow-mediated dilation was seen for those with type
abnormal mri - MedHelps abnormal mri Center for Information, Symptoms, Resources, Treatments and Tools for abnormal mri. Find abnormal mri information, treatments for abnormal mri and abnormal mri symptoms.
A) Diffusion tensor imaging (DTI) demonstrates a clear U-fibre density reduction in the left frontal area, illustrated by high signal in the colour scale. (B) Three-dimensional reconstructed brain surface created by coregistration of preoperative MRI and post-implantation CT shows placement of intracranial depth electrodes on the left hemisphere. Electrode 1 represents the innermost contact; A1-A12: left superior frontal gyrus (frontobasal, anterior); B1-B8: left superior frontal gyrus (frontobasal); C1-C10: left superior frontal gyrus (medial); D1-D8: left superior frontal gyrus (posterior); E1-E12: left middle frontal gyrus (anterior); F1-F8: left middle frontal gyrus (posterior); G1-G8: left inferior frontal gyrus; H1-H8: left anterior insula; J1-J6: left posterior insula; K1-K8: left anterior temporal lobe; L1-11: right superior frontal gyrus (frontobasal); and M1-12: right middle frontal gyrus. (C) Results of extraoperative electrical stimulation mapping (monopolar stimulation was performed ...
Background: The monoclonal antibody, C595, against breast cancer cell line was conjugated with cyclic anhydride gadolinium-diethylenetriaminepenta-acetic acid (Gd-cDTPAa) to produce Gd-DTPA-C595 and used as specific breast cancer cell line (MCF-7) contrast agents in magnetic resonance imaging (MRI). Methods: After incubation of breast cancer cell line (MCF-7), with different contrast agents ...
Finite element models have become more sophisticated in both detail and their ability to predict human responses to various loading conditions. More
TY - JOUR. T1 - Functional brain mapping by blood oxygenation level-dependent contrast magnetic resonance imaging. A comparison of signal characteristics with a biophysical model. AU - Ogawa, S.. AU - Menon, R. S.. AU - Tank, D. W.. AU - Kim, S. G.. AU - Merkle, H.. AU - Ellermann, J. M.. AU - Ugurbil, K.. PY - 1993. Y1 - 1993. N2 - It recently has been demonstrated that magnetic resonance imaging can be used to map changes in brain hemodynamics produced by human mental operations. One method under development relies on blood oxygenation level-dependent (BOLD) contrast: a change in the signal strength of brain water protons produced by the paramagnetic effects of venous blood deoxyhemoglobin. Here we discuss the basic quantitative features of the observed BOLD-based signal changes, including the signal amplitude and its magnetic field dependence and dynamic effects such as a pronounced oscillatory pattern that is induced in the signal from primary visual cortex during photic stimulation ...
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BACKGROUND:Diabetes is a major risk factor for cardiovascular disease. In particular, type 1 diabetes compromises the cardiac function of individuals at a relatively early age due to the protracted course of abnormal glucose homeostasis. The functional abnormalities of diabetic myocardium have been attributed to the pathological changes of diabetic cardiomyopathy.METHODS:In this study, we used high field magnetic resonance imaging (MRI) to evaluate the left ventricular functional characteristics of streptozotocin treated diabetic Sprague-Dawley rats (8 weeks disease duration) in comparison with age/sex matched controls.RESULTS:Our analyses of EKG gated cardiac MRI scans of the left ventricle showed a 28% decrease in the end-diastolic volume and 10% increase in the end-systolic volume of diabetic hearts compared to controls. Mean stroke volume and ejection fraction in diabetic rats were decreased (48% and 28%, respectively) compared to controls. Further, dV/dt changes were suggestive of phase ...
Magnetic resonance images (MRI) of the brain revealed an intrasellar and suprasellar cystic mass with well defined smooth borders, which displaced the optic chiasm superiorly. The lesion displayed high signal intensity on T1 weighted images (Images 1a and 1b, sagittal and axial, respectively) and showed peripheral enhancement with Gadolinium administration (Image 1c). The lesion also showed high signal intensity on T2 weighted images (Image 1d). A previous brain MRI from 1991 did not reveal sellar or suprasellar lesions. PATHOLOGICAL FINDINGS. FINAL DIAGNOSIS. ...
TY - JOUR. T1 - Diffusion and perfusion MRI findings of the signal-intensity abnormalities of brain associated with developmental venous anomaly. AU - Jung, H. N.. AU - Kim, Sung Tae. AU - Cha, J.. AU - Kim, H. J.. AU - Byun, H. S.. AU - Jeon, P.. AU - Kim, K. H.. AU - Kim, B. J.. AU - Kim, H. J.. PY - 2014/8. Y1 - 2014/8. N2 - BACKGROUND AND PURPOSE: Developmental venous anomalies are the most common intracranial vascular malformation. Increased signal-intensity on T2-FLAIR images in the areas drained by developmental venous anomalies are encountered occasionally on brain imaging studies. We evaluated diffusion and perfusion MR imaging findings of the abnormally high signal intensity associated with developmental venous anomalies to describe their pathophysiologic nature. MATERIALS AND METHODS: We retrospectively reviewed imaging findings of 34 subjects with signal-intensity abnormalities associated with developmental venous anomalies. All subjects underwent brain MR imaging with contrast and ...
BACKGROUND:Maintaining the quality of magnetic resonance images acquired with the current implantable coil technology is challenging in longitudinal studies. To overcome this challenge, the principle of inductive overcoupling is introduced as a method to tune and match a dual coil system. This system consists of an imaging coil built with fixed electrical elements and a matching coil equipped with tuning and matching capabilities. Overcoupling here refers to the condition beyond which the peak of the current in the imaging coil splits.METHODS:The combined coils are coupled inductively to operate like a transformer. Each coil circuit is electrically represented by equivalent lumped-elements. A theoretical analysis is given to identify the frequency response characteristics of the currents in each coil. The predictions from this analysis are translated into experiments and applied to locally image rat spinal cord at 9.4 T using an implantable coil as the imaging coil and an external volume coil ...
OBJECTIVES: Our goal was to validate myocardium at risk on T2-weighted short tau inversion recovery (T2-STIR) cardiac magnetic resonance (CMR) over time, compared with that seen with perfusion single-photon emission computed tomography (SPECT) in patients with ST-segment elevation myocardial infarction, and to assess the amount of salvaged myocardium after 1 week. BACKGROUND: To assess reperfusion therapy, it is necessary to determine how much myocardium is salvaged by measuring the final infarct size in relation to the initial myocardium at risk of the left ventricle (LV). METHODS: Sixteen patients with first-time ST-segment elevation myocardial infarction received (99m)Tc tetrofosmin before primary percutaneous coronary intervention. SPECT was performed within 4 h and T2-STIR CMR within 1 day, 1 week, 6 weeks, and 6 months. At 1 week, patients were injected with a gadolinium-based contrast agent for quantification of infarct size. RESULTS: Myocardium at risk at occlusion on SPECT was 33 +/- ...
Lactating rats must continuously maintain a critical balance between caring for pups and aggressively responding to nest threats. We tested the neural response of lactating females to the presentation of their own pups and novel intruder males using blood oxygen level-dependent functional magnetic resonance imaging at 7 T. Dams were presented with a single sequence of a control stimulus, pups or a male intruder in one imaging session (n = 7-9). To further determine the selectivity of neural processing, dams were imaged for their response to a male intruder in both the absence and presence of their pups (n = 6). Several maternal cortical and limbic brain regions were significantly activated by intruder presentation but not by pups or a control stimulus. These included the nucleus accumbens, periaqueductal gray, anterior cingulate, anterior thalamus, basal nucleus of the amygdala, temporal cortex, prelimbic/orbital area and insula. The nucleus accumbens, periaqueductal gray, temporal cortex and
TY - JOUR. T1 - Resting-state functional connectivity magnetic resonance imaging and outcome after acute stroke. AU - Puig, Josep. AU - Blasco, Gerard. AU - Alberich-Bayarri, Angel. AU - Schlaug, Gottfried. AU - Deco, Gustavo. AU - Biarnes, Carles. AU - Navas-Martí, Marian. AU - Rivero, Mireia. AU - Gich, Jordi. AU - Figueras, Jaume. AU - Torres, Cristina. AU - Daunis-I-Estadella, Pepus. AU - Oramas-Requejo, Celia L.. AU - Serena, Joaquín. AU - Stinear, Cathy M.. AU - Kuceyeski, Amy. AU - Soriano-Mas, Carles. AU - Thomalla, Götz. AU - Essig, Marco. AU - Figley, Chase R.. AU - Menon, Bijoy. AU - Demchuk, Andrew. AU - Nael, Kambiz. AU - Wintermark, Max. AU - Liebeskind, David S.. AU - Pedraza, Salvador. PY - 2018/1/1. Y1 - 2018/1/1. N2 - © 2018 American Heart Association, Inc. Background and Purpose: Physiological effects of stroke are best assessed over entire brain networks rather than just focally at the site of structural damage. Resting-state functional magnetic resonance imaging can map ...
In animal models of Parkinsons disease (PD), 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is one of the most widely used agents that damages the nigrostriatal dopaminergic pathway. However, brain structural changes in response to MPTP remain unclear. This study aimed to investigate in vivo longitudinal changes in gray matter (GM) volume and white matter (WM) microstructure in primate models administered with MPTP. In six cynomolgus monkeys, high-resolution magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) scans were acquired 7 times over 32 weeks, and assessments of motor symptoms were conducted over 15 months, before and after the MPTP injection ...
A new method of detecting structured changes in trabecular bone, such as those associated with osteoporosis, was evaluated on magnetic resonance images of the wrist. The method was based on gray-scale morphological granulometries which classify image texture by iteratively filtering an image and measuring the rate of change of structural diminution in a filtered-image sequence. A classification scheme capable of distinguishing structural changes in trabecular bone starting from normal trabeculae through sclerotic, cystic, and grossly porotic bone is presented. Results of the application of this technique to the evaluation of high resolution magnetic resonance images of the wrist are presented ...
The prevalence of PML has increased greatly over the last 15 years, concomitantly with the rise of AIDS (1). Since the introduction of HAART, reports have indicated that AIDS-associated PML may show clinical and neuroradiologic improvement with longer survival (2-10). However, in our series of four consecutive AIDS patients with PML treated with HAART, two were short-term survivors and two were long-term survivors.. On MR images, PML typically appears as multifocal, scalloping lesions located in the white matter. The lesions are hypointense on T1-weighted images and show high signal intensity on T2-weighted images (11). Increased hypointensity on T1-weighted images has been observed on follow-up MR studies, and has been suggested to be indicative of an aggressive form of the disease (12, 13). This feature has also been described in pathologic series (14). It was suggested recently that such imaging findings as increased atrophy, confluence of lesions, and increased hypointensity on follow-up ...
PURPOSE: To prospectively compare the black-blood ( BB black blood ) imaging efficiency of a delay alternating with nutation for tailored excitation ( DANTE delay alternating with nutation for tailored excitation ) preparation module with conventional double inversion-recovery ( DIR double inversion recovery ) and motion-sensitive driven equilibrium ( MSDE motion-sensitive driven equilibrium ) preparation modules and to introduce a new three-dimensional ( 3D three-dimensional ) T1-weighted magnetic resonance (MR) imaging sequence. MATERIALS AND METHODS: Carotid artery wall imaging was performed in 10 healthy volunteers and 15 patients in accordance with an institutional review board-approved protocol. Two-dimensional ( 2D two-dimensional ) turbo spin-echo ( TSE turbo spin echo ) and 3D three-dimensional fast low-angle shot ( FLASH fast low-angle shot ) sequences served as readout modules. DANTE delay alternating with nutation for tailored excitation -prepared T1-, T2-, and proton density-weighted 2D two
Background and Purpose- Relative signal intensity of acute ischemic stroke lesions in fluid-attenuated inversion recovery (fluid-attenuated inversion recovery relative signal intensity [FLAIR-rSI]) magnetic resonance imaging is associated with time elapsed since stroke onset with higher intensities signifying longer time intervals. In the randomized controlled WAKE-UP trial (Efficacy and Safety of MRI-Based Thrombolysis in Wake-Up Stroke Trial), intravenous alteplase was effective in patients with unknown onset stroke selected by visual assessment of diffusion weighted imaging fluid-attenuated inversion recovery mismatch, that is, in those with no marked fluid-attenuated inversion recovery hyperintensity in the region of the acute diffusion weighted imaging lesion. In this post hoc analysis, we investigated whether quantitatively measured FLAIR-rSI modifies treatment effect of intravenous alteplase. Methods- FLAIR-rSI of stroke lesions was measured relative to signal intensity in a mirrored ...
Results A 73 year old male with rheumatic heart disease presented with blood pressure dependent dizziness, dysarthria, and right sided weakness. Workup revealed basilar occlusion above the left AICA with minimal leptomeningeal flow to the superior basilar segment, posterior cerebral and superior cerebellar arteries. The patient improved with, and thus was maintained on, IV vasopressor medications but could not be weaned from these medications after 8 days. High resolution MRI of the basilar segment was obtained. Endovascular revascularisation with mechanical thrombectomy (stent retriever) followed by stenting of the basilar artery was performed. The patient was neurologically stable after recanalisation despite return of blood pressure to baseline. Pathological evaluation of the removed thrombus was obtained.. ...
Neurosurgery may be the only option for the 15%-30% of people suffering from epilepsy who are refractory to drug therapy. Due to excellent soft tissue contrast...
STUDY DESIGN Postoperative back muscle injury was evaluated in rats by magnetic resonance imaging and histologic analyses. OBJECTIVE To compare the magnetic resonance imaging manifestation of back muscle injury with the histologic findings in rats and to subsequently clarify the histopathologic appearance of the high intensity regions on T2-weighted images in human postoperative back muscles. SUMMARY OF BACKGROUND DATA In a previous study, it was found that the signal intensity on T2-weighted images of the postoperative back muscles was increased in patients who had postsurgical lumbar muscle impairment, especially in those with a prolonged surgery duration. However, the specific histopathologic changes that cause the high signal intensity on T2-weighted images remain unclear. METHODS Rats were divided into three groups: sham operation group, 1-hour retraction group, and 2-hour retraction group. Magnetic resonance imaging and histology of the multifidus muscles were examined before surgery and at
A 33-year-old woman underwent buttock liposuction and fat injection to the breast at a cosmetic clinic 2 years previously. After the operation, she became aware of indurations and disfiguration of both breasts and visited our facility. Asymmetry of the breasts and huge indurations were palpable (Fig. 18). On preoperative blood examination, high levels of antinuclear antibodies were detected. On mammography, huge masses were detected in the subcutaneous tissue (Fig. 19). Chest computed tomography revealed multiple low-density areas encapsulated with high-density areas in the subdermis in both breasts. Magnetic resonance imaging indicated multiple injected fat with high-iso signal intensity on T1-weighted images and low signal intensity on T2-weighted images (Fig. 20). Surgery to remove the subcutaneous masses was performed. Our routine examination for foreign bodies using nuclear magnetic resonance detected a small amount of silicone contamination. This suggests that the high levels of ...
To clarify whether amnesia after treatment of anterior communicating aneurysm (ACoA)is related to infarcts caused by occlusion or damage of the perforating artery of the ACoA, we used 3.0-T 3D high resolution MR imaging to identify and localize infarcts in patients with amnesia following treatment of ACoA aneurysm ...
TY - JOUR. T1 - Automated method for accurate abdominal fat quantification on water-saturated magnetic resonance images. AU - Peng, Qi. AU - McColl, Roderick W.. AU - Ding, Yao. AU - Wang, Jihong. AU - Chia, Jonathan M.. AU - Weatherall, Paul T.. PY - 2007/9. Y1 - 2007/9. N2 - Purpose: To introduce and evaluate the performance of an automated fat quantification method for water-saturated magnetic resonance images. Materials and Methods: A fat distribution model is proposed for fat quantification on water saturated magnetic resonance images. Fat from both full- and partial-volume voxels are accounted for in this model based on image intensity histogram analysis. An automated threshold method is therefore proposed to accurately quantify total fat. This method is compared to a traditional full-volume-fat-only method in phantom and human studies. In the phantom study, fat quantification was performed on MR images obtained from a human abdomen oil phantom and was compared with the true oil volumes. ...
Recent Advances in MRI-based Diagnosis and Treatment of Back Pain. Recent advances suggest that axial-loaded MRI is preferable to recumbent MRI in obese patients suffering from back pain. It may enhance the diagnostic benefit of lumbar spine MRI in such individuals with possible spinal canal stenosis.[14]. Screening with a rapid lumbar spine (LS) MRI protocol using a single 3D-T2 fat-saturation sequence in patients with acute back pain admitted to the emergency department revealed fractures, cord signal abnormalities, and severe spinal canal stenosis in addition to detecting cord compression more rapidly and effectively than conventional LS MRI.[15]. The coronal short tau inversion recovery (STIR)-weighted magnetic resonance (MR) sequence, incorporated in lumbar spine MRI allowed the detection of extraspinal degenerative conditions contributing to lower back pain: sacroiliac joint defects, sacroiliitis, degeneration of the coxofemoral joint, renal and adrenal masses, genitourinary infarcts, ...
Orbital magnetic resonance imaging (MRI) scans show rhabdomyosarcoma in left ethmoid sinus with low signal intensity on T1-weighted image (A,B) and moderate enh
On MRI a subchondral fracture is best seen on T1-weighted images as linear subcortical low signal intensity. It may not be well seen on T2-weighted images unless there is trabecular impaction, which causes a low signal intensity line on both T1 and T2-weighted images. The double line sign on T2-weighted images is considered diagnostic of osteonecrosis. The inner increased signal intensity line represents vascularized granulation tissue and the outer low signal intensity line is due to sclerotic appositional new bone.6 The double line sign can be visible in epiphyseal or metadiaphyseal lesions and has no predictive value in and of itself for eventual outcome in cases of pre-existing osteonecrosis, which can either resolve, stabilize, or progress to cortical collapse. However, the development of the double line sign in follow up imaging of a previously uncomplicated subchondral fracture may herald the progression to irreversible damage. It is only in the relatively more recent literature of ...
Coronary heart disease (CHD) has been associated with impaired cognition, but the mechanisms underlying these changes remain unclear. We designed this study to determine whether adults with CHD show regional brain losses of grey matter volume relative to controls. We used statistical parametric mapping (SPM5) to determine regional changes in grey matter volume of T 1-weighted magnetic resonance images of 11 adults with prior history of myocardial infarction relative to seven healthy controls. All analyses were adjusted for total grey and white matter volume, age, sex and handedness. CHD participants showed a loss of grey matter volume in the left medial frontal lobe (including the cingulate), precentral and postcentral cortex, right temporal lobe and left middle temporal gyrus, and left precuneus and posterior cingulate. CHD is associated with loss of grey matter in various brain regions, including some that play a significant role in cognitive function and behaviour. The underlying causes of ...
Purpose To refine methods that assess structural brain abnormalities and calculate intracranial volumes in fetuses with congenital heart diseases (CHD) using in utero MR (iuMR) imaging. Our secondary objective was to assess the prevalence of brain abnormalities in this high-risk cohort and compare the brain volumes with normative values. Methods We performed iuMR on 16 pregnant women carrying a fetus with CHD and gestational age ≥ 28-week gestation and no brain abnormality on ultrasonography. All cases had fetal echocardiography by a pediatric cardiologist. Structural brain abnormalities on iuMR were recorded. Intracranial volumes were made from 3D FIESTA acquisitions following manual segmentation and the use of 3D Slicer software and were compared with normal fetuses. Z scores were calculated, and regression analyses were performed to look for differences between the normal and CHD fetuses. Results Successful 2D and 3D volume imaging was obtained in all 16 cases within a 30-min scan. Despite ...
The dorsolateral prefrontal cortex (DLPFC) is a brain region that has figured prominently in studies of schizophrenia and working memory, yet the exact neuroanatomical localization of this brain region remains to be defined. DLPFC primarily involves the superior frontal gyrus and middle frontal gyrus (MFG). The latter, however is not a single neuroanatomical entity but instead is comprised of rostral (anterior, middle, and posterior) and caudal regions. In this study we used structural MRI to develop a method for parcellating MFG into its component parts. We focused on this region of DLPFC because it includes BA46, a region involved in working memory. We evaluated volume differences in MFG in 20 patients with chronic schizophrenia and 20 healthy controls. Mid-rostral MFG (MR-MFG) was delineated within the rostral MFG using anterior and posterior neuroanatomical landmarks derived from cytoarchitectonic definitions of BA46. Gray matter volumes of MR-MFG were then compared between groups, and a ...
Objective To ascertain whether high-field magnetic resonance imaging (MRI) allows accurate estimation of the weight of various fetal organs at postmortem before 20 weeks gestation. Methods From 23 fetuses at 920 weeks, following termination of pregnancy or in-utero fetal death (IUFD), 207 assorted fetal organs were evaluated by high-field MRI at 9.4 T prior to conventional autopsy. Fetal organ density was calculated by correlating volume and weight at autopsy using linear regression analysis, and this was used to estimate fetal organ weight by MRI. The relative error in MRI estimation of organ weight was calculated as follows: (,MRI weight - autopsy weight,/autopsy weight) x 100 (%). Multiple regression analysis was used to investigate the effect on the relative error of MRI organ weight estimates of gestational age at TOP or delivery following IUFD, autopsy weight, fetal organ examined, IUFD and fetal maceration. Results Of the 207 organs evaluated, 133 (64%) were examined for fetal organ ...
MRI signal abnormalities in the disc have been described predominantly as low signal intensity on T2 weighted images. Loss of disc height and disc
TY - JOUR. T1 - Default mode network alterations in individuals with high-trait-anxiety: An EEG functional connectivity study. AU - Della Marca, Giacomo. AU - Imperatori, Claudio. AU - Farina, Benedetto. AU - Adenzato, Mauro. AU - Valenti, Enrico Maria. AU - Murgia, Cristina. AU - Brunetti, Riccardo. AU - Fontana, Elena. AU - Ardito, Rita B.. PY - 2019. Y1 - 2019. N2 - Background: Although several researches investigated Default Mode Network (DMN) alterations in individuals with anxiety disorders, up to now no studies have investigated DMN functional connectivity in non-clinical individuals with high-trait-anxiety using quantitative electroencephalography (EEG). Here, the main aim was to extend previous findings investigating the association between trait anxiety and DMN EEG functional connectivity. Methods: Twenty-three individuals with high-trait-anxiety and twenty-four controls were enrolled. EEG was recorded during 5 min of resting state (RS). EEG analyses were conducted by means of the ...
PubMed journal article: Magnetic resonance T2 image signal intensity ratio and clinical manifestation predict prognosis after surgical intervention for cervical spondylotic myelopathy. Download Prime PubMed App to iPhone, iPad, or Android
Background: Magnetic Resonance Imaging (MRI) of the carotid artery can detect features of atherosclerotic plaque that may be associated with an increased stroke risk. This study tested the ability of MRI at 3 Tesla to identify features of acutely symptomatic carotid plaques and their association with downstream brain injury.. Methods: 41 patients presenting acutely with TIA or minor stroke and 40 asymptomatic controls underwent dark-blood T1, T2 and proton density-weighted turbo spin echo MRI of the carotid arteries, followed by diffusion-weighted (DWI) and FLAIR imaging of the brain on 2 separate occasions. Plaques were graded (MRI modified American Heart Association system) and related to the extent of MRI-determined brain injury.. Results: AHA type VI (ruptured) plaque was seen in 22 / 41 (54 %) in the symptomatic group vs. 8 / 40 (20 %) in the asymptomatic group (P , 0.05), and was due to intra-plaque haemorrhage (34% vs. 18%, P = 0.08; figure A), luminal thrombus (7% vs. 0%, P = 0.24; ...
DOI: 10.14704/nq.2021.19.1.NQ21001. Diagnostic Accuracy and Correlation between Double Inversion Recovery (DIR), FLAIR and T2W Imaging Sequences with EDSS in Detection of Lesions at different Anatomical Regions in MS Patients. Abdullah Dhaifallah Almutairi, Hasyma Abu Hassan, Subapriya Suppiah, Othman I Alomair, Abdulrahim Almotairy, Ali M. Muslim, Abdullah Almanaa and Rozi Mahmud. Abstract. The aim of our study is to evaluate the diagnostic accuracy of double inversion recovery (DIR) in detection of multiple sclerosis (MS) lesions as well as the correlation between the expanded disability status scale (EDSS) and lesion load measurement detected by DIR, fluid attenuated inversion recovery (FLAIR) and T2 weighted imaging (T2WI) in order to reveal the essential role of DIR sequence in assessing clinical inability as a practicable experiment. A total of 97 patients were assessed on a 3T Siemens Skyra MRI scanner using DIR, FLAIR, and T2W_TSE sequences. EDSS was used to assess the physical ...
Few tasks are simpler to perform than a breath hold; however, the neural basis underlying this voluntary inhibitory behaviour, which must suppress spontaneous respiratory motor output, is unknown. Here, using blood oxygen level-dependent functional magnetic resonance imaging (BOLD fMRI), we investig …
Lesions of the menisci on MRI are divided into four grades. Normal meniscus has uniformly low signal intensity on T2-weighted images (T2W). Grade I and II lesions can be a normal appearance of ageing in older patients.
Assessment of acute spinal inflammation in patients with ankylosing spondylitis by magnetic resonance imaging: a comparison between contrast enhanced T1 and short tau inversion recovery (STIR) ...
TY - JOUR. T1 - Sugar-based biopolymers as novel imaging agents for molecular magnetic resonance imaging. AU - Han, Zheng. AU - Liu, Guanshu. PY - 2019/7/1. Y1 - 2019/7/1. N2 - Sugar-based biopolymers have been recognized as attractive materials to develop macromolecule- and nanoparticle-based cancer imaging and therapy. However, traditional biopolymer-based imaging approaches rely on the use of synthetic or isotopic labeling, and because of it, clinical translation often is hindered. Recently, a novel magnetic resonance imaging (MRI) technology, chemical exchange saturation transfer (CEST), has emerged, which allows the exploitation of sugar-based biopolymers as MRI agents by their hydroxyl protons-rich nature. In the study, we reviewed recent studies on the topic of CEST MRI detection of sugar-based biopolymers. The CEST MRI property of each biopolymer was briefly introduced, followed by the pre-clinical and clinical applications. The findings of these preliminary studies imply the enormous ...
TY - JOUR. T1 - Gadolinium-enhanced fat-suppressed T1-weighted imaging of the head and neck. T2 - Comparison of gradient and conventional SE sequences. AU - Hirsch, Joshua A.. AU - Loevner, Laurie A.. AU - Yousem, David M.. AU - Siegelman, Evan S.. AU - Keiper, Mark D.. AU - Marquis, Robert P.. AU - Grossman, Robert I.. PY - 1998. Y1 - 1998. N2 - Purpose: The purpose of this study was to compare contrast-enhanced GRE and conventional SE (CSE) fat-suppressed T1-weighted techniques in the evaluation of head and neck lesions. A hybrid, opposed phase, frequency- selective, fat-suppressed fast multiplanar spoiled GRE (FMPSPGR) sequence was compared with a fat-suppressed CSE sequence. Method: Thirty-two patients with head and neck pathology were evaluated With both fat-suppressed CSE and FMPSPGR sequences. Regions of interest obtained by two viewers in consensus were used to establish contrast-to-noise (CNR) and signal-to-noise ratios for both sequences. Three neuroradiologists also independently ...
Gd3L is a trinuclear Gd3R complex of intermediate size, designed for contrast agent applications in high field magnetic resonance imaging (H12L is based on a trimethylbenzene core bearing three methylene-diethylenetriamine-N,N,N00,N00-tetraacetate moieties). Thanks to its appropriate size, the presence of two inner sphere water molecules and a fast water exchange, Gd3L has remarkable proton relaxivities at high magnetic field (r1¼10.2 vs 3.0mM S1 sS1 for GdDOTA at 9.4 T, 37-C, in H2O). Here we report an in vivo MRI feasibility study, complemented with dynamic g scintigraphic imaging and biodistribution experiments using the 153Sm-enriched analog. MRI experiments were performed at 9.4 T in mice with Gd3L and the commercial contrast agent gadolinium(III)-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate (GdDOTA). Gd3L was well tolerated by the animals at the dose of 8mmol Gd kgS1 body weight. Dynamic contrast enhanced (DCE) images showed considerably higher signal enhancement in the kidney medulla and
TY - JOUR. T1 - High payload Gd(III) encapsulated in hollow silica nanospheres for high resolution magnetic resonance imaging. AU - Lin, Wan Ing. AU - Lin, Chien Yuan. AU - Lin, Yu Shen. AU - Wu, Si Han. AU - Huang, Yu Ru. AU - Hung, Yann. AU - Chang, Chen. AU - Mou, Chung Yuan. PY - 2013/2/7. Y1 - 2013/2/7. N2 - For clear MR imaging of blood vessels, a long blood circulation time of effective T1 contrast agents is necessary. Nanoparticulate MR contrast agents are much more effective owing to their enhanced relaxivity, a result of reduced tumbling rates, and large payloads of active magnetic species. PEGylated yolk-shell silica nanospheres containing high payloads of Gd(iii) with cross-linking ligands are synthesized and evaluated as a blood-pool magnetic resonance contrast agent. The hydrophilic PEG coating and the microporous silica shell allow water exchange while keeping the multi-nuclear Gd species from leaching out. These Gd(iii)-containing yolk-shell silica nanoparticles with PEGylated ...
Alexander disease is a rare disorder resulting from a glial fibrillary acidic protein gene mutation which causes progressive degeneration of white matter. With the usual poor prognosis, there are few case reports with long-term follow-up. We report the five-year clinical course of Alexander disease in one case using serial magnetic resonance imaging. A 12-month-old Japanese male was referred to the pediatrics department in our hospital because of developmental retardation. Alexander disease was diagnosed by gene examination of the mutation of a glial fibrillary acidic protein. Magnetic resonance imaging findings showed abnormalities in white matter, deep gray matter, and medulla oblongata. Serial magnetic resonance imaging examinations until the age of five were performed and changes in magnetic resonance imaging findings were compared to the progression in clinical symptoms. Alexander disease is a very rare disease with a variety of clinical phenotypes. Therefore serial magnetic resonance imaging
TY - JOUR. T1 - High-resolution three-dimensional magnetic resonance angiography and three-dimensional spoiled gradient-recalled imaging in the evaluation of neurovascular compression in patients with trigeminal neuralgia. T2 - A double-blind pilot study. AU - Anderson, Valerie C.. AU - Berryhill, Phillip C.. AU - Sandquist, Michael A.. AU - Ciaverella, David P.. AU - Nesbit, Gary M.. AU - Burchiel, Kim J.. PY - 2006/4/1. Y1 - 2006/4/1. N2 - OBJECTIVE: To assess the value of high-resolution three-dimensional (3D) time-of-flight (TOF) magnetic resonance (MR) angiography and gadolinium (Gad)-enhanced 3D spoiled gradient-recalled imaging in the visualization of neurovascular compression in patients with trigeminal neuralgia. METHODS: Forty-eight patients with unilateral trigeminal neuralgia underwent high-resolution 3D TOF MR angiography. After administration of a contrast agent, a 3D spoiled gradient-recalled sequence (3D Gad) was run. Images were reviewed by a radiologist blinded to clinical ...
TY - JOUR. T1 - The influence of the amplitude of low-frequency fluctuations on resting-state functional connectivity. AU - Di, Xin. AU - Kim, Eun H.. AU - Huang, Chu Chung. AU - Tsai, Shih Jen. AU - Lin, Ching Po. AU - Biswal, Bharat B.. PY - 2013/3/18. Y1 - 2013/3/18. N2 - Studies of brain functional connectivity have provided a better understanding of organization and integration of large-scale brain networks. Functional connectivity using resting-state functional magnetic resonance imaging (fMRI) is typically based upon the correlations of the low-frequency fluctuation of fMRI signals. Reproducible spatial maps in the brain have also been observed using the amplitude of low-frequency fluctuations (ALFF) in resting-state. However, little is known about the influence of the ALFF on the functional connectivity measures. In the present study, we analyzed resting-state fMRI data on 79 healthy old individuals. Spatial independent component analysis (ICA) and regions of interest (ROIs) based ...
COSTA, Flávia Martins et al. Proton magnetic resonance spectroscopy and perfusion magnetic resonance imaging in the evaluation of musculoskeletal tumors. Radiol Bras [online]. 2009, vol.42, n.4, pp.215-223. ISSN 1678-7099. OBJECTIVE: To assess the role of proton magnetic resonance spectroscopy and dynamic contrast-enhanced magnetic resonance imaging in the differentiation between malignant and benign musculoskeletal tumors. MATERIALS AND METHODS: Fifty-five patients with musculoskeletal tumors (27 malignant and 28 benign) were studied. The examinations were performed in a 1.5 T magnetic resonance scanner with standard protocol, and single voxel proton magnetic resonance spectroscopy with 135 msec echo time. The dynamic contrast study was performed using T1-weighted gradient-echo sequence after intravenous gadolinium injection. Timesignal intensity curves and slope values were calculated. The statistical analysis was performed with the Levenes ...
BACKGROUND AND PURPOSE: White matter hyperintensities (WMH) on MRI are a quantitative marker for sporadic cerebral small vessel disease and are highly heritable. To date, large-scale genetic studies have identified only a single locus influencing WMH burden. This might in part relate to biological heterogeneity of sporadic WMH. The current study searched for genetic modifiers of WMH volume in cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), a monogenic small vessel disease.. METHODS: We performed a genome-wide association study to identify quantitative trait loci for WMH volume by combining data from 517 CADASIL patients collected through 7 centers across Europe. WMH volumes were centrally analyzed and quantified on fluid attenuated inversion recovery images. Genotyping was performed using the Affymetrix 6.0 platform. Individuals were assigned to 2 distinct genetic clusters (cluster 1 and cluster 2) based on their genetic background.. RESULTS: ...
Primary angiitis of the central nervous system is a rare disease of unclear etiology. There is no single test diagnostic of primary angiitis of the central nervous system. We report an unusual pattern on brain magnetic resonance imaging that might be specific for primary angiitis of the central nervous system. A 47-year-old Caucasian man developed progressive bilateral hand tremor, difficulty walking, cognitive slowing and headache. A physical examination showed bilateral hand tremor with dysmetria, hyperreflexia and abnormal gait. Magnetic resonance imaging of his brain showed bilateral, symmetrical, increased intensity on T2-weighted images concurrent with linear contrast enhancement in a radial distribution throughout his white matter, sparing subcortical regions in his centrum semiovale, corona radiata, basal ganglia and brainstem. Magnetic resonance spectroscopy demonstrated elevated choline and decreased N-acetyl aspartate. Except for elevated protein and lymphocytic pleocytosis, examination of
White matter hyperintensities were associated with an increased risk of dementia in the general population, but not in studies on high risk populations (mainly with mild cognitive impairment or a history of stroke). When subtypes of dementia were assessed, the three studies that investigated the relation of white matter hyperintensities with incident vascular dementia found a significant association, both in the general population and in patients with mild cognitive impairment.31 33 41 Conversely, although the meta-analysis testing the relation of white matter hyperintensities with incident Alzheimers disease yielded an overall significant association, this association was driven by the large population based study,31 whereas the two smaller studies on patients with mild cognitive impairment did not identify any association.41 49 Finally, our systematic review suggests that, in most studies looking at the association of white matter hyperintensities with decline in cognitive performance, white ...
Differential diagnosis must be done from other cyst-like lesions of that region. PACs arise from the adjacent Meckels cave, and secondary erode into the petrous apex [4], whereas lesions such as cholesteatoma, cholesterol granuloma, mucocele, apical petrositis and petrous apex effusion, arise from the petrous apex and expand it from within [3, 4]. Furthermore, epidermoid cysts have high signal intensity on fluid-attenuation inversion-recovery sequence, whereas the signal of arachnoid cysts is suppressed. Diffusion weighted imaging (DWI) also allows differentiation of epidermoid and arachnoid cysts i.e. epidermoid cysts yield high signal on DWI due to their restricted diffusion while arachnoid cysts, like CSF, show very low signal intensity. In addition, lesions that have high signal intensity on T2W sequences such as paraganglioma, chondroma, chordoma and apex petrositis show contrast enhancement [2 ...
Background/Aims: The high incidence of cardiovascular disease (CVD) in patients with autoimmune rheumatic diseases (ARDs) is the main driver towards increased mortality in this patient group. Cardiovascular magnetic resonance (CMR) can non-invasively and robustly detect CVD in ARD patients at an early stage of development. The review summarises the diagnostic information provided by CMR in ARD patients. Summary : CMR uses a strong magnetic field combined with radio-frequency pulses (pulse sequences) to generate images. Firstly, balanced steady-state free precession(bSSFP) can be used for evaluating cardiac anatomy, mass, wall motion, atrial/ventricular function. Secondly, T2-weighted imaging (T2-W) can be used for oedema detection, which appears as a high signal intensity area on STIR (short tau inversion recovery) images. T2 mapping is a newer T2-W technique that can provide more optimal identification of myocardial oedema. Lastly, late gadolinium enhanced (LGE) T1-W images, taken 15 min. after
TY - JOUR. T1 - White Matter Hyperintensity Volume and Cerebral Perfusion in Older Individuals with Hypertension Using Arterial Spin-Labeling. AU - van Dalen, J. W.. AU - Mutsaerts, H. J. M. M.. AU - Nederveen, A. J.. AU - Vrenken, H.. AU - Steenwijk, M. D.. AU - Caan, M. W. A.. AU - Majoie, C. B. L. M.. AU - van Gool, W. A.. AU - Richard, E.. PY - 2016/10. Y1 - 2016/10. U2 - 10.3174/ajnr.A4828. DO - 10.3174/ajnr.A4828. M3 - Article. C2 - 27282862. VL - 37. SP - 1824. EP - 1830. JO - American Journal of Neuroradiology. JF - American Journal of Neuroradiology. SN - 0195-6108. IS - 10. ER - ...
TY - JOUR. T1 - Small (,2-cm) upper-tract urothelial carcinoma. T2 - Evaluation with gadolinium-enhanced three-dimensional spoiled gradient-recalled echo MR urography. AU - Takahashi, Naoki. AU - Kawashima, Akira. AU - Glockner, James F.. AU - Hartman, Robert P.. AU - Leibovich, Bradley C.. AU - Brau, Anja C.S.. AU - Beatty, Philip J.. AU - King, Bernard F.. PY - 2008/5/1. Y1 - 2008/5/1. N2 - Purpose: To retrospectively evaluate the detection of small (,2-cm) urothelial tumors by using gadolinium-enhanced three-dimensional (3D) spoiled gradient-recalled echo (GRE) magnetic resonance (MR) urography. Materials and Methods: This HIPAA-compliant study received institutional review board approval. All patients included had previously consented to the use of their medical records for research purposes. Eleven of 110 patients (10 men, one woman; mean age, 73.5 years) who underwent MR urography were ultimately identified to have 23 upper-tract urothelial carcinomas smaller than 2 cm or carcinoma in ...
OBJECTIVE: Our goal was to assess the value of MR imaging to patient care in the setting of angiographically negative subarachnoid hemorrhage and to evaluate the potential of MR imaging for revealing the mechanism for idiopathic perimesencephalic subarachnoid hemorrhage.. MATERIALS AND METHODS: We retrospectively reviewed 71 patients who presented with subarachnoid hemorrhage and in whom the results of a four-vessel cerebral arteriogram were negative, a CT scan showed no evidence of intraaxial hemorrhage, and MR imaging had been performed within 72 hr of presentation. MR imaging of the brain included sagittal spin-echo T1-weighted, turbo spin-echo proton density-weighted, T2-weighted, and axial T2-weighted gradient-echo sequences. MR imaging of the cervical spine, which was performed in 41 of the 71 patients, included sagittal spin-echo T1-weighted, turbo spin-echo proton density-weighted, T2-weighted, and axial T2-weighted gradient-echo sequences.. RESULTS: Perimesencephalic subarachnoid ...
TY - JOUR. T1 - Proton and multinuclear magnetic resonance spectroscopy in the human brain at ultra-high field strength. T2 - A review. AU - Henning, Anke. PY - 2018/3. Y1 - 2018/3. N2 - Magnetic Resonance Spectroscopy (MRS) allows for a non-invasive and non-ionizing determination of in vivo tissue concentrations and metabolic turn-over rates of more than 20 metabolites and compounds in the central nervous system of humans. The aim of this review is to give a comprehensive overview about the advantages, challenges and advances of ultra-high field MRS with regard to methodological development, discoveries and applications from its beginnings around 15 years ago up to the current state. The review is limited to human brain and spinal cord application at field strength of 7T and 9.4T and includes all relevant nuclei (1H, 31P, 13C).. AB - Magnetic Resonance Spectroscopy (MRS) allows for a non-invasive and non-ionizing determination of in vivo tissue concentrations and metabolic turn-over rates of ...
The ordered electrical stimulation of the ventricles is achieved by a specialized network of fibres known as the Purkinje system. The gross anatomy and basic functional role of the Purkinje system is well understood. However, very little is known about the detailed anatomy of the Purkinje system, its inter-individual variability and the implications of the variability in ventricular function, in part due to limitations in experimental techniques. In this study, we aim to provide new insight into the inter-individual variability of the free running Purkinje system anatomy and its impact on ventricular electrophysiological function. As a first step towards achieving this aim, high resolution magnetic resonance imaging (MRI) datasets of rat and the rabbit ventricles are obtained and analysed using a novel semi-automatic image processing algorithm for segmentation of the free-running Purkinje system. Segmented geometry from the MRI datasets is used to construct a computational model of the Purkinje system,
Dive into the research topics of Association of white matter hyperintensity volume with decreased cognitive functioning: The Framingham Heart Study. Together they form a unique fingerprint. ...
TY - JOUR. T1 - Exome chip analysis identifies low-frequency and rare variants in MRPL38 for white matter hyperintensities on brain magnetic resonance imaging. AU - neuroCHARGE Working Group. AU - Jian, Xueqiu. AU - Satizabal, Claudia L.. AU - Smith, Albert V.. AU - Wittfeld, Katharina. AU - Bis, Joshua C.. AU - Smith, Jennifer A.. AU - Hsu, Fang Chi. AU - Nho, Kwangsik. AU - Hofer, Edith. AU - Hagenaars, Saskia P.. AU - Nyquist, Paul A.. AU - Mishra, Aniket. AU - Adams, Hieab H.H.. AU - Li, Shuo. AU - Teumer, Alexander. AU - Zhao, Wei. AU - Freedman, Barry I.. AU - Saba, Yasaman. AU - Yanek, Lisa R.. AU - Chauhan, Ganesh. AU - Van Buchem, Mark A.. AU - Cushman, Mary. AU - Royle, Natalie A.. AU - Nick Bryan, R.. AU - Niessen, Wiro J.. AU - Windham, Beverly G.. AU - DeStefano, Anita L.. AU - Habes, Mohamad. AU - Heckbert, Susan R.. AU - Palmer, Nicholette D.. AU - Lewis, Cora E.. AU - Eiriksdottir, Gudny. AU - Maillard, Pauline. AU - Mathias, Rasika A.. AU - Homuth, Georg. AU - ...
An MRI scan is the best way to locate multiple sclerosis (MS) lesions (also called plaques) in the brain or spinal cord. An MRI scan is abnormal in more than 95% of people recently diagnosed with MS.footnote 1. But abnormal MRI results do not always mean that you have MS. Abnormalities show up on scans from many illnesses other than MS. An abnormal finding on an MRI scan alone is not enough to diagnose MS. Your doctor will confirm a diagnosis of MS based on your symptoms, your neurological exam, and the results from an MRI and other tests.. When abnormal MRI results occur along with a medical history, abnormal nervous system exam, and other test results that are typical of MS, it is very likely that you have MS.. If you have already been diagnosed with MS, MRI scans can sometimes distinguish new lesions from older ones and can help your doctor(s) follow the progress of the disease. Continuing to have periodic MRI scans if you have relapsing-remitting MS may help identify new lesions even when ...
Regarding diagnosis with AAM, the characteristic MRI findings of AAM include the following: On T1-weighted MRI, it has low signal intensity. That is, it is of the same signal intensity as the skeletal muscle. On T2-weighted MRI, it has high signal intensity. These appearances likely relate to the loose myxoid matrix and high water content of angiomyxoma [11]. The CT findings demonstrated that the tumor, later identified as AAM, had a well-defined margin and an attenuation less than that of a muscle [11]. On ultrasonography, AAM appears as a hypoechoic or cystic mass [12]. In our case, the liver mass showed high signal intensity on T2-weighted MRI, as an attenuated mass on CT, and as a hypoechoic cystic region on ultrasound (Fig. 1). In our case, CT and FDG-PET unable to detect any mass in other regions including the pelvi-perineal region. Therefore, the AAM was concluded as of liver origin.. Immunohistochemically, AAM has been found to be positive for vimentin, desmin, CD 34, ER, PgR, and ...
A 48 year old left handed man presented with a history of a burst, very brief electrical tingling in the left forearm, hand, and lower leg for almost 2 years. The symptom occurred only on flexion of the neck and abated even when the neck was kept flexed. No other neck movements caused this symptom. A year later, the patient noted mild dysaesthesia in the left arm and leg. A sagittal heavily T2 weighted fast spin echo MR image of the cervical spine showed a small ovoid area of T2 hyperintensity within the posterior cervical spinal cord at the cervical 3-4 level with minimal mass effect. Subtle low signal intensity about its rim suggested hemosiderin deposition (figure). A few weeks later, after raking his yard, the patient experienced acute neck pain. A day later, he noticed diminished coordination of the left arm and leg. A sagittal T2 weighted fast spin echo MRI of the cervical spine obtained a few days later showed an extensive intramedullary low signal intensity area in the midposterior ...
METHODS: Proton density and T2 weighted images were obtained on a 1.0 Tesla MRI scanner in patients with dementia with Lewy bodies (consensus criteria; n=27, mean age=75.9 years), Alzheimers disease (NINCDS/ADRDA; n=28, mean age=77.4 years), vascular dementia (NINDS/AIREN; n=25, mean age=76.8 years), and normal controls (n=26, mean age=76.2 years). Cognitive function, depressive symptoms, and psychotic features were assessed using a standardised protocol. Periventricular hyperintensities (PVHs), white matter hyperintensities (WMHs) and basal ganglia hyperintensities (BGHs) were visually rated blind to diagnosis using a semiquantitative scale ...
The aim of this study is to describe the association of bone marrow lesions (BMLs) present on two different MRI sequences with clinical outcomes, cartilage defect progression, cartilage volume loss over 2.7 years, and total knee replacement (TKR) over 13.3 years. 394 participants (50-80 years) were assessed at baseline and 2.7 years. BML presence at baseline was scored on T1-weighted fat-suppressed 3D gradient-recalled acquisition (T1) and T2-weighted fat-suppressed 2D fast spin-echo (T2) sequences. Knee pain, function, and stiffness were assessed using WOMAC. Cartilage volume and defects were assessed using validated methods. Incident TKR was determined by data linkage. BMLs were mostly present on both MRI sequences (86%). BMLs present on T2, T1, and both sequences were associated with greater knee pain and functional limitation (odds ratio = 1.49 to 1.70; all p p p p p , 0.05). BMLs present on T2, T1, and both sequences were strongly associated with incident TKR. BMLs can be assessed on either ...
TY - JOUR. T1 - Preoperative Magnetic Resonance and Intraoperative Ultrasound Fusion Imaging for Real-Time Neuronavigation in Brain Tumor Surgery. AU - Prada, F.. AU - Del Bene, M.. AU - Mattei, L.. AU - Lodigiani, L.. AU - Debeni, S.. AU - Kolev, V.. AU - Vetrano, I.. AU - Solbiati, L.. AU - Sakas, G.. AU - Dimeco, F.. PY - 2015/4/1. Y1 - 2015/4/1. N2 - Purpose: Brain shift and tissue deformation during surgery for intracranial lesions are the main actual limitations of neuro-navigation (NN), which currently relies mainly on preoperative imaging. Ultrasound (US), being a real-time imaging modality, is becoming progressively more widespread during neurosurgical procedures, but most neurosurgeons, trained on axial computed tomography (CT) and magnetic resonance imaging (MRI) slices, lack specific US training and have difficulties recognizing anatomic structures with the same confidence as in preoperative imaging. Therefore real-time intraoperative fusion imaging (FI) between preoperative imaging ...
A thin line of cortical low signal intensity (motor dark line or hypointense rim) of the precentral gyrus on T2WI or FLAIR images has been advocated to be a marker of UMN compromise in ALS, particularly in advanced disease20,27. However, this T2 shortening effect results from excessive iron deposition, fibrillary gliosis, and/or macrophage infiltration, and such a change is neither sensitive nor specific to the pathology of UMN degeneration in ALS and can be found in healthy people, as well as in those with other degenerative diseases10,28-30.. Precentral gyrus subcortical hyperintensity on T2WI or FLAIR images has been reported as an important finding that represents CST abnormalities in UMN degeneration20,27,29. This hyperintensity is probably due to ALS-related degenerative changes and contributes to the diagnosis of ALS in some studies, although with a low sensitivity20,28,31. Central sulcus enlargement and CST hyperintensity on FLAIR images have demonstrated low sensitivity and ...
A core symptom of anxiety disorders is the tendency to interpret ambiguous information as threatening. Using electroencephalography and blood oxygenation level dependent magnetic resonance imaging (BOLD-MRI), several studies have begun to elucidate brain processes involved in fear-related perceptual biases, but thus far mainly found evidence for general hypervigilance in high fearful individuals. Recently, multi-voxel pattern analysis (MVPA) has become popular for decoding cognitive states from distributed patterns of neural activation. Here, we used this technique to assess whether biased fear generalization, characteristic of clinical fear, is already present during the initial perception and categorization of a stimulus, or emerges during the subsequent interpretation of a stimulus. Individuals with low spider fear (n = 20) and high spider fear (n = 18) underwent functional MRI scanning while viewing series of schematic flowers morphing to spiders. In line with previous studies, individuals ...
Diabetes mellitus is associated with an increase in proliferative lesions in the small cerebral vessels.1 Functionally, the blood-retinal barrier is closely related to the blood-brain barrier (BBB)2 and cortical capillaries in experimental models of diabetes exhibit similar microangiopathy to that found in the human retina in diabetes.3, 4. A principal neuroradiological feature that may be associated with cerebral microvascular disease is white matter hyperintensities or leukoaraiosis, a mixed condition of uncertain aetiology manifested on CT scans as hypodensity in the cerebral white matter, and as hyperintensities on T2, proton density or fluid attenuated inversion recovery (FLAIR) MR imaging.5 Recent longitudinal studies have highlighted diabetes as a risk factor for dementia, doubling the risk of senile dementia of the Alzheimer type.6 Several studies have established a correlation between the presence and extent of white matter hyperintensities and cognitive impairment, ranging from ...
Poor response inhibition has been implicated in the development of alcohol dependence, yet little is known about how neural pathways underlying cognitive control are affected in this disorder. Moreover, endogenous opioid levels may impact the functionality of inhibitory control pathways. This study investigated the relationship between alcohol dependence severity and functional connectivity of fronto-striatal networks during response inhibition in an alcohol-dependent sample. A secondary aim of this study was to test the moderating effect of a functional polymorphism (A118G) of the μ-opioid receptor (OPRM1) gene. Twenty individuals with alcohol dependence (six females; 90% Caucasian; mean age = 29.4) who were prospectively genotyped on the OPRM1 gene underwent blood oxygen level-dependent functional magnetic resonance imaging while performing a Stop-Signal Task. The relationship between alcohol dependence severity and functional connectivity within fronto-striatal networks important for ...
A method for determining a pore characteristic of a substance includes the following steps: subjecting the substance to a substantially uniform static magnetic field; applying a magnetic pulse sequence to the substance, the pulse sequence being selected to produce nuclear magnetic resonance signals that are responsive to internal magnetic field inhomogeneities in the pore structure of the substance, and detecting, as measurement signals, nuclear magnetic resonance signals from the substance; applying a reference magnetic pulse sequence to the substance, the reference pulse sequence being selected to produce nuclear magnetic resonance signals that are substantially unresponsive to internal magnetic field inhomogeneities in the pore structure of the substance, and detecting, as reference measurement signals, nuclear magnetic resonance signals from the substance; and determining a pore characteristic of the substance from the measurement signals and the reference measurement signals.
The diagnosis of discospondylitis is based mainly on diagnostic imaging and laboratory results. Herein, we describe the magnetic resonance imaging (MRI) findings in 13 dogs with confirmed discospondylitis. In total there were 17 sites of discospondylitis. Eleven (81.1%) of the dogs had spinal pain for ,3 weeks and a variable degree of neurologic signs. Two dogs had spinal pain and ataxia for 4 days. Radiographs were available in nine of the dogs. In MR images there was always involvement of two adjacent vertebral endplates and the associated disk. The involved endplates and adjacent marrow were T1-hypointense with hyperintensity in short tau inversion recovery (STIR) images in all dogs, and all dogs also had contrast enhancement of endplates and paravertebral tissues. The intervertebral disks were hyperintense in T2W and STIR images and characterized by contrast enhancement in 15 sites (88.2%). Endplate erosion was present in 15 sites (88.2%) and was associated with T2-hypointense bone marrow ...
PURPOSE: As Quantitative Susceptibility Mapping (QSM) is maturing, more clinical applications are being explored. With this comes the question whether QSM is sufficiently robust and reproducible to be directly used in a clinical setting where patients are possibly not cooperative and/or unable to suppress involuntary movements sufficiently. Subjects and Methods: Twenty-nine patients with Alzheimers Disease (AD), 31 patients with Mild Cognitive Impairment (MCI) and 41 healthy controls (HC) were scanned on a 3T scanner, including a multi-echo gradient-echo sequence for QSM and an inversion-prepared segmented gradient-echo sequence (T1-TFE, MPRAGE). The severity of motion artifacts (excessive/strong /noticeable/invisible) was categorized via visual inspection by two independent raters. Quantitative susceptibility was reconstructed using Joint background-field removal and segmentation-Enhanced Dipole Inversion (JEDI), based on segmented subcortical gray-matter regions, as well as using ...
TY - JOUR. T1 - Magnetic resonance imaging appropriate for construction of subject-specific head models for diffuse optical tomography. AU - Kurihara, Kazuki. AU - Kawaguchi, Hiroshi. AU - Obata, Takayuki. AU - Ito, Hiroshi. AU - Okada, Eiji. PY - 2015. Y1 - 2015. N2 - Subject-specific head models of which their geometry is based on structural magnetic resonance images are essential to accurately estimate the spatial sensitivity profiles for image reconstruction in diffuse optical tomography. T1-weighted magnetic resonance images, which are commonly used for structural imaging, are not sufficient for the thresholdbased segmentation of the superficial tissues. Two types of pulse sequences, which provide a high contrast among the superficial tissues, are introduced to complement the segmentation to construct the subject-specific head models. The magnetic resonance images acquired by the proposed pulse sequences are robust to the threshold level and adequate for the thresholdbased segmentation of ...
Recent Notus Publications Bigler, E. D. , Allen, M. D. , Stimac, G. K, (2012). MRI and functional MRI. In Simpson, J. R. (Ed. ) Neuroimaging in Forensic Psychiatry: From the clinic to the courtroom. Wiley-Blackwell Press. Abstract Woon, F. L. , Allen, M. D. , Hedges, D. , Miller, C. (2012). The functional magnetic resonance imaging-based verbal fluency test in Obsessive Compulsive Disorder. Neurocase. Abstract Allen, M. D. , Hedges, D. W. , Farrer, T. J. , and Larson, M. J. (2012). Assessment of Brain Activity during Memory Encoding in a Narcolepsy Patient On and Off Modafinil using Normative f. MRI data. Neurocase, 18, 13 -25. Abstract Allen, M. D. , Owens, T. E. , Fong, A. K. , Richards, D. R. (2011). A Functional Neuroimaging Analysis of the Trail Making Test-B: Implications for Clinical Application. Behavioural Neurology, 24, 159 -171. Abstract Allen, M. D. , Wu, T. C. , & Bigler, E. , (2011). Traumatic Brain Injury Alters Word Memory Test Performance by Slowing Response Time and Increasing ...
Figure. . . Maps showing axial fluid attenuated inversion recovery (FLAIR), diffusion-weighted imaging (DWI), and apparent diffusion coefficient (ADC) at the level of the basal nuclei (top row) and dorsal frontoparietal cortex (bottom row) of the brain of a 33.8-year-old man with agenesis of the corpus callosum, schizencephaly, and heterotopia. Note the symmetrical DWI signal hyperintensities in the striatum and dorsomedial part of the thalami. In addition, DWI signal hyperintensities occurred in the cingulate, precuneus and in the dysplastic gray matter along the anterior lips of the schizencephalic clefts at the level of the precentral gyri. The signal abnormalities are associated with decreased diffusivity on ADC maps and are much less prominent on FLAIR images. These findings are highly suggestive of Creutzfeldt-Jakob disease. ...
Background/aim. The safety of amateur and professional boxing is a contentious issue. We hypothesised that advanced magnetic resonance imaging and neuropsychological testing could provide evidence of acute and early brain injury in amateur boxers.. Methods. We recruited 30 participants from a university amateur boxing club in a prospective cohort study. Magnetic resonance imaging (MRI) and neuropsychological testing was performed at three time points: prior to starting training; within 48 h following a first major competition to detect acute brain injury; and one year follow-up. A single MRI acquisition was made from control participants. Imaging analysis included cortical thickness measurements with Advanced Normalization Tools (ANTS) and FreeSurfer, voxel based morphometry (VBM), and Tract Based Spatial Statistics (TBSS). A computerized battery of neuropsychological tests was performed assessing attention, learning, memory and impulsivity.. Results. During the study period, one boxer developed ...
PURPOSE: The purpose of this study was to measure potential changes of the apparent diffusion coefficient (ADC) in diffusion-weighted imaging of the liver before and after caloric challenge in correlation to the induced changes in portal vein flow. MATERIALS AND METHODS: The study was approved by the local ethics committee. Each of 10 healthy volunteers underwent 4 measurements in a 1.5-T whole-body magnetic resonance scanner on 2 different days: a first scan after fasting for at least 8 hours and a second scan 30 minutes after intake of a standardized caloric either a protein- or carbohydrate-rich meal. Diffusion-weighted spin-echo echo-planar magnetic resonance images were acquired at b values of 0, 50, 150, 250, 500, 750, and 1000 s/mm. In addition, portal vein flow was quantified with 2-dimensional phase-contrast imaging (velocity encoding parallel to flow direction, 60 cm/s). Mean ADC values for regions of interest in 3 different slices were measured from b50 to b250 and from b500 to b1000 ...
Most of the resting-state functional magnetic resonance imaging (fMRI) studies demonstrated the correlations between spatially distinct brain areas from the perspective of functional connectivity or functional integration. The functional connectivity approaches do not directly provide information of the amplitude of brain activity of each brain region within a network. Alternatively, an index named amplitude of low-frequency fluctuation (ALFF) of the resting-state fMRI signal has been suggested to reflect the intensity of regional spontaneous brain activity. However, it has been indicated that the ALFF is also sensitive to the physiological noise. The current study proposed a fractional ALFF (fALFF) approach, i.e., the ratio of power spectrum of low-frequency (0.01-0.08 Hz) to that of the entire frequency range and this approach was tested in two groups of resting-state fMRI data. The results showed that the brain areas within the default mode network including posterior cingulate cortex, ...
We describe an MRI phenotype seen in a series of patients with mutations in PTEN who have clinical features consistent with PTEN hamartoma tumor syndrome (PHTS). Retrospective review of clinical data and MRI was performed in 23 subjects evaluated in four different tertiary care centers with clinical programs in inherited disorders of the white matter. Patients were referred due to abnormal MRI features and abnormal PTEN sequencing was identified. All subjects had significant macrocephaly (on average |4 SD above the mean), developmental delay with or without autism spectrum disorder and uniform MRI features of enlarged perivascular spaces and multifocal periventricular white matter abnormalities. The phenotype of PHTS may include MRI abnormalities such as multifocal periventricular white matter abnormalities and enlarged perivascular spaces. These neuroimaging findings, in association with macrocephaly and developmental delay, should prompt consideration of PTEN as a diagnostic possibility.
Spondylodiscitis is an infection of the intervertebral disc and adjacent vertebral bodies. Magnetic resonance imaging is the method of choice for the spondylodiscitis. The characteristic findings in the spondylodiscitis are hypointense on T1-weighted (W) image and hyperintense on T2W and fat-saturation T2W images, contrast enhancement on contrast-enhanced T1W with fat saturation images in the disc space and adjacent vertebral bodies, and phlegmon or abscess of the paraspinal soft tissues and epidural space. Phlegmon shows homogenous contrast enhancement, while abscess shows peripheral ring-enhancement on contrast-enhanced T1W with fat saturation images. Differentiation of tuberculous, brucellar and pyogenic spondylodiscitis is radiological difficult. Features that also favor tuberculosis infection include multilevel disease, large paravertebral abscess, meningeal involvement and subligamentous spread. Brucellar spondylodiscitis most commonly affects the lumbar spine. Bone destruction is less ...
Amyotrophic lateral sclerosis as a system failure is a concept supported by the finding of consistent extramotor as well as motor cerebral pathology. The functional correlates of the structural changes detected using advanced magnetic resonance imaging techniques such as diffusion tensor imaging and voxel-based morphometry have not been extensively studied. A group of 25 patients with amyotrophic lateral sclerosis was compared to healthy control subjects using a multi-modal neuroimaging approach comprising T(1)-weighted, diffusion-weighted and resting-state functional magnetic resonance imaging. Using probabilistic tractography, a grey matter connection network was defined based upon the prominent corticospinal tract and corpus callosum involvement demonstrated by white matter tract-based spatial statistics. This amyotrophic lateral sclerosis-specific network included motor, premotor and supplementary motor cortices, pars opercularis and motor-related thalamic nuclei. A novel analysis protocol, using
Amyotrophic lateral sclerosis as a system failure is a concept supported by the finding of consistent extramotor as well as motor cerebral pathology. The functional correlates of the structural changes detected using advanced magnetic resonance imaging techniques such as diffusion tensor imaging and voxel-based morphometry have not been extensively studied. A group of 25 patients with amyotrophic lateral sclerosis was compared to healthy control subjects using a multi-modal neuroimaging approach comprising T(1)-weighted, diffusion-weighted and resting-state functional magnetic resonance imaging. Using probabilistic tractography, a grey matter connection network was defined based upon the prominent corticospinal tract and corpus callosum involvement demonstrated by white matter tract-based spatial statistics. This amyotrophic lateral sclerosis-specific network included motor, premotor and supplementary motor cortices, pars opercularis and motor-related thalamic nuclei. A novel analysis protocol, using
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Previous studies have detected abnormal serum ferritin levels in patients with depression; however, the results have been inconsistent. This study used quantitative susceptibility mapping (QSM) for the first time to examine brain iron concentration in depressed patients and evaluated whether it is related to severity. We included three groups of age- and gender-matched participants: 30 patients with mild-moderate depression (MD), 14 patients with major depression (MDD) and 20 control subjects. All participants underwent MR scans with a 3D gradient-echo sequence reconstructing for QSM and performed the 17-item Hamilton Depression Rating Scale (HDRS) test. In MDD, the susceptibility value in the bilateral putamen was significantly increased compared with MD or control subjects. In addition, a significant difference was also observed in the left thalamus in MDD patients compared with controls. However, the susceptibility values did not differ between MD patients and controls. The susceptibility values
Functional MRI studies have identified a distributed set of brain activations to be associated with auditory verbal hallucinations (AVH). However, very little is known about how activated brain regions may be linked together into AVH-generating networks. Fifteen volunteers with schizophrenia or schizoaffective disorder pressed buttons to indicate onset and offset of AVH during fMRI scanning. When a general linear model was used to compare blood oxygenation level dependence signals during periods in which subjects indicated that they were versus were not experiencing AVH (
Coronary heart disease (CHD) has been linked with cognitive decline and dementia in several studies. CHD is strongly associated with blood pressure, but it is not clear how blood pressure levels or changes in blood pressure over time affect the relation between CHD and dementia-related pathology. The aim of this study was to investigate relations between CHD and cortical thickness, gray matter volume and white matter lesion (WML) volume on MRI, considering CHD duration and blood pressure levels from midlife to three decades later. The study population included 69 elderly at risk of dementia who participated in the Cardiovascular Risk Factors, Aging and Dementia (CAIDE) study. CAIDE participants were examined in midlife, re-examined 21 years later, and then after additionally 7 years (in total up to 30 years follow-up). MRIs from the second re-examination were used to calculate cortical thickness, gray matter and WML volume. CHD diagnoses were obtained from the Finnish Hospital Discharge ...
Converging evidence from epidemiological, clinical and neuropsychological research suggests a link between cannabis use and increased risk of psychosis. Long-term cannabis use has also been related to deficit-like negative symptoms and cognitive impairment that resemble some of the clinical and cognitive features of schizophrenia. The current functional brain imaging study investigated the impact of a history of heavy cannabis use on impaired executive function in first-episode schizophrenia patients. Whilst performing the Tower of London task in a magnetic resonance imaging scanner, event-related blood oxygenation level-dependent (BOLD) brain activation was compared between four age and gender-matched groups: 12 first-episode schizophrenia patients; 17 long-term cannabis users; seven cannabis using first-episode schizophrenia patients; and 17 healthy control subjects. BOLD activation was assessed as a function of increasing task difficulty within and between groups as well as the main effects ...
Functional magnetic resonance imaging (fMRI) studies of the human brain have suggested that low-frequency fluctuations in resting fMRI data collected using blood oxygen level dependent (BOLD) contrast correspond to functionally relevant resting state networks (RSNs). Whether the fluctuations of resting fMRI signal in RSNs are a direct consequence of neocortical neuronal activity or are low-frequency artifacts due to other physiological processes (e.g., autonomically driven fluctuations in cerebral blood flow) is uncertain. In order to investigate further these fluctuations, we have characterized their spatial and temporal properties using probabilistic independent component analysis (PICA), a robust approach to RSN identification. Here, we provide evidence that: i. RSNs are not caused by signal artifacts due to low sampling rate (aliasing); ii. they are localized primarily to the cerebral cortex; iii. similar RSNs also can be identified in perfusion fMRI data; and iv. at least 5 distinct RSN patterns
TY - JOUR. T1 - Endometrial polyps. T2 - MR imaging features and distinction from endometrial carcinoma. AU - Grasel, Ralf P.. AU - Outwater, Eric K.. AU - Siegelman, Evan S.. AU - Capuzzi, David. AU - Parker, Laurence. AU - Hussain, Shahid M.. PY - 2000. Y1 - 2000. N2 - PURPOSE: To determine the magnetic resonance (MR) imaging characteristics of endometrial polyps and the accuracy or MR imaging in distinguishing endometrial polyps from endometrial carcinomas in a case- control study. MATERIALS AND METHODS: Cross-referencing pathology records with MR studies from two institutions disclosed 35 patients with surgically proved endometrial polyp or carcinoma after controlling for tumor size. All MR examinations were performed at 1.5 T with T2-weighted fast spin-echo sequences in multiple planes. Three independent readers blinded to histologic diagnoses and clinical data scored each image for the presence of several defined findings. RESULTS: A central fibrous core (low signal intensity on ...
The Framingham Offspring Cohort were recruited in 1971 and consisted of 5124 children and spouses of children of the original Framingham Cohort.28 Offspring subjects have been examined 7 times since 1971, and between 1999 and 2001, they were invited to undergo a brain MRI using a standard protocol. For the current analysis, only subjects attending examination 5 were included, and risk factor data from this examination were related to findings from brain MRI examinations. Data from examination 5 were used because a larger number of subjects had risk factor and MRI data available than from exam 6 or 7. Subjects were excluded from MRI examination if they had metal in the eyes or central nervous system, claustrophobia, valvular prosthesis, cardiac pacemaker, vascular clip, cochlear implant or other implantable device, or if they refused.. Of those offspring who attended examination 5, 3562 were alive as of September 2001, the cutoff for the analysis. Of them, 1939 had an MRI examination of the brain ...
A 30-year-old female has experienced amenorrhea and progressive loss of vision for four years. Physical examinations were normal except bitemporal hemianopsia revealed by ophthalmic examination. Preoperative neuroendocrine examinations showed a mild hyperprolactinemia of 72.3ng/ml (normal range, 2.8 ng/ml-29.2 ng/ml). MRI scan revealed a 31 mm 34 mm 31 mm well-circumscribed roundness mass in the suprasellar region, with intermediate signal intensity on T1-weighted images, intermediate to slightly increased signal intensity on T2-weighted images, and homogeneous enhancement with gadolinium administration with obviously homogeneous enhancement after gadolinium administration (Fig. 1). Extended endoscopic endonasal transsphenoidal approach was chosen to resect the tumor. Intraoperatively, we encountered active bleeding, however, the bleeding stopped after the tumor was completely resected. Postoperative, the patient had serious diabetes insipidus and electrolyte disturbance. Blood sodium was as ...
"Oxygenation-sensitive contrast in magnetic resonance image of rodent brain at high magnetic fields", Magnetic Resonance in ... "Magnetic Resonance, a critical peer-reviewed introduction; functional MRI". European Magnetic Resonance Forum. Retrieved 17 ... "Journal of Magnetic Resonance Imaging. 35 (5): 1026-1037. doi:10.1002/jmri.23581. ISSN 1522-2586. PMC 3326188. PMID 22246782.. ... Functional magnetic resonance imaging or functional MRI (fMRI) measures brain activity by detecting changes associated with ...
Magnetic resonance imaging (MRI) is a powerful tool for disease diagnosis such as cancer metastasis and inflammation, using ... displaying an overall decreasing concentration of contrast agent and a decrease of magnetic resonance (MR) signal in time. This ... and nuclear magnetic resonance spectroscopy. These models are associated with electrophysiological measurements and ... In both studies, spectral imaging and autofluorescent subtraction allowed multicolour in vivo visualization of cells and ...
Magnetic Resonance Imaging[edit]. Magnetic resonance imaging is capable of measuring the thickness of different areas of the ... Cardiac Magnetic Resonance Imaging[edit]. Cardiac magnetic resonance shows the characterization of myocardial tissue through ... greater use of cardiac magnetic resonance has increased diagnosing rates.[3] Symptoms[edit]. Amyloid deposition in the heart ... Scintigraphy/Radionuclide Imaging[edit]. Scintigraphy can be used to measure the extent and distribution of the amyloid ...
Functional magnetic resonance imaging (fMRI)[edit]. The self-serving bias has been investigated by the fMRI method in normal ... as well as functional magnetic resonance imaging (fMRI).[11] These procedures allow for insight into brain area activity during ... This may be due to the fact that the self-image of actors is challenged directly and therefore actors feel the need to protect ... their own self-image, but do not feel the same inclination to do so when the self-image of others is threatened.[25] ...
Magnetic resonance imaging (MRI)[edit]. MRI is the optimal choice for the imaging of soft tissues surrounding the TMJ.[60][57] ... In those studies allowing images, imaging conducted by either arthrography or magnetic resonance reveals disc displacement ... "Real-time magnetic resonance imaging of temporomandibular joint dynamics" (PDF). The Open Medical Imaging Journal. 5: 1-9.. ... Limchaichana N, Petersson A, Rohlin M (October 2006). "The efficacy of magnetic resonance imaging in the diagnosis of ...
Schenck, John F. (1996). "The role of magnetic susceptibility in magnetic resonance imaging: MRI magnetic compatibility of the ... but this use has decreased with the advent of high-resolution anatomical imaging techniques such as magnetic resonance imaging ... Murphy, Kieran J.; Brunberg, James A. (1997). "Adult claustrophobia, anxiety and sedation in MRI". Magnetic Resonance Imaging. ... Several other methods to study brain function exist, including functional magnetic resonance imaging (fMRI), positron emission ...
NSF is an iatrogenic disease caused by exposure to gadolinium-based contrast agents used in magnetic resonance imaging.[12] ... Magnetic Resonance Imaging. 8 (4): 467-81. PMID 2118207.. *^ Scheinfeld NS, Cowper S, Kovarik CL, Butler DF. "Nephrogenic ... Topics in Magnetic Resonance Imaging. 24 (1): 57-65. doi:10.1097/RMR.0b013e3182a14e79. PMID 25654421.. ... Journal of Magnetic Resonance Imaging. 30 (6): 1289-97. doi:10.1002/jmri.21975. PMID 19937929.. ...
... as well as advanced image analysis algorithms for diffusion tensor imaging, functional magnetic resonance imaging and image- ... "3D Slicer as an image computing platform for the Quantitative Imaging Network". Magnetic Resonance Imaging. 30 (9): 1323-41. ... Handling DICOM images and reading/writing a variety of other formats. *Interactive visualization of volumetric Voxel images, ... 3D Slicer provides image registration, processing of DTI (diffusion tractography), an interface to external devices for image ...
Demb, J.; Desmond, J.; Wagner, A.; Vaidya, C.; Glover, G.; Gabrieli, J. (1995). "Functional magnetic resonance imaging". The ... Cortical activation in the processing of passive sentences in L1 and L2: An Functional magnetic resonance imaging study. ... In the study "Semantic Encoding and Retrieval in the Left Inferior Prefrontal Cortex: A Functional magnetic resonance imaging ... Transcranial magnetic stimulation applied to the left BA45 facilitated incongruent reasoning performance and impaired congruent ...
Magnetic resonance imaging (MRI). The diagnosis of coronary disease underlying particular symptoms depends largely on the ... stress cardiac imaging, and/or advanced non-invasive imaging is not recommended on individuals who are exhibiting no symptoms ...
"Magnetic resonance imaging and permanent cosmetics (tattoos): survey of complications and adverse events". Journal of Magnetic ... Stecco A, Saponaro A, Carriero A (2007). "Patient safety issues in magnetic resonance imaging: state of the art". Radiol Med. ... Offret, H; Offret M; Labetoulle M; Offret O. (February 2009). "Permanent cosmetics and magnetic resonance imaging". Journal ... Resonance Imaging. 15 (2): 180-4. doi:10.1002/jmri.10049. PMID 11836774. Murphy, Cheryl G. (30 October 2017). "The Terrifying ...
Journal of Magnetic Resonance Imaging. 40 (6): 1437-1444. doi:10.1002/jmri.24509.. ... Whole body magnetic resonance tomography.[6]. References[edit]. *^ a b c d Fields, David A; Goran, Michael I; McCrory, Megan A ...
Magnetic resonance imaging (MRI) of the head provides superior information as compared to CT scans when seeking information ... Journal of Magnetic Resonance Imaging. 25 (5): 900-909. doi:10.1002/jmri.20895. PMID 17457809.. ... Left image is a sinogram which is a graphic representation of the raw data obtained from a CT scan. At right is an image sample ... "Image Gently". The Alliance for Radiation Safety in Pediatric Imaging. Archived from the original on 9 June 2013. Retrieved 19 ...
A functional magnetic resonance imaging study". Neuroscience Letters. 278 (3): 189-93. doi:10.1016/S0304-3940(99)00930-1. PMID ... Hyde, Peretz and Zatorre (2008) used functional magnetic resonance imaging (fMRI) in their study to test the involvement of ... examined the functional anatomy of pitch memory using functional magnetic resonance imaging (fMRI).[81] An analysis of ... in its reliance on direct observations of the brain and use of such techniques as functional magnetic resonance imaging (fMRI ...
"Journal of magnetic resonance imaging: JMRI. 35 (5): 1026-1037. doi:10.1002/jmri.23581. ISSN 1522-2586. PMC 3326188. PMID ... Two main categories of magnetic resonance imaging (MRI) techniques can be used to measure tissue perfusion in vivo. ... Huettel, S. A.; Song, A. W.; McCarthy, G. (2009), Functional Magnetic Resonance Imaging (2 ed.), Massachusetts: Sinauer, ISBN ... "The measurement of diffusion and perfusion in biological systems using magnetic resonance imaging". Phys Med Biol. 45 (8): R97- ...
Functional magnetic resonance imaging is a technique used for multiple purposes which shows the uses of oxygen by the brain, ... Mar 2002). "Lie detection by functional magnetic resonance imaging". Hum Brain Mapp. 15 (3): 157-164. doi:10.1002/hbm.10020. ... Studies using functional magnetic resonance imaging (fMRI) have shown that it has potential to be used as a method of lie ... Oct 2016). "Polygraphy and Functional Magnetic Resonance Imaging in Lie Detection: A Controlled Blind Comparison Using the ...
"Neurosyphilis with Mesiotemporal Magnetic Resonance Imaging Abnormalities". Internal Medicine. 47 (20): 1813-7. doi:10.2169/ ... MRI scan image shows high signal in the temporal lobes and right inferior frontal gyrus in someone with HSV encephalitis. ... MRI imaging reveals T2 hyperintensity in the structures of the medial temporal lobes, and in some cases, other limbic ... Based on symptoms, supported by blood tests, medical imaging, analysis of cerebrospinal fluid[2]. ...
ISBN 0-9761552-7-3. [page needed] Aortic Coarctation Imaging at eMedicine Nielsen, J. C. (2005). "Magnetic Resonance Imaging ... "The Role of Cardiovascular Magnetic Resonance in Pediatric Congenital Heart Disease". Journal of Cardiovascular Magnetic ... as mean heart rate-corrected flow deceleration in the descending aorta as measured by phase contrast magnetic resonance imaging ... Coarctation of the aorta can be accurately diagnosed with magnetic resonance angiography. In teenagers and adults ...
"Magnetic Resonance Imaging Clinics of North America. 20 (4): 699-713. doi:10.1016/j.mric.2012.07.007. PMC 3479680. PMID ... Magnetic resonance imaging of the brain and spine may show areas of demyelination (lesions or plaques). Gadolinium can be ... Improvement in neuroimaging techniques such as positron emission tomography (PET) or magnetic resonance imaging (MRI) carry a ... and functional magnetic resonance imaging.[142] These techniques are more specific for the disease than existing ones, but ...
"Granular Convection Observed by Magnetic Resonance Imaging". Science. 267 (5204): 1632-4. Bibcode:1995Sci...267.1632E. doi: ...
... magnetic resonance imaging (MRI) 3-90...3-90: other imaging techniques 3-99...3-99: additional information on imaging ...
"BestBets: Magnetic resonance imaging of suspected scaphoid fractures". Archived from the original on 2010-06-16.. ... Diagnosis is generally based on examination and medical imaging.[2] Some fractures may not be visible on plain X-rays.[2] In ...
"Monitoring Tissue Engineering Using Magnetic Resonance Imaging". Journal of Bioscience and Bioengineering. 106 (6): 515-527. ...
"Detection of dimethyl sulfone in the human brain by in vivo proton magnetic resonance spectroscopy". Magnetic Resonance Imaging ... Nuclear magnetic resonance (NMR) studies have demonstrated that oral doses of MSM are absorbed into the blood and cross the ... identification by multinuclear magnetic resonance spectroscopy". Toxicology Letters. 123 (2-3): 169-77. doi:10.1016/S0378-4274( ...
Magnetic Resonance Imaging. Elsevier. 22 (2): 245-250. doi:10.1016/j.mri.2003.09.002. PMID 15010117. Foley, BS; Buschbacher, RM ... There is a new imaging test SPECT/CT which can sometimes detect sacroiliac joint dysfunction. There is also a lack of evidence ... for misdiagnosis or lack of diagnosis of sacroiliac joint dysfunction is based on the inability of common radiological imaging ...
Magnetic Resonance Imaging. 25 (3): 319-27. doi:10.1016/j.mri.2006.09.041. PMID 17371720. Rini B, Rixe O, Bukowski R, ... breast cancer growth and decreases vascular permeability as detected by dynamic contrast-enhanced magnetic resonance imaging". ...
Magnetic Resonance Imaging. 24 (3): 321-31. doi:10.1016/j.mri.2005.10.036. PMID 16563962. Zeddies DG, Fay RR, Alderks PW, Shaub ... Forbes JG, Morris HD, Wang K (April 2006). "Multimodal imaging of the sonic organ of Porichthys notatus, the singing midshipman ...
Magnetic resonance imaging (MRI) can trigger claustrophobia. An MRI scan entails lying still for some time in a narrow tube. In ... "Claustrophobia and the Magnetic Resonance Imaging Procedure." Journal of Behavioral Medicine 21.3 (1998): 255-68. Harris, Lynne ... "Claustrophobia in MRI: the Role of Cognitions". Magnetic Resonance Imaging. Vol. 26, Issue 8. 3 June 2008. Walding, Aureau. " ... "Use of Virtual Reality Distraction to Reduce Claustrophobia Symptoms during a Mock Magnetic Resonance Imaging Brain Scan: A ...
Magnetic Resonance Imaging. 28 (2): 217-225. doi:10.1016/j.mri.2009.07.008. PMID 19695825. Snaidero, N.; Simons, M. (14 July ... CATANI, M; THIEBAUT DE SCHOTTEN, M (1 September 2008). "A diffusion tensor imaging tractography atlas for virtual in vivo ... "A qualitative and quantitative review of diffusion tensor imaging studies in reading and dyslexia". Neuroscience & ...
Diagnosis is made via imaging tests such as magnetic resonance imaging (MRI) which involves high-frequency radio waves and a ... Diagnosis occurs through physical exams such as X-rays and magnetic resonance imaging which find the decrease in bone mass ( ... Berger, A. (2002-01-05). "How does it work?: Magnetic resonance imaging". BMJ. 324 (7328): 35. doi:10.1136/bmj.324.7328.35. ... whereas magnetic resonance imaging highlights the damaged tissue. The treatments of severe skull fractures include surgery and ...
Similar to functional magnetic resonance imaging, which uses changes in the magnetic properties of blood resulting from ... 2007). Infrared imaging and neurofeedback: initial reliability and validity. Journal of Neurotherapy, 11 (3), 3-12. ... oxygenation to form an image of brain activity, NIR utilizes the changes in blood translucence resulting from oxygenation to ...
Brain structures of children with craniosynostosis were evaluated using magnetic resonance imaging.[10] Differences were seen ... scans and magnetic resonance imaging (MRI) to identify differences between the structures of the brains of healthy children and ... "The Indian Journal of Radiology & Imaging. 21 (1): 49-56. doi:10.4103/0971-3026.76055. PMC 3056371. PMID 21431034.. .mw-parser- ... Medical imagingEdit. Radiographic analysis by performing a computed axial tomographic scan is the gold standard for diagnosing ...
... magnetic resonance imaging (MRI) and functional magnetic resonance imaging (fMRI), ultrasound and single-photon emission ... PET scans are increasingly read alongside CT or magnetic resonance imaging (MRI) scans, with the combination (called "co- ... "Magnetic Resonance-Based Attenuation Correction for PET/MR Hybrid Imaging Using Continuous Valued Attenuation Maps". ... "Magnetic Resonance Materials in Physics, Biology and Medicine. 26 (1): 99-113. doi:10.1007/s10334-012-0353-4. ISSN 0968-5243. ...
... and nuclear magnetic resonance tomography. Interventional radiologists can access areas in the body under imaging for an ... Diagnostic radiology is concerned with imaging of the body, e.g. by x-rays, x-ray computed tomography, ultrasonography, ... The treatment plan may include ordering additional medical laboratory tests and medical imaging studies, starting therapy, ... which can then be imaged outside the body by a gamma camera or a PET scanner. Each radiopharmaceutical consists of two parts: a ...
"Magnetic Resonance Imaging. 27 (8): 1163-74. doi:10.1016/j.mri.2009.01.006. PMID 19249168.. ... Then the brain images are smoothed so that each voxel represents the average of itself and its neighbors. Finally, the image ... characterizing between groups'regional volume and tissue concentration differences from structural magnetic resonance imaging ( ... Segmentation and extraction of brain image, e.g., removal of scalp tissue in the image. ...
Magnetic resonance imaging (MRI) and single-photon emission computed tomography (SPECT) are two of the tests that can identify ... However, SPECT images are known to be nonspecific because they show a heterogeneous pattern in the imaging. The abnormalities ... Imaging[edit]. Neuroimaging is controversial in whether it provides specific patterns unique to neuroborreliosis, but may aid ... Images produced using SPECT show numerous areas where an insufficient amount of blood is being delivered to the cortex and ...
... nuclear medicine and magnetic resonance imaging as well. Although a nonspecialist dictionary might define radiography quite ... Image quality[edit]. Image quality will depend on resolution and density. Resolution is the ability an image to show closely ... It is not used for bone imaging, as the image quality is not good enough to make an accurate diagnostic image for fractures, ... Other medical imaging[edit]. Although not technically radiographic techniques due to not using X-rays, imaging modalities such ...
Andreev, S.V.; Letokhov, V.S.; Mishin, V.I. (1987). "Laser resonance photoionization spectroscopy of Rydberg levels in Fr". ... which may have significant impacts on their interior magnetic fields.[169][170] It has been estimated that the transition from ... visible in Argentina image). ...
2008). "Monitoring Tissue Engineering Using Magnetic Resonance Imaging". Journal of Bioscience and Bioengineering. 106 (6): 515 ...
Brain metastasis in the right cerebral hemisphere from lung cancer, shown on magnetic resonance imaging. ... Diagnosis is usually by medical examination along with computed tomography or magnetic resonance imaging.[2] The result is then ... especially magnetic resonance imaging (MRI) and computed tomography (CT) scans. Neoplasms will often show as differently ... Medical imaging plays a central role in the diagnosis of brain tumors. Early imaging methods - invasive and sometimes dangerous ...
Similarly, the magnetic field creates a disturbance proportional to the magnetic susceptibility.) As the electromagnetic fields ... Fitzgerald, Richard (July 2000). "Phase‐Sensitive X‐Ray Imaging". Physics Today. 53 (7): 23. Bibcode:2000PhT....53g..23F. doi: ... In the X-ray regime the refractive indices are lower than but very close to 1 (exceptions close to some resonance frequencies). ... In non-magnetic media with μ. r. =. 1. {\displaystyle \mu _{\mathrm {r} }=1}. , ...
... angiography or magnetic resonance imaging (MRI). In certain circumstances, less invasive testing may not provide a certain ... Structural abnormalities of the kidneys are identified with imaging tests. These may include Medical ultrasonography/ultrasound ...
Using functional magnetic resonance imaging with specialized multivariate analyses to study the temporal dimension in the ... In a recent study using functional magnetic resonance imaging, alien movements were characterized by a relatively isolated ... "For whom He foreknew, He also predestined to become conformed to the image of His Son, that He might be the first-born among ... Nora D Volkow; Joanna S Fowler; Gene-Jack Wang (2007). "The addicted human brain: insights from imaging studies". In Andrew R ...
Verification of a 4 micron narrow-band high-contrast imaging approach for planet searches. Astronomy and Astrophysics. 2008, ... Structure in the ε Eridani Dusty Disk Caused by Mean Motion Resonances with a 0.3 Eccentricity Planet at Periastron. ... Gray, David F.; Baliunas, Sallie L. Magnetic activity variations of epsilon Eridani. Astrophysical Journal, Part 1. 1995, 441 ( ...
Assignments as a Basis for Determination of Spatial Protein Structures by High Resolution Proton Nuclear Magnetic Resonance" ( ... Proceedings of the Workshop on Microscopic Image Analysis with Applications in Biology held in association with MICCAI06 ( ... Medical Image Computing and Computer-Assisted Intervention) - Copenhague, 5 de outubro de 2006. Páxs. 65-72.. ... "Origins of... Image analysis in clinical pathology". Journal of Clinical Pathology 50 (5). Páxs. 365-370. ...
X-ray crystallographic and nuclear magnetic resonance structure studies have shown how this binding distorts the DNA[23] by ...
Sadato, N. (2005). How the blind "see" Braille: lessons from functional magnetic resonance imaging. The Neuroscientist: A ...
Figures of merit of MEMS magnetic sensor[edit]. MEMS magnetic sensors have several parameters: Quality Factor (Q), Resonance ... Optical, light, imaging. *Active pixel sensor. *Angle-sensitive pixel. *Back-illuminated sensor ... Nuclear precession magnetic field sensor, optically pumped magnetic field sensor, fluxgate magnetometer, search coil magnetic ... Another type of Lorentz force based MEMS magnetic field sensor utilizes the shift of mechanical resonance due to the Lorentz ...
Magnetic resonance angiography and duplex ultrasonography appear to be slightly more cost-effective in diagnosing peripheral ... Visser K, Kuntz KM, Donaldson MC, Gazelle GS, Hunink MG (2003). "Pretreatment imaging workup for patients with intermittent ...
Oxford Centre for Functional Magnetic Resonance Imaging of the Brain (FMRIB), Department of Clinical Neurology, University of ...
... and functional magnetic resonance (fMRI) tests.[4][10] Many of the studies and experiments build on the initial approach of ... However, when the image was only presented to the left visual field (which maps to the right brain hemisphere) the patients ... In these experiments when patients were shown an image within the right visual field (which maps to the left brain hemisphere ... Gazzaniga interpreted this by postulating that although the right brain could see the image it could not generate a verbal ...
... using functional magnetic resonance imaging. In their research, published in the Proceedings of the National Academy of ...
"for his resonance method for recording the magnetic properties of atomic nuclei"[۸۸] ... "Legislature of the State of Minnesota (image via University of Minnesota, 9 April 2007. Archived from the original on ... "for their development of new methods for nuclear magnetic precision measurements and discoveries in connection therewith"[۹۱] ...
As technology continues to develop, psychologists are starting to use functional magnetic resonance imaging to observe mind- ... Gusnard, D.A.; Raichle, M.E. (2001). "Searching for a baseline: functional imaging and the resting human brain". Nature Reviews ...
Magnetic resonance imaging (MRI scan): A special MRI technique (diffusion MRI) may show evidence of an ischemic stroke within ...
MAC - macrophage - macrophage-tropic virus - magnetic resonance imaging (MRI) - MAI - maintenance therapy - major ...
Neuroimaging studies on loss aversion involves measuring brain activity with functional magnetic resonance imaging (fMRI) to ...
Maxwell proposed that light is an undulation in the same medium that is the cause of electric and magnetic phenomena.[6] The ... It was remarked in the published account of the lecture that "if the red and green images had been as fully photographed as the ... The problem took on a particular resonance at that time because St John's College, Cambridge had chosen it as the topic for the ... In the second additional part, he dealt with the rotation of the plane of the polarisation of light in a magnetic field, a ...

No data available that match "magnetic resonance imaging"

  • An fMRI image with yellow areas showing increased activity compared with a control condition. (
  • Functional magnetic resonance imaging or functional MRI ( fMRI ) measures brain activity by detecting changes associated with blood flow . (
  • What is Functional Magnetic Resonance Imaging (fMRI)? (
  • Functional magnetic resonance imaging, or fMRI, is a technique for measuring brain activity. (
  • The attractions of FMRI have made it a popular tool for imaging normal brain function - especially for psychologists. (
  • In fMRI it is the magnetic signal from hydrogen nuclei in water (H2O) that is detected. (
  • The image shown is the result of the simplest kind of fMRI experiment. (
  • Functional magnetic resonance imaging (fMRI) of the brain is used to determine the specific location in the brain where a certain function, such as speech or memory, occurs. (
  • Professor Trevor Robbins describes functional magnetic resonance imaging (fMRI) technology, which is used to take detailed images of the functioning brain. (
  • Functional Magnetic Resonance Imaging (fMRI) maps brain activity by detecting changes in image intensity related to neural activity by the blood-oxygenation-level dependend (BOLD) contrast. (
  • The chapter outlines an analysis pipeline for functional Magnetic Resonance Imaging (fMRI) experiments completely based on R packages. (
  • The role of demographic similarity in people's decision to interact with online anthropomorphic recommendation agents: Evidence from a functional magnetic resonance imaging (fMRI) study. (
  • Classical creativity: A functional magnetic resonance imaging (fMRI) investigation of pianist and improviser Gabriela Montero. (
  • Functional magnetic resonance imaging (fMRI) is a non-invasive neuroimaging technique used to investigate human brain function and cognition in both healthy individuals and populations with abnormal brain states. (
  • Real‐time functional magnetic resonance imaging (rt‐fMRI) allows fMRI data to be analysed during data acquisition and provides a number of advantages over traditional fMRI. (
  • Schematic illustration of (a) standard fMRI (functional magnetic resonance imaging) environment and (b) rt‐fMRI (real‐time functional magnetic resonance imaging) environment. (
  • The latest additions to MRI technology are angiography (MRA) and spectroscopy (MRS). MRA was developed to study blood flow, while MRS can identify the chemical composition of diseased tissue and produce color images of brain function. (
  • Magnetic resonance angiography (MRA) is a procedure used to evaluate blood flow through arteries. (
  • In addition to localized spectroscopy (2) and chemical shift imaging (3) that are applicable to many chemical species, MRI of water protons has been functionally extended to NMR angiography (4), perfusion imaging It has previously been demonstrated (8, 9) that the presence of deoxyhemoglobin in blood changes the proton signal from water molecules surrounding a blood vessel in gradientecho MRI, producing blood oxygenation level-dependent (BOLD) contrast. (
  • Using MRI to look at blood vessels and how blood flows through them is called magnetic resonance angiography (MRA). (
  • magnetic resonance angiography. (
  • Magnetic resonance angiography refers to noninvasive radiography of blood vessels with magnetic resonance imaging technology. (
  • Motion Artifacts, Motion Compensation and Magnetic Resonance Angiography (M. Haacke). (
  • Imaging approaches include ultrasonography, computerized tomography scanning, routine MRI, magnetic resonance angiography (MRA), and magnetic resonance venography, some of which require sedation or anesthesia and are thus not without risks. (
  • Magnetic resonance angiography (MRA) is a new procedure used to evaluate blood flow through arteries in a noninvasive (the skin is not pierced) manner. (
  • In some cases, your physician may request an MRA (Magnetic Resonance Angiography) in addition to your MRI exam. (
  • Diagnostic imaging is roughly equivalent to radiology, the branch of medicine that uses radiation to diagnose and treat diseases. (
  • Dr. MacKenzie is an American Board of Radiology B. Leonard Holman Research Pathway Resident with a focus on Molecular Imaging applications for arthritis. (
  • Dr. Oliva is a Clinical Fellow, Division of Abdominal Imaging and Intervention, Department of Radiology, Brigham and Women's Hospital-Harvard Medical School, Boston, MA. (
  • Dr. Mortelé is the Associate Director, Division of Abdominal Imaging and Intervention, and the Director, Abdominal and Pelvic MRI, Brigham and Women's Hospital, and an Associate Professor of Radiology, Harvard Medical School. (
  • Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. (
  • Recent refinements in MRI technology may make this form of diagnostic imaging even more useful in evaluating patients with brain cancer, stroke, schizophrenia, or epilepsy. (
  • MAGNETIC RESONANCE (MR) is a test that uses an electromagnetic field in the diagnostic process to create a detailed picture of the anatomical structures of the human body. (
  • Cardiac magnetic resonance imaging (CMR) , also called cardiac MRI or heart MRI , three-dimensional diagnostic imaging technique used to visualize the heart and its blood vessels without the need for X-rays or other forms of radiation. (
  • Magnetic resonance imaging (MRI) is a widely used diagnostic modality with an excess of 30 million scans performed every year in the U.S. Although MRI is considered an exceedingly safe modality, there is an underlying potential for injury to patients due to the strong electromagnetic (EM) fields used in MR scanning. (
  • MRI is a type of diagnostic test that can create detailed images of nearly every structure and organ inside the body. (
  • Bilateral symmetrical rib notching, readily appreciated on the chest image, is diagnostic of aortic coarctation. (
  • Magnetic resonance imaging (MRI) is the diagnostic tool that currently offers the most sensitive non-invasive way of imaging the brain, spinal cord, or other areas of the body. (
  • Because MRIs use a strong magnetic field to produce images of the body, magnetic resonance imaging technologists must review a patient's medical information to determine if pacemakers or other implanted devices may preclude the patient from having the diagnostic procedure. (
  • Magnetic resonance imaging technologists may also provide leadership and work guidance to fellow diagnostic imaging staff, radiography students and other health care professionals during the course of their work. (
  • Magnetic Resonance Imaging, or MRI, is a valuable, painless, diagnostic test that allows radiologists to see inside some areas of the body that cannot be seen using conventional X-rays. (
  • Magnetic resonance imaging refers to diagnostic radiography that uses the behavior of protons within magnetic fields to make images of organs and tissues. (
  • 1,2 The goal is to reveal the early underlying biochemical and genetic events responsible for disease rather than indirect and late changes (eg, altered blood flow or tumor size) as seen with most current clinical diagnostic imaging modalities. (
  • Magnetic Resonance Imaging (MRI) is a medical imaging technique used in Diagnostic Imaging to investigate the anatomy and function of the body in both health and disease. (
  • In the recent years, with the development of ultrafast sequences, magnetic resonance imaging (MRI) has been established as a valuable diagnostic modality in body imaging. (
  • The goal of this study is to develop advances in cardiovascular diagnostic and treatment methods using magnetic resonance imaging (MRI), a test that uses a strong magnetic field and radio waves to show anatomic detail. (
  • Magnetic resonance imaging (MRI) is a diagnostic procedure that uses a combination of a large magnet, radiofrequencies, and a computer to produce detailed images of organs and structures within the body. (
  • By end user, the market was segmented as hospitals, ambulatory centers and diagnostic imaging laboratories. (
  • Today, they provide a cost-effective and safe alternative to other invasive forms of diagnostic imaging. (
  • Standard magnetic resonance imaging, MRI, is a superb diagnostic tool but one that suffers from low sensitivity, requiring patients to remain motionless for long periods of time inside noisy, claustrophobic machines. (
  • The new method holds the promise of combining a set of proven NMR tools for the first time into a practical, supersensitive diagnostic system for imaging the distribution of specific molecules on such targets as tumors in human subjects," says lead author Schröder, "or even on individual cancer cells. (
  • The development of surface coils oriented to image a specific volume of the body (phased-array surface multicoil system or torso coil) proved to be an important tool that improves the diagnostic value of the individual pulse sequences and produces higher-resolution images compared with the whole-volume body coil. (
  • While MRI is most prominently used in diagnostic medicine and biomedical research, it also may be used to form images of non-living objects. (
  • Magnetic resonance imaging and spectroscopy for monitoring liver steatosis. (
  • To compare noninvasive MRI and magnetic resonance spectroscopy (MRS) methods with liver biopsy to quantify liver fat content. (
  • It refers to nuclear magnetic resonance spectroscopy. (
  • Three different classes of contrast agents may be tailored for molecular applications to produce visible signal changes on MR images: paramagnetic contrast agents, superparamagnetic particles, and metabolite detection with MR spectroscopy. (
  • A third, and substantially different, means of imaging molecular events is with MR spectroscopy. (
  • In MR spectroscopy, instead of using image contrast, a metabolite that is produced by or heralds the molecular event is detected by the metabolite's spectroscopic peak at a precise anatomic location. (
  • In vivo magnetic resonance spectroscopy of brain and muscle in a type of mitochondrial encephalomyop. (
  • Magnetic resonance spectroscopy (MRS) is another noninvasive procedure used to assess chemical abnormalities in body tissues, such as the brain. (
  • MRI is a medical application of nuclear magnetic resonance (NMR) which can also be used for imaging in other NMR applications, such as NMR spectroscopy. (
  • Magnetic resonance imaging, or MRI, is a noninvasive medical imaging test that produces detailed images of almost every internal structure in the human body, including the organs, bones, muscles and blood vessels. (
  • Since BOLD contrast depends on the state of blood oxygenation, physiological events that change the oxy/ deoxyhemoglobin ratio should lend themselves to noninvasive detection through the accentuation of BOLD contrast in gradient-echo proton images at high magnetic fields. (
  • Echocardiography remains the first-line and most widely available imaging test for the assessment of MR. Cardiovascular magnetic resonance imaging (CMR) has also emerged in the past 20 years as a robust, noninvasive imaging modality for the assessment of patients with MR 4 . (
  • Magnetic resonance imaging (MRI) is a noninvasive test that uses a magnetic field and radiofrequency waves to create detailed pictures of organs and structures inside your body. (
  • Advances in our understanding of the molecular and genetic basis for disease have led to the need for noninvasive imaging techniques that can reveal molecular events in vivo. (
  • Advances in nanoparticle contrast agents for molecular imaging have made magnetic resonance imaging a promising modality for noninvasive visualization and assessment of vascular and cardiac disease processes. (
  • 2. MRIPRINCIPLEMRIPRINCIPLE  MRI isbased on theprincipleof nuclear magnetic resonance.MRI isbased on theprincipleof nuclear magnetic resonance. (
  • The frequency of the energy that is emitted is known as the Nuclear Magnetic Resonance (NMR)) frequency. (
  • Principles of Nuclear Magnetic Resonance Microscopy New York: Clarendon Press. (
  • 1984. Technology Of Nuclear Magnetic Resonance . (
  • Nuclear magnetic resonance imaging has the potential to assess the blood flow in the microcirculation of preserved organs prior to implantation. (
  • Nuclear magnetic resonance (NMR) is inherently sensitive to motion of the nuclear spins through regions having different magnetic field strengths. (
  • Magnetic resonance imaging (MRI), also known as nuclear magnetic resonance imaging, is a scanning technique for creating detailed images of the human body. (
  • In order to provide a fast and reliable method for T 1 -weighted imaging, which gives a high T 1 contrast and also a sufficient signal-to-noise ratio, the phase of the RF drive pulse (β X ) is selected such that nuclear magnetization at the time of the additional spin echo is transformed into negative longitudinal magnetization. (
  • Magnetic resonance imaging is also sometimes called nuclear magnetic resonance (NMR) imaging. (
  • MRI uses a powerful magnetic field, radiofrequency waves, and a computer to create detailed cross-sectional (2-dimensional) and 3-dimensional images of the inside of your body without using ionizing radiation (like X-rays, computed tomography, or nuclear imaging). (
  • The majority of MR images are based upon the nuclear MR signal from water protons. (
  • It is based on a well established scientific technique, nuclear magnetic resonance, which uses the interaction of magnetic fields with the spin of the nuclei of atoms to provide detailed information on the constituents of chemicals and biological materials. (
  • It builds on a series of previous developments in MRI and the closely related field of nuclear magnetic resonance, NMR (which instead of an image yields a spectrum of molecular information), by members of the laboratories of Alexander Pines and David Wemmer at Berkeley Lab and UC Berkeley. (
  • Under an applied magnetic field, induced magnetic spins in magnetic nanoparticles perturb the nuclear spin relaxation processes of protons of water molecules surrounding magnetic nanoparticles. (
  • Instead of using X-rays, MRI is based on nuclear magnetic resonance. (
  • MRI was originally called NMRI (nuclear magnetic resonance imaging), but "nuclear" was dropped to avoid negative associations. (
  • Pulses of radio waves excite the nuclear spin energy transition, and magnetic field gradients localize the polarization in space. (
  • MRI images have greater natural contrast than standard x rays, computed tomography scan ( CT scan ), or ultrasound, all of which depend on the differing physical properties of tissues. (
  • Magnetic resonance imaging is used in situations when it is necessary to deepen the diagnosis and when the result of computed tomography is ambiguous or doubtful. (
  • Aortogram refers to an image of the aorta obtained through radiography, computed tomography or magnetic resonance imaging. (
  • MRI can provide excellent, detailed images of the body's soft tissue and is an alternative to using x-ray techniques such as computed tomography (CT). (
  • Reviews images created by MRI and Computed Tomography as well as gross anatomical images. (
  • Magnetic resonance (MRI) may be used instead of computed tomography (CT) in situations where organs or soft tissue are being studied, because MRI is better at telling the difference between normal and abnormal soft tissue. (
  • Recently revised international guidelines for hepatocellular carcinoma (HCC) suggest that selected patients with inadequate surveillance ultrasonography to be assessed by alternative imaging modalities such as computed tomography or magnetic resonance imaging (MRI). (
  • Currently, magnetic resonance imaging (MRI) plays a secondary role in the diagnosis and imaging workup of patients with pancreatic diseases, when compared with multidetector-row computed tomography (MDCT). (
  • ABSTRACT Paramagnetic deoxyhemoglobin in venous blood is a naturally occurring contrast agent for magnetic resonance imaging (MRI). (
  • You'll also be asked questions to make sure your child doesn't have any internal metal clips from previous surgery or anything else that might cause a problem near a strong magnetic field. (
  • The scan uses a strong magnetic field and radio waves to generate images of parts of the body that can't be seen as well with X-rays, CT scans or ultrasound. (
  • The machine itself will generate a strong magnetic field around the person and radio waves will be directed at the body, according to the Mayo Clinic. (
  • An MRI scanner applies a very strong magnetic field (about 0.2 to 3 teslas, or roughly a thousand times the strength of a typical fridge magnet), which aligns the proton "spins. (
  • The MRI machine is a large, cylindrical (tube-shaped) machine that creates a strong magnetic field around the patient and sends pulses of radio waves from a scanner. (
  • The strong magnetic field created by the MRI scanner causes the atoms in your body to align in the same direction. (
  • A very strong magnetic field causes a small percentage of the hydrogen protons in water molecules to line up in the direction of the magnetic field. (
  • The MRI machine creates a strong magnetic field inside your body. (
  • The work of magnetic resonance imaging technologists can also expose them to strong magnetic fields and biohazardous materials. (
  • An MRI machine produces a strong magnetic field and radio waves. (
  • MRI scanners use strong magnetic fields and radiowaves to form images of the body. (
  • For an MRI test, you are placed inside the magnet so that your belly is inside the strong magnetic field. (
  • nuclei with odd numbers of protons or neutrons have net magnetic moment and will orient themselves like tiny bar magnets, spin "up" or spin "down," in a strong magnetic field. (
  • MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body. (
  • To perform a study, the person is positioned within an MRI scanner that forms a strong magnetic field around the area to be imaged. (
  • D. Le Bihan, E. Breton, M. Gueron, B. Roger, and M. Laval-Jeantet, Separation of Perfusion and Diffusion in Intra-Voxel Incoherent Motion (IVIM) MR Imaging, Fifth Annual Meeting, Society of Magnetic Resonance in Medicine (1986). (
  • In:Society of Magnetic Resonance in Medicine. (
  • this arrangement improves image quality by increasing radio signal strength, since the coil is located close to the tissue being examined. (
  • 3D view of the computational model of a radiofrequency (RF) coil system at 64 MHz used in magnetic resonance imaging (MRI). (
  • 2. The magnetic resonance imaging receiver system according to claim 1, wherein said at least two antenna coils are formed in a rectangular coil configuration on said printed circuit boards. (
  • an electrically insulating material affixing the spring tip to a distal end of the probe shaft and preventing electrical conduction between the spring tip and the imaging coil. (
  • 7. The probe of claim 1 , wherein the spring tip is attached to the imaging coil by an adhesive joint. (
  • 8. The probe of claim 1 , wherein the imaging coil comprises a helical whip with a proximate end and a distal end, the helical whip having coils with a diameter and a spacing, and wherein the distal end of the helical whip is connected to the spring tip. (
  • 10. The probe of claim 9 , wherein an electrical length of the imaging coil is chosen so as to compensate for the biocompatible material or covering. (
  • Hinged upon the unique FlexCoverage Posterior coil that provides neck-to-toe coverage without the need for any manual removal or repositioning, FlexStream enables imaging with fewer coils and reduces coil postioning and patient set-up time. (
  • A recent advance in MRI breast imaging is the CP Breast Array Coil, which allows for bilateral breast imaging and improved differentiation between various breast tissue. (
  • This is a type of specialized brain and body scan used to map neural activity in the brain or spinal cord of humans or other animals by imaging the change in blood flow ( hemodynamic response ) related to energy use by brain cells. (
  • MRI brain scans use a strong, permanent, static magnetic field to align nuclei in the brain region being studied. (
  • MRI is particularly useful for imaging the brain and spine, as well as the soft tissues of joints and the interior structure of bones. (
  • The MRI process produces cross-sectional images of the body that are as sharp in the middle as on the edges, even of the brain through the skull. (
  • MRI technology was developed because of the need for brain imaging. (
  • In particular, a new 3-D approach to MRI imaging known as diffusion tensor imaging, or DTI, measures the flow of water within brain tissue, allowing the radiologist to tell where the normal flow of fluid is disrupted, and to distinguish more clearly between cancerous and normal brain tissue. (
  • In some cases, MRI can provide clear images of parts of the brain that can't be seen as well with an X-ray, CAT scan, or ultrasound, making it particularly valuable for diagnosing problems with the pituitary gland and brain stem. (
  • In addition to structural imaging, MRI can also be used to visualize functional activity in the brain. (
  • This provides a means of discriminating between gray matter, white matter and cerebral spinal fluid in structural images of the brain. (
  • Operate optical systems to capture dynamic magnetic resonance imaging (MRI) images, such as functional brain imaging, real-time organ motion tracking, or musculoskeletal anatomy and trajectory visualization. (
  • Brain magnetic resonance imaging with contrast dependent on blood oxygenation. (
  • ARTICLE{Ogawa90brainmagnetic, author = {S Ogawa and T M Lee and A R Kay and D W Tank}, title = {Brain magnetic resonance imaging with contrast dependent on blood oxygenation. (
  • By accentuating the effects of this agent through the use of gradient-echo techniques in high fields, we demonstrate in vivo images of brain microvasculature with image contrast reflecting the blood oxygen level. (
  • Segmentation results of total brain (orange), cortical gray matter (green), white matter (blue), deep gray matter (brown), brainstem (yellow), cerebellum (light blue), left hippocampus (purple) and right hippocampus (red) on a 3-Dimensional reconstructed T2-weighted MR image of a fetus at 26.4 gestational weeks. (
  • deBettencourt MT, Cohen JD, Lee RF, Norman KA and Turk‐Browne NB (2015) Closed‐loop training of attention with real‐time brain imaging. (
  • This book discusses the modeling and analysis of magnetic resonance imaging (MRI) data acquired from the human brain. (
  • His interests include magnetic resonance imaging data from the human brain, and data modeling and analysis problems with a focus on structural adaptive smoothing methods and biophysical models. (
  • Objective To quantify the prevalence of incidental findings on magnetic resonance imaging (MRI) of the brain. (
  • Apparently asymptomatic intracranial abnormalities of potential clinical significance, or incidental brain findings (box), are fast becoming problematic, with the increasing use of magnetic resonance imaging (MRI) of the brain by clinicians, 1 researchers, 2 and companies that carry out health "check-ups. (
  • During functional resonance imaging of the brain, you will be asked to perform a specific task, such as recite the Pledge of Allegiance, while the scan is being done. (
  • Magnetic resonance imaging of the brain with no visible abnormalities. (
  • Researchers of the ICAI Group -Computational Intelligence and Image Analysis- of the University of Malaga (UMA) have designed an unprecedented method that is capable of improving brain images obtained through magnetic resonance imaging using artificial intelligence. (
  • This new model manages to increase image quality from low resolution to high resolution without distorting the patients' brain structures, using a deep learning artificial neural network -a model that is based on the functioning of the human brain- that 'learns' this process. (
  • According to the experts, the results will enable specialists to identify brain-related pathologies, like physical injuries, cancer or language disorders, among others, with increased accuracy and definition, because image details are thinner, thus avoiding the performance of additional tests when diagnoses are uncertain. (
  • The MRI scan sends a high frequency alternating magnetic field through the brain via electromagnets surrounding the brain, thereby disturbing the various nuclei. (
  • A computer then generates a two- or three-dimensional image of the brain. (
  • These signals are converted into an image, and during a single session a doctor collects a series of images, often from several different angles. (
  • When pointing in the same direction, the tiny magnetic signals from individual nuclei add up coherently resulting in a signal that is large enough to measure. (
  • These signals are received by a computer and converted into an image of the part of the body being examined. (
  • The magnetic resonance imaging receiver comprises an antenna for receiving resonance signals produced by a magnetic resonance imaging, radio frequency excitation magnetic. (
  • The system utilizes fixed local coils which operate in the receive only mode for receiving electromagnetic signals from resonating nuclei produced by a whole body MRI scanner system or the like to produce high quality images. (
  • As they relax, the protons release resonance signals that are transmitted to a computer, analyzed and converted into an image. (
  • The invention describes a system, method, and means for an MRI transseptal needle that can be visible on an MRI, can act as an antenna and receive MRI signals from surrounding subject matter to generate high-resolution images and can enable real-time active needle tracking during MRI guided transseptal puncture procedures. (
  • We report that visual stimulation produces an easily detectable (5-20%) transient increase in the intensity of water proton magnetic resonance signals in human primary visual cortex in gradient echo images at 4-T magnetic-field strength. (
  • These signals are received by a computer that analyzes and converts them into a two-dimensional (2D) image of the body structure or organ being examined. (
  • Different types of molecular tissue spin at different rates, helping technicians to create the necessary image detailing unwanted tissues such as tumors. (
  • Definition of liver tumors in the presence of diffuse liver disease: comparison of findings at MR imaging with positive and negative contrast agents. (
  • PURPOSE: The potential to define liver tumors at magnetic resonance (MR) imaging was compared with a positive and a negative contrast agent (gadoxetic acid disodium, or gadolinium EOB-DTPA [a hepatocyte-directed agent], and ferumoxides, or superpara-magnetic iron oxide particles [a Kupffer cell-directed agent], respectively) in normal rats and in rats with induced acute hepatitis, fatty liver, or cirrhosis. (
  • 9 It has been shown that the conspicuity of pancreatic tumors and the delineation of the pancreas from surrounding fat are best established on fat-suppressed T1W images. (
  • Exploiting sparse spectrum to accelerate spiral magnetic resonance spectroscopic imaging : method, simulation and applications to the functional exploration of skeletal muscle. (
  • Spin-Echo Train in a Spectroscopic Imaging Sequence. (
  • Morrell G, Adalsteinsson E, Irarrazabal P, Macovski A. Fast Spectroscopic Imaging with Time-Varying Gradients. (
  • Rapid Spectroscopic Reference Acquisition for Volumetric Metabolite Imaging. (
  • Lim KO, Adalsteinsson E, Spielman DM, Sullivan EV, Pfefferbaum A. Normal NAA Concentration in Gray Matter of Schizophrenic Patients Observed with Magnetic Resonance Spectroscopic Imaging (MRSI). (
  • Spielman DM, Adalsteinsson E. Narrowband Proton Spectroscopic Imaging. (
  • The spectroscopic technique of magnetic resonance imaging (MRI) has recently provided a new window into transport of solvents in polymer networks. (
  • When an external magnetic field is appliedWhen an external magnetic field is applied protons in the body align in one direction.protons in the body align in one direction. (
  • A background magnetic field is used to align protons within the nuclei of hydrogen atoms in the heart tissue (hydrogen occurs abundantly in heart tissue in the form of water). (
  • The radio-frequency field (essentially a second magnetic field) is then pulsed on and off, causing the protons to change their orientation and thereby generating a signal that is detected by the scanner. (
  • Water molecules (H 2 O) contain hydrogen nuclei (protons), which become aligned in a magnetic field. (
  • The protons absorb the energy from the magnetic field and flip their spins. (
  • Once the hydrogen protons have been lined up, radio waves and some additional but weaker magnetic fields are used to knock them out of line. (
  • In magnetic resonance imaging (MRI), Larmor frequency refers to the frequency of the radio wave that will resonate with all the protons in the nucleus of a given element. (
  • This effect leads to the shortening of spin-spin relaxation time (T2) of the protons due to inhomogeneities in local magnetic field and fluctuating magnetic fields at molecular level, which results in darkening of MR images. (
  • MR images studied will be reviewed for quality, anatomy and pathology. (
  • Magnetic resonance imaging (MRI) is a widely accepted modality for providing anatomical information. (
  • ConclusionWith the proper technique and knowledge of the ankle anatomy, high-frequency US proved to be an effective imaging modality in the diagnosis of CFL lesions in chronic lateral ankle injuries. (
  • In MRI this signal is spatially encoded by the selective application of three magnetic field gradients along the X, Y, and Z axis. (
  • NMR imaging relies on magnetic field gradients for spatial location information. (
  • Explains resonance, interaction of radiofrequency, gradients including data collection and image formation. (
  • There are multiple sources giving rise to gradient infidelity, including: non-linear gradient amplifier amplification and limited gradient amplifier frequency response, incomplete eddy current compensation, including gradient cross terms, the existence of a non-linear gradient field itself, and so-called concomitant gradients, which are higher order spatially varying magnetic fields which necessarily accompany the desired linear gradient fields [ 2 ]. (
  • However, technical innovations in MRI, such as the development of phased-array multicoils, enhanced gradients, and methods to reduce motion-related artifacts, allow us to obtain images of the pancreas with excellent contrast resolution in a reasonable examination time. (
  • Another magnetic field, the gradient field, is then applied to spatially locate different nuclei. (
  • In a magnetic resonance imaging system of this invention, a static magnetic field is applied to a patient, and a gradient magnetic field and an excitation pulse signal are applied to the patient in accordance with a predetermined pulse sequence, so as to cause a magnetic resonance phenomenon in a selected. (
  • Thereafter, during an interval TDRV, an additional spin echo is generated by subjecting the body to at least one further refocusing RF pulse and/or magnetic field gradient pulse, and a RF drive pulse (β X ) is irradiated at the time of this additional spin echo. (
  • The sequence is repeated beginning with another sequence of RF and magnetic field gradient pulses after a recovery period TREC. (
  • Gradient-induced electric field refers to the electric field that may surround an object placed in a rapidly changing magnetic resonance imaging device. (
  • The signal intensity produced in any given voxel (3D volume) is a function of the imaging sequence (eg, gradient echo, spin echo, fast spin echo, etc.) and the selected sequence parameters, such as the repetition time (TR), and echo time (TE), as well as of the intrinsic tissue properties. (
  • Local variations in these intrinsic tissue parameters provide the image contrast offered by MR. The paramagnetic and superparamagnetic contrast agents primarily affect the local microenvironment to produce image contrast by altering the tissue relaxations times, in particular T2*, which dramatically decreases the signal intensity in typical gradient-echo acquisitions. (
  • Recently, gradient performance and fidelity has become of increasing interest, as the fidelity of the magnetic resonance (MR) image is somewhat dependent on the fidelity of the gradient system. (
  • In particular, for high fidelity non-Cartesian imaging, due to non-fidelity of the gradient system, it becomes necessary to know the actual k-space trajectory as opposed to the requested trajectory. (
  • In modern magnetic resonance imaging (MRI) instruments, the fidelity of the MR image is dependent upon the fidelity of the gradient system, such that the actual gradient outputs closely match the requested outputs. (
  • For conventional imaging, in which k-space points on a Cartesian grid are acquired, the image fidelity is somewhat immune to small gradient discrepancies, as long as the gradient areas are largely preserved. (
  • On the other hand, more efficient MRI data collection schemes that do not acquire the data on a Cartesian grid, such as spiral imaging, are sensitive to even small discrepancies in the gradient waveforms, which can give rise to significant blurring in the resulting images [ 1 ]. (
  • As there has been increased interest in recent years in more efficient data collection efficiencies for MRI, in which the data are not collected on a Cartesian grid, there has been a corresponding increased interest in methods for measuring the actual gradient output, with the purpose of providing corrections to improve the fidelity of the resulting image. (
  • Nanoparticles that possess magnetic properties can be manipulated by an external magnetic field gradient and thus useful for novel biomedical applications, such as magnetic drug targeting, hyperthermia, MRI contrast enhancement and magnetic separation. (
  • 2 Instead, we use breath-hold T1W spoiled gradient recalled echo (GRE) imaging. (
  • 5 These spoiled gradient images (eg, fast low-angle shot [FLASH], multiplanar gradient-recalled [MPGR]) can be obtained with and without fat suppression. (
  • Scanning with X and Y gradient coils causes a selected region of the patient to experience the exact magnetic field required for the energy to be absorbed. (
  • The RF signal may be processed to deduce position information by looking at the changes in RF level and phase caused by varying the local magnetic field using gradient coils. (
  • The major components of an MRI scanner are the main magnet, which polarizes the sample, the shim coils for correcting shifts in the homogeneity of the main magnetic field, the gradient system which is used to localize the region to be scanned and the RF system, which excites the sample and detects the resulting NMR signal. (
  • The nuclei absorb this energy and flip out of alignment with the magnetic field. (
  • The brighter the area of the image, the more intense the signal which is related to the quantity of nuclei present in the sample and to their environment. (
  • The magnetic field inside the scanner affects the magnetic nuclei of atoms. (
  • Normally atomic nuclei are randomly oriented but under the influence of a magnetic field the nuclei become aligned with the direction of the field. (
  • As the higher-energy nuclei distributes energy to the lower-energy nuclei, the rotation and vibration increases and ultimately dissipates, allowing a technician to create an image from this adjustment. (
  • The magnetic resonance scan produces a field that causes the nuclei to change its orientation in accordance with its access. (
  • The magnetic sensors in the scanner pick up the activity of the nuclei. (
  • In most medical applications, hydrogen nuclei, which consist solely of a proton, that are in tissues create a signal that is processed to form an image of the body in terms of the density of those nuclei in a specific region. (
  • Magnetic Resonance Microscopy, Methods and Application In Materials Science, Agriculture and Biomedicine. (
  • A panel of individuals with vast expertise in MR assessment by standard and emerging methods of CMR gathered in a closed group meeting titled 'Mitral Valve Regurgitation Assessment by Cardiac Magnetic Resonance' held at the joint EuroCMR-Society for Cardiovascular Magnetic Resonance (SCMR) meeting in Barcelona, Spain, in January 2018. (
  • ⅲ) Compared to existing deep learning reconstruction methods, our experimental results show that our paper has encouraging capability in exploiting the spatial and temporal redundancy of dynamic MR images. (
  • STANDARD RADIOLOGICAL METHODS: Ultrasound and magnetic resonance imaging (MRI). (
  • Although MRI is a safe and valuable test for looking at structures and organs inside the body, it is more expensive than other imaging methods and may not be available in all medical centers. (
  • Cardiac MRI employs a steady magnetic field , a radio-frequency transmission system, and computer technology to generate detailed pictures and brief videos of the beating heart. (
  • The scanner also produces a radio frequency current that creates a varying magnetic field. (
  • c) tuning/impedance matching means mounted within said foot cradle assembly, for providing a maximum transfer of radio frequency energy from said antenna means to a receiver of said magnetic resonance imaging, radio frequency excitation magnet apparatus. (
  • 13. The apparatus of claim 1 , wherein the device comprises a plurality of markers susceptible to detection under magnetic radio frequency imaging about its length. (
  • The Larmor radio frequency induces the magnetic resonance. (
  • A radiologist or MRI technologist usually performs the scan in a hospital, clinic or imaging center using special equipment. (
  • Coursework (including academic and clinic studies) prepares the technologist to provide patient care, perform studies using specialized imaging equipment, communicate professionally, and provide quality assurance in scheduled and emergency procedures. (
  • Chapter 7 Cardiac Magnetic Resonance Cine Image Analysis. (
  • A case series of the cardiac magnetic resonance imaging findings in seven adult Alström patients. (
  • Seven patients from the National Specialist Commissioning Group Centre for Alström Disease, Torbay, England, UK, completed the cardiac magnetic resonance imaging protocol to assess cardiac structure and function in Alström cardiomyopathy. (
  • Serial cardiac magnetic resonance scanning has helped clarify the underlying disease progression and responses to treatment. (
  • The computer performs millions of calculations, resulting in clear, cross-sectional black and white images of the body. (
  • The Magnetic Resonance Imaging diploma prepares students to visualize cross-sectional anatomical structures and aid physicians in the demonstration of pathologies and disease processes. (
  • Designed for registered radiologic technologists, this program will teach you how to produce cross-sectional images of the body utilizing magnetic resonance equipment to diagnose abnormalities that are difficult to evaluate with conventional radiography. (
  • This 16 credit-hour, year-long certificate program prepares ARRT registered radiologic technologists to produce cross-sectional images of the body, utilizing magnetic resonance equipment, in order to diagnose abnormalities that are difficult to evaluate with conventional radiography. (
  • Assessing the spatial distribution of cervical spinal cord activity during tactile stimulation of the upper extremity in humans with functional magnetic resonance imaging. (
  • the use of electromagnetic radiation to produce images of internal structures of the human body for the purpose of accurate diagnosis. (
  • The diagnosis of coarctation of the aorta may be established from the posteroanterior (PA) chest image alone in up to 92% of patients. (
  • It is the preferred imaging method to help establish a diagnosis of MS and to monitor the course of the disease. (
  • Cardiac imaging is crucial for diagnosis, identifying the cause of the disease, monitoring disease progression and planning definitive treatment for MR 3 . (
  • Magnetic Resonance Imaging (MRI) was first developed 30 years ago as an aid to medical diagnosis. (
  • A program that prepares individuals who are AART-certified radiological technicians to utilize MRI technology to obtain still and moving images of various vascular structures in the human body that aid the physician in the diagnosis or treatment of disease and injury. (
  • Magnetic resonance imaging (MRI) is one of the most powerful tools for non invasive clinical diagnosis due to contrast in soft tissues. (
  • Magnetic resonance imaging (MRI) is widely used in medical diagnosis for its various advantageous features, such as high-resolution capability, the ability to produce an. (
  • By using strong magnets and pulses of radio waves to manipulate the natural magnetic properties in the body, this technique makes better images of organs and soft tissues than those of other scanning technologies. (
  • Magnetic resonance imaging (MRI) is a safe and painless test that uses a magnetic field and radio waves to produce detailed pictures of the body's organs and structures. (
  • Images produced by an MRI scan can show organs, bones, muscles and blood vessels. (
  • Complexes of iron(II), iron(III), manganese(II), manganese(III), gadolinium(III), chromium(III), cobalt(II), and nickel(II) and such compounds are useful for enhancing magnetic resonance images of body organs and tissues. (
  • The aim of the TRAC project is the creation of a prototype based on reality techniques which enable doctors to obtain 3-D images of patients' internal organs. (
  • Magnetic resonance imaging (MRI) is a test done with a large machine that uses a magnetic field and pulses of radio wave energy to make pictures of organs and structures inside the belly. (
  • The normal pancreas has the highest signal intensity of the intra-abdominal organs on fat-suppressed T1W images (Figure 1). (
  • H. K. Aggarwal , M. P. Mani and M. Jacob , Modl: Model-based deep learning architecture for inverse problems, IEEE Transactions on Medical Imaging , 38 (2018), 394-405. (
  • T. Eo , Y. Jun , T. Kim , J. Jang , H. Lee and D. Hwang , KIKI-Net: Cross-domain convolutional neural networks for reconstructing undersampled magnetic resonance images, Magnetic Resonance in Medicine , 80 (2018), 2188-2201. (
  • K. Hammernik , T. Klatzer , E. Kobler , M. P. Recht , D. K. Sodickson , T. Pock and F. Knoll , Learning a variational network for reconstruction of accelerated MRI data, Magnetic Resonance in Medicine , 79 (2018), 3055-3071. (
  • Y. Han , J. Yoo , H. H. Kim , H. J. Shin , K. Sung and J. C. Ye , Deep learning with domain adaptation for accelerated projection-reconstruction MR, Magnetic Resonance in Medicine , 80 (2018), 1189-1205. (
  • Magnetic resonance imaging in pulmonary arterial hypertension. (
  • Then, the work of Le Bihan on NMR imaging of perfusion is described. (
  • Thought you might appreciate this item(s) I saw at Topics in Magnetic Resonance Imaging. (
  • Topics in Magnetic Resonance Imaging. (
  • B, Axial gadolinium-enhanced T1-weighted image demonstrates minimal rim enhancement. (
  • Background: Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) is a novel method to investigate cartilaginous and fibrocartilaginous structures. (
  • Contrast dye is injected to brighten the images of the blood vessels. (
  • CMR offers a comprehensive evaluation of MR and its effects on the heart by providing precise volumetric assessment (using cine images) and myocardial scar or fibrosis assessment (using the late gadolinium enhancement (LGE) technique). (
  • This geometry provides a very large relaxivity enhancement (r 1 ∼ 24 mM −1 ⋅s −1 ) compared with conventional chelating agents (Gd-DOTA: r 1 ∼ 3 mM −1 ⋅s −1 ) at high magnetic fields (4.7 T). This MRI-enhancing nanoparticle geometry opens opportunities for the development of multifunctional MRI-active nanoparticles for biomedical applications. (
  • During the examination, radio waves manipulate the magnetic position of the atoms of the body, which are picked up by a powerful antenna and sent to a computer. (
  • The magnetic field, along with radio waves, alters the hydrogen atoms' natural alignment in the body. (
  • Magnetic resonance imaging technologists play an important part in ensuring Albertans receive quality patient care by producing and recording magnetic resonance images (MRIs). (
  • Magnetic resonance imaging technologists work mostly at hospitals and health centers. (
  • Although they often work independently with their patients, magnetic resonance imaging technologists work as part of an interprofessional team that can include other technologists, therapists, physicians and nurses, as well as staff on cancer care and inpatient units. (
  • Magnetic resonance imaging technologists may work full-time or part-time hours or on a call-in (casual) basis. (
  • Magnetic resonance imaging technologists often sit or stand for long periods of time, such as when they perform MRIs. (
  • MRI creates precise images of the body based on the varying proportions of magnetic elements in different tissues. (
  • Moreover, MRI scans are not obstructed by bone, gas, or body waste, which can hinder other imaging techniques. (
  • These images help to pinpoint problems in the body. (
  • In some cases, it can provide clear images of body parts that can't be seen as well with an X-ray, CAT scan, or ultrasound. (
  • MRI scanners create images of the body using a large magnet and radio waves. (
  • Instead, MRI uses magnetic fields and radio waves to measure the relative water content in tissues - both normal tissue and abnormal - in the body. (
  • Place and secure small, portable magnetic resonance imaging (MRI) scanners on body part to be imaged, such as arm, leg, or head. (
  • Magnetic resonance imaging (MRI) is a test that uses powerful magnets, radio waves, and a computer to make detailed pictures inside your body. (
  • Substances used in magnetic resonance imaging (MRI) to improve the visibility of internal body structures. (
  • It uses magnetic field and radio waves to create a detailed, 3-D image inside your body. (
  • All images are read by a radiologist with specialty expertise in the area of the body being studied. (
  • This book is an excellent addition to the body of knowledge that can be of immediate benefit to everybody studying this area and interested in acquiring a hands-on experience in the specialized data analysis of image data. (
  • In the most basic sense, the magnetic resonance scan can identity the water molecules within the body. (
  • MRI techniques have been recently introduced for non-invasive qualification of regional myocardial mechanics, which is not achievable with other imaging modalities. (
  • The main chapters cover three common MR imaging modalities and their data modeling and analysis problems: functional MRI, diffusion MRI, and Multi-Parameter Mapping. (
  • He is also interested in reconstruction problems from physics-based imaging modalities. (
  • When compared with other imaging modalities, the excellent anatomical resolution 3 and multiplanar capabilities make MRI particularly worthy to pinpoint molecular events (Table 1). (
  • Anderson C.L., Dyke J.P., Green J.F., Gwinn K.D., Kabalka G.W. (1997) Magnetic Resonance Imaging of Tall Fescue. (
  • C, On the proton density image, the signal intensity becomes brighter, being isointense with gray matter and brighter than white matter. (
  • As the MRI signal intensity is directly proportional to the tissue proton density, even under perfect imaging conditions (i.e. neglecting relaxation effects), the MRI signal from the lung is ten-times weaker than that from adjacent tissues. (
  • A radiofrequency (RF) signal, which is dependent on the magnetic field strength, is applied to the sample that is in thermal equilibrium. (
  • Functional MRI data essentially consists of time series of 3D images associated with a description of the experimental conditions. (
  • Functional MRI utilizes a magnetic resonance signal to detect changes in blood flow that are coupled to neuronal activation when a specific task is performed. (
  • Diffusion MRI and Functional MRI extends the utility of MRI to capture neuronal tracts and blood flow respectively in the nervous system, in addition to detailed spatial images. (
  • 4. The magnetic resonance imaging receiver system according to claim 3, wherein said at least two antenna coils each comprise first and second capacitors, said first and second capacitors being serially connected in each of said at least two antenna coils for resonating the at least two antenna coils to operate at or near a Larmor frequency and to force a uniform magnetic field between said at least two antenna coils. (
  • 2. The apparatus of claim 1 wherein at least one of the device and the antenna comprises a portion comprising a material that is not susceptible to magnetic resonance frequency detection. (
  • Nicotine Addiction Decreases Dynamic Connectivity Frequency In Functional Magnetic Resonance Imaging. (
  • The rotational frequency of free water is faster than hydration, allowing the magnetic fields to identify the different types. (
  • First, energy from an oscillating magnetic field is temporarily applied to the patient at the appropriate resonance frequency. (
  • The spatially encoded NMR signal is Fourier transformed into a peak, it is then converted into a gray scale image based on the intensity of the resultant peak. (
  • This dispersion reduces the signal intensity and the voxel appears dark in the image. (
  • These intensity losses, which at high magnetic fields (-4 T) extend significantly beyond the boundary of the blood vessel, are the source of BOLD contrast. (
  • We report a biopsy-diagnosed patient with Creutzfeldt-Jacob disease showing on magnetic resonance images bilateral increased signal intensity in the basal ganglia on long repetition time images. (
  • Magnetic resonance imaging (MRI) is the newest, and perhaps most versatile, medical imaging technology available. (
  • These images give your physician important information in diagnosing your medical condition and planning a course of treatment. (
  • Instruct medical staff or students in magnetic resonance imaging (MRI) procedures or equipment operation. (
  • The Medical Image Computing and Computer Assisted Intervention Society, 2012. (
  • A definition of the medical term "magnetic resonance imaging" is presented. (
  • His main research interests include computational and nonparametric statistics, with a focus on statistical modeling and data analysis in medical imaging. (
  • The exposures to patients and medical staff from the magnetic fields can be high and there is a shortage of information on possible adverse long term health effects. (
  • In particular the Chairman of AGNIR, Professor Anthony Swerdlow, said "There is a pressing need for a well-conducted study of mortality and cancer incidence in workers with high occupational exposures to static magnetic fields, particularly those associated with medical MRI scanners. (
  • These bidimensional images are printed separately on to acetate and it is the medical consultant, on examining them, who makes a mental representation of the volume of the liver, in three-dimensional terms, based on her or his knowledge and experience. (
  • Do not attempt to draw conclusions or make diagnoses by comparing these images to other medical images, particularly your own. (
  • the radiologist is the physician expert trained in medical imaging. (
  • Image courtesy of Siemens Medical. (
  • J. Caballero , A. N. Price , D. Rueckert and J. V Hajnal , Dictionary learning and time sparsity for dynamic MR data reconstruction, IEEE Transactions on Medical Imaging , 33 (2014), 979-994. (
  • So, if you have experience in MRI and have the support from your department to allow monitored clinical practice, then our PgCert Medical Imaging (MRI) ensures you have the clinical competencies and safe practice to further your career and provide excellent understanding of the MRI environment. (
  • Corporate-level profiles of key companies operating in the United States and other key countries' Medical Magnetic Resonance Imaging (MRI) Devices market, which includes a brief overview of the company, its business activities and its hold or presence in the respective market. (
  • News-Medical spoke to Professor Natan Shaked about his new sperm cell imaging technique that could be used to help improve the outcomes of IVF treatments. (
  • Dr. Erturk is a Research Fellow, Division of Abdominal Imaging and Intervention, Brigham and Women's Hospital-Harvard Medical School. (
  • As shown in the image below, 3 main types of biliary atresia are defined. (
  • We have also demonstrated that the size of the susceptibility-induced local field depends on (i) the concentration of paramagnetic deoxyhemoglobin and (ii) the orientation of the vessel relative to the main magnetic field (8, 9). (
  • Massachusetts General Hospital Imaging provides prostate MRI services using a 3T scanner on our main campus in Boston. (
  • The main advantage of MRI of the lungs is its unique combination of morphological and functional assessment in a single imaging session. (
  • This article addresses the current techniques, the main indications, and the imaging features of common pancreatic diseases using state-of-the-art MRI. (
  • MRI is also excellent at imaging the augmented breast , including both the breast implant itself and the breast tissue surrounding the implant (abnormalities or signs of breast cancer can sometimes be obscured by the implant on a mammogram). (
  • This contrast agent helps produce stronger and clearer images and 'highlight' any abnormalities. (
  • Deoxygenated hemoglobin (dHb) is more magnetic ( paramagnetic ) than oxygenated hemoglobin (Hb), which is virtually resistant to magnetism ( diamagnetic ). (
  • The presence of paramagnetic molecules in blood produces a difference in magnetic susceptibility between the blood vessel and the surrounding tissue. (
  • In magnetic resonance imaging, contrast media are chosen for their paramagnetic property, which shortens relaxation time. (
  • It is one of the few imaging tools that can see through bone (the skull) and deliver high quality pictures of the brain's delicate soft tissue structures. (
  • Studies human anatomical structures in multiple imaging planes. (
  • The magnetic resonance imaging allows high resolution imaging of all anatomic structures, including the glenoid, the articular cartilage, the acromion, the biceps tendon, and the glenohumeral ligaments, in multiple orthogonal planes. (
  • After graduating and successfully passing your MRI exam, you can explore career opportunities in health care facilities including hospitals and clinics, specialized imaging centers, urgent care clinics, and physician offices. (
  • Iterative image reconstruction using a total variation constraint, Magnetic Resonance in Medicine , 57 (2007), 1086-1098. (
  • Sequences and Imaging Nomenclature (M. Haacke). (
  • W. A. Kaiser and E. Zeitler , MR imaging of the breast: Fast imaging sequences with and without Gd-DTPA. (
  • The return process produces a radio signal that can be measured by receivers in the scanner and made into an image, Filippi explained. (
  • People are exposed to high magnetic fields in industry and elsewhere, but MRI produces the highest magnetic fields in use today, and hence the need for a study of people who regularly work with the machines. (
  • Magnetic Resonance Imaging (MRI) is the first international multidisciplinary journal encompassing physical, life, and clinical science investigations as they relate to the development and use of magnetic resonance imaging . (
  • Because of improvements in speed and image quality, MRI is now ready for routine clinical use also in the study of pulmonary diseases. (
  • Signal averaging can be employed to increase the signal-to-noise ratio, but this extends the image acquisition times beyond 10 min per data set, which would make the protocols unsuitable for clinical routine. (
  • Learn about the physics and instrumentation of magnetic imaging, clinical procedures and protocols, patient care and safety. (
  • Decisions about which clinical pathway to follow may be guided by results of hormonal stimulation testing and/or imaging, particularly when the testicle is nonpalpable. (
  • Contrast agents have made a significant impact in the use of MRI for various clinical indications and improve quality of images. (
  • Magnetic resonance arthrography (MRA) is a useful pre-operative investigation for patients with clinical signs and symptoms of femoroacetabular impingement. (
  • Magnetic Resonance Imaging is a peer-reviewed scientific journal published by Elsevier, encompassing biology, physics, and clinical science as they relate to the development and use of magnetic resonance imaging technology. (
  • Published four times each year (February, May, August, and November), Magnetic Resonance Imaging Clinics of North America updates you on the latest trends in patient management, keeps you up to date on the newest advances, and provides a sound basis for choosing treatment options. (
  • Often, doctors prescribe an MRI scan to more fully investigate earlier findings of the other imaging techniques. (
  • The resonance imaging often shows the associated pathological findings, including joint effusion. (
  • We have developed real-time magnetic resonance imaging (MRI) to guide heart catheterization with tissue visualization but without X-ray radiation. (
  • Magnetic resonance cholangiopancreatographyrefers to visualization of pancreatic and biliary ducts with magnetic resonance imaging. (
  • Currently images of the liver are being worked with, but it is hoped that the technique will be useful for any internal structure or tissue. (
  • A Machine Learning Approach to the Differentiation of Functional Magnetic Resonance Imaging Data of Chronic Fatigue Syndrome (CFS) From a Sedentary Control. (