Encyclopedias as Topic: Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)Magnetic Resonance Imaging: 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.Cardiac Volume: The volume of the HEART, usually relating to the volume of BLOOD contained within it at various periods of the cardiac cycle. The amount of blood ejected from a ventricle at each beat is STROKE VOLUME.Magnetic Resonance Imaging, Cine: 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.Cardiovascular System: The HEART and the BLOOD VESSELS by which BLOOD is pumped and circulated through the body.Magnetic Resonance Spectroscopy: 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).Reproducibility of Results: 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.Magnetic Resonance Angiography: 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.Contrast Media: Substances used to allow enhanced visualization of tissues.MedlinePlus: NATIONAL LIBRARY OF MEDICINE service for health professionals and consumers. It links extensive information from the National Institutes of Health and other reviewed sources of information on specific diseases and conditions.Magnetic Resonance Imaging: 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.Neurosciences: The scientific disciplines concerned with the embryology, anatomy, physiology, biochemistry, pharmacology, etc., of the nervous system.Image Processing, Computer-Assisted: 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.Brain: 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.Magnetic Resonance Spectroscopy: 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).Image Interpretation, Computer-Assisted: Methods developed to aid in the interpretation of ultrasound, radiographic images, etc., for diagnosis of disease.Brain Mapping: Imaging techniques used to colocalize sites of brain functions or physiological activity with brain structures.Imaging, Three-Dimensional: 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.Neuroimaging: Non-invasive methods of visualizing the CENTRAL NERVOUS SYSTEM, especially the brain, by various imaging modalities.Reproducibility of Results: 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.Magnetic Resonance Imaging: 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.Magnetic Resonance Imaging, Cine: 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.Magnetic Resonance Spectroscopy: 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).Contrast Media: Substances used to allow enhanced visualization of tissues.Gadolinium DTPA: 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)Magnetic Resonance Angiography: 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.Edema, Cardiac: 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).Gadolinium: 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.Heart: The hollow, muscular organ that maintains the circulation of the blood.Predictive Value of Tests: 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.Encyclopedias as Topic: Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)Magnetic Resonance Imaging: 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.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Image Processing, Computer-Assisted: 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.Imaging, Three-Dimensional: 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.Brain Mapping: Imaging techniques used to colocalize sites of brain functions or physiological activity with brain structures.Brain: 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.Brain Neoplasms: 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.MedlinePlus: NATIONAL LIBRARY OF MEDICINE service for health professionals and consumers. It links extensive information from the National Institutes of Health and other reviewed sources of information on specific diseases and conditions.Reproducibility of Results: 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.Magnetic Resonance Imaging: 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.Magnetic Resonance Spectroscopy: 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).Magnetic Fields: Areas of attractive or repulsive force surrounding MAGNETS.Nuclear Magnetic Resonance, Biomolecular: 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.Magnetics: The study of MAGNETIC PHENOMENA.Patents as Topic: Exclusive legal rights or privileges applied to inventions, plants, etc.Electromagnetic Fields: Fields representing the joint interplay of electric and magnetic forces.Protein Conformation: 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).Magnetic Resonance Angiography: 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.Magnetic Resonance Imaging, Cine: 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.

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)

*Centre for Magnetic Resonance Investigations

Balan, P; Turnbull, LW Dynamic contrast enhanced magnetic resonance imaging and magnetic resonance spectroscopy in diabetic ... and is devoted to the application of magnetic resonance imaging and magnetic resonance spectroscopy techniques to the study of ... Diffusion-weighted imaging of normal and malignant prostate tissue at 3.0 T. JOURNAL OF MAGNETIC RESONANCE IMAGING, 23 (2): 130 ... The Kingston Upon Hull Centre for Magnetic Resonance Investigations (CMRI), which opened in 1992, is a magnetic resonance ...

*Magnetic resonance imaging

... neuroimaging software Magnetic immunoassay Magnetic particle imaging Magnetic resonance elastography Magnetic Resonance Imaging ... Magnetic resonance imaging is a medical application of nuclear magnetic resonance (NMR). NMR can also be used for imaging in ... www.magnetic-resonance.org/ch/20-01.html Guadalupe Portal; Aliosvi Rodriguez Whole body magnetic resonance imaging in early ... Magnetic Resonance in Medicine. 69: 1795-1804. doi:10.1002/mrm.24413. "Magnetic Resonance Imaging". University of Wisconsin. ...

*Functional magnetic resonance imaging

"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 ... Functional magnetic resonance imaging or functional MRI (fMRI) measures brain activity by detecting changes associated with ... In general, fMRI studies acquire both many functional images with fMRI and a structural image with MRI. The structural image is ...

*Interventional magnetic resonance imaging

... , also Interventional MRI or IMRI, is the use of magnetic resonance imaging (MRI) to ... The non-magnetic environment required by the scanner and the strong magnetic radiofrequency and quasi-static fields generated ... Higher field magnet systems are beginning to be deployed in intraoperative imaging suites, which can combine high-field MRI ... For example, use of non-magnetic (e.g. Titanium) surgical instruments and MR compatible patient surveillance accessories in ...

*Cardiac magnetic resonance imaging

Cardiovascular magnetic resonance imaging (CMR), sometimes known as cardiac MRI, is a medical imaging technology for the non- ... "4D flow cardiovascular magnetic resonance consensus Statement, Dyverfeldt et. al". Journal of Cardiovascular Magnetic Resonance ... The Society for Cardiovascular Magnetic Resonance The Journal for Cardiovascular Magnetic Resonance An Atlas of normal cardiac ... MRA (magnetic resonance angiography) can produce 3D and 4D images of blood vessels and the flow of blood through the vessels. A ...

*Magnetic Resonance Imaging (journal)

... and clinical science as they relate to the development and use of magnetic resonance imaging technology. Magnetic Resonance ... Magnetic Resonance Imaging is a peer-reviewed scientific journal published by Elsevier, encompassing biology, physics, ... Imaging was established in 1982 and the current editor-in-chief is John C. Gore. The journal produces 10 issues per year. ...

*Magnetic resonance imaging burn

... (also known as an "MRI burn") is a cutaneous condition characterized by first-, second- or ...

*Physics of magnetic resonance imaging

"In vivo MR Imaging at 21.1 T" (PDF). Duggan-Jahns, Terry. "The Evolution of Magnetic Resonance Imaging: 3T MRI in Clinical ... "Magnetic Resonance Imaging". University of Wisconsin. Retrieved 2016-03-14. Keith A. Johnson. "Basic proton MR imaging. Tissue ... The physics of magnetic resonance imaging (MRI) involves the interaction of biological tissue with electromagnetic fields. MRI ... Perry Sprawls (2000). Magnetic Resonance Imaging: Principles, Methods, and Techniques. Medical Physics Publishing. ISBN ...

*Phase contrast magnetic resonance imaging

... (PC-MRI) is a specific type of magnetic resonance imaging used primarily to determine ... Elkins, C.; Alley, M.T. (2007). "Magnetic resonance velocimetry: applications of magnetic resonance imaging in the measurement ... PC-MRI can be considered a method of Magnetic Resonance Velocimetry. It also provides a method of magnetic resonance ... contrast MR imaging of flow". Journal of Magnetic Resonance Imaging. 1 (4): 405-413. Pelc, Norbert J.; Bernstein, Matt A.; ...

*K-space (magnetic resonance imaging)

k-space is a formalism widely used in magnetic resonance imaging introduced in 1979 by Likes and in 1983 by Ljunggren and Twieg ... Journal of Magnetic Resonance 1983; 54:338. Twieg D (1983). "The k-trajectory formulation of the NMR imaging process with ... In MRI physics, k-space is the 2D or 3D Fourier transform of the MR image measured. Its complex values are sampled during an MR ... When k-space is full (at the end of the scan) the data are mathematically processed to produce a final image. Thus k-space ...

*Strain-encoded magnetic resonance imaging

... (SENC-MRI) is a magnetic resonance imaging a technique for imaging the strain of ... It is an improvement on magnetic resonance elastography in that it has a faster imaging time, and less post-processing time, to ... Osman, N. F. (2003). "Detecting stiff masses using strain-encoded (SENC) imaging". Magnetic Resonance in Medicine. 49 (3): 605 ... Summer 2004 Getting to the Heart of Cardiac Imaging Deanna Pogorelc for MedCity News. April 29, 2014 In tech transfer, an idea ...

*Safety of magnetic resonance imaging

"Magnetic Field Interactions of Copper-Containing Intrauterine Devices in 3.0-Tesla Magnetic Resonance Imaging: In Vivo Study". ... Magnetic resonance imaging (MRI) is in general a safe technique, although injuries may occur as a result of failed safety ... "Physics of magnetic resonance imaging". My-MS.org. Retrieved 27 April 2012. Colletti, P.M.; Shinbane, J; S, Shellock; F. G. ( ... Lee JW; Kim MS; Kim YJ; Choi YJ; Lee Y; Chung HW (2011). "Genotoxic effects of 3 T magnetic resonance imaging in cultured human ...

*Cardiac magnetic resonance imaging perfusion

"Magnetic resonance first-pass myocardial perfusion imaging: clinical validation and future applications". J Magn Reson Imaging ... Cardiac magnetic resonance imaging perfusion (cardiac MRI perfusion, CMRI perfusion), also known as stress CMR perfusion, is a ... "Cardiac magnetic resonance perfusion imaging for the functional assessment of coronary artery disease: a comparison with ... clinical magnetic resonance imaging test performed on patients with known or suspected coronary artery disease to determine if ...

*Electroencephalography functional magnetic resonance imaging

... and functional Magnetic Resonance Imaging (fMRI)". Magnetic Resonance Imaging. 28 (8): 1192-1199. doi:10.1016/j.mri.2010.01.001 ... EEG-fMRI (short for EEG-correlated fMRI or electroencephalography-correlated functional magnetic resonance imaging) is a ... ability to image blood dynamics through the entire brain with high spatial resolution. Up to now, EEG-fMRI has been mainly seen ... due to currents induced by the MR image forming process in the circuits created by the subject and EEG recording system) and ...

*History of magnetic resonance imaging

In 1973, Lauterbur published the first nuclear magnetic resonance image and the first cross-sectional image of a living mouse ... While researching the analytical properties of magnetic resonance, Damadian created a hypothetical magnetic resonance cancer- ... "discoveries concerning magnetic resonance imaging". The Nobel citation acknowledged Lauterbur's insight of using magnetic field ... The history of magnetic resonance imaging includes many researchers who have discovered NMR and described its underlying ...

*Endorectal coil magnetic resonance imaging

... or endorectal coil MRI is a type of medical imaging in which MRI is used in ... evaluation with endorectal MR imaging and three-dimensional proton MR spectroscopic imaging". Radiol Med (Torino). 108 (5-6): ... MR imaging with pelvic phased-array coils versus integrated endorectal-pelvic phased-array coils". Radiology. 193 (3): 703-709 ... conjunction with a coil placed into the rectum in order to obtain high quality images of the area surrounding the rectum. The ...

*Magnetic resonance imaging of the brain

Magnetic resonance imaging (MRI) of the nervous system uses magnetic fields and radio waves to produce high quality two- or ... Howe, F. A.; Filler, A. G.; Bell, B. A.; Griffiths, J. R. (December 1992). "Magnetic resonance neurography". Magnetic Resonance ... "Dynamic imaging with lanthanide chelates in normal brain: contrast due to magnetic susceptibility effects". Magnetic Resonance ... "Human magnetic resonance imaging at 8 T". NMR Biomed. 11 (6): 263-5. doi:10.1002/(SICI)1099-1492(199810)11:6. 3.0.CO;2-0. PMID ...

*Event-related functional magnetic resonance imaging

... (efMRI) is a technique in magnetic resonance imaging that can be used to ... which provided a 2-d image. Next, endogenous contrast mechanisms were discovered by Detre, Koretsky, and colleagues was based ... on the net longitudinal magnetization within an organ, and a "second based on changes in the magnetic susceptibility induced by ...

*Positron emission tomography-magnetic resonance imaging

... (PET-MRI) is a hybrid imaging technology that incorporates magnetic ... Currently, the combination of positron emission tomography (PET) and magnetic resonance imaging (MRI) as a hybrid imaging ... "Positron emission tomography/magnetic resonance imaging: the next generation of multimodality imaging?". Semin Nucl Med. 38: ... resonance imaging (MRI) soft tissue morphological imaging and positron emission tomography (PET) functional imaging. Presently ...

*Fast low angle shot magnetic resonance imaging

... (FLASH MRI) is a particular sequence of magnetic resonance imaging. It is a ... "Magnetic resonance imaging in real time: Advances using radial FLASH". Journal of Magnetic Resonance Imaging. 31 (1): 101-109. ... "FLASH imaging: rapid NMR imaging using low flip angle pulses". Journal of Magnetic Resonance. 67 (2): 258-266. doi:10.1016/0022 ... CS1 maint: Multiple names: authors list (link) A SHORT HISTORY OF MAGNETIC RESONANCE IMAGING FROM A EUROPEAN POINT OF VIEW ...

*Erwin L. Hahn Institute for Magnetic Resonance Imaging

The Erwin L. Hahn Institute for Magnetic Resonance Imaging is a research institute which develops magnetic resonance imaging ( ... In contrast to the magnetic resonance imagers used in hospitals and clinics throughout the world, which commonly operate at a ... a physicist who has made innumerable contributions to the field of magnetic resonance. The centerpiece of the institute is a 7 ... magnetic field strength of 1.5 Tesla, the ultra high magnetic field strength of this imager provides significantly higher ...

*Delayed gadolinium-enhanced magnetic resonance imaging of cartilage

... or dGEMRIC measures the fixed-charge density and relative ... Journal of magnetic resonance imaging : JMRI. 31 (5): 1203-9. doi:10.1002/jmri.22159. PMID 20432357. The Impact of the ... Gadolinium-Enhanced MRI of Cartilage Association between findings on delayed gadolinium-enhanced magnetic resonance imaging of ... enhanced MR imaging". Radiology. 205 (2): 551-8. doi:10.1148/radiology.205.2.9356644. PMID 9356644. Siversson, C; Tiderius, CJ ...

*Magnetic resonance spectroscopic imaging

MRSI is also called 1H-nuclear magnetic resonance spectroscopic imaging and proton magnetic resonance spectroscopic imaging. ... Whereas traditional magnetic resonance imaging (MRI) generates a black-and-white image in which brightness is determined ... Magnetic resonance spectroscopic imaging (MRSI) is a noninvasive imaging method that provides spectroscopic information in ... Magnetic resonance spectroscopic imaging entry in the public domain NCI Dictionary of Cancer Terms [1] - article about ...

*DMOZ - Health: Medicine: Imaging: Magnetic Resonance Imaging

How Stuff Works: Magnetic Resonance Imaging (MRI) Informative illustrated explanation of Magnetic Resonance Imaging (MRI) ... Clinical research in the imaging sciences within the areas of Magnetic Resonance Imaging, Magnetic Resonance Spectroscopy, ... Magnetic Resonance Technology Information Portal Information about Magnetic Resonance Imaging - MRI - acronyms, artifacts, ... "Health ... Magnetic Resonance Imaging" search on: AOL - Ask - Bing - DuckDuckGo - Gigablast - Google - ixquick - Yahoo - Yandex ...

*DMOZ - Health: Medicine: Imaging: Magnetic Resonance Imaging: Functional MRI

... is an advanced magnetic resonance imaging technique which can localize the brain areas activated by a stimulus. ... Functional MRI (fMRI) is an advanced magnetic resonance imaging technique which can localize the brain areas activated by a ... Oxford centre for functional magnetic resonance imaging of the brain: information and software package. ...

*Avid Radiopharmaceuticals

Other diagnostic tools, such as analysis of cerebrospinal fluid, magnetic resonance imaging scans looking for brain shrinkage ... "F.D.A. Sees Promise in Alzheimer's Imaging Drug", The New York Times, January 20, 2011. Accessed January 20, 2011. "A Trial of ... "Avid Radiopharmaceuticals Selected to Receive Seed Funding from BioAdvance; Funds to Be Used to Develop Molecular Imaging Tools ... "Avid Radiopharmaceuticals Initiates First Phase II Trial Of Novel Compound For Imaging Alzheimer's Disease", Medical News Today ...

*Methylsulfonylmethane

"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( ...
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 ...
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).. ...
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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
Results One hundred and thirty-three patients were recruited. Ninety patients (67.7%) had a clinical diagnosis of SpA. Average back pain duration was 8.5±8.9 years. The presence of Human Leukocyte Antigen (HLA) B27 was found in 42.9% of the study population. Inter-observer correlations were excellent (STIR 95.4%, p,0.001; DWI 69.5%, p,0001). DWI was found to be comparable to STIR in disease diagnosis (sensitivity DWI 34.1% vs STIR 34.3%; specificity DWI 85% vs STIR 93.8%) and when applied to the Assessment of SpondyloArthritis international Society (ASAS) criteria for axial SpA (sensitivity DWI 78.9% vs 79.5%; specificity DWI 75.0% vs 78.8%). DWI is better than STIR in non-radiographic axial SpA group (sensitivity DWI 37.8% vs STIR 33.8%; specificity DWI 85.3% vs STIR 95.6%). In the group with disease duration less than 3 years, the two images showed improved sensitivity (sensitivity DWI 34.5% vs STIR 41.4%; specificity DWI 84.6% vs STIR 88.5%). ...
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. ...
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 ...
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
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
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 ...
MRI showed a heterogeneous multi-loculated cystic lesion located in the posterior arch of T5, T6, with extension in the T5 vertebral body and mass effect on the adjacent spinal cord. This lesion had multiple cavities with fluid-fluid levels, appeared in low signal intensity on T1-weighted images (figure 3) and in mixed low and high intensity on T2 FAT SAT-weighted images (figure 1 and 2). The enhanced series of this study (T1 FAT SAT GD, figure 4) demonstrated rim enhancement of the fluid-fluid levels cavities ...
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 ...
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 ...
Towards quantitative MR-based functional imaging : evaluation of blood oxygen level dependent (BOLD), perfusion and blood volume imaging methods ...
Polylysine-DTPA-Gd, a new MR contrast agent, was injected into the aorta of rats 7 days after C6 glioblastoma was implanted in their brains; MR imaging was performed 3 days later. The imaging was done at two field strengths: (1) 1.5 T with a 3-mm slice thickness and in-plane resolutions of 600 microns and (2) 9.4 T with a 125- or 500-microns slice thickness and in-plane resolutions of 95 microns. In animals injected with polylysine-DTPA-Gd (1 microgram or more per rat), the T1-weighted images and mixed T1, T2 images of the C6 glioblastoma revealed a higher signal intensity at the marginal region between tumor and normal brain than that seen in surrounding normal brain. The central tumor region had a low signal intensity. The concentration of Gd in the C6 glioblastoma, after injection of 1 microgram polylysine-DTPA-Gd per rat, was calculated to be 0.14 mumol/l. The central tumor region also had a low signal intensity in animals that were not injected with the contrast agent, but the margin ...
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; ...
OBJECTIVES: To evaluate the diagnostic performance of preoperative multiparametric MRI with extracapsular extension (ECE) risk-scoring in the assessment of prostate cancer tumour stage (T-stage) and prediction of ECE at final pathology. MATERIALS AND METHODS: Eighty-seven patients with clinically localised prostate cancer scheduled for radical prostatectomy were prospectively enrolled. Multiparametric MRI was performed prior to prostatectomy, and evaluated according to the ESUR MR prostate guidelines by two different readers. An MRI clinical T-stage (cTMRI), an ECE risk score, and suspicion of ECE based on tumour characteristics and personal opinion were assigned. Histopathological prostatectomy results were standard reference. RESULTS: Histopathology and cTMRI showed a spearman rho correlation of 0.658 (p , 0.001) and a weighted kappa = 0.585 [CI 0.44;0.73](reader A). ECE was present in 31/87 (36 %) patients. ECE risk-scoring showed an AUC of 0.65-0.86 on ROC-curve for both readers, with ...
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
Major depression is a prevalent disease among the elderly, significantly decreasing the quality of life. The age of first onset of depression can be early in life, so called early-onset depression (EOD), as well as first occur in old age, i.e. late-onset depression (LOD). Some previous studies have suggested aetiological ... read more differences between EOD and LOD in the elderly. However, the number of these studies investigating elderly EOD and LOD patients is small. Therefore the importance of age of onset in the aetiology of late-life depression remains unclear. We used Magnetic Resonance Imaging (MRI) to examine hippocampal volume and subcortical white matter lesions in elderly patients with EOD and LOD and healthy elderly subjects. Both the hippocampus and subcortical white matter lesions have been implicated in the aetiology and treatment outcome of late-life depression. Hippocampal volume decrease and increased prevalence of subcortical white matter lesions in depressed patients might ...
CT findings of meningiomas include a hyperdense (75%) smooth mass abutting the dura. Hyperostosis is a common occurrence in meningiomas; this may be secondary to local calvarial invasion, reaction to the adjacent dural mass or a primary osseous lesion. Calcification is identified in 25% of meningiomas which may cause focal areas of low signal intensity on MR imaging. The T1 weighted MR imaging appearance of meningiomas is an isodense extraaxial mass with a dural base and gray matter buckling. The appearance of meningiomas on T2 weighted images is isointense to cortex with a rim of CSF or trapped CSF clefts. Occasionally meningiomas may appear high in signal on T2 weighted imaging, indicating syncytial or angioblastic histology. Visualized flow voids may also be present within larger meningiomas, implying their vascularity. More than 95% of meningiomas demonstrate avid, uniform enhancement on post-contrast images. Meningiomas may display varying degrees of associated parenchymal edema ...
Choi, J.Soo.; Ko, E.Sook.; Ko, E.Young.; Han, B-Kyung.; Nam, S.Jin., 2016: Background Parenchymal Enhancement on Preoperative Magnetic Resonance Imaging: Association With Recurrence-Free Survival in Breast Cancer Patients Treated With Neoadjuvant Chemotherapy
CONTEXT: Disruption of frontal-subcortical and limbic networks is hypothesized to have a key role in late-life depression (LLD) and can be examined using magnetic resonance imaging (MRI) techniques. Gray matter can be examined using T1-weighted MRI, white matter using T2-weighted MRI and diffusion tensor imaging, and functional connectivity in resting-state networks using functional MRI. Although independent MRI studies have supported gray and white matter abnormalities in frontosubcortical and limbic networks and increased functional connectivity in the default-mode network in depression, no study has concurrently examined gray matter, white matter, and functional connectivity. OBJECTIVE: To examine whether results of different MRI techniques are complementary, multimodal MRI was used to compare gray matter, white matter, and resting-state networks between LLD and control groups. DESIGN: Cross-sectional, case-control, multimodal MRI analysis. SETTING: University research department. PARTICIPANTS:
Introduction: White matter hyperintensity volume (WMHv) is an important and highly heritable cerebrovascular phenotype; however, manual or semi-automated approaches to clinically acquired MRI analysis hinder large-scale studies in acute ischemic stroke (AIS). In this work, we develop a high-throughput, fully automated WMHv analysis pipeline for clinical fluid-attenuated inversion recovery (FLAIR) images to facilitate rapid genetic discovery in AIS.. Methods: Automated WMHv extraction from multiple subjects relies on significant pre-processing of medical scans, including co-registration of the images. To reduce the effects of anisotropic voxel sizes, each FLAIR image is upsampled using bi-cubic interpolation. Brain extraction is performed using RObust Brain EXtraction (ROBEX). Images are then registered to an in-house FLAIR template using Advanced Normalization Tools (ANTs). The spatial covariation of WMH is learned through principal component analysis (PCA) of manual outlines from 100 subjects. ...
http://sig2perspectives.pubs.asha.org/article.aspx?articleid=1758160 A Primer on Functional Magnetic Resonance Imaging (fMRI) The use of neuroimaging techniques is becoming increasingly prevalent in the study of cognitive processes, including language. Understanding how the brain works in the service of transforming simple sensory signals-such as sounds, hand motions, or lines on a page- into the infinitely creative and flexible code that is human ... 2003-04-01T00:00:00 Article Susan A. McLaughlin ...
14. A magnetic resonance apparatus to correct distortions due to inhomogeneities of a basic magnetic field in magnetic resonance image data, comprising: a magnetic resonance data acquisition unit comprising a basic field magnet that generates a basic magnetic field exhibiting inhomogeneities, a gradient coil system and a radio-frequency system; a control unit configured to operate said magnetic resonance data acquisition unit to excite nuclear spins, with said radio-frequency system, in an examination subject at least partially located in said basic magnetic field and to acquire a first measurement data set and at least one additional measurement data set representing magnetic resonance signals resulting from the excitation of said nuclear spins, each of said first and said at least one additional measurement data set comprising a plurality of measurement points, said measurement points in said first measurement data set being acquired by operating said gradient coil system to activate a first ...
Type I Decreased signal on T1, and increased signal on T2.. Represents marrow edema.. Associated with an acute process.. Histological examination shows disruption and fissuring of the endplate and vascularized fibrous tissues within the adjacent marrow. Type II - the most common type Increased signal on T1, and isointense or slightly hyperintense signal on T2.. Represents fatty degeneration of subchondral marrow.. Associated with a chronic process.. Histological examination shows endplate disruption with yellow marrow replacement in the adjacent vertebral body.. Type I changes convert to Type II changes with time, while Type II changes seem to remain stable.. Type III Decreased signal on both T1 and T2.. Correlate with extensive bony sclerosis on plain radiographs.. Histological examination shows dense woven bone; hence, no marrow to produce MRI signal.. ...
The fluctuations in a brain regions activation levels over a functional magnetic resonance imaging (fMRI) time-course are used in functional connectivity (FC) to identify networks with synchronous responses. It is increasingly recognized that multi-voxel activity patterns contain information that cannot be extracted from univariate activation levels. Here we present a novel analysis method that quantifies regions synchrony in multi-voxel activity pattern discriminability, rather than univariate activation, across a timeseries. We introduce a measure of multi-voxel pattern discriminability at each time-point, which is then used to identify regions that share synchronous time-courses of condition-specific multi-voxel information. This method has the sensitivity and access to distributed information that multi-voxel pattern analysis enjoys, allowing it to be applied to data from conditions not separable by univariate responses. We demonstrate this by analyzing data collected while people viewed four
As a graduate student 15 years ago, I was extremely interested in regional brain contributions to motor learning. Magnetic resonance imaging scanners were not common, and to address my research questions, I was forced to recruit subjects with focal brain lesions. This was a tedious and inexact process that certainly extended my doctoral studies by a year. How times change. In my research laboratory today, we can induce temporary, virtual lesions with just a few minutes of noninvasive brain stimulation. Coupled with a stereotaxic system that employs the research participants own magnetic resonance imaging-based anatomy, we can target any location and easily increase or decrease cortical excitability. Pairing noninvasive brain stimulation with practice of novel tasks has rapidly become a primary research tool for scientists who study motor learning and recovery of function after brain damage. This is just one small example; overall, rehabilitation-related technology has rapidly advanced to a ...
7 Tesla MR scanning provides 34 µ resolution ocular anatomy which is an order of magnitude higher than 3 tesla MR scans. High frequency ocular ultrasound (20 - 50 MHz) provide high resolution of the eye, however, only the anterior portion of the globe can be imaged. The 5 - 10 MHz probes used for the posterior segment are significantly lower resolution. Spectral domain OCT give very high resolution images, however OCT is light based and depends on clear media and only displays the superficial anatomy of the posterior pole of the eye. This suggests that 7T MR may be superiorfor imaging the retro-laminar optic nerve, the posterior chamber the episclera, and the retina and choroid anterior to the equator. ...
Sorry vegans and vegetarians, but it takes a long time removing a fibroid tumor your body to absorb iron through non-meat products. MRI characteristics that indicate a successful treatment include high signal intensity on T1W images and homogenously decreased T2 signal intensity. Most patients undergoing UAE will experience this syndrome, which includes pain, cramping, nausea, vomiting, fever, tiredness, body aches. We used data from a case-control study on risk factors for uterine fibroids conducted in Italy between 1986 and 1997.
During a 46-month period, 143 patients underwent 152 DBS surgeries including 289 lead placements utilizing intraoperative 1.5-T MR imaging. Imaging was supervised by an MR imaging physicist to maintain the specific absorption rate below the required level of 0.1 W/kg and always included T1 magnetization-prepared rapid gradient echo and T2* gradient echo sequences with selected use of T2 fluid attenuated inversion recovery (FLAIR) and T2 fast spin echo (FSE). Retrospective review of the intraoperative MR imaging examinations was performed to quantify the amount of hemorrhage and the amount of air introduced during the DBS surgery. ...
Aysel Sabuncu Brain Research Center. Ultra-high field (UHF) MRI offers improved signal- and contrast-to-noise ratio (SNR/CNR), which can be leveraged towards higher-resolution images. However, acquiring higher-resolution images increases scan times, making MRI scans prone to patient motion. Motion may become a problem especially with uncooperative patients such as in paediatric imaging and patients with Parkinsons or dementia. A common solution in such cases is to use sedatives. Unfortunately, sedation makes MRI an invasive imaging modality, and may commonly have side effects. Alternatively, real-time motion correction techniques can adapt the scan parameters accordingly and freeze patient motion from a data processing perspective these techniques are not directly applicable at UHF MRI.. At higher field strengths, artificial contrast variations are imposed on the acquired images due to the shorter wavelength. To correct such effects, parallel-transmit (pTx) arrays are commonly used. However, ...
MRI, with its superior contrast resolution, is increasingly preferred over computed tomography in the evaluation of suspected dementia.2 A basic dementia sequence including a high resolution structural volumetric T1 weighted scan and T2 weighted or fluid attenuated inversion recovery (FLAIR) sequences can be obtained in approximately 20 minutes. MRI does not involve ionising radiation, but claustrophobia may be a limiting factor in some patients. MRI is contraindicated in patients with pacemakers and certain metallic implants, and earplugs should be worn to prevent the possibility of cochlear damage.. T1 weighted volumetric MRI scanning provides a very detailed assessment of brain structure, allowing for the assessment of the presence or absence and pattern of brain volume loss, ie, atrophy. When evaluating a patient with cognitive impairment it is particularly valuable to assess for medial temporal lobe atrophy on coronal reformats, either qualitatively or using simple rating scales. The ...
Classification analysis view. Classification analysis view presenting the result of executing a Bayes Net classifier using a 10-fold cross validation scheme. Th
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 slice of the patient. The magnetic resonance data of the magnetic resonance phenomenon is acquired, and the magnetic resonance image is obtained from the magnetic resonance data. The system has an announcement section for intermittently urging the patient to stop a body movement. In this system, a data acquisition section is operated under the control of a control section only while the patient stands still in response to the announcement of the announcement section, thereby intermittently acquiring magnetic resonance data in units of a predetermined volume.
A gradient coil system of a magnetic resonance tomography apparatus is fashioned as a hollow cylinder whose hollow interior cross-section is an ellipse with a minor ellipse axis and a major ellipse axis, and contains first and second transverse gradient coils. A first gradient field having a first gradient can be generated with the gradient coil in an imaging volume, and a second gradient field having a second gradient can be generated in said imaging volume with the second gradient coil. The gradient coils are arranged so that the first and the second gradients exhibit an oblique position relative to the major and the minor ellipse axes.
We thank Dr. Mewton and colleagues for adding to the discussion regarding T2-weighted cardiac magnetic resonance (CMR). Often, a candid debate will invoke strong reactions, but we are hopeful that readers of our Pro/Con article (1) with Dr. Friedrich will carefully consider the merits of the respective arguments. Here, we present our perspective on the issues raised by Dr. Mewton and colleagues.. At the outset, philosophically, we take exception to the comment that: "As always, in such a debate truth probably relies somewhere in between." At issue is whether or not T2-weighted CMR depicts post-infarct myocardium at risk. Fundamentally, it can only be one or the other.. With regard to the other issues raised:. 1. We agree that T2-CMR can show myocardial edema-which we believe is a marker of necrosis in the setting of acute ischemic injury.. 2. We agree that T2-CMR can provide incremental data to delayed-enhancement imaging.. 3. We agree that T2-short tau inversion recovery (as well as ...
Both HIV disease and advanced age have already been associated with alterations to cerebral white matter as measured with white matter hyperintensities (WMH) on fluid attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI) and more recently with diffusion tensor imaging (DTI). HJC0350 spatial statistics (TBSS). An age by HIV connection was found indicating a significant association between WMH and older age in HIV+ participants only. Similarly significant age group by HIV connections were discovered indicating stronger organizations between older age group and reduced FA in the posterior limbs of the inner tablets cerebral peduncles and anterior corona radiata in HIV+ vs. HIV- individuals. The interactive ramifications of HIV and age group were stronger regarding whole-brain WMH than for just about any from the FA methods. Among HIV+ individuals better WMH and lower anterior corona radiata FA had been associated with energetic hepatitis C trojan infection a brief history of Helps ...
We prospectively collected data from 420 consecutive patients with acute ischemic stroke admitted to our neurology ward from January 1998 to September 2000 and from control subjects recruited during the same period. A stroke was defined as rapidly developing signs of focal or global disturbance of cerebral function lasting ,24 hours with no apparent cause other than vascular. Exclusion criteria were age ,45 years, isolated transient ischemic attacks (TIAs), and history of previous stroke. Neurological status was assessed by the National Institutes of Health Stroke Scale. All patients underwent a CT scan on admission as part of standard stroke patient care. MRI (or CT when MRI was unperformable because of the presence of a metal implant or if the patient refused or was claustrophobic) was performed within 1 week from the onset of symptoms. Axial T1-,T2-, and proton density-weighted images were obtained with a 1.5-T MRI (Gyroscan ACS, NT Philips Medical Systems). Images were evaluated at a central ...
Whitman et al. (1) should be congratulated for their important contribution on the electrocardiogram (ECG) diagnosis of right ventricular hypertrophy (RVH). The authors database comprised 3,719 patients with normal left ventricular morphology and function who had an ECG and a cardiac magnetic resonance imaging-based assessment for RVH and were free of clinical cardiac disease, although some patients had hypertension, diabetes, or hypercholesterolemia. The authors implemented 22 ECG diagnostic criteria (Table 1 in their paper) and found that "a total of 6% had RVH, which was generally mild," and that the "ECG criteria were specific (many ,95%) but had low sensitivity…The positive predictive values were not sufficiently high as to be clinically useful (maximum 12%)" (Table 4 in their paper). Use of these criteria for the diagnosis of RVH may be different in patients with cardiac disease, although "the clinical usefulness of screening ECG would be precisely in individuals without a previous ...
Typical information available on T2-weighted sequences includes: the presence of increased fluid in acutely inflamed diseased tissue,which has high signal intensity; the presence of chronic non-inflammatory fibrotic tissue which has low signal intensity; and the presence of iron deposition or heme products, which has very low signal intensity.. ...
Our results demonstrate that QSM reduced the TE dependence of GRE MRI HV measurements from magnitude, SWI, and R2* images, providing a HV measurement independent of imaging parameters in GRE MRI.. This result is consistent with the report that QSM can provide a reliable measurement of the burden of cerebral microbleeds and is understood from physics underlying the GRE MRI data acquisition. Micro- and macrohemorrhages contain paramagnetic components (hemosiderins, methohemoglobins, etc.) that generate magnetic fields. Fields extending beyond their source locations cause blooming artifacts in GRE magnitude images. Blooming artifacts depend on phase accumulation, which is proportional to TE and local fields. Consequently, the SWI and R2* images are dependent on TE, resulting in TE-dependent overestimation in HV measurements from GRE MRI. Quantitatively, the magnetic field at a point in space, measurable from GRE phase images, is determined by convolving paramagnetic sources with the dipole kernel. ...
Nuclear magnetic resonance (NMR) can be used in-vivo in a vast array of applications, such as anatomical imaging (magnetic resonance imaging, MRI), localized chemical composition characterization (magnetic resonance spectroscopy, MRS), cellular structure assessment (diffusion tensor imaging, DTI) and cerebral activity mapping (functional imaging, fMRI) for the most important one. This thesis focused on the development of diffusion NMR spectroscopy and imaging methods at ultra-high magnetic field, with the aim of a better characterization of the diffusion mechanism in-vivo. DTI measures the water molecule displacement due to the thermal agitation in the sample. In cellular tissue, the molecules are restrained in compartments delimited by the cell membranes, which mean that DTI can provide information on the cerebral cellular microstructure. DTI is thus widely used to investigate cerebral disorders such as brain ischemia, trauma, and tumors, as well as the structural changes occurring during brain ...
Background: Previous studies have shown that the activity of the amygdala is elevated in people experiencing clinical and subclinical levels of anxiety and depression (negative affect). It has been proposed that a reduction in inhibitory input to the amygdala from the prefrontal cortex and resultant over-activity of the amygdala underlies this association. Prior studies have found relationships between negative affect and 1) amygdala over-activity and 2) reduced amygdala-prefrontal connectivity. However, it is not known whether elevated amygdala activity is associated with decreased amygdala-prefrontal connectivity during negative affect states. Methods: Here we used resting-state arterial spin labeling (ASL) and blood oxygenation level dependent (BOLD) functional magnetic resonance imaging (fMRI) in combination to test this model, measuring the activity (regional cerebral blood flow, rCBF) and functional connectivity (correlated fluctuations in the BOLD signal) of one subregion of the amygdala ...
TY - JOUR. T1 - Cervical degenerative disease at flexion-extension MR imaging. T2 - Prediction criteria. AU - Chen, Chi J.. AU - Hsu, Hui-Ling. AU - Niu, Chi Chien. AU - Chen, Tzu Yung. AU - Chen, Min C.. AU - Tseng, Ying C.. AU - Wong, Yon Cheong. AU - Wang, Li J.. PY - 2003/4/1. Y1 - 2003/4/1. N2 - PURPOSE: To determine if there are any neutral-position imaging criteria that can help predict functional cord impingement at flexion-extension cervical magnetic resonance (MR) imaging. MATERIALS AND METHODS: Sixty-two patients with cervical degenerative disease were evaluated with regard to the dynamic changes of canal stenosis at flexion-extension MR imaging. Functional cord impingement was considered if the cord was impinged or more impinged after neck flexion or extension. Selection criteria for neutral-position MR imaging, such as cervical curvature, canal space, degenerative stage, intramedullary high signal intensity on T2-weighted images, and resting instability, were evaluated for their ...
OBJECTIVE: The limbic structures in early-onset schizophrenia-spectrum illness (SZ) and bipolar disorder (BPD) were studied to discern patterns associated with diagnosis and sex. METHODS: Thirty-five youths with DSM-IV BPD without psychosis, 19 with BPD with psychosis, 20 with SZ, and 29 healthy controls (HC), similar in age (6-17 years) and sex, underwent structured and clinical interviews, neurological examination, and cognitive testing. Structural magnetic resonance images (MRIs) were acquired on a 1.5 Tesla, General Electric Signa Scanner. Differences in subcortical brain volumes, including the amygdala and hippocampus, were evaluated using two-way (diagnosis, sex) univariate analyses covarying for total cerebral volume and age. RESULTS: Youth with SZ and BPD showed no differences in amygdala and hippocampal volumes. However, boys with SZ had smallest left amygdala and girls with BPD had the smallest left hippocampal volumes. In exploratory analyses, SZ showed reduced thalamic volumes bilaterally
The cohort included 110 patients with a total of 121 masses. The mean tumor size was 2.4 cm, and 50% of the lesions were clear cell carcinoma.. The mpMRI studies were performed on both 1.5-tesla and 3-tesla MRI scanners at several institutions. Sequences included T2-weighted, axial chemical shift T1-weighted, and dynamic contrast enhanced T1-weighted imaging. Because diffusion-weighted MR images were routinely acquired at UT Southwestern -- but not always at other facilities -- the researchers did not evaluate results using that sequence (Journal of Urology, October 2017, Vol. 198:4, pp. 780-786).. Seven radiologists independently reviewed the results; the radiologists had different levels of experience and were blinded to the final pathology findings. Their task was to rank the likelihood of clear cell carcinoma on a six-point scale, with 1 as "definitely not" cancer and 5 as "definitely" cancer.. By setting a parameter score of 4 or greater for clear cell carcinoma, the researchers achieved ...
Nociceptive processing within the human brain takes place within two distinct and parallel systems: the lateral and medial pain systems. Current knowledge indicates that the lateral system is involved in processing the sensory-discriminative aspects of pain, and that the medial system is involved in processing the affective-motivational aspects of pain. Hemispheric differences in brain activation (lateralisation) during nociceptive processing were studied to further clarify the division of function between the lateral and medial pain systems. Hemispheric lateralisation was studied by applying painful CO(2) laser stimuli of 3-s duration sequentially to the left and right medial lower calves of five normal right-handed human subjects. The resultant brain activity was measured using 3-T functional magnetic resonance imaging, by determining significant changes in blood oxygen level dependent (BOLD) signal and applying a general linear modelling approach. Volumes of interest were defined for the primary and
Description of disease Abdominal MRI scan. Treatment Abdominal MRI scan. Symptoms and causes Abdominal MRI scan Prophylaxis Abdominal MRI scan
Poster: ECR 2019 / C-1999 / Role of Multiparametric MRI in Brainstem Lesions by: M. Harley, M. D. Patel, M. Bowen, W. Muhammad, S. Jacob, M. Douglas, I. Ughratdar, J. Herbert, V. Sawlani; Birmingham/UK
A 37-year-old Japanese man with a serum creatinine level of 2.5 mg/dL and hepatomegaly was admitted to our hospital for investigation of renal failure. Magnetic resonance imaging (MRI) showed hepatomegaly with small cystic lesions that had high signal intensity on T2-weighted images. There was no splenomegaly, and the kidneys were nearly normal in size with a few small cystic lesions. Renal biopsy revealed that interstitial fibrosis and tubular atrophy affected 60% of the cortex. There was cystic tubular dilation, mainly affecting the distal loop of Henle and distal tubules, since immunohistochemical staining of the dilated tubules was positive for cytokeratin 7 and Tamm-Horsfall protein but was negative for aquaporin 3 and CD10 ...
A higher frequency resolution enables a nuclear magnetic resonance tomography (NMR) for individual proteins, as demonstrated by a team led by Jörg Wrachtrup from the Max Planck Institute for Solid State Research and the University of Stuttgart.
TY - JOUR. T1 - A topography of executive functions and their interactions revealed by functional magnetic resonance imaging. AU - Fassbender, Catherine. AU - Murphy, K.. AU - Foxe, J. J.. AU - Wylie, G. R.. AU - Javitt, D. C.. AU - Robertson, I. H.. AU - Garavan, H.. PY - 2004/7/1. Y1 - 2004/7/1. N2 - We used fMRI to study the brain processes involved in the executive control of behavior. The Sustained Attention to Response Task (SART), which allows unpredictable and predictable NOGO events to be contrasted, was imaged using a mixed (block and event-related) fMRI design to examine tonic and phasic processes involved in response inhibition, error detection, conflict monitoring and sustained attention. A network of regions, including right ventral prefrontal cortex (PFC), left dorsolateral PFC (DLPFC) and right inferior parietal cortex, was activated for successful unpredictable inhibitions, while rostral anterior cingulate was implicated in error processing and the pre-SMA in conflict ...
A large-scale, coordinate-based meta-analysis of task-related deactivations was performed on studies archived in the BrainMap database to identify consistent nodes of the default mode network. Using ALE (Eickhoff et al., 2009b), DMN regions were identified in the precuneus, posterior and ventral anterior cingulate cortices, medial prefrontal cortex, bilateral inferior parietal lobules, bilateral middle temporal gyri, and left middle frontal gyrus. For each DMN node, behavioral profiles were constructed using BrainMap tools to quantitatively assess their functional attributes when active (not during rest), and MACM were created to identify dissociable patterns of functional connectivity when unconstrained by any specific task. MACM maps were compared to determine which DMN nodes had the greatest degree of connectivity with other nodes, yielding a meta-analytic model of connectivity between default mode regions. Behavioral profiles of node sets were tested to determine significant functional ...
An application which greatly benefits from Ultra High Field (UHF) MRI is Blood Oxygenation Level Dependent (BOLD) fMRI. The increased susceptibility effects at UHF translate into a greater observable BOLD signal change and therefore improved fMRI experiments [1], as demonstrated in rat forepaw stimulation study at 15.2 Tesla, where an over 11% BOLD response was seen [2]. Functional MRI is used to study functional connectivity to further understand brain function in health and disease [3]. Using the high sensitivity provided by UHF, high resolution fMRI preclinical experiments thus become feasible [4]. Forepaw somatosensory stimulation, for example, only commonly shows BOLD response in S1FL. A recent study at 9.4 T and 15.2 T, however, detected only S1FL response at 9.4 T, but S2 and thalamus as well as S1FL at 15.2 T [5]. Functional sensitivity will additionally benefit from UHF in situations where thermal noise is dominant, as it is directly dependent on sensitivity and indirectly dependent on ...
The objective of this study was to investigate how acetylcholinesterase inhibitor (ChEI) treatment affects brain function in Parkinsons disease (PD). Twelve patients with PD and either dementia or mild cognitive impairment underwent task-free functional magnetic resonance imaging before and after 3 months of ChEI treatment and were compared with 15 age- and sex-matched neurologically healthy controls. Regional spontaneous brain activity was measured using the fractional amplitude of low-frequency fluctuations. At baseline, patients showed reduced spontaneous brain activity in regions important for motor control (eg, caudate, supplementary motor area, precentral gyrus, thalamus), attention and executive functions (eg, lateral prefrontal cortex), and episodic memory (eg, precuneus, angular gyrus, hippocampus). After treatment, the patients showed a similar but less extensive pattern of reduced spontaneous brain activity relative to controls. Spontaneous brain activity deficits in the left ...
Blood oxygenation level dependent (BOLD) functional magnetic resonance imaging (fMRI) is a powerful approach to defining activity in the healthy and diseased human brain. BOLD fMRI detects local increases in relative blood oxygenation that are most probably a direct consequence of neurotransmitter action and thus reflect local neuronal signalling. The method allows localisation to volumes of the order of a few to several cubic millimetres and can be used in serial studies of individual subjects. Basic approaches to experimental design and analysis are reviewed briefly, as well as potential clinical applications. The latter include three broad areas: anatomical characterisation of normal or pathological patterns of brain functioning; distinguishing pathological traits; and monitoring treatment responses. New research is emphasising the integration of fMRI with other techniques, particularly electrophysiological. In conjunction with MRI methods for characterising pathological load, fMRI promises a refined
SEEG recordings of Patient 1. (A) Location of the SEEG electrodes used to investigate the left hemisphere, shown on the sagittal planes of 3D CT/MRI fusion images. Electrode entry points are represented as circles or lines that correspond to orthogonal or to oblique electrode trajectories, respectively. Electrode Y was used to investigate the posterior insula (internal contacts) and hand SI area (lateral contacts); R the superior insula (INS) and face MI area; M the cingulate motor area (CMA) and the premotor part of the superior frontal gyrus (SFG BA6, residual lesion on MRI); S the supplementary motor area (SMA), the premotor part of the superior frontal sulcus (SFS BA6, residual lesion on MRI) and the premotor part of the middle frontal gyrus; X the anterior insula, as well as the premotor parts of the inferior frontal sulcus (IFS BA6) and of the middle frontal gyrus; G the anterior insula and the frontal operculum (FOp); and H the pre-supplementary motor area (preSMA) and the premotor ...
Neuroimaging studies have revealed that low-back pain (LBP) alters spatiotemporal dynamics of the blood oxygen level-dependent signal in response to persistent noxious stimulus. This study aimed to investigate changes in spontaneous neural activity of various brain regions in acute LBP using resting...
To determine whether frontal lobe regions, including Brocas area, dorsolateral prefrontal cortex (DLPFC) and supplementary motor area (SMA), are differentially activated during lexical and semantic language tasks, we used functional magnetic resonance imaging in eight healthy right-handed subjects silently performing two semantic tasks (adjective and verb generation) and a lexical retrieval task (noun recall). Activation was observed in Brocas area, DLPFC and SMA for all tasks. Brocas area activation was approximately doubled during the semantic tasks compared with the lexical task (verbs vs nouns: 19.1 ± 4.5 vs 8.9 ± 1.6 voxels, p = 0.02; adjectives vs nouns 24.4 ± 7.5 vs 10.1 ± 2.8 voxels, p = 0.04); however, there were no significant differences in the DLFPC or SMA across tasks. We conclude that Brocas area is more active during tasks that have a semantic content, whereas areas involved in preparatory processing (SMA) and memory retrieval (DLPFC) are engaged equally during both types ...
Previous imaging studies that investigated morphometric group differences of subcortical regions outside the substantia nigra between non-demented Parkinsons patients and controls either did not find any significant differences, or reported contradictory results. Here, we performed a comprehensive morphometric analysis of 20 cognitively normal, early-stage PD patients and 19 matched control subjects. In addition to relatively standard analyses of whole-brain grey matter volume and overall regional volumes, we examined subtle localized surface shape differences in striatal and limbic grey matter structures and tested their utility as a diagnostic marker. Voxel-based morphometry and volumetric comparisons did not reveal significant group differences. Shape analysis, on the other hand, demonstrated significant between-group shape differences for the right pallidum. Careful diffusion tractography analysis showed that the affected parts of the pallidum are connected subcortically with the subthalamic
The ability to stop motor responses depends critically on the right inferior frontal cortex (IFC) and also engages a midbrain region consistent with the subthalamic nucleus (STN). Here we used diffusion-weighted imaging (DWI) tractography to show that the IFC and the STN region are connected via a white matter tract, which could underlie a hyperdirect pathway for basal ganglia control. Using a novel method of triangulation analysis of tractography data, we also found that both the IFC and the STN region are connected with the presupplementary motor area (preSMA). We hypothesized that the preSMA could play a conflict detection/resolution role within a network between the preSMA, the IFC, and the STN region. A second experiment tested this idea with functional magnetic resonance imaging (fMRI) using a conditional stop-signal paradigm, enabling examination of behavioral and neural signatures of conflict-induced slowing. The preSMA, IFC, and STN region were significantly activated the greater the
NBD can be defined as meningoencephalitis with predilection for brainstem, basal ganglia and thalamus, subcortical white matter damage and spinal cord lesions.1 Well-known conventional MRI features of acute/subacute parenchymal NBD include hyperintense lesions on T2WI with contrast enhancement on T1-weighted imaging. These lesions tend to resolve or decrease in size in the chronic phase.2 The DWI findings in NBD are (A) hyperintensity with ADC values (possibly due to vasogenic oedema and vasculitis) in acute/active disease2 and (B) hyperintensity on DWI with decreased ADC value (due to cytotoxic oedema following ischaemic changes caused by vasculitis) in subacute NBD.3 Furthermore, chronic lesions may show high ADC values consistent with demyelisation or reactive gliosis.2 ...
Based on the basic principle of MR imaging, the different content of water hydrogen nuclei in different organizations results in different image contrast along the longitudinal and transverse planes of the applied magnetic field. Consequently, like other MRI contrast agents that can increase the MRI signal intensity by shortening the hydrogen longitudinal relaxation time (T1) or decreasing the signal intensity by shortening the hydrogen transverse relaxation time (T2), as a superparamagnetic contrast agent, SPIO can significantly decrease the signal intensity by shortening the hydrogen transverse relaxation time (T2) and can cause darkening of the interfered regions. A normal lymph node with phagocytic function can take a substantial amount of contrast agent particles and, therefore, significantly reduce the T2 signal intensity of MRI. However, in the metastasis of lymph nodes, the macrophages are decreased due to the normal tissue being replaced by tumor cells [13, 20, 21], the fewer macrophage ...
A segmentation framework is proposed to determine the wall thickness, carotid artery plaque volume as morphological markers. MRI features, NMR peaks, oxida
The intrinsic functional connectivity networks of human lateral frontal cortex are displayed for a 4-mm seed region that is gradually moved along the cortical surface. The functional connectivity networks are estimated on the surface using resting-state functional MRI data from 1000 young adults. The seed region begins in a region at or near the human homologue of FEF and gradually moves through distinct lateral frontal regions including those primarily coupled to limbic regions. The borders reflect estimates of networks from the 17-network parcellation of Yeo et al. (2011; see Figure 13). Note that multiple interdigitated networks converge on contiguous regions of frontal cortex. Some of these regions are embedded within sensory-motor circuits; others are absent coupling to sensory or motor regions and are embedded within networks comprising what has come to be known as the default network. Thus, human lateral frontal cortex represents a nexus of multiple, interdigitated association pathways. ...
The intrinsic functional connectivity networks of human lateral frontal cortex are displayed for a 4-mm seed region that is gradually moved along the cortical surface. The functional connectivity networks are estimated on the surface using resting-state functional MRI data from 1000 young adults. The seed region begins in a region at or near the human homologue of FEF and gradually moves through distinct lateral frontal regions including those primarily coupled to limbic regions. The borders reflect estimates of networks from the 17-network parcellation of Yeo et al. (2011; see Figure 13). Note that multiple interdigitated networks converge on contiguous regions of frontal cortex. Some of these regions are embedded within sensory-motor circuits; others are absent coupling to sensory or motor regions and are embedded within networks comprising what has come to be known as the default network. Thus, human lateral frontal cortex represents a nexus of multiple, interdigitated association pathways. ...
A key challenge in functional neuroimaging is the meaningful combination of results across subjects. Even in a sample of healthy participants, brain morphology and functional organization exhibit considerable variability, such that no two individuals have the same neural activation at the same location in response to the same stimulus. This inter-subject variability limits inferences at the group-level as average activation patterns may fail to represent the patterns seen in individuals. A promising approach to multi-subject analysis is group independent component analysis (GICA), which identifies group components and reconstructs activations at the individual level. GICA has gained considerable popularity, particularly in studies where temporal response models cannot be specified. However, a comprehensive understanding of the performance of GICA under realistic conditions of inter-subject variability is lacking. In this study we use simulated functional magnetic resonance imaging (fMRI) data to ...
A system and method for facilitating RF pulse sequence generation and modification and for real-time sequence input modification for use in conjunction with magnetic resonance imaging equipment. A graphical user interface is provided through a display coupled to a digital computer operating as the primary control system for a magnetic resonance imaging scanner and associated hardware. Through the graphical user interface, an operator may choose or design sequences of radiofrequency pulses, gradient waveforms and other input parameters for the magnetic resonance imaging apparatus. Real-time information is also communicated to the operator through the graphical user interface allowing for real-time manipulation of the magnetic resonance imaging inputs and for displaying the magnetic resonance response thereto.
Magnetic resonance imaging (MRI) is a sensitive technique for assessing white matter (WM) lesions in multiple sclerosis (MS), but there is a low correlation between MRI findings and clinical disability. Because of this, other pathological changes are of interest, including changes in normal appearing white matter (NAWM) and diffusely abnormal white matter (DAWM). Even so, the mechanisms leading to permanent disability in MS remain unclear.. In contrast to conventional MRI, quantitative MRI (qMRI) is aimed at the direct measurement of the physical tissue properties, such as the relaxation times, T1 and T2, as well as the proton density (PD). QMRI is promising for characterising and quantifying changes in MS and for brain tissue segmentation.. The present work describes a novel method of qMRI for the human brain (QMAP), and a segmentation method based on this. The developed methods were validated in control subjects and MR phantoms. Furthermore, an application in diseased human brain was ...
The refurbished GE EchoSpeed Plus 1.5 T MRI machine is a high resolution 4 channel, whole body imaging system known for its excellent performance. The magnet is Short Bore LCC/K4 which has a zero boil off technology. This used GE EchoSpeed Plus 1.5 T MRI Scanner is uniquely designed with a dock able table that allows for patient preparation and transportation outside the exam room. Moreover, your same GE EchoSpeed Plus 1.5 T MRI scanner can be upgraded to Signa Excite or any other higher models like Signa HD, Signa HDx or Signa HDxt. The magnet will remain the same. Only the Electronics, Coils and Computer will be changed. So if you have a limited budget now, you can go for this model now with an eye on the upgrade economically. ...
To the Editor,. In the last decade, stress cardiac magnetic resonance (CMR) imaging has become well-established as an excellent technique for the diagnosis and prognostic stratification of patients with acute or chronic ischemic heart disease.. The main advantages of CMR over other stress techniques relate to the high spatial and temporal resolution (superior to myocardial perfusion scintigraphy), the lack of ionizing radiation, and the high-quality images that are not limited by an echocardiographic window. Stress CMR is diagnostic in more than 97% of cases1 and can be successfully performed and interpreted in 95% of patients with a body mass index ≥ 30. The images allow diagnosis of subendocardial ischemia, nontransmural necrosis, viable myocardium, and dysfunctional myocardium in patients with ischemic heart disease.. Another advantage of stress CRM is its safety and low complication rate. A recent study by Monmeneu et al.,1 which included 11 984 patients, showed a nonsevere complication ...
Abstract: : Purpose: To compare the BOLD (Blood Oxygen Level Dependant) responses to magnocellular (M) and parvocellular (P) biased stimuli in normal subjects using functional magnetic resonance imaging (fMRI). Methods: Seven normal subjects underwent fMRI scanning. The M-biased stimulus was a 60 black and white chequerboard reversing at 10 Hz (50% duty cycle). The P-biased stimulus was a 10 black and white chequerboard, reversing at 2 Hz (50% duty cycle). The fMRI paradigm was an on/off design with a 21 second on and 21 second off period. The viewing distance was 2 metres with a visual field of 13 degrees. Stimuli were presented at 5, 10, 20, 40 and 80% contrast and were viewed monocularly using a mirror mounted on the head coil of the magnet. Scans were performed in a 1.5 Tesla scanner and analysed using in-house software (1). Analysis of variance was performed using the F-test. Results: The M-biased stimulus produced significant activation of V1at all contrast levels, with the exception of ...
Phosphatidylinositol 3-kinases (PI3Ks) have recently been implicated in apoptosis and ischemic cell death. We tested the efficacy of early intervention with a peptide PI3K activator in focal cerebral ischemia. After determining the most effective dose (24 mu g/kg) and time window (2 h after MCAO) of treatment, a total of 48 rats were subjected to middle cerebral artery occlusion (MCAO). Diffusion weighted MRI (DWI) was performed 1 h after MCAO and rats with lesion sizes within a predetermined range were randomized to either PI3K activator or vehicle treatment arms. Fluid attenuated inversion recovery (FLAIR) MRI, neurological function, western blots, and immunohistochemistry were blindly assessed. Initial DWI lesion volumes were nearly identical between two groups prior to treatment. However, FLAIR showed significantly smaller infarct volumes in the PI3K activator group compared with vehicle (146 +/- 81 mm(3) and 211 +/- 96 mm(3), p = 0.045) at 48 h. The PI3K activator group also had better ...
Magnetic Resonance Imaging - MedHelps Magnetic Resonance Imaging Center for Information, Symptoms, Resources, Treatments and Tools for Magnetic Resonance Imaging. Find Magnetic Resonance Imaging information, treatments for Magnetic Resonance Imaging and Magnetic Resonance Imaging symptoms.
THURSDAY, Oct. 11, 2018 (HealthDay News) - Common carotid artery (CCA) wall thickness measured using magnetic resonance imaging (MRI) is more consistently associated with incident cardiovascular disease (CVD) outcomes than intima-media thickness measured by ultrasound, according to a study published online Oct. 9 in Radiology.. Yiyi Zhang, Ph.D., from the Johns Hopkins University Bloomberg School of Public Health in Baltimore, and colleagues conducted a prospective study involving 698 participants without a history of clinical cardiovascular disease from the Multi-Ethnic Study of Atherosclerosis. CCA wall thickness was measured with ultrasound and with non-contrast proton density-weighted and intravenous gadolinium-enhanced MRI. The correlations between wall thickness measured with ultrasound and MRI were assessed with CVD outcomes.. The researchers found that per standard deviation increase in intima-media thickness, the adjusted hazard ratios for coronary heart disease, stroke, and CVD were ...
This chapter focuses on potential confounding factors in the interpretation of the blood oxygen level dependent (BOLD) signal in fMRI studies of cognitive aging. Studies generally attribute age-related changes in BOLD signal to age-related changes in neural activity, thereby assuming that the coupling between BOLD signal and neural activity is the same for young and older adults. However, this coupling may be altered by age-related changes in the neurovascular system and by comorbidities associated with aging. Age-related changes of the neurovascular system likely to affect the BOLD signal include changes in ultrastructure (e.g., sclerosis), resting cerebral blood flow (CBF), vascular reactivity, and cerebral metabolic rate of oxygen consumption. The BOLD signal may also be affected by comorbidities associated with aging, such as leukoariosis and small strokes, and by medications. ...
AbstractObjective: Early-onset Parkinsons disease (EOPD) is distinct from late-onset PD (LOPD) as it relates to the clinical profile and response to medication. The objective is to investigate whether characteristics of spontaneous brain activity in the resting state are associated with the age of disease onset. Methods: We assessed the correlation between neural activity and age-at-onset in a sample of 39 PD patients (18 EOPD and 21 LOPD) and 37 age-matched normal control subjects. Regional homogeneity (ReHo) approaches were employed using ANOVA with two factors: PD and age.Results: In the comparisons between LOPD and EOPD, EOPD revealed lower ReHo values in the right putamen gyrus and higher ReHo values in the left superior frontal gyrus. Compared with age-matched control subjects, EOPD exhibited lower ReHo values in the right putamen and higher ReHo values in the left inferior temporal gyrus; however, LOPD showed lower ReHo values in the right putamen and left insula. The ReHo values were negatively
The University Hospital at the University of Navarra and the Applied Medicine Research Centre (CIMA) of the University has recently acquired a 3 Teslas magnetic resonance imager for joint use, the first for research applications in Spain. The 3 Teslas is the magnetic resonance imaging unit with the highest strength currently permitted by international medical bodies for the morphological study of the human body.
Purpose: Pancreatic cancer is one of the cancers with the poorest survival prognosis. At the time of diagnosis most of pancreatic cancers are unresectable and those patients can be treated by radiotherapy. Radiotherapy for pancreatic cancer is limited due to uncertainties in CT-based delineations. MRI provides an excellent soft tissue contrast. Here, an MR protocol is developed to improve delineations for radiotherapy treatment of pancreatic cancer. In a later stage this protocol can also be used for on-line visualization of the pancreas during MRI guided treatments. Methods: Nine pancreatic cancer patients were included. The MR protocol included T2 weighted(T2w), T1 weighted(T1w), diffusion weighted(DWI) and dynamic contrast enhanced(DCE) techniques. The tumor was delineated on T2w and T1w MRI by an experienced radiation oncologist. Healthy pancreas or pancreatitis (assigned by the oncologist based on T2w) areas were also delineated. Apparent diffusion coefficient(ADC), and area under the ...
A paramagnetic oil emulsion for magnetic resonance imaging composed of about 5 to about 30 volume percent oil and about 70 to about 95 volume percent aqueous-based paramagnetic agent carrier, at least one of the aqueous-based paramagnetic agent carrier and the oil having dissolved therein a magnetic resonance image contrast effective and less than a toxic amount of at least one soluble paramagnetic agent. The paramagnetic oil emulsion provides high intensity magnetic resonance signals in the gastrointestinal tract for MRI evaluation of the abdomen and pelvis, particularly in the distal bowel regions.
The relationship between neurophysiological and cerebrovascular-metabolic findings in patients affected by severe cerebrovascular deficits was investigated by comparing magnetoencephalographic (MEG-evoked fields) and blood oxygen level-dependent functional MRI (BOLD fMRI) responses to median nerve electric stimulation. Despite the use of identical stimuli, the two techniques elicited always-detectable responses in the control group (10 subjects), but demonstrated uncorrelated activation properties in our patient sample (10 subjects). All patients showed clear MEG signals in both the affected and unaffected hemispheres, indicating well synchronized, stimulus-locked firing of neurons in the primary sensorimotor cortex, but some patients showed no fMRI activation in either the affected or the unaffected hemisphere. In order to clarify the origin of this uncoupling, we investigated the possible role of lesion site, white matter hyperintensities, current medication, risk factors, anatomy of the neck ...
Objectives: Advances in multiparametric magnetic resonance imaging (mpMRI) and ultrasound/MRI fusion imaging offer a powerful alternative to the typical undirected approach to diagnosing prostate cancer. However, these methods require the time and expertise needed to interpret mpMRI image scenes. In this paper, a machine learning framework for automatically detecting and localizing cancerous lesions within the prostate is developed and evaluated. Methods: Two studies were performed to gather MRI and pathology data. The 12 patients in the first study underwent an MRI session to obtain structural, diffusion-weighted, and dynamic contrast enhanced image vol- umes of the prostate, and regions suspected of being cancerous from the MRI data were manually contoured by radiologists. Whole-mount slices of the prostate were obtained for the patients in the second study, in addition to structural and diffusion-weighted MRI data, for pathology verification. A 3-D feature set for voxel-wise appear- ance ...
Define functional magnetic resonance imaging: magnetic resonance imaging used to detect physical changes (as of blood flow) in the brain resulting…
A magnetic resonance imaging receiver system for producing high resolution images of the foot and ankle regions of a human subject. The magnetic resonance imaging receiver comprises an antenna for receiving resonance signals produced by a magnetic resonance imaging, radio frequency excitation magnetic apparatus, a free standing foot cradle assembly for supporting and rigidly holding the foot and ankle of the subject, and a tuning/impedance matching circuit for providing for the maximum transfer of radio frequency energy from the antenna to the receiver unit in the magnetic resonance imaging, radio frequency excitation magnet apparatus. 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.
The neural circuit underlying blue-yellow color vision in the rat was investigated using high resolution functional magnetic resonance imaging (fMRI) under a variety of stimulus conditions. Rodents and other mammals share evolutionarily conserved neural circuits for processing the output of two classes of spectrally distinct cone photoreceptor. Unlike other mammals, their availability combined with their brain and body size make them ideal subjects for experiments using a high field strength 9.4T MRI system coupled with pharmacological intervention. Herein, the well established agonist of metabotropic glutamate receptors, 2-amino-4-phosphonobutyric acid (APB), was used intravitreously to block the ON-pathways in the rat retina. A computer controlled binocular visual stimulator was designed to operate in the MRI scanner. Light from arrays of colored LEDs was delivered via fiber optic bundles to produce binocular stimulation. fMRI responses were compared under stimulus conditions that isolated ...
Brain morphometry is a subfield of both morphometry and the brain sciences, concerned with the measurement of brain structures and changes thereof during development, aging, learning, disease and evolution. Since autopsy-like dissection is generally impossible on living brains, brain morphometry starts with noninvasive neuroimaging data, typically obtained from magnetic resonance imaging (or MRI for short). These data are born digital, which allows researchers to analyze the brain images further by using advanced mathematical and statistical methods such as shape quantification or multivariate analysis. This allows researchers to quantify anatomical features of the brain in terms of shape, mass, volume (e.g. of the hippocampus, or of the primary versus secondary visual cortex), and to derive more specific information, such as the encephalization quotient, grey matter density and white matter connectivity, gyrification, cortical thickness, or the amount of cerebrospinal fluid. These variables can ...
BACKGROUND: The cerebrovascular reactivity (CVR) results of blood oxygen level-dependent (BOLD) and arterial spin labeling (ASL) MRI studies performed in patients with cerebrovascular disease (steno-occlusive vascular disease or stroke) were systematically reviewed. SUMMARY: Thirty-one articles were included. Twenty-three (74.2%) studies used BOLD MRI to evaluate the CVR, 4 (12.9%) studies ... read more used ASL MRI and 4 (12.9%) studies used both BOLD and ASL MRI. Thirteen studies (3 significant) found a lower BOLD CVR, 2 studies found a similar CVR and 3 studies found a higher CVR in the ipsilateral compared to the contralateral hemisphere. Nine (5 significant) out of 10 studies found a lower BOLD CVR in the ipsilateral hemispheres of patients compared to controls. Six studies (2 significant) found a lower ASL CVR in the ipsilateral compared to the contralateral hemispheres. Three out of 5 studies found a significant lower ASL CVR in the ipsilateral hemispheres of patients compared to ...
Magnetic resonance mammography (MRM) has been used in clinical diagnosis over the last few decades, especially among high-risk community. There is a critical need for developing a real-time computer-aided diagnosis (CAD) system for the efficient diagnosis of breast cancer to improve the workflow of radiologists, limiting the number of clinical visits a patient makes before the final diagnosis is made. This thesis aims to develop such a CAD system that processes images obtained from dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) to aid the diagnosis of breast cancer, as it is known to differentiate between benign and malignant lesions. A DCE-MRI study involves injection of a contrast agent immediately prior to the image acquisitions. The presence of contrast agent within an imaging voxel would result in an increased signal that can be observed over the time course of the experiment. Different pathological characteristics of tissues present different localized dynamic responses. ...
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: ...
TY - CONF. T1 - Reward networks changes in the brain of pathological gamblers: a resting state functional magnetic resonance imaging study. AU - Gagliardo, Cesare. AU - La Barbera, Daniele. AU - Piccoli, Tommaso. AU - Marrale, Maurizio. AU - Lagalla, Roberto. AU - Maniaci, Giuseppe. AU - Cannizzaro, Carla. AU - Collura, Giorgio. AU - La Tona, Giuseppe. PY - 2018. Y1 - 2018. N2 - Aims and objectivesTo investigate functional connectivity changes in pathological gamblers (PGs) in comparison to healthy controls (HCs) by means of resting state functional Magnetic Resonance Imaging (RS-fMRI).Methods and materialsThirteen HCs and fourteen PGs were recruited (all right handed males; drugs free; mean age 35.96±9.56). All subjects underwent brain scan using a 1,5T MRI scanner. Activations data of functionally linked brain regions were obtained using a multi-session temporal concatenated Independent Component Analysis (concat-ICA). The resulted components were than matched and compared between groups. ...
Imaging of facial nerve schwannomas includes both MRI and CT. On noncontrast temporal bone CT, the findings include a tubular soft tissue mass along the course of the facial nerve with enlargement of the facial nerve canal. The bony margins are usually smooth and benign-appearing. On MRI, these lesions have intermediate to low signal intensity on T1-weighted imaging and high signal intensity on T2-weighted imaging. Following the administration of intravenous gadolinium, facial nerve schwannomas enhance homogenously. The differential diagnosis includes normal intratemporal facial nerve enhancement, Bells palsy, facial nerve hemangioma, and facial nerve perineural parotid malignancy. Based on clinical presentation, facial nerve schwannoma can be distinguished from Bells palsy and a hemangioma by a more gradual onset of facial nerve paralysis vs an acute onset in these other entities. Normal facial nerve enhancement is asymptomatic, and facial nerve perineural parotid malignancy is associated ...
Investigators at Childrens Hospital of Montefiore, Albert Einstein College of Medicine, NY, determined the incidence of posterior reversible encephalopathy syndrome (PRES) in a pediatric critical care unit. Ten patients ,21 years of age with PRES (incidence of 1 in 259 admissions, 0.4%) were studied. Nine patients presented with generalized tonic and/or clonic seizures. Continuous EEG showed generalized slowing but no epileptiform activity. Risk factors included hypertension, cytotoxin medication use, and anemia. Comorbidities included systemic lupus erythematosus, inflammatory bowel disease, ulcerative colitis, liver cirrhosis, pulmonary embolism, renal insufficiency, septic shock, and acute chest syndrome. One-year follow-up showed no residual neurological deficits and resolution of white matter signal abnormalities on neuroimaging. [1]. COMMENT. PRES, also referred to as hypertensive encephalopathy or reversible posterior leukoencephalopathy syndrome, is a clinical syndrome that results from ...
This study reviews the literature on the anatomy of the connective tissues surrounding the distal interphalangeal joint and further characterizes the three-dimensional relationships of these structures with ultra-high field magnetic resonance imaging. Ten cadaver fingers, fixed in a solution of 5% agar and 4% formalin, were imaged utilising an ultrashield 16.4 Tesla ultra-high field magnetic resonance imaging, yielding a total of 4000 images. Images were analysed using Osirix™ (version 5.5.1 32 bit edition) for three-dimensional reconstruction. We found numerous conflicting descriptions of the connective tissue structures around the distal interphalangeal joint. Based upon our literature review and imaging studies we have defined precisely Clelands ligaments, the oblique proximal septum, Graysons ligaments, the dorsal plate, and the interosseous ligaments of the distal interphalangeal joint ...
Posterior reversible encephalopathy syndrome is a clinico-neuroradiological entity characterized by headache, vomiting, altered mental status, blurred vision and seizures with neuroimaging studies demonstrating white-gray matter edema involving predominantly the posterior region of the brain. We report a 47-year-old Caucasian man with liver cirrhosis who developed posterior reversible encephalopathy syndrome following an upper gastrointestinal hemorrhage and who was managed with induced hypothermia for control of intracranial hypertension and continuous veno-venous hemodiafiltration for severe hyperammonemia. We believe this is the first documented case report of posterior reversible encephalopathy syndrome associated with cirrhosis as well as the first report of the use of induced hypothermia and continuous veno-venous hemodiafiltration in this setting.
Spinal cord infarction (SCI) is a rare type of stroke. The initial magnetic resonance imaging (MRI) is usually normal and can mimic the presentation of the acute transverse myelitis (ATM), acute inflammatory demyelinating polyneuropathy, and compressive myelopathies from neoplasm, epidural or subdural hematoma, or abscess. The aim of this report is to describe and discuss the case of a patient with SCI presenting as a diagnostic confusion with acute transverse myelitis. A 64-year-old male with a medical history of hypertension presented with an acute onset of urinary retention with lower limb weakness. Based on the initial MRI and evaluation, a diagnosis of acute transverse myelitis was made. Despite thorough evaluation, the etiology of transverse myelitis was undetermined. Hence, the MRI of the thoracic spine was repeated which showed patchier enhancements of the vertebral body with features suggestive of the spinal cord and vertebral body infarction. Thus, a repeat MRI is required to make an accurate
RETIEF, Chris; SCHUTTE, Clara-Maria and BAKER, Malcolm Kevin. Cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy (CADASIL). SAMJ, S. Afr. med. j. [online]. 2009, vol.99, n.6, pp.461-465. ISSN 2078-5135.. BACKGROUND: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leuco-encephalopathy (CADASIL) is a hereditary autosomal dominant non-atherosclerotic non-amyloid cerebral arteriopathy. The disease was identified in 1993. We are not aware of reports in the literature of its occurrence in South Africa, and we present the clinical and laboratory features of 5 patients with CADASIL. METHODS: Patients with the characteristic radiological white matter disease and typical features (family history, ischaemic events, migraine or dementia) were evaluated for possible CADASIL by means of clinical examination, routine investigations for strokes, magnetic resonance imaging, skin biopsy electron microscopy, evoked potentials and ...
Posterior reversible encephalopathy syndrome (PRES) is a neurotoxic clinico-radiological diagnosis typically presenting with headache, encephalopathy and visual disturbance accompanied by a unique neuroradiological pattern of symmetrical parieto-occi

MRI Scans: MedlinePlusMRI Scans: MedlinePlus

Magnetic resonance imaging (MRI) uses a large magnet and radio waves to look at organs and structures inside the body. Read ... Magnetic Resonance Imaging (International Society for Magnetic Resonance in Medicine) * Magnetic Resonance Imaging (MRI) ( ... Magnetic Resonance Imaging (MRI) (For Parents) (Nemours Foundation) * Magnetic Resonance Imaging (MRI): Brain (For Parents) ( ... Magnetic Resonance Imaging (MRI) Safety (American College of Radiology, Radiological Society of North America) Also in Spanish ...
more infohttps://medlineplus.gov/mriscans.html

Magnetic resonance imagingMagnetic resonance imaging

MAGNETIC RESONANCEMAGNETIC RESONANCE IMAGINGIMAGING Dr.Shahzad Ahmad DaulaDr.Shahzad Ahmad Daula MID,DMLT,DDC The University of ... Magnetic resonance imaging * 1. MAGNETIC RESONANCEMAGNETIC RESONANCE IMAGINGIMAGING Dr.Shahzad Ahmad DaulaDr.Shahzad Ahmad ... MR SPECTROSCOPY  Magnetic resonance spectroscopy (MRS) is a means of noninvasive physiologic imaging of the brain that ... MRI isbased on theprincipleof nuclear magnetic resonance.MRI isbased on theprincipleof nuclear magnetic resonance.  Two basic ...
more infohttps://www.slideshare.net/shahzadahmaddaula/magnetic-resonance-imaging-44654180

Cardiac magnetic resonance imaging - WikipediaCardiac magnetic resonance imaging - Wikipedia

Cardiovascular magnetic resonance imaging (CMR), sometimes known as cardiac MRI, is a medical imaging technology for the non- ... "4D flow cardiovascular magnetic resonance consensus Statement, Dyverfeldt et. al". Journal of Cardiovascular Magnetic Resonance ... Cardiac magnetic resonance imaging. An example of CMR movies in different orientations of a cardiac tumor - in this case, an ... MRA (magnetic resonance angiography) can produce 3D and 4D images of blood vessels and the flow of blood through the vessels. ...
more infohttps://en.wikipedia.org/wiki/Cardiac_magnetic_resonance_imaging

Functional magnetic resonance imaging - WikipediaFunctional magnetic resonance imaging - Wikipedia

"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 ...
more infohttps://en.wikipedia.org/wiki/FMRI

Magnetic Resonance Imaging (MRI): BrainMagnetic Resonance Imaging (MRI): Brain

... a safe and painless test that produces detailed images of the brain and the brain stem, can help detect cysts, tumors, bleeding ... Magnetic Resonance Imaging (MRI): Brain. Resources. Please Note: By clicking a link to any resource listed on this page, you ... Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com. ...
more infohttp://kidshealth.org/en/parents/mri-brain.html?view=rr

Magnetic Resonance ImagingMagnetic Resonance Imaging

... images. *develop your ability to critically analyse and evaluate a broad range of magnetic resonance (MRI) imaging applications ... Postgraduate provision in Medical Imaging at the University of Bradford has long been established and is known for its quality ... The module is designed to support healthcare practitioners develop the knowledge, understanding and skills in medical imaging ... production and presentation of magnetic resonance (MRI) ... based on case studies with accompanying medical images.. All ...
more infohttps://www.bradford.ac.uk/courses/cpd/magnetic-resonance-imaging/

magnetic resonance imaging (MRI)magnetic resonance imaging (MRI)

Magnetic resonance imaging is a non-invasive medical diagnostic technique that gives high-quality cross-sectional or 3D images ... Magnetic resonance imaging (MRI) is a non-invasive medical diagnostic technique that gives high-quality cross-sectional or ... MRI also produces detailed images of the heart and major blood vessels (see cardiac MRI), provides images of blood flow, and is ... MRI provides clear images of tumors of the brain and spinal cord. Also shown clearly by MRI is the internal structure of the ...
more infohttp://www.daviddarling.info/encyclopedia/M/magnetic_resonance_imaging.html

Magnetic Resonance Imaging News, ResearchMagnetic Resonance Imaging News, Research

Magnetic Resonance Imaging News and Research. RSS Magnetic resonance imaging (MRI) is an imaging technique which physicians use ... New method can improve resolution of brain magnetic resonance imaging using artificial intelligence Researchers of the ICAI ... Researchers at Osaka University have developed a computer method that uses magnetic resonance imaging (MRI) and machine ... have designed an unprecedented method that is capable of improving brain images obtained through magnetic resonance imaging ...
more infohttps://www.news-medical.net/?tag=/Magnetic-Resonance-Imaging

Magnetic Resonance Imaging (MRI): Cervical SpineMagnetic Resonance Imaging (MRI): Cervical Spine

Magnetic resonance imaging (MRI) of the cervical spine is a safe and painless test that uses a magnetic field and radio waves ... Images provided by iStock, Getty Images, Corbis, Veer, Science Photo Library, Science Source Images, Shutterstock, and Clipart. ... The MRI images will be looked at by a radiologist whos specially trained in interpreting the scans. The radiologist will send ... These images can be converted into three-dimensional (3-D) pictures of the scanned area. This helps pinpoint problems in the ...
more infohttp://kidshealth.org/NemoursXML/en/parents/test-mri-spine.html

Nuclear magnetic resonance imaging. | The BMJNuclear magnetic resonance imaging. | The BMJ

Nuclear magnetic resonance imaging. Br Med J (Clin Res Ed) 1987; 295 :390 ... Nuclear magnetic resonance imaging.. Br Med J (Clin Res Ed) 1987; 295 doi: https://doi.org/10.1136/bmj.295.6594.390-a ( ...
more infohttp://www.bmj.com/content/295/6594/390.2/related

Functional magnetic resonance imaging | medicine | Britannica.comFunctional magnetic resonance imaging | medicine | Britannica.com

Functional magnetic resonance imaging (fMRI), neuroimaging technique used in biomedical research and in diagnosis that detects ... To examine brain activity, functional magnetic resonance imaging (fMRI) is used to measure the magnetic fields created by the ... It combines the high-spatial-resolution noninvasive imaging of brain anatomy offered by standard magnetic resonance imaging ( ... Functional magnetic resonance imaging (fMRI), a research and diagnostic method developed in the early 1990s, has been used to ...
more infohttps://www.britannica.com/science/functional-magnetic-resonance-imaging

Magnetic Resonance Imaging of Tall Fescue | SpringerLinkMagnetic Resonance Imaging of Tall Fescue | SpringerLink

Magnetic resonance imaging (MRI) has proven to be a valuable tool to radiologists since its introduction in the early 1 970s ( ... Nuclear Magnetic Resonance Static Magnet Field Tall Fescue Gray Scale Image Magnetic Field Gradient These keywords were added ... Magnetic resonance imaging (MRI) has proven to be a valuable tool to radiologists since its introduction in the early 1 970s ( ... Anderson C.L., Dyke J.P., Green J.F., Gwinn K.D., Kabalka G.W. (1997) Magnetic Resonance Imaging of Tall Fescue. In: Bacon C.W ...
more infohttps://link.springer.com/chapter/10.1007/978-1-4899-0271-9_41

Magnetic Resonance Imaging - HealthLibraryMagnetic Resonance Imaging - HealthLibrary

Magnetic Resonance Imaging. (Imaging, Magnetic Resonance; MRI Scan; MRI). by Cynthia M. Johnson, MA ... J Magn Reson Imaging. 2013;37(3):501-530.. Magnetic resonance imaging (MRI)-body. Radiology Info-Radiological Society of North ... The use of magnetic resonance imaging in the obstetric patient. J Obstet Gynaecol Can. 2014;36(4):349-355. Available at: https ... You will be asked to wait while the images are studied. More images may be needed. ...
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Magnetic Resonance Imaging - Journal - ElsevierMagnetic Resonance Imaging - Journal - Elsevier

Magnetic Resonance Imaging (MRI) is the first international multidisciplinary journal encompassing physical, life, and clinical ... Recently published articles from Magnetic Resonance Imaging. * An accurate and robust skull stripping method for 3-D magnetic ... Magnetic Resonance Imaging (MRI) is the first international multidisciplinary journal encompassing physical, life, and clinical ... Magnetic Resonance Imaging (MRI) is the first international multidisciplinary journal encompassing physical, life, and clinical ...
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Magnetic Resonance Image Analysis | SpringerLinkMagnetic Resonance Image Analysis | SpringerLink

Wood, M. L., & Henkelman, R. M. (1985). Truncation artifacts in magnetic resonance imaging. Magnetic Resonance in Medicine, 2, ... The dependence of nuclear magnetic resonance (NMR) image contrast on intrinsic and pulse timing parameters. Magnetic Resonance ... Methodology for measurement and analysis of relaxation times in proton imaging. Magnetic Resonance Imaging, 5, 209-220.PubMed ... In C. L. Partain, R. R. Price, J. A. Patton, M. V. Kularni, & A. E. James (Eds.), Magnetic resonance imaging: Vol. 1 (pp. 117- ...
more infohttps://link.springer.com/chapter/10.1007/978-1-4899-1701-0_2

cardiac magnetic resonance imaging (CMR) | medicine | Britannica.comcardiac magnetic resonance imaging (CMR) | medicine | Britannica.com

CMR three-dimensional diagnostic imaging technique used to visualize the heart and its blood vessels without the need for X- ... Cardiac magnetic resonance imaging (CMR), also called cardiac MRI or heart MRI, three-dimensional diagnostic imaging technique ... Cardiac Magnetic Resonance Imaging * Southampton University Hospitals - National Health ServiceTrust - Cardiac Magnetic ... The University of Chicago Medical Center - Cardiac Magnetic Resonance Imaging * University of Maryland Medical Center - Cardiac ...
more infohttps://www.britannica.com/topic/cardiac-magnetic-resonance-imaging

magnetic resonance imagingmagnetic resonance imaging

A definition of the medical term "magnetic resonance imaging" is presented. Magnetic resonance imaging refers to diagnostic ... Magnetic resonance angiography refers to noninvasive radiography of blood vessels with magnetic resonance imaging technology. ... Aortogram refers to an image of the aorta obtained through radiography, computed tomography or magnetic resonance imaging. The ... Magnetic resonance cholangiopancreatographyrefers to visualization of pancreatic and biliary ducts with magnetic resonance ...
more infohttp://connection.ebscohost.com/c/reference-entries/21234870/magnetic-resonance-imaging

Magnetic Resonance Imaging (MRI) | Johns Hopkins MedicineMagnetic Resonance Imaging (MRI) | Johns Hopkins Medicine

Magnetic resonance imaging, or MRI, is a noninvasive medical imaging test that produces detailed images of almost every ... Newer uses for MRI have contributed to the development of additional magnetic resonance technology. Magnetic resonance ... Magnetic Resonance Imaging (MRI). Facebook Twitter Linkedin Pinterest Print. Radiology Breast Cancer Screening and Diagnostics ... Functional magnetic resonance imaging (fMRI) of the brain is used to determine the specific location in the brain where a ...
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Global Magnetic Resonance Imaging Market Growth - kbvresearchGlobal Magnetic Resonance Imaging Market Growth - kbvresearch

The Global Magnetic Resonance Imaging Market is expected to reach $7.3 billion by 2022, growing at a CAGR of 5.4% during the ... global magnetic resonance imaging marketglobal magnetic resonance imaging market sizeglobal magnetic resonance imaging market ... shareglobal magnetic resonance imaging market trendglobal magnetic resonance imaging market growth ... The Global Magnetic Resonance Imaging Market is expected to reach $7.3 billion by 2022, growing at a CAGR of 5.4% during the ...
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Cardiovascular Magnetic Resonance Imaging | Raymond Y. Kwong | SpringerCardiovascular Magnetic Resonance Imaging | Raymond Y. Kwong | Springer

... edition of this important work provides an up-to-date and comprehensive overview of cardiovascular magnetic resonance imaging ( ... and offers new directions in noninvasive imaging. The Second Edition of Cardiovascular Magnetic Resonance Imaging is an ... Cardiovascular Magnetic Resonance Imaging. Editors: Kwong, Raymond Y., Jerosch-Herold, Michael, Heydari, Bobak (Eds.) ... Myocardial Perfusion and Late Gadolinium Enhancement Imaging in Cardiovascular Magnetic Resonance to Assess Coronary Artery ...
more infohttps://www.springer.com/us/book/9781493988396?wt_mc=

Functional Magnetic Resonance Imaging (fMRI) | CurrikiFunctional Magnetic Resonance Imaging (fMRI) | Curriki

... which is used to take detailed images of the functioning brain. ... www.curriki.org/oer/Functional-Magnetic-Resonance-Imaging-fMRI ... Professor Trevor Robbins describes functional magnetic resonance imaging (fMRI) technology, ... imaging,Physics,Technology,trevor,oai:nsdl.org:2200/20100426020932203T,Image/Image Set,mri,resonance,resolution ... Professor Trevor Robbins describes functional magnetic resonance imaging (fMRI) technology, which is used to take detailed ...
more infohttps://www.curriki.org/oer/Functional-Magnetic-Resonance-Imaging-fMRI--256990

Simulation Magnetic Resonance Imaging scanner - WURSimulation Magnetic Resonance Imaging scanner - WUR

Simulation Magnetic Resonance Imaging scanner. In addition to the 3T Wageningen University & Research, Shared Research ... 3T Magnetic Resonance Imaging (3T MRI) Wageningen University & Research, Shared Research Facilities offers the use of a state- ...
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Magnetic Resonance Imaging | Fanshawe CollegeMagnetic Resonance Imaging | Fanshawe College

The Magnetic Resonance Imaging Technologist is a valuable member of the health care team who utilizes strong magnetic fields ... Advanced techniques such as Magnetic Resonance Spectroscopy (MRS), Magnetic Resonance Angiography (MRA/MRV), and Echo planar ... 1. Perform, in accordance with current standards, various magnetic resonance imaging procedures involving the head and neck, ... This course focuses on the physical principles, equipment and instrumentation of Magnetic Resonance Imaging (MRI). The ...
more infohttps://www.fanshawec.ca/programs/mri1-magnetic-resonance-imaging/next

29-2035.00 - Magnetic Resonance Imaging Technologists29-2035.00 - Magnetic Resonance Imaging Technologists

Medical magnetic resonance imaging MRI coils - Magnetic resonance imaging MRI coils *Medical magnetic resonance imaging MRI ... Magnetic resonance imaging MRI monitors *Medical magnetic resonance imaging MRI positioning aids - Magnetic resonance imaging ... Magnetic resonance imaging MRI systems; Portable magnetic resonance imaging MRI scanners *Medical magnetic resonance imaging ... Magnetic Resonance Imaging Coordinator (MRI Coordinator), Magnetic Resonance Imaging Director, Magnetic Resonance Imaging ...
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Magnetic resonance imaging (in SafetyLit)Magnetic resonance imaging (in SafetyLit)

SafetyLit: The weekly online update of injury research and prevention literature. SafetyLit is produced by the Center for Injury Prevention Policy and Practice at San Diego State University.
more infohttps://www.safetylit.org/week/journalpage.php?jid=16772
  • 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. (slideshare.net)
  • 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). (britannica.com)
  • 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. (britannica.com)
  • Magnetic resonance imaging refers to diagnostic radiography that uses the behavior of protons within magnetic fields to make images of organs and tissues. (ebscohost.com)
  • 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. (ebscohost.com)
  • In most medical applications, protons (hydrogen atoms) in tissues containing water molecules create a signal that is processed to form an image of the body. (wikipedia.org)
  • Magnetic coils in the MRI machine detect these signals and a computer changes them into a cross-sectional or three-dimensional image based on the strength of signal produced by different types of tissue. (daviddarling.info)
  • Select appropriate imaging techniques or coils to produce required images. (onetonline.org)
  • Troubleshoot technical issues related to magnetic resonance imaging (MRI) scanner or peripheral equipment, such as monitors or coils. (onetonline.org)
  • Some of these sequences require the use of new types of imaging coils, which are also investigational. (bioportfolio.com)
  • The radio signal may be made to encode position information by varying the main magnetic field using gradient coils. (wikipedia.org)
  • 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 MR signal and the RF system, which excites the sample and detects the resulting NMR signal. (wikipedia.org)
  • It is derived from and based on the same basic principles as magnetic resonance imaging (MRI) but with optimization for use in the cardiovascular system. (wikipedia.org)
  • The book presents a state-of-the-art compilation of expert contributions to the field, each examining normal and pathologic anatomy of the cardiovascular system as assessed by magnetic resonance imaging. (springer.com)
  • MRI also provides movie-like sequential imaging of the cardiovascular system that is important to assess the health and function of these structures (heart, valves, great vessels, etc. (radiologyinfo.org)
  • Another magnetic field, the gradient field, is then applied to spatially locate different nuclei. (wikipedia.org)
  • Gradient-induced electric field refers to the electric field that may surround an object placed in a rapidly changing magnetic resonance imaging device. (ebscohost.com)
  • 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. (google.de)
  • 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. (appliedradiology.com)
  • 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. (appliedradiology.com)
  • The significantly updated second edition of this important work provides an up-to-date and comprehensive overview of cardiovascular magnetic resonance imaging (CMR), a rapidly evolving tool for diagnosis and intervention of cardiovascular disease. (springer.com)
  • assess abnormal masses, including cancer of the lungs or other tissues, which either cannot be assessed adequately with other imaging modalities (typically CT) or which are particularly well-suited to MR imaging. (radiologyinfo.org)
  • characterize mediastinal or pleural lesions seen by other imaging modalities, such as chest x-ray or CT. (radiologyinfo.org)
  • When compared with other imaging modalities, the excellent anatomical resolution 3 and multiplanar capabilities make MRI particularly worthy to pinpoint molecular events (Table 1). (appliedradiology.com)
  • 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. (wikipedia.org)
  • An MRI scan uses magnetic waves and computers to make pictures of the inside of the body. (epnet.com)
  • Images produced by an MRI scan can show organs, bones, muscles and blood vessels. (hopkinsmedicine.org)
  • Pictures from an MRI scan are digital images that can be saved and stored on a computer for more study. (adventisthealthcare.com)
  • A radiologist or MRI technologist usually performs the scan in a hospital, clinic or imaging center using special equipment. (heart.org)
  • Detailed MR images allow physicians to evaluate various parts of the body and determine the presence of certain diseases. (radiologyinfo.org)
  • The purpose of this study is to evaluate normal volunteers and patients with a variety of diseases with magnetic resonance imaging. (bioportfolio.com)
  • Postgraduate provision in Medical Imaging at the University of Bradford has long been established and is known for its quality and success in supporting development of healthcare professionals in their diverse roles, with students coming from around the UK, and full time international students choosing to study here. (bradford.ac.uk)
  • Achievement of the learning outcomes will be demonstrated through the completion of a written examination based on the physical principles, and a second examination which involves responding to questions based on case studies with accompanying medical images. (bradford.ac.uk)
  • A definition of the medical term "magnetic resonance imaging" is presented. (ebscohost.com)
  • These images give your physician important information in diagnosing your medical condition and planning a course of treatment. (hopkinsmedicine.org)
  • Instruct medical staff or students in magnetic resonance imaging (MRI) procedures or equipment operation. (onetonline.org)
  • The Medical Image Computing and Computer Assisted Intervention Society, 2012. (mit.edu)
  • Exogenous contrast agents may be given to the person to make the image clearer. (wikipedia.org)
  • Direct imaging of events fundamental to disease processes with molecular imaging should ultimately translate into better patient care through earlier and more specific detection and intervention. (appliedradiology.com)
  • In this system, a data acquisition section is operated under the control of a control section only while the patient stands still in response to the announcement of the announcement section, thereby intermittently acquiring magnetic resonance data in units of a predetermined volume. (google.de)
  • Rapid Spectroscopic Reference Acquisition for Volumetric Metabolite Imaging. (mit.edu)
  • There is no proven risk of biological harm from even very powerful static magnetic fields. (wikipedia.org)
  • Magnetic resonance imaging (MRI) has proven to be a valuable tool to radiologists since its introduction in the early 1 970's (Esser and Johnson, 1984). (springer.com)
  • Since its development in the 1970s and 1980s, MRI has proven to be a highly versatile imaging technique. (wikipedia.org)
  • The Global Magnetic Resonance Imaging Market is expected to reach $7.3 billion by 2022, growing at a CAGR of 5.4% during the forecast period. (mynewsdesk.com)
  • C, On the proton density image, the signal intensity becomes brighter, being isointense with gray matter and brighter than white matter. (aao.org)
  • Spielman DM, Adalsteinsson E. Narrowband Proton Spectroscopic Imaging. (mit.edu)
  • This difference leads to an improved MR signal since the diamagnetic blood interferes with the magnetic MR signal less. (wikipedia.org)
  • Differences in magnetic properties between arterial (oxygen-rich) and venous (oxygen-poor) blood provided this link. (wikipedia.org)
  • These optimizations are principally in the use of ECG gating and rapid imaging techniques or sequences. (wikipedia.org)
  • Thus, MRI is still to be considered the safest of the advanced imaging techniques. (wikipedia.org)
  • Functional techniques such as myocardial perfusion imaging and assessment of flow velocity are emphasized, along with the exciting areas of artherosclerosis plaque imaging and targeted MRI. (springer.com)
  • In recent years, there has been intense interest in molecular imaging with MR techniques. (appliedradiology.com)
  • The list of tools available to aid in the development of molecular imaging techniques continues to grow. (appliedradiology.com)
  • Monitor patient safety and comfort, and view images of area being scanned to ensure quality of pictures. (onetonline.org)
  • Test magnetic resonance imaging (MRI) equipment to ensure proper functioning and performance in accordance with specifications. (onetonline.org)