Tomography, X-Ray Computed: Tomography using x-ray transmission and a computer algorithm to reconstruct the image.Tomography: Imaging methods that result in sharp images of objects located on a chosen plane and blurred images located above or below the plane.Positron-Emission Tomography: An imaging technique using compounds labelled with short-lived positron-emitting radionuclides (such as carbon-11, nitrogen-13, oxygen-15 and fluorine-18) to measure cell metabolism. It has been useful in study of soft tissues such as CANCER; CARDIOVASCULAR SYSTEM; and brain. SINGLE-PHOTON EMISSION-COMPUTED TOMOGRAPHY is closely related to positron emission tomography, but uses isotopes with longer half-lives and resolution is lower.Tomography, Optical Coherence: An imaging method using LASERS that is used for mapping subsurface structure. When a reflective site in the sample is at the same optical path length (coherence) as the reference mirror, the detector observes interference fringes.Tomography, Emission-Computed: Tomography using radioactive emissions from injected RADIONUCLIDES and computer ALGORITHMS to reconstruct an image.Tomography, Spiral Computed: Computed tomography where there is continuous X-ray exposure to the patient while being transported in a spiral or helical pattern through the beam of irradiation. This provides improved three-dimensional contrast and spatial resolution compared to conventional computed tomography, where data is obtained and computed from individual sequential exposures.Tomography, Optical: Projection of near-IR light (INFRARED RAYS), in the 700-1000 nm region, across an object in parallel beams to an array of sensitive photodetectors. This is repeated at various angles and a mathematical reconstruction provides three dimensional MEDICAL IMAGING of tissues. Based on the relative transparency of tissues to this spectra, it has been used to monitor local oxygenation, brain and joints.Multidetector Computed Tomography: Types of spiral computed tomography technology in which multiple slices of data are acquired simultaneously improving the resolution over single slice acquisition technology.Tomography, Emission-Computed, Single-Photon: A method of computed tomography that uses radionuclides which emit a single photon of a given energy. The camera is rotated 180 or 360 degrees around the patient to capture images at multiple positions along the arc. The computer is then used to reconstruct the transaxial, sagittal, and coronal images from the 3-dimensional distribution of radionuclides in the organ. The advantages of SPECT are that it can be used to observe biochemical and physiological processes as well as size and volume of the organ. The disadvantage is that, unlike positron-emission tomography where the positron-electron annihilation results in the emission of 2 photons at 180 degrees from each other, SPECT requires physical collimation to line up the photons, which results in the loss of many available photons and hence degrades the image.Cone-Beam Computed Tomography: Computed tomography modalities which use a cone or pyramid-shaped beam of radiation.Electron Microscope Tomography: A tomographic technique for obtaining 3-dimensional images with transmission electron microscopy.Tomography, X-Ray: Tomography using x-ray transmission.Fluorodeoxyglucose F18: The compound is given by intravenous injection to do POSITRON-EMISSION TOMOGRAPHY for the assessment of cerebral and myocardial glucose metabolism in various physiological or pathological states including stroke and myocardial ischemia. It is also employed for the detection of malignant tumors including those of the brain, liver, and thyroid gland. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1162)Tomography Scanners, X-Ray Computed: X-ray image-detecting devices that make a focused image of body structures lying in a predetermined plane from which more complex images are computed.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.Sensitivity and Specificity: Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)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.X-Ray Microtomography: X-RAY COMPUTERIZED TOMOGRAPHY with resolution in the micrometer range.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.Multimodal Imaging: The use of combination of imaging techniques or platforms (e.g., MRI SCAN and PET SCAN) encompassing aspects of anatomical, functional, or molecular imaging methods.Fluorine Radioisotopes: Unstable isotopes of fluorine that decay or disintegrate emitting radiation. F atoms with atomic weights 17, 18, and 20-22 are radioactive fluorine isotopes.Radiographic Image Interpretation, Computer-Assisted: Computer systems or networks designed to provide radiographic interpretive information.Phantoms, Imaging: Devices or objects in various imaging techniques used to visualize or enhance visualization by simulating conditions encountered in the procedure. Phantoms are used very often in procedures employing or measuring x-irradiation or radioactive material to evaluate performance. Phantoms often have properties similar to human tissue. Water demonstrates absorbing properties similar to normal tissue, hence water-filled phantoms are used to map radiation levels. Phantoms are used also as teaching aids to simulate real conditions with x-ray or ultrasonic machines. (From Iturralde, Dictionary and Handbook of Nuclear Medicine and Clinical Imaging, 1990)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.Diagnostic Imaging: Any visual display of structural or functional patterns of organs or tissues for diagnostic evaluation. It includes measuring physiologic and metabolic responses to physical and chemical stimuli, as well as ultramicroscopy.Four-Dimensional Computed Tomography: Three-dimensional computed tomographic imaging with the added dimension of time, to follow motion during imaging.Retrospective Studies: Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.Contrast Media: Substances used to allow enhanced visualization of tissues.Radiography, Abdominal: Radiographic visualization of the body between the thorax and the pelvis, i.e., within the peritoneal cavity.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.Calcinosis: Pathologic deposition of calcium salts in tissues.Radiographic Image Enhancement: Improvement in the quality of an x-ray image by use of an intensifying screen, tube, or filter and by optimum exposure techniques. Digital processing methods are often employed.Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Radiography, Thoracic: X-ray visualization of the chest and organs of the thoracic cavity. It is not restricted to visualization of the lungs.Prospective Studies: Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.Macula Lutea: An oval area in the retina, 3 to 5 mm in diameter, usually located temporal to the posterior pole of the eye and slightly below the level of the optic disk. It is characterized by the presence of a yellow pigment diffusely permeating the inner layers, contains the fovea centralis in its center, and provides the best phototropic visual acuity. It is devoid of retinal blood vessels, except in its periphery, and receives nourishment from the choriocapillaris of the choroid. (From Cline et al., Dictionary of Visual Science, 4th ed)Coronary Angiography: Radiography of the vascular system of the heart muscle after injection of a contrast medium.Oxygen Radioisotopes: Unstable isotopes of oxygen that decay or disintegrate emitting radiation. O atoms with atomic weights 13, 14, 15, 19, and 20 are radioactive oxygen isotopes.Diagnostic Techniques, Ophthalmological: Methods and procedures for the diagnosis of diseases of the eye or of vision disorders.Carbon Radioisotopes: Unstable isotopes of carbon that decay or disintegrate emitting radiation. C atoms with atomic weights 10, 11, and 14-16 are radioactive carbon isotopes.Algorithms: A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.Observer Variation: The failure by the observer to measure or identify a phenomenon accurately, which results in an error. Sources for this may be due to the observer's missing an abnormality, or to faulty technique resulting in incorrect test measurement, or to misinterpretation of the data. Two varieties are inter-observer variation (the amount observers vary from one another when reporting on the same material) and intra-observer variation (the amount one observer varies between observations when reporting more than once on the same material).Coronary Artery Disease: Pathological processes of CORONARY ARTERIES that may derive from a congenital abnormality, atherosclerotic, or non-atherosclerotic cause.Image Enhancement: Improvement of the quality of a picture by various techniques, including computer processing, digital filtering, echocardiographic techniques, light and ultrastructural MICROSCOPY, fluorescence spectrometry and microscopy, scintigraphy, and in vitro image processing at the molecular level.Cerebrovascular Circulation: The circulation of blood through the BLOOD VESSELS of the BRAIN.Bronchography: Radiography of the bronchial tree after injection of a contrast medium.Anatomy, Cross-Sectional: Descriptive anatomy based on three-dimensional imaging (IMAGING, THREE-DIMENSIONAL) of the body, organs, and structures using a series of computer multiplane sections, displayed by transverse, coronal, and sagittal analyses. It is essential to accurate interpretation by the radiologist of such techniques as ultrasonic diagnosis, MAGNETIC RESONANCE IMAGING, and computed tomography (TOMOGRAPHY, X-RAY COMPUTED). (From Lane & Sharfaei, Modern Sectional Anatomy, 1992, Preface)Radiation Dosage: The amount of radiation energy that is deposited in a unit mass of material, such as tissues of plants or animal. In RADIOTHERAPY, radiation dosage is expressed in gray units (Gy). In RADIOLOGIC HEALTH, the dosage is expressed by the product of absorbed dose (Gy) and quality factor (a function of linear energy transfer), and is called radiation dose equivalent in sievert units (Sv).Follow-Up Studies: Studies in which individuals or populations are followed to assess the outcome of exposures, procedures, or effects of a characteristic, e.g., occurrence of disease.Nerve Fibers: Slender processes of NEURONS, including the AXONS and their glial envelopes (MYELIN SHEATH). Nerve fibers conduct nerve impulses to and from the CENTRAL NERVOUS SYSTEM.Equipment Design: Methods of creating machines and devices.Optic Disk: The portion of the optic nerve seen in the fundus with the ophthalmoscope. It is formed by the meeting of all the retinal ganglion cell axons as they enter the optic nerve.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Artifacts: Any visible result of a procedure which is caused by the procedure itself and not by the entity being analyzed. Common examples include histological structures introduced by tissue processing, radiographic images of structures that are not naturally present in living tissue, and products of chemical reactions that occur during analysis.Incidental Findings: Unanticipated information discovered in the course of testing or medical care. Used in discussions of information that may have social or psychological consequences, such as when it is learned that a child's biological father is someone other than the putative father, or that a person tested for one disease or disorder has, or is at risk for, something else.Optical Phenomena: LIGHT, it's processes and properties, and the characteristics of materials interacting with it.Angiography: Radiography of blood vessels after injection of a contrast medium.Solitary Pulmonary Nodule: A single lung lesion that is characterized by a small round mass of tissue, usually less than 1 cm in diameter, and can be detected by chest radiography. A solitary pulmonary nodule can be associated with neoplasm, tuberculosis, cyst, or other anomalies in the lung, the CHEST WALL, or the PLEURA.Lung Neoplasms: Tumors or cancer of the LUNG.Organotechnetium Compounds: Organic compounds that contain technetium as an integral part of the molecule. These compounds are often used as radionuclide imaging agents.Thallium Radioisotopes: Unstable isotopes of thallium that decay or disintegrate emitting radiation. Tl atoms with atomic weights 198-202, 204, and 206-210 are thallium radioisotopes.Visual Acuity: Clarity or sharpness of OCULAR VISION or the ability of the eye to see fine details. Visual acuity depends on the functions of RETINA, neuronal transmission, and the interpretative ability of the brain. Normal visual acuity is expressed as 20/20 indicating that one can see at 20 feet what should normally be seen at that distance. Visual acuity can also be influenced by brightness, color, and contrast.Feasibility Studies: Studies to determine the advantages or disadvantages, practicability, or capability of accomplishing a projected plan, study, or project.Fluorescein Angiography: Visualization of a vascular system after intravenous injection of a fluorescein solution. The images may be photographed or televised. It is used especially in studying the retinal and uveal vasculature.Aortography: Radiographic visualization of the aorta and its branches by injection of contrast media, using percutaneous puncture or catheterization procedures.Optic Nerve Diseases: Conditions which produce injury or dysfunction of the second cranial or optic nerve, which is generally considered a component of the central nervous system. Damage to optic nerve fibers may occur at or near their origin in the retina, at the optic disk, or in the nerve, optic chiasm, optic tract, or lateral geniculate nuclei. Clinical manifestations may include decreased visual acuity and contrast sensitivity, impaired color vision, and an afferent pupillary defect.Cryoelectron Microscopy: Electron microscopy involving rapid freezing of the samples. The imaging of frozen-hydrated molecules and organelles permits the best possible resolution closest to the living state, free of chemical fixatives or stains.Coronary Stenosis: Narrowing or constriction of a coronary artery.Severity of Illness Index: Levels within a diagnostic group which are established by various measurement criteria applied to the seriousness of a patient's disorder.Myocardial Perfusion Imaging: The creation and display of functional images showing where the blood is flowing into the MYOCARDIUM by following over time the distribution of tracers injected into the blood stream.Ultrasonography: The visualization of deep structures of the body by recording the reflections or echoes of ultrasonic pulses directed into the tissues. Use of ultrasound for imaging or diagnostic purposes employs frequencies ranging from 1.6 to 10 megahertz.Coronary Vessels: The veins and arteries of the HEART.Prognosis: A prediction of the probable outcome of a disease based on a individual's condition and the usual course of the disease as seen in similar situations.Macular Edema: Fluid accumulation in the outer layer of the MACULA LUTEA that results from intraocular or systemic insults. It may develop in a diffuse pattern where the macula appears thickened or it may acquire the characteristic petaloid appearance referred to as cystoid macular edema. Although macular edema may be associated with various underlying conditions, it is most commonly seen following intraocular surgery, venous occlusive disease, DIABETIC RETINOPATHY, and posterior segment inflammatory disease. (From Survey of Ophthalmology 2004; 49(5) 470-90)Retinal Ganglion Cells: Neurons of the innermost layer of the retina, the internal plexiform layer. They are of variable sizes and shapes, and their axons project via the OPTIC NERVE to the brain. A small subset of these cells act as photoreceptors with projections to the SUPRACHIASMATIC NUCLEUS, the center for regulating CIRCADIAN RHYTHM.Preoperative Care: Care given during the period prior to undergoing surgery when psychological and physical preparations are made according to the special needs of the individual patient. This period spans the time between admission to the hospital to the time the surgery begins. (From Dictionary of Health Services Management, 2d ed)Technetium Tc 99m Sestamibi: A technetium imaging agent used to reveal blood-starved cardiac tissue during a heart attack.Retina: The ten-layered nervous tissue membrane of the eye. It is continuous with the OPTIC NERVE and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the CHOROID and the inner surface with the VITREOUS BODY. The outer-most layer is pigmented, whereas the inner nine layers are transparent.Interferometry: Measurement of distances or movements by means of the phenomena caused by the interference of two rays of light (optical interferometry) or of sound (acoustic interferometry).Equipment Failure Analysis: The evaluation of incidents involving the loss of function of a device. These evaluations are used for a variety of purposes such as to determine the failure rates, the causes of failures, costs of failures, and the reliability and maintainability of devices.Neoplasm Staging: Methods which attempt to express in replicable terms the extent of the neoplasm in the patient.Copper Radioisotopes: Unstable isotopes of copper that decay or disintegrate emitting radiation. Cu atoms with atomic weights 58-62, 64, and 66-68 are radioactive copper isotopes.Retinal DiseasesNitrogen Radioisotopes: Unstable isotopes of nitrogen that decay or disintegrate emitting radiation. N atoms with atomic weights 12, 13, 16, 17, and 18 are radioactive nitrogen isotopes.Radioactive Tracers: Radioactive substances added in minute amounts to the reacting elements or compounds in a chemical process and traced through the process by appropriate detection methods, e.g., Geiger counter. Compounds containing tracers are often said to be tagged or labeled. (Hawley's Condensed Chemical Dictionary, 12th ed)ROC Curve: A graphic means for assessing the ability of a screening test to discriminate between healthy and diseased persons; may also be used in other studies, e.g., distinguishing stimuli responses as to a faint stimuli or nonstimuli.Ophthalmoscopy: Examination of the interior of the eye with an ophthalmoscope.Gallium Radioisotopes: Unstable isotopes of gallium that decay or disintegrate emitting radiation. Ga atoms with atomic weights 63-68, 70 and 72-76 are radioactive gallium isotopes.Iopamidol: A non-ionic, water-soluble contrast agent which is used in myelography, arthrography, nephroangiography, arteriography, and other radiological procedures.Raclopride: A substituted benzamide that has antipsychotic properties. It is a dopamine D2 receptor (see RECEPTORS, DOPAMINE D2) antagonist.Hematoma: A collection of blood outside the BLOOD VESSELS. Hematoma can be localized in an organ, space, or tissue.Mediastinum: A membrane in the midline of the THORAX of mammals. It separates the lungs between the STERNUM in front and the VERTEBRAL COLUMN behind. It also surrounds the HEART, TRACHEA, ESOPHAGUS, THYMUS, and LYMPH NODES.Lung: Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.Glaucoma: An ocular disease, occurring in many forms, having as its primary characteristics an unstable or a sustained increase in the intraocular pressure which the eye cannot withstand without damage to its structure or impairment of its function. The consequences of the increased pressure may be manifested in a variety of symptoms, depending upon type and severity, such as excavation of the optic disk, hardness of the eyeball, corneal anesthesia, reduced visual acuity, seeing of colored halos around lights, disturbed dark adaptation, visual field defects, and headaches. (Dictionary of Visual Science, 4th ed)Subtraction Technique: Combination or superimposition of two images for demonstrating differences between them (e.g., radiograph with contrast vs. one without, radionuclide images using different radionuclides, radiograph vs. radionuclide image) and in the preparation of audiovisual materials (e.g., offsetting identical images, coloring of vessels in angiograms).Skull: The SKELETON of the HEAD including the FACIAL BONES and the bones enclosing the BRAIN.Cardiac-Gated Imaging Techniques: Timing the acquisition of imaging data to specific points in the cardiac cycle to minimize image blurring and other motion artifacts.Optical Processes: Behavior of LIGHT and its interactions with itself and materials.Heart: The hollow, muscular organ that maintains the circulation of the blood.Ultrasonography, Interventional: The use of ultrasound to guide minimally invasive surgical procedures such as needle ASPIRATION BIOPSY; DRAINAGE; etc. Its widest application is intravascular ultrasound imaging but it is useful also in urology and intra-abdominal conditions.Fundus Oculi: The concave interior of the eye, consisting of the retina, the choroid, the sclera, the optic disk, and blood vessels, seen by means of the ophthalmoscope. (Cline et al., Dictionary of Visual Science, 4th ed)Fatal Outcome: Death resulting from the presence of a disease in an individual, as shown by a single case report or a limited number of patients. This should be differentiated from DEATH, the physiological cessation of life and from MORTALITY, an epidemiological or statistical concept.Models, Anatomic: Three-dimensional representation to show anatomic structures. Models may be used in place of intact animals or organisms for teaching, practice, and study.Iodine Radioisotopes: Unstable isotopes of iodine that decay or disintegrate emitting radiation. I atoms with atomic weights 117-139, except I 127, are radioactive iodine isotopes.Wounds, Nonpenetrating: Injuries caused by impact with a blunt object where there is no penetration of the skin.Iohexol: An effective non-ionic, water-soluble contrast agent which is used in myelography, arthrography, nephroangiography, arteriography, and other radiographic procedures. Its low systemic toxicity is the combined result of low chemotoxicity and low osmolality.Reference Values: The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.Brain Diseases: Pathologic conditions affecting the BRAIN, which is composed of the intracranial components of the CENTRAL NERVOUS SYSTEM. This includes (but is not limited to) the CEREBRAL CORTEX; intracranial white matter; BASAL GANGLIA; THALAMUS; HYPOTHALAMUS; BRAIN STEM; and CEREBELLUM.Radioisotopes: Isotopes that exhibit radioactivity and undergo radioactive decay. (From Grant & Hackh's Chemical Dictionary, 5th ed & McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Fovea Centralis: An area approximately 1.5 millimeters in diameter within the macula lutea where the retina thins out greatly because of the oblique shifting of all layers except the pigment epithelium layer. It includes the sloping walls of the fovea (clivus) and contains a few rods in its periphery. In its center (foveola) are the cones most adapted to yield high visual acuity, each cone being connected to only one ganglion cell. (Cline et al., Dictionary of Visual Science, 4th ed)Coronary Circulation: The circulation of blood through the CORONARY VESSELS of the HEART.Liver Neoplasms: Tumors or cancer of the LIVER.Temporal Bone: Either of a pair of compound bones forming the lateral (left and right) surfaces and base of the skull which contains the organs of hearing. It is a large bone formed by the fusion of parts: the squamous (the flattened anterior-superior part), the tympanic (the curved anterior-inferior part), the mastoid (the irregular posterior portion), and the petrous (the part at the base of the skull).Optics and Photonics: A specialized field of physics and engineering involved in studying the behavior and properties of light and the technology of analyzing, generating, transmitting, and manipulating ELECTROMAGNETIC RADIATION in the visible, infrared, and ultraviolet range.Molecular Imaging: The use of molecularly targeted imaging probes to localize and/or monitor biochemical and cellular processes via various imaging modalities that include RADIONUCLIDE IMAGING; ULTRASONOGRAPHY; MAGNETIC RESONANCE IMAGING; FLUORESCENCE IMAGING; and MICROSCOPY.Oximes: Compounds that contain the radical R2C=N.OH derived from condensation of ALDEHYDES or KETONES with HYDROXYLAMINE. Members of this group are CHOLINESTERASE REACTIVATORS.Anterior Eye Segment: The front third of the eyeball that includes the structures between the front surface of the cornea and the front of the VITREOUS BODY.Deoxyglucose: 2-Deoxy-D-arabino-hexose. An antimetabolite of glucose with antiviral activity.Biopsy: Removal and pathologic examination of specimens in the form of small pieces of tissue from the living body.Rupture, Spontaneous: Tear or break of an organ, vessel or other soft part of the body, occurring in the absence of external force.Technetium Tc 99m Exametazime: A gamma-emitting RADIONUCLIDE IMAGING agent used in the evaluation of regional cerebral blood flow and in non-invasive dynamic biodistribution studies and MYOCARDIAL PERFUSION IMAGING. It has also been used to label leukocytes in the investigation of INFLAMMATORY BOWEL DISEASES.Plaque, Atherosclerotic: Lesions formed within the walls of ARTERIES.Mandible: The largest and strongest bone of the FACE constituting the lower jaw. It supports the lower teeth.False Positive Reactions: Positive test results in subjects who do not possess the attribute for which the test is conducted. The labeling of healthy persons as diseased when screening in the detection of disease. (Last, A Dictionary of Epidemiology, 2d ed)Bronchoscopy: Endoscopic examination, therapy or surgery of the bronchi.Visual Field Tests: Method of measuring and mapping the scope of vision, from central to peripheral of each eye.Acute Disease: Disease having a short and relatively severe course.Tissue Distribution: Accumulation of a drug or chemical substance in various organs (including those not relevant to its pharmacologic or therapeutic action). This distribution depends on the blood flow or perfusion rate of the organ, the ability of the drug to penetrate organ membranes, tissue specificity, protein binding. The distribution is usually expressed as tissue to plasma ratios.Thallium: A heavy, bluish white metal, atomic number 81, atomic weight [204.382; 204.385], symbol Tl.Craniocerebral Trauma: Traumatic injuries involving the cranium and intracranial structures (i.e., BRAIN; CRANIAL NERVES; MENINGES; and other structures). Injuries may be classified by whether or not the skull is penetrated (i.e., penetrating vs. nonpenetrating) or whether there is an associated hemorrhage.Bone Density: The amount of mineral per square centimeter of BONE. This is the definition used in clinical practice. Actual bone density would be expressed in grams per milliliter. It is most frequently measured by X-RAY ABSORPTIOMETRY or TOMOGRAPHY, X RAY COMPUTED. Bone density is an important predictor for OSTEOPOROSIS.Surgery, Computer-Assisted: Surgical procedures conducted with the aid of computers. This is most frequently used in orthopedic and laparoscopic surgery for implant placement and instrument guidance. Image-guided surgery interactively combines prior CT scans or MRI images with real-time video.Cerebral Infarction: The formation of an area of NECROSIS in the CEREBRUM caused by an insufficiency of arterial or venous blood flow. Infarcts of the cerebrum are generally classified by hemisphere (i.e., left vs. right), lobe (e.g., frontal lobe infarction), arterial distribution (e.g., INFARCTION, ANTERIOR CEREBRAL ARTERY), and etiology (e.g., embolic infarction).Technetium: The first artificially produced element and a radioactive fission product of URANIUM. Technetium has the atomic symbol Tc, atomic number 43, and atomic weight 98.91. All technetium isotopes are radioactive. Technetium 99m (m=metastable) which is the decay product of Molybdenum 99, has a half-life of about 6 hours and is used diagnostically as a radioactive imaging agent. Technetium 99 which is a decay product of technetium 99m, has a half-life of 210,000 years.Microscopy, Acoustic: A scientific tool based on ULTRASONOGRAPHY and used not only for the observation of microstructure in metalwork but also in living tissue. In biomedical application, the acoustic propagation speed in normal and abnormal tissues can be quantified to distinguish their tissue elasticity and other properties.Retinal Perforations: Perforations through the whole thickness of the retina including the macula as the result of inflammation, trauma, degeneration, etc. The concept includes retinal breaks, tears, dialyses, and holes.Choroid: The thin, highly vascular membrane covering most of the posterior of the eye between the RETINA and SCLERA.Gonioscopy: Examination of the angle of the anterior chamber of the eye with a specialized optical instrument (gonioscope) or a contact prism lens.Cerebral Angiography: Radiography of the vascular system of the brain after injection of a contrast medium.Tibia: The second longest bone of the skeleton. It is located on the medial side of the lower leg, articulating with the FIBULA laterally, the TALUS distally, and the FEMUR proximally.Mediastinal Neoplasms: Tumors or cancer of the MEDIASTINUM.Radionuclide Imaging: The production of an image obtained by cameras that detect the radioactive emissions of an injected radionuclide as it has distributed differentially throughout tissues in the body. The image obtained from a moving detector is called a scan, while the image obtained from a stationary camera device is called a scintiphotograph.Pilot Projects: Small-scale tests of methods and procedures to be used on a larger scale if the pilot study demonstrates that these methods and procedures can work.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.Abdominal Pain: Sensation of discomfort, distress, or agony in the abdominal region.Risk Factors: An aspect of personal behavior or lifestyle, environmental exposure, or inborn or inherited characteristic, which, on the basis of epidemiologic evidence, is known to be associated with a health-related condition considered important to prevent.Disease Progression: The worsening of a disease over time. This concept is most often used for chronic and incurable diseases where the stage of the disease is an important determinant of therapy and prognosis.Multiple Pulmonary Nodules: A number of small lung lesions characterized by small round masses of 2- to 3-mm in diameter. They are usually detected by chest CT scans (COMPUTED TOMOGRAPHY, X-RAY). Such nodules can be associated with metastases of malignancies inside or outside the lung, benign granulomas, or other lesions.Bronchiectasis: Persistent abnormal dilatation of the bronchi.Cardiac-Gated Single-Photon Emission Computer-Assisted Tomography: Tomography using single-photon emitting RADIONUCLIDES to create images that are captured in times corresponding to various points in the cardiac cycle.Pelvis: The space or compartment surrounded by the pelvic girdle (bony pelvis). It is subdivided into the greater pelvis and LESSER PELVIS. The pelvic girdle is formed by the PELVIC BONES and SACRUM.Risk Assessment: The qualitative or quantitative estimation of the likelihood of adverse effects that may result from exposure to specified health hazards or from the absence of beneficial influences. (Last, Dictionary of Epidemiology, 1988)Aortic Aneurysm, Abdominal: An abnormal balloon- or sac-like dilatation in the wall of the ABDOMINAL AORTA which gives rise to the visceral, the parietal, and the terminal (iliac) branches below the aortic hiatus at the diaphragm.Iofetamine: An amphetamine analog that is rapidly taken up by the lungs and from there redistributed primarily to the brain and liver. It is used in brain radionuclide scanning with I-123.Visual Fields: The total area or space visible in a person's peripheral vision with the eye looking straightforward.Cysts: Any fluid-filled closed cavity or sac that is lined by an EPITHELIUM. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues.Abdominal Injuries: General or unspecified injuries involving organs in the abdominal cavity.Pulmonary Emphysema: Enlargement of air spaces distal to the TERMINAL BRONCHIOLES where gas-exchange normally takes place. This is usually due to destruction of the alveolar wall. Pulmonary emphysema can be classified by the location and distribution of the lesions.Perfusion Imaging: The creation and display of functional images showing where the blood flow reaches by following the distribution of tracers injected into the blood stream.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.Bone and Bones: A specialized CONNECTIVE TISSUE that is the main constituent of the SKELETON. The principle cellular component of bone is comprised of OSTEOBLASTS; OSTEOCYTES; and OSTEOCLASTS, while FIBRILLAR COLLAGENS and hydroxyapatite crystals form the BONE MATRIX.Technology, Radiologic: The application of scientific knowledge or technology to the field of radiology. The applications center mostly around x-ray or radioisotopes for diagnostic and therapeutic purposes but the technological applications of any radiation or radiologic procedure is within the scope of radiologic technology.Radiotherapy Planning, Computer-Assisted: Computer-assisted mathematical calculations of beam angles, intensities of radiation, and duration of irradiation in radiotherapy.Femur: The longest and largest bone of the skeleton, it is situated between the hip and the knee.Blood Vessel Prosthesis Implantation: Surgical insertion of BLOOD VESSEL PROSTHESES to repair injured or diseased blood vessels.Refractometry: Measurement of the index of refraction (the ratio of the velocity of light or other radiation in the first of two media to its velocity in the second as it passes from one into the other).Cardiac Imaging Techniques: Visualization of the heart structure and cardiac blood flow for diagnostic evaluation or to guide cardiac procedures via techniques including ENDOSCOPY (cardiac endoscopy, sometimes refered to as cardioscopy), RADIONUCLIDE IMAGING; MAGNETIC RESONANCE IMAGING; TOMOGRAPHY; or ULTRASONOGRAPHY.Intra-Abdominal Fat: Fatty tissue inside the ABDOMINAL CAVITY, including visceral fat and retroperitoneal fat. It is the most metabolically active fat in the body and easily accessible for LIPOLYSIS. Increased visceral fat is associated with metabolic complications of OBESITY.Cerebral Hemorrhage: Bleeding into one or both CEREBRAL HEMISPHERES including the BASAL GANGLIA and the CEREBRAL CORTEX. It is often associated with HYPERTENSION and CRANIOCEREBRAL TRAUMA.Epiretinal Membrane: A membrane on the vitreal surface of the retina resulting from the proliferation of one or more of three retinal elements: (1) fibrous astrocytes; (2) fibrocytes; and (3) retinal pigment epithelial cells. Localized epiretinal membranes may occur at the posterior pole of the eye without clinical signs or may cause marked loss of vision as a result of covering, distorting, or detaching the fovea centralis. Epiretinal membranes may cause vascular leakage and secondary retinal edema. In younger individuals some membranes appear to be developmental in origin and occur in otherwise normal eyes. The majority occur in association with retinal holes, ocular concussions, retinal inflammation, or after ocular surgery. (Newell, Ophthalmology: Principles and Concepts, 7th ed, p291)Spiral Cone-Beam Computed Tomography: Modality of computed tomography in which the patient is irradiated in a spiral path around the body with a cone or pyramid-shaped beam.Triiodobenzoic Acids: Triiodo-substituted derivatives of BENZOIC ACID.Prosthesis Design: The plan and delineation of prostheses in general or a specific prosthesis.Lymphatic Metastasis: Transfer of a neoplasm from its primary site to lymph nodes or to distant parts of the body by way of the lymphatic system.Abdominal NeoplasmsFinite Element Analysis: A computer based method of simulating or analyzing the behavior of structures or components.Hematoma, Subdural: Accumulation of blood in the SUBDURAL SPACE between the DURA MATER and the arachnoidal layer of the MENINGES. This condition primarily occurs over the surface of a CEREBRAL HEMISPHERE, but may develop in the spinal canal (HEMATOMA, SUBDURAL, SPINAL). Subdural hematoma can be classified as the acute or the chronic form, with immediate or delayed symptom onset, respectively. Symptoms may include loss of consciousness, severe HEADACHE, and deteriorating mental status.Coronary Disease: An imbalance between myocardial functional requirements and the capacity of the CORONARY VESSELS to supply sufficient blood flow. It is a form of MYOCARDIAL ISCHEMIA (insufficient blood supply to the heart muscle) caused by a decreased capacity of the coronary vessels.Stents: Devices that provide support for tubular structures that are being anastomosed or for body cavities during skin grafting.IodobenzenesSubarachnoid Hemorrhage: Bleeding into the intracranial or spinal SUBARACHNOID SPACE, most resulting from INTRACRANIAL ANEURYSM rupture. It can occur after traumatic injuries (SUBARACHNOID HEMORRHAGE, TRAUMATIC). Clinical features include HEADACHE; NAUSEA; VOMITING, nuchal rigidity, variable neurological deficits and reduced mental status.Corneal Pachymetry: Measurement of the thickness of the CORNEA.Regional Blood Flow: The flow of BLOOD through or around an organ or region of the body.Brain Mapping: Imaging techniques used to colocalize sites of brain functions or physiological activity with brain structures.False Negative Reactions: Negative test results in subjects who possess the attribute for which the test is conducted. The labeling of diseased persons as healthy when screening in the detection of disease. (Last, A Dictionary of Epidemiology, 2d ed)Vascular Calcification: Deposition of calcium into the blood vessel structures. Excessive calcification of the vessels are associated with ATHEROSCLEROTIC PLAQUES formation particularly after MYOCARDIAL INFARCTION (see MONCKEBERG MEDIAL CALCIFIC SCLEROSIS) and chronic kidney diseases which in turn increase VASCULAR STIFFNESS.Echocardiography: Ultrasonic recording of the size, motion, and composition of the heart and surrounding tissues. The standard approach is transthoracic.Aortic Diseases: Pathological processes involving any part of the AORTA.Endosonography: Ultrasonography of internal organs using an ultrasound transducer sometimes mounted on a fiberoptic endoscope. In endosonography the transducer converts electronic signals into acoustic pulses or continuous waves and acts also as a receiver to detect reflected pulses from within the organ. An audiovisual-electronic interface converts the detected or processed echo signals, which pass through the electronics of the instrument, into a form that the technologist can evaluate. The procedure should not be confused with ENDOSCOPY which employs a special instrument called an endoscope. The "endo-" of endosonography refers to the examination of tissue within hollow organs, with reference to the usual ultrasonography procedure which is performed externally or transcutaneously.Xenon Radioisotopes: Unstable isotopes of xenon that decay or disintegrate emitting radiation. Xe atoms with atomic weights 121-123, 125, 127, 133, 135, 137-145 are radioactive xenon isotopes.Retinal Pigment Epithelium: The single layer of pigment-containing epithelial cells in the RETINA, situated closely to the tips (outer segments) of the RETINAL PHOTORECEPTOR CELLS. These epithelial cells are macroglia that perform essential functions for the photoreceptor cells, such as in nutrient transport, phagocytosis of the shed photoreceptor membranes, and ensuring retinal attachment.Electric Impedance: The resistance to the flow of either alternating or direct electrical current.Radius: The outer shorter of the two bones of the FOREARM, lying parallel to the ULNA and partially revolving around it.Radiography, Interventional: Diagnostic and therapeutic procedures that are invasive or surgical in nature, and require the expertise of a specially trained radiologist. In general, they are more invasive than diagnostic imaging but less invasive than major surgery. They often involve catheterization, fluoroscopy, or computed tomography. Some examples include percutaneous transhepatic cholangiography, percutaneous transthoracic biopsy, balloon angioplasty, and arterial embolization.Retinal Photoreceptor Cell Outer Segment: The light sensitive outer portion of a retinal rod or a cone photoreceptor cell. The outer segment contains a stack of disk membranes laden with photoreceptive pigments (RETINAL PIGMENTS). The outer segment is connected to the inner segment by a PHOTORECEPTOR CONNECTING CILIUM.Computer Simulation: Computer-based representation of physical systems and phenomena such as chemical processes.Diagnostic Errors: Incorrect diagnoses after clinical examination or technical diagnostic procedures.Radiography, Dual-Energy Scanned Projection: A method of producing a high-quality scan by digitizing and subtracting the images produced by high- and low-energy x-rays.Acoustics: The branch of physics that deals with sound and sound waves. In medicine it is often applied in procedures in speech and hearing studies. With regard to the environment, it refers to the characteristics of a room, auditorium, theatre, building, etc. that determines the audibility or fidelity of sounds in it. (From Random House Unabridged Dictionary, 2d ed)Skull Fractures: Fractures of the skull which may result from penetrating or nonpenetrating head injuries or rarely BONE DISEASES (see also FRACTURES, SPONTANEOUS). Skull fractures may be classified by location (e.g., SKULL FRACTURE, BASILAR), radiographic appearance (e.g., linear), or based upon cranial integrity (e.g., SKULL FRACTURE, DEPRESSED).
  • ABSTRACT - A retrospective study was performed in order to evaluate the frequency of abnormalities found by computed tomography (CT) scan of the head in 78 patients with migraine or tension-type headache. (scielo.br)
  • To analyze the computed tomography (CT) findings of lymphocytic interstitial pneumonia (LIP). (scielo.br)
  • We retrospectively reviewed the clinical and CT findings of 36 patients with LIP, including 25 women and 11 men, with a mean age of 52.5 years (age range, 22-78 years). (scielo.br)
  • To investigate the prevalence of macular abnormalities in patients affected by Usher syndrome (USH), by comparing the clinical findings between two types (i.e. (nih.gov)
  • Based on these findings, OCT screening in USH patients is recommended for early detection of macular changes and early treatment. (nih.gov)
  • In 39 patients who harbored previously untreated astrocytomas (21 patients), oligoastrocytomas (9 patients), or oligodendrogliomas (9 patients), computed tomographic (CT) and magnetic resonance imaging (MRI) findings were correlated with stereotactic serial biopsy findings. (nih.gov)
  • Up to 15% of patients with endometrioid G3 cancer had clinically relevant incidental findings that necessitated medical or surgical intervention. (ovid.com)
  • The aim of the present study was to investigate correlations between the levels of antibody against GPL core and chest computed tomography (CCT) findings in patients with MAC lung disease. (ersjournals.com)
  • The present results document that the levels of immunoglobulin A antibody against glycopeptidolipid core correlate with the chest computed tomography findings of Mycobacterium avium complex lung disease. (ersjournals.com)
  • Therefore, the present authors assess herein the levels of GPL core antibody in relation to chest computed tomography (CCT) findings in patients with MAC-culture positive sputum whose radiographic findings were infiltrate, nodular cavitary lesions or bronchiectasis and/or multiple small nodules. (ersjournals.com)
  • Whole-body positron emission tomography (WB PET) was performed preoperatively in 24 patients with primary colorectal cancer, and the results were compared with the histopathological findings. (spandidos-publications.com)
  • Patient records were assessed for age, sex, clinical presentation, standard uptake values (SUV max ), on FDG-PET/CT, and CT findings in those patients undergoing FDG-PET/CT, fine-needle aspiration (FNA) cytology, and surgical pathologic examination. (ajnr.org)
  • Five (27.8%) of 18 patients with incidental focal FDG-PET/CT uptake in the thyroid gland demonstrated papillary thyroid carcinoma on final pathologic findings. (ajnr.org)
  • No statistical difference in SUV max was noted between patients with papillary thyroid carcinoma and patients with benign pathologic findings ( P = .63). (ajnr.org)
  • First, the authors classified patients into groups of those with CCI and those without CCI, and they compared clinical and radiological findings between them. (thejns.org)
  • Adventage and disadvantage of Computerized tomography were summarized after comparetive analysis of the radiological findings of the 26 cases. (koreamed.org)
  • Consecutive patients with minor head injury (loss of consciousness with normal findings on a brief neurological examination and a score of 15 on the Glasgow Coma Scale) in 2 phases (520 in the derivation set, 909 in the validation set, each with mean age 36 y, 65% men). (bmj.com)
  • Patients were separated into 2 groups: those who had 0 findings and those who had ≥1 of the 7 findings. (bmj.com)
  • We report preliminary findings from a study of patient-volunteer experience in a clinical trial of optical mammography. (spie.org)
  • In this post-hoc analysis we described findings on head computed tomography (CT) after CA. We also examined whether generalised oedema on CT alone or together with the biomarker Neuron-specific enolase (NSE) could predict poor outcome. (lu.se)
  • Compared to CT alone, FDG-PET/CT provided more supplemental findings suggesting malignant manifestations in 48 (47%) of the 103 patients. (lu.se)
  • The additional FDG-PET/CT findings led to an altered provisional treatment plan in 28 out of 103 patients (27%), detection of disseminated bladder cancer and subsequent cancellation of the initially intended cystectomy in 16 patients, and identification of disseminated disease and treatment with induction chemotherapy before radical cystectomy in 12 patients. (lu.se)
  • The study used a scan called Single Photon Emission Computed Tomography (or SPECT) to evaluate heart damage. (oncolink.org)
  • The effect of acetazolamide on regional cerebral blood flow in normal human subjects as measured by single-photon emission computed tomography. (thejns.org)
  • 564 - 568 , 1988 Bonte F, Devous M, Reisch JS: The effect of acetazolamide on regional cerebral blood flow in normal human subjects as measured by single-photon emission computed tomography. (thejns.org)
  • The purpose of the study was to investigate the usefulness of quantitative salivary single-photon emission computed tomography/computed tomography (SPECT/CT) using Tc-99m pertechnetate in Sjögren's syndrome (SS). (springer.com)
  • To test the hypothesis, we reanalyzed 2-h-long [ 18 F]fluorodopa (FDOPA)/PET recordings from eight unmedicated patients with schizophrenia and 15 healthy age-matched control subjects, using new methods for the quantification of [ 18 F]fluorodopamine steady-state kinetics. (jneurosci.org)
  • To test this hypothesis, we used our new methods to calculate the magnitudes of the steady-state parameters K , k loss , and V d in brain of eight nonmedicated male patients with schizophrenia and in 15 age-matched healthy male control subjects. (jneurosci.org)
  • Materials and Methods: Retrospective study of patients' records retrieved from radiology and medical records departments of the hospital. (who.int)
  • Patients and Methods: This prospective study included 7 patients with UCH and a control group of 6 volunteers. (uva.nl)
  • Methods- Patients suspicious of SAH and a normal level of consciousness presenting to our tertiary care hospital between 2005 and 2012 were included. (ahajournals.org)
  • Methods We analysed data from two large sequential prospective cohorts of ED patients with acute headache undergoing CT for suspected SAH. (bmj.com)
  • METHODS One hundred and fifty consecutive patients with RA were selected from a hospital outpatient department, irrespective of the presence or absence of chest disease. (bmj.com)
  • Conventional imaging methods such as computed tomography (CT) show the structure and location of healthy and abnormal tissue. (healthcanal.com)
  • Patients and methods 10 patients scheduled for revision hip replacement due to suspected wear or loosening were scanned twice with CT under torsion loading of the prosthesis. (diva-portal.org)
  • Methods A retrospective, comparative cohort analysis of 95 patients who had IVP and 109 patients who had NHCT was performed. (bmj.com)
  • Although optical colonoscopy has been the dominant method for CRC screening in the United States to date, other methods that are also recommended by established guidelines include computed tomography (CT) colonography, guaiac-based fecal occult blood test, fecal immunochemical test, fecal immunochemical test-DNA (ie, Cologuard), flexible sigmoidoscopy, and flexible sigmoidoscopy with fecal immunochemical test. (ahdbonline.com)
  • Methods: A post hoc analysis was performed in a national prospective cohort of 639 patients with necrotizing pancreatitis. (eur.nl)
  • In 2004, during the evaluation of dissemination of the asymptomatic disease, positron emission tomography revealed a high uptake by the descending colon despite the failure of other imaging methods. (diva-portal.org)
  • Previous studies have not determined the predictive value of ascites detected on computed tomography (CT) for the presence of PM. We aimed to analyze the factors that are associated with PM in patients with CT-detected ascites.A total of 2207 consecutive patients who were diagnosed with gastric cancer between 2004 and 2013 were identified. (deepdyve.com)
  • In the earlier histopathology study, assessing ACA specimens after trabeculotomy and/or trabeculectomy (10 eyes), Anderson found that patients with PCG had thicker trabecular beams with both histologic and clinical evidence of iris root traction that obstructs the aqueous outflow. (nature.com)
  • The main objective of this observational cohort study is to explore the correlation between changes on OCT retinal parameters and and clinical disability as measured by the ALS Functional Rating Scale (ALS-FRS-r) in patients with ALS at baseline, 3 and 6 months. (clinicaltrials.gov)
  • ii) clinical course and (iii) Corticosteroid Randomisation after Significant Head Injury acute calculator protocol (CRASH) model and clinical outcome in patients with severe traumatic brain injury (sTBI). (diva-portal.org)
  • The aim of this study was to determine the clinical utility of routine preoperative pelvic and abdominal computed tomography (CT) examinations in patients with endometrial cancer (EC). (ovid.com)
  • Prospective data on clinical outcomes in patients with coronary artery calcium were assessed. (annals.org)
  • However, too few data currently exist to support the broad use of this tool in clinical decision making during the evaluation of patients with known or suspected coronary artery disease. (annals.org)
  • These PET results are in contrast to the characteristic clinical picture of UCH patients and suggest the possibility of subgroups in patients with a mandibular asymmetry caused by UCH. (uva.nl)
  • Therefore, we investigated test characteristics of head CT in patients with a clinical suspicion of SAH. (ahajournals.org)
  • We included all patients presenting to our emergency department between January 1, 2005, and January 1, 2012, with a clinical suspicion of nontraumatic SAH and a normal level of consciousness (defined as Glasgow Coma scale score of 15). (ahajournals.org)
  • The present study shows the feasibility and potential clinical relevance of quantitative [ 11 C]docetaxel PET studies in patients with lung cancer. (aacrjournals.org)
  • However, clinical failure of docetaxel therapy remains a major problem, and often patients are subjected to therapy-related toxicity without gaining benefit. (aacrjournals.org)
  • We report a summary of the evidence supporting the role of CCTA in the detection of subclinical and clinical coronary artery disease in both asymptomatic and symptomatic patients and discuss the potential of CCTA to augment the identification of at-risk individuals. (ahajournals.org)
  • The purpose of this study was to determine the clinical significance of incidental FDG-PET/CT uptake in the thyroid in patients with lymphomas and/or cancers of nonthyroidal origin and develop a management algorithm on the basis of the available data. (ajnr.org)
  • Although the number of clinical applications for fluorine-18 fluorodeoxyglucose ( 18 F-FDG) cardiac positron emission tomography (PET) has continued to grow, there remains a lack of consensus regarding the ideal method of suppressing normal myocardial glucose utilization for image optimization. (springer.com)
  • QUESTION: In patients with minor head injury, can a clinical decision rule using 7 clinical criteria identify those patients who do not need computed tomography (CT)? (bmj.com)
  • All of these patients had ≥1 of the clinical findingsbefore CT scanning (sensitivity 100%, specificity 25%) (table). (bmj.com)
  • In patients with at least mild AS, the presence of severe AVC on noncontrast CT provides prognostic data that are incremental to clinical variables and AS severity by echocardiography. (acc.org)
  • We hypothesise that this qualitative data can usefully supplement the technical data collected during clinical tests and be of practical value in decision-making about design modifications, development priorities, and improving acceptability to patients. (spie.org)
  • Computed tomography (CT), in particular, is one of the diagnostic tools that has broken new ground in the field of modern medicine and has expanded its clinical usefulness since its development in 1972. (signavitae.com)
  • Background: Identification of patients with necrotizing pancreatitis at high risk for a complicated course could facilitate clinical decision-making. (eur.nl)
  • The aim of this study was to evaluate the clinical use of [F-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) in addition to conventional preoperative radiological investigations in a defined group of patients with high-risk muscle-invasive bladder cancer. (lu.se)
  • We analyzed the prevalence and clinical relevance of MVs in patients with coronary artery disease. (onlinejacc.org)
  • To briefly review the role of calcium in the pathophysiology of atherosclerosis and to comprehensively review and analyze studies of coronary artery calcium detected by electron-beam computed tomography (CT). (annals.org)
  • A Report of the American College of Cardiology Foundation Appropriate Use Criteria Task Force, the Society of Cardiovascular Computed Tomography, the American College of Radiology, the American Heart Association, the American Society of Echocardiography, the American Society of Nuclear Cardiology, the North American Society for Cardiovascular Imaging, the Society for Cardiovascular Angiog. (medscape.com)
  • Beaumont Health System research, published in the June 20 online issue of the Journal of Cardiovascular Computed Tomography , found that the use of advanced CT scanning equipment is helping to address this important concern. (bio-medicine.org)
  • Serum antibodies against myelin-oligodendrocyte-glycoprotein (MOG-IgG) are detectable in a proportion of patients with acute or relapsing neuroinflammation. (unboundmedicine.com)
  • Background and Purpose- A recent study suggested that in patients with acute headache suspicious of nontraumatic subarachnoid hemorrhage (SAH), cerebrospinal fluid (CSF) analysis is not needed to rule out SAH if head CT performed ≤6 hours after ictus is negative. (ahajournals.org)
  • Conclusions- In patients presenting with acute headache and a normal head CT ≤6 hours after ictus, as interpreted by experienced neuroradiologists, there is no added value of CSF analysis. (ahajournals.org)
  • Providing computed tomography colonography (CTC) otherwise known as v...CRC is the second leading cause of cancer in the U.S. While colonosco. (bio-medicine.org)
  • Providing computed tomography colonography (CTC) otherwise known as virtual colonoscopy as an alternative to conventional colonoscopy could improve colorectal cancer (CRC) screening rates, according to a study in the November issue of the American Journal of Roentgenology ( www.ajronline.org ). (bio-medicine.org)
  • Our study, for the first time in the literature, showed the distribution of all macular abnormalities assessed by SD-OCT in a large USH cohort, comparing USH1 and USH2 patients. (nih.gov)
  • We observed that ocular abnormalities are highly prevalent in USH patients compared to general population, with ERM and CME being the most common alterations. (nih.gov)
  • Stereotactic histologic correlations of computed tomography- and magnetic resonance imaging-defined abnormalities in patients with glial neoplasms. (nih.gov)
  • Fortunately, the majority of these lesions are benign anomalies.The incidence of such abnormalities depends on the age, gender, and race of the patient as well as the environmental or geographic influences, which may predominate in a given population. (scielo.br)
  • In this regard, at least two thirds of the patients, referred to a neurologist because of headache, are worried about the presence of brain tumor or other intracranial abnormalities 3 . (scielo.br)
  • These patients should be followed closely to determine if abnormalities on SPECT are a way to predict who might develop cardiac complications, allowing them to be more closely monitored. (oncolink.org)
  • Our results demonstrate that as many as 60% of HIV-infected patients have unexpected abnormalities on HRCT at the time of starting PCP prophylaxis. (ersjournals.com)
  • A total of 47 patients with MAC-positive culture from their sputum and who had radiographic abnormalities were investigated. (ersjournals.com)
  • This study was conducted to determine the value of computed tomography [‎CT]‎ pelvimetry in patients with previous caesarean section. (who.int)
  • Fields WS: Study group on computed tomography: Computed tomography in the management of cerebrovascular disease. (springer.com)
  • These patients had a significantly higher age, but were otherwise similar to the remaining part of the study population. (springer.com)
  • Furthermore, we sincerely thank all the patients who agreed to participate in our study. (springer.com)
  • The main purpose of this study is to compare the incidence of contrast induced nephrotoxicity following the administration of Isovue (iopamidol) or Visipaque in diabetic patients with moderate to severe chronic renal impairment undergoing clinically indicated contrast enhanced multidetector computed tomography (MDCT). (clinicaltrials.gov)
  • This study examined the ability of the extreme lateral interbody fusion (XLIF) procedure to restore coronal and sagittal alignments for patients with adult spinal deformity (ASD) using computed tomography multiplanar reconstruction (CT-MPR). (nature.com)
  • This study evaluated the alignment improvement effect of stand-alone XLIF in ASD patients using CT-MPR. (nature.com)
  • Twenty-eight eyes of 28 patients were included in the study. (dovepress.com)
  • The study, performed at the National Naval Medical Center in Bethesda, MD, included 250 consecutive average-risk patients undergoing CRC screening who completed a survey that assessed reasons for choosing CTC in lieu of colonoscopy, compliance with CRC screening if CTC was not offered and which of the two tests they preferred. (bio-medicine.org)
  • The study of 2085 patients at nine centers in the U.S. and Middle Ea. (bio-medicine.org)
  • The study, of 2,085 patients at nine centers in the U.S. and Middle East, found that using newer generation, dual-source CT scanners significantly reduced radiation exposure for patients when compared with first generation, 64-slice, single-source scanners or first generation, dual-source CT scanners. (bio-medicine.org)
  • Therefore, this study aimed to investigate longitudinally intra-retinal layer changes in eyes without new optic neuritis (ON) in MOG-IgG-seropositive patients. (unboundmedicine.com)
  • Our institutional review board approved the study protocol, and all patients gave informed consent. (ahajournals.org)
  • In this study, we included data from 1000 consecutive patients with blunt trauma who were transferred directly from the scene to the emergency department of our institution, a metropolitan trauma centre, between July 2006 and November 2008. (cmaj.ca)
  • Background: The objective is to study intracranial complications of HIV/AIDS using brain-computed tomography in patients who presented with neurological features before the advent of subsidized HIV/AIDS treatment program with highly active antiretroviral therapy (HAART) in Nigeria. (who.int)
  • Prospective study of patients with ST undergoing reintervention with OCT imaging. (revespcardiol.org)
  • The study included a total of 40 consecutive patients with ST. Mean age was 69 ± 13 years and 83% were male. (revespcardiol.org)
  • Provision of study materials or patients: D.C. Christiani, J.K. Field. (annals.org)
  • Purpose: The purpose of this study was to assess bone growth and blood flow in the condylar region in patients with unilateral condylar hyperactivity (UCH) by use of positron emission tomography (PET). (uva.nl)
  • After completion of study therapy, patients are followed up every 3 months for 1 year, every 4 months for 2-3 years, every 6 months for 4-5 years, and then annually for up to 10 years. (bioportfolio.com)
  • This study was conducted at the University Medical Center Utrecht, the Netherlands, which is a tertiary referral center for patients with SAH. (ahajournals.org)
  • A computed tomography (CT) study of the morphology of the C1 vertebra. (ovid.com)
  • Doctor of Philosophy (PhD) Student in Medical Physics, 2017-PresentAs an early Medical Physics PhD student in the "Imaging" track, I currently study contrast-enhanced Computed Tomography (CT) imaging, with the goal of quantifying, managing, mitigating, monitoring, and optimizing variability of the protocol. (duke.edu)
  • The primary objective of this study was to assess the usefulness of early [ 18 F]-FDG PET to monitor treatment efficacy and its correlation with Response Evaluation Criteria in Solid Tumors (RECIST) in patients with TETs. (aacrjournals.org)
  • The purpose of this study was to determine the significance of incidental fluorodeoxyglucose (FDG) uptake in the thyroid gland on [ 18 F]FDG-positron-emission tomography (FDG-PET/CT) in patients being initially staged for lymphomas and/or cancers other than of thyroid origin. (ajnr.org)
  • The aim of this study was to determine the prevalence of FA, as assessed by HRCT scanning, in a hospital outpatient population of patients with RA. (bmj.com)
  • On the basis of these study results, a patient-relevant benefit of PET can neither be proven nor refuted. (healthcanal.com)
  • In this study the authors use positron emission tomography (PET) to investigate cerebral blood flow (CBF) and cerebrovascular reserve (CVR) in chronic hydrocephalus. (thejns.org)
  • After completion of study therapy, patients are followed up every 3 months for 2 years and then every 6 months thereafter. (bioportfolio.com)
  • Conformal Radiation Therapy for Pediatric Patients with Low-Grade Glioma: Results from the Children's Oncology Group Phase II Study XXXX. (bioportfolio.com)
  • The mean age of study patients was 30 years and the median visual acuity was 20/30. (arvojournals.org)
  • We conducted a retrospective cohort study of all code stroke patients presenting to our ED over a 3 year period ending in February 2011. (ahajournals.org)
  • Finally, a study was performed to quantify the effects of matching a patient by height, weight, and body mass index (BMI) to a patient-dependent phantom for four exam protocols with and without ATCM. (ufl.edu)
  • The study involved 27 adult patients, whose simulated organ doses were compared with those of the patient-dependent phantoms. (ufl.edu)
  • Compared to IVP, NHCT has not impacted positively on the speed of patient processing in the ED under study. (bmj.com)
  • This study evaluated 794 patients with at least mild AS by echocardiography undergoing noncontrast CT at three centers. (acc.org)
  • The study cohort comprises 22 patients (22 eyes) with uveitic CMO receiving a sub-Tenon's triamcinolone acetonide (STTA) injection. (bmj.com)
  • The primary objective of this study was to assess the liberal use of CT induced radiation exposure in patients with multiple blunt traumas. (signavitae.com)
  • This study was a retrospective study performed for multiple blunt trauma patients visiting the Korea University Guro Hospital via emergency room from July 2012 to June 2013. (signavitae.com)
  • In total, 103 patients with high-risk muscle-invasive bladder cancer defined as stage T3/T4 disease or as stage T2 with hydronephrosis or high-risk histological features, who were provisionally scheduled to undergo cystectomy, were prospectively recruited to the study. (lu.se)
  • prevalence of significant CAD in the study population was 26% (13 of 50 patients). (uzh.ch)
  • A prospective cohort study on blood pressure control and risk of ischemic stroke in patients with hypertension]. (physiciansweekly.com)
  • One study about unnecessary screening before surgery reported that physicians order unnecessary tests because of tradition in the practice of medicine, anticipation that other physicians will expect the test results when they see the patient, defensive medicine, worries that a surgery may be canceled if the test is not done, and lack of understanding about when a test is actually indicated. (wikipedia.org)
  • The radiopharmaceutical [18F] 2-deoxyglucose will be used as both an imaging modality and to evaluate tumor metabolism in patients with breast cancer. (knowcancer.com)
  • To evaluate the complete response rate in patients treated with these regimens. (bioportfolio.com)
  • Our objective was to evaluate which patient and hospital factors were associated with earlier neuroimaging in alert, neurologically intact ED patients with suspected SAH. (bmj.com)
  • We sought to evaluate the rate of normal CTA and the use of tPA in AIS patients with and without blockages using modern CT technology. (ahajournals.org)
  • It has been considered that guideline committees might not appropriately do cost-effectiveness analysis, consider opportunity cost, or evaluate risks to patients when they broaden screening recommendations. (wikipedia.org)
  • A secondary objective is to explore the correlation between changes in retinal OCT parameters and pulmonary function tests (FVC and FEV1) in this cohort of patients with ALS. (clinicaltrials.gov)
  • Lung transplantation is an established therapeutic option for patients with irreversible end-stage pulmonary disease limiting life expectancy and quality of life. (medworm.com)
  • Fifty four percent of patients with HRCT evidence of FA had bilateral basal chest crackles, 82% had a reduced carbon monoxide transfer factor (T lco ), 14% had restrictive pulmonary function tests, and 14% had bilateral chest radiographic signs of FA. (bmj.com)
  • Chest radiographic changes occur in 1-5% of patients with RA, depression of carbon monoxide transfer factor (T lco ) in up to 41%, 6 and pulmonary fibrosis in 60% of volunteers undergoing open lung biopsy. (bmj.com)
  • Optic coherence tomography measures retinal layer thickness, macular volume , and cell inner plexiform layer. (clinicaltrials.gov)
  • Retinal angiomatous proliferation may be successfully managed with ranibizumab monotherapy in Korean patients, with the number of treatments required comparable to other forms of neovascular age-related macular degeneration. (biomedsearch.com)
  • In all RP patients imaged by OMAG, abnormal microvasculature was detected in both the deeper retinal vasculature layer (from the inner nuclear layer to the external limiting membrane) and the choroidal vasculature. (arvojournals.org)
  • On examination, the patient was dehydrated but alert and oriented. (bmj.com)
  • Digital rectal examination was tender for the patient and there were firm stools in the rectum. (bmj.com)
  • Since pain is a subjective complaint, the indications for neuroimaging examination for patients with headache are still disputed with. (scielo.br)
  • For each patient examination Volumetric Computed Tomography Dose Index (CTDIvol) and Dose Length Product (DLP) should be collected from the dose report. (knowcancer.com)
  • Movement of the patient support plate and the diaphragm plates between respective end positions is coordinated during a dynamic computed tomography examination of a subject so as to reduce and homogenize the dose of x-ray radiation to which the subject is exposed during the examination. (patentgenius.com)
  • and coordinating the back and forth movement of said support plate between said first andsecond support plate end positions and the back and forth movement of said diaphragm elements between said first and second diaphragm element end positions to homogenize a dose of x-ray radiation applied to the patient by said x-ray beam during saiddynamic computed tomography examination. (patentgenius.com)
  • Accordingly, such examination can potentially improve the preoperative staging of cystectomy patients with high-risk features, and may also reduce the number of futile operations in patients with advanced disease who are beyond cure. (lu.se)
  • CCTA and coronary artery calcium scoring offer the ability to improve risk stratification, discrimination, and reclassification of the risk in patients with suspected coronary artery disease and to noninvasively determine the measures of stenosis severity and atherosclerotic plaque features. (ahajournals.org)
  • In conclusion, computerized tomography/magnetic resonance imaging and octreotide scintigraphy may be insufficient to show disseminated disease and asymptomatic second primary malignancies. (diva-portal.org)
  • The records of consecutive patients who received a thoracic epidural catheter were reviewed. (hindawi.com)
  • The first database included consecutive patients with confirmed SAH and the second included all patients receiving lumbar puncture with CSF spectrophotometry. (ahajournals.org)
  • However, these studies have been retrospective in symptomatic patients 8-10 or the appearances consistent with interstitial lung disease (ILD) have not been specifically identified as being in keeping with FA. (bmj.com)
  • Swain SM, Whaley FS, Ewer MS. Congestive heart failure in patients treated with doxorubicin a retrospective analysis of three trials. (springer.com)
  • In this retrospective analysis of prospectively collected data, we found that effective treatment with chemotherapy or targeted therapy causes rapid reduction in [ 18 F]-FDG uptake in patients with advanced or recurrent TETs. (aacrjournals.org)
  • A retrospective review was conducted on patients who were incidentally found to have focal FDG uptake in the thyroid bed on initial staging for cancer. (ajnr.org)
  • OBJECTIVE: To determine the correlation between patient attributes and contrast enhancement in liver parenchyma and demonstrate the potential for patient-informed prediction and optimization of contrast enhancement in liver imaging. (duke.edu)
  • To determine the proportion of haemorrhagic strokes misdiagnosed as infarcts on computed tomography (CT) in patients with mild stroke, and the implications for health care. (bmj.com)
  • The present authors have previously reported the usefulness of a serodiagnostic test to detect serum glycopeptidolipid (GPL) core antibody in diagnosing Mycobacterium avium complex (MAC) lung disease in immunocompetent patients. (ersjournals.com)
  • The present authors examined the usefulness of the GPL serodiagnostic test in immunocompetent patients with lung disease and found that MAC lung disease could be clearly differentiated from colonisation with MAC and from lung diseases caused by either M. tuberculosis or M. kansasii . (ersjournals.com)
  • Docetaxel is an effective drug for the treatment of patients with several advanced malignancies including breast cancer, prostate cancer, and lung cancer. (aacrjournals.org)
  • The primary tumor site was correctly identified by FDG-PET/CT in 24 patients (24/68, 35.3%): lung (n=9), rino/oro-pharynx (n=6), pancreas (n=5), colon (n=2), uterus (n=2). (minervamedica.it)
  • The mean tidal volume values obtained with pneumotach and TIE4sys on the second group of COPD patients (M:4) were: 0.798±0.395 L and 0.732±0.327 L. The mean of the differences was 0.066±0.114L. The differences of determinations estimated with pneumotach and TIE4sys can be attributed to changes of anthropometric characteristics like subscapular skinfold. (upc.edu)
  • A number of studies have measured the mean skin to epidural space depth (SES) in various patient populations and have proposed prediction models based on anthropometric measures and imaging. (hindawi.com)
  • However, changes in the epidural space that occur during pregnancy, as well as differences between the morphology of the thoracic and lumbar regions of the spine, make these studies inapplicable to nonobstetric patients receiving an epidural at the thoracic intervertebral levels. (hindawi.com)
  • Visual evoked potentials studies in patients with ALS suggest visual pathway involvement. (clinicaltrials.gov)
  • Clinicians must understand that imaging studies not only have a major impact on the care of an individual patient, but also on trends in radiation exposure, as well as overall health care costs," says Dr. Chinnaiyan. (bio-medicine.org)
  • Previous positron emission tomography (PET) studies with levodopa analogs have revealed a modestly increased capacity for dopamine synthesis in the striatum of patients with schizophrenia compared with healthy age-matched control subjects. (jneurosci.org)
  • To date, PET studies with DOPA decarboxylase substrates in patients with schizophrenia have used incomplete kinetic models, not accommodating the dynamics of the entire pathway for dopamine synthesis and turnover but incorrectly assuming irreversible trapping of the decarboxylated radiotracers. (jneurosci.org)
  • All studies of electron-beam CT in symptomatic and asymptomatic patients with and without known coronary artery disease were selected. (annals.org)
  • Patients may undergo blood sample collection for biomarker studies. (bioportfolio.com)
  • In the future, microdosing studies using [ 11 C]docetaxel may be used to predict benefit from docetaxel in individual patients. (aacrjournals.org)
  • Using [ 11 C]docetaxel and positron emission tomography (PET), microdosing studies can be carried out to monitor pharmacokinetics and pharmacodynamics of docetaxel noninvasively in patients. (aacrjournals.org)
  • 7 HRCT based studies have reported changes consistent with FA in up to 62.6% of patients with RA. (bmj.com)
  • This randomized phase II trial studies how well positron emission tomography (PET)/computed tomography (CT)-guided radiation therapy works compared to standard radiation therapy in treatin. (bioportfolio.com)
  • This review describes various patient preparation protocols that have been used as well as the success rates achieved in different studies. (springer.com)
  • The 2 studies show that for both conditions a small but important, clinically identifiable subset of patients can have imaging studies safely omitted. (bmj.com)
  • Of these patients, 188 were found to have brain metastases, and it is estimated that for this subgroup prophylactic diazepam reduces the risk of contrast-associated seizure by a factor of 0.26. (ajnr.org)
  • Introduction Non-contrast helical CT (NHCT) became the procedure of choice for investigating Emergency Department (ED) patients presenting with suspected renal colic at Beaumont Hospital, Dublin, in 2008. (bmj.com)
  • Skeletal muscle mass, skeletal muscle density, and visceral adipose tissue were measured at the third lumbar vertebra level (L3) on contrast-enhanced computed tomography (CT) within 10 days after initial admission and 1 month thereafter. (eur.nl)
  • Furthermore, the presence of neoatherosclerosis was very high (67%) in patients with late ST. After intervention, improvements were observed in malapposition length and the amount of residual thrombus. (revespcardiol.org)