magnetic resonance imaging


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Related to magnetic resonance imaging: functional magnetic resonance imaging

magnetic resonance imaging

(MRI), noninvasive diagnostic technique that uses nuclear magnetic resonancemagnetic resonance,
in physics and chemistry, phenomenon produced by simultaneously applying a steady magnetic field and electromagnetic radiation (usually radio waves) to a sample of atoms and then adjusting the frequency of the radiation and the strength of the magnetic field
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 to produce cross-sectional images of organs and other internal body structures. The patient lies inside a large, hollow cylinder containing a strong electromagnet, which causes the nuclei of certain atoms in the body (especially those of hydrogen) to align magnetically. The patient is then subjected to radio waves, which cause the aligned nuclei to "flip"; when the radio waves are withdrawn the nuclei return to their original positions, emitting radio waves that are then detected by a receiver and translated into a two-dimensional picture by computer. Unhampered by bone and capable of producing images in a variety of planes, MRI is used in the diagnosis of brain tumors and disorders, spinal disorders, multiple sclerosis, and cardiovascular disease. The procedure is considered to be without risk, but the scanner may interfere with pacemakers, hearing aids, or other mechanical devices. Although the images are similar in many ways to those of CAT scansCAT scan
[computerized axial tomography], X-ray technique that allows relatively safe, painless, and rapid diagnosis in previously inaccessible areas of the body; also called CT scan.
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, they are obtained without X rays or other radiation, and generally provide more contrast between normal and abnormal tissue.

magnetic resonance imaging

[mag′ned·ik ′rez·ən·əns ′im·ij·iŋ]
(engineering)
A technique in which an object placed in a spatially varying magnetic field is subjected to a pulse of radio-frequency radiation, and the resulting nuclear magnetic resonance spectra are combined to give cross-sectional images. Abbreviated MRI.
References in periodicals archive ?
The competition in the magnetic resonance imaging industry is intense and has an immense potential opportunity for vendors (especially technology service providers) to integrate with medical devices for new product launches.
Cardiac Magnetic resonance imaging (CMRI) with its high quality spatial resolution is generally regarded to be the gold standard in determining cardiac functions and volumes.
The predictive value of endorectal 3 Tesla multiparametric magnetic resonance imaging for extraprostatic extension in patients with low, intermediate and high risk prostate cancer.
The etiology of cirrhosis is a strong determinant of brain reserve: A multimodal magnetic resonance imaging study.
Out of 55 patients 43 patients (78.2%) had acoustic neuroma on magnetic resonance imaging while 12 patients (21.8%) had no acoustic neuroma on magnetic resonance imaging.
There are several studies comparing Doppler echocardiography and radionuclide assays with cardiac magnetic resonance imaging in the assessment of regurgitant fraction (9); however, there is no study that compares cardiac angiography and cardiac magnetic resonance imaging (CMR) in determining the amount of pulmonary regurgitation.
Flaccid paraparesis with urinary retention developed at this point, and magnetic resonance imaging of the spine demonstrated signal enhancement at the level of the conus medullaris.
For more information about the brain and functional magnetic resonance imaging, visit this site: http://faculty.washington.edu/chudler/neurok.html
Using brain scans taken with magnetic resonance imaging, Lawrence Lowery, a professor emeritus at the University of California at Berkeley, makes an argument for inquiry-based instruction, rather than simply reading about a particular subject.
The right kind of training, it now appears, can do the same for the brain, though the enlargement can be shown off only to observers with magnetic resonance imaging (MRI) machines.
TORONTO -- High-resolution magnetic resonance imaging is potentially a better way to assess carotid plaque than is conventional carotid arteriography or ultrasound, Dr.
Professor Sir Peter Mansfield, of the University of Nottingham, received the prize jointly with American Paul C Lauterbur who also worked in the field of magnetic resonance imaging.

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