magnetic resonance imaging


Also found in: Dictionary, Thesaurus, Medical, Acronyms, Wikipedia.
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
..... Click the link for more information.
 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 The patient is then subjected to radio waves, which cause the aligned nuclei to "flip"; when the radio waves are withdrawn the nuclei return to their original positions, emitting radio waves that are then detected by a receiver and translated into a two-dimensional picture by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.
..... Click the link for more information.
, 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 ?
2%) had acoustic neuroma on magnetic resonance imaging while 12 patients (21.
Value of fat suppression magnetic resonance imaging in the diagnosis of lipomas of the internal auditory canal.
Functional magnetic resonance imaging (fMRI) provides a mechanism for imaging patterns of ongoing activity in various regions of the brain.
These centers develop products of the latest-generation diagnostic techniques, from X-ray and computed tomography (CT) to magnetic resonance imaging (MRI), echocontrast and nuclear medicine.
a leading developer of next-generation solutions for high-performance preclinical and clinical Magnetic Resonance Imaging (MRI) coils, probes and accessories, has raised $3.
Now, through the use of magnetic resonance imaging -- a technique that exposes the anatomy of living brains--scientists have identified an abnormality in the hippocampal formation of amnesia patients.
NASDAQ: EPIX), a developer of innovative pharmaceuticals for magnetic resonance imaging (MRI) which recently announced a definitive agreement to merge with Predix Pharmaceuticals Holdings, Inc.
Halperin and his co-workers did spinal taps on 53 patients and tested various patients with brain magnetic resonance imaging and "evoked potentials," a measure of electrical activity in stimulated sensory nerve cells.
InMed Diagnostic Services uses advanced imaging technologies such as Magnetic Resonance Imaging (MRI), Computed Tomography (CT), Digital Mammography, Breast MRI and Nuclear Medicine as well as X-Ray, General Radiography, Ultrasound and Bone Densitometry.
In magnetic resonance imaging, certain atomic nuclei in samples held within a magnetic field absorb, then emit, radio waves at characteristic frequencies.
NASDAQ: EPIX), a developer of innovative pharmaceuticals for magnetic resonance imaging (MRI), and Predix Pharmaceuticals, which has signed a definitive merger agreement with EPIX, announced today that the companies' presentation at the Pacific Growth Equities Life Sciences Growth Conference 2006 will be webcast live.

Full browser ?