magnetic resonance imaging

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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 The patient is then subjected to radio waves, which cause the aligned nuclei to "flip"; when the radio waves are withdrawn the nuclei return to their original positions, emitting radio waves that are then detected by a receiver and translated into a two-dimensional picture by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 ?
Four physicians estimated the cost of an MRI scan at $200, whereas two estimated it at $1500.
Having experienced the benefits of having an MRI scan, Graham is backing the appeal as it will enable more patients to benefit from the most advanced technology available.
The seven-times capped player said: "I just wanted to get the MRI scan done quickly.
Mr Jones spoke out after John Saxby, chief executive of the University Hospital of North Durham, criticised the Government's purchase of MRI scans from a private health firm while his own scanner was "considerably under-employed".
Studies with a series of MRI scans over time showed how MS plaques actually develop and permitted researchers to track the "burden of disease" in individual patients.
I have another MRI scan in a couple of weeks so it will tell more hopefully."
Dacuycuy described an MRI scan as similar to a computed tomography (CT) scan.
Every year, about 200,000 patients in the US are implanted with ICDs, and studies estimate that 50 to 75 percent of them will develop a clinical need for an MRI scan during their lifetime.1, 2 MRI scans often provide improved diagnostic capabilities for certain diseases or conditions that cannot be adequately examined by X-ray, computerized tomography or ultrasound.
Globally, several million patients currently are implanted with pacemaker systems, and recent studies have estimated that a sizeable portion of them will develop a clinical need for an MRI scan during their lifetimes Entovis devices include Biotronik Flome Monitoring technology, which provides daily monitoring of the patient's device, and offer the most advanced physiological therapy available through closed loop stimulation.
Several million patients are currently implanted with pacemaker systems worldwide, and recent studies estimate that a sizeable portion of them will develop a clinical need for a MRI scan during their lifetimes.1,2 MRI scans often provide improved diagnostic capabilities for certain diseases or conditions that cannot be adequately examined by X-ray, computerized tomography (CT), or ultrasound.