Magnetic resonance imaging

Synonyms: MRI, Functional MRI

Medical Specialties: Family practice, Internal medicine, Radiology

Clinical Definition

Magnetic resonance imaging is a scan that employs a powerful magnetic field, radio frequency pulses and a computer to create detailed pictures of bone, soft tissues, organs and other structures. Functional MRI or fMRI is newer, using the scan to measure tiny metabolic changes taking place in an active neurological area to help examine anatomy, assess disease effects, monitor tumors or diagnose a disease.

In Our Own Words

Magnetic resonance imaging, or MRI, is a scan that produces clear images of the body without the use of x-rays. Instead, this noninvasive procedure uses a large magnet and radio waves along with a computer to create the images. Functional MRI or fMRI is a newer technique. It uses MRI technology to measure small changes that go on in an active part of the brain. The MRI unit is a large cylinder-like tube surrounded by the magnet. A patient lies on a moveable table that slides into the magnet.


Although less widely available, fMRI can help diagnose diseases, examine brain anatomy, and aid researchers study the effects of stroke, Alzheimer’s or other disease, as well as monitor brain tumors or help doctors plan brain surgery or radiation therapy.

Relevant Conditions
  • Alzheimer's disease
  • Cancer
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