Functional Magnetic Resonance Imaging of the Brain

doi:10.1059/0003-4819-122-4-199502150-00010

Functional Magnetic Resonance Imaging of the Brain

Denis Le Bihan, MD, PhD;
Peter Jezzard, PhD;
James Haxby, PhD;
Norihiro Sadato, MD, PhD;
Linda Rueckert, PhD; and
Venkata Mattay, MD

An edited summary of a Combined Clinical Staff Conference held 26 January 1994 at the National Institutes of Health, Bethesda, Maryland. The conference was sponsored by the Warren G. Magnuson Clinical Center, the National Institutes of Health, U.S. Department of Health and Human Services. Authors who wish to cite a section of the conference and specifically indicate its author may use this example for the form of the reference: Ruckert L. Use of functional magnetic resonance imaging in language, pp 299-300. In: Le Bihan D, moderator. Functional magnetic resonance imaging of the brain. Ann Intern Med. 1995; 122:296-303. Requests for Reprints: Denis Le Bihan, MD, PhD, Service Hospitalier Frederic Joliot, DRIPP, CEA, 4, place du General-Leclerc, 91401 Orsay Cedex, France.

Abstract

This conference reviewed the potential scope of application for recently developed techniques for functional magnetic resonance imaging (fMRI) of the brain.The most successful technique is based on the sensitivity of magnetic resonance imaging (MRI) to magnetic effects caused by the modulation of the oxygenation state of hemoglobin, which is induced by local variations in blood flow during task activation. Typically, the MRI signal increases by a few percentage points during brain activation because blood flow and oxygen supply sharply increase. Brain activation images with excellent combined spatial and temporal resolution have been obtained noninvasively using visual, sensorimotor, or auditory stimuli, or during higher-order cognitive processes such as language or mental imagery. Although sensitive to misregistration artifacts and macroscopic vessels, MRI permits both the direct correlation of function with underlying anatomy and repeated studies on the same person. It may become the method of choice for studies of mental and cognitive processes, presurgical mapping, monitoring recovery from stroke or head injuries, exploration of seizure disorders, or monitoring the effects of neuropharmaceuticals.