FUNCTIONAL MAGNETIC-RESONANCE-IMAGING (FMRI) VISUALIZES THE BRAIN AT WORK

Functional Magnetic Resonance Imaging (fMRI) is a recent MRT technique capable of visualising neuronal activity in humans in a non-invase wa y. The technique visualises the physiological changes in oxy- and deox yhemoglobin concentration changes in small cortical blood vessels upon neuronal activation without the need for radiation or the administrat ion of contrast media or radioactive tracers. The spatial accuracy of the technique is of the order of millimeters and the temporal resoluti on of the order of one second The concept has captured the interest of neuroradiologists as well as neuroscientists, who now have a means to visualise their theories in human volunteers. In the clinical environ ment the non-invasive studies should aid neurosurgeons in adopting a s afe course into the brain and assist neurologists in unraveling neurol ogical hypotheses. This report describes the technical principals of f MRI and presents some of our clinical results on the mapping of severa l cortical functions, such as motor, auditory and language functions, in a large group of patients.