FUNCTIONAL MAPPING OF ACTIVATED HUMAN PRIMARY CORTEX WITH A CLINICAL MR-IMAGING SYSTEM

Functional activation of the human brain can be visualized with magnet ic resonance (MR) imaging, but most studies so far have used echo-plan ar imaging or magnetic fields of 2 T and above, neither of which are a t present widely available. The authors used a standard 1.5-T MR imagi ng system to map regions of the brain that are activated with visual a nd motor tasks, using a long echo time (60 msec) fast low-angle shot s equence. Eleven visual and 14 motor studies were performed, and activa tion was seen in all cases. Up to 15% signal intensity change was appa rent in gray matter but not in white matter. The precise anatomic loca tion and extent of activation were defined by reference to T1-weighted images acquired during the same examination. This method of relating brain structure to function uses equipment that is widely available, w hich has considerable implications for the investigation of many neuro logic and neurosurgical diseases and for our understanding of brain fu nction and dysfunction.