Development of a System for Functional Mapping of the Human Brain Using 1.5-Tesla Magnet, and Its Applications

ABSTRACT

Functional magnetic resonance imaging(fMRI) is a promising new imaging technique for functional mapping of cerebral cortex activation ; adequate image post-processing software is not readily available, however, we recently developed such a system based on the use of a personal computer, and evaluated its usefulness. With the cooperation of ten normal volunteers, 24 motor and five visual fMRIs activated by hand movement and photic stimulation, respectively, were performed on a 1.5-T MR unit using the gradient-echo technique(TR/TE/flip angle : 80/60/40degrees, 64X128 matrix). Functional maps were created by image post-processing, which consisted of subtraction, noise elimination by a statistical method, and coloration and overlapping of the images in sequence. All functional maps were successfully obtained. Twenty-four motor activation signals were detected in the sulci around the precentral gyrus, and five visual activation signals in the occipital lobes around the calcarine fissure. The image post-processing system developed in this study was useful for obtaining functional maps of human cerebral cortex activation. In conjunction with this system, fMRI can be successfully performed using a widely available 1.5-T MR unit.