ON THE CHARACTERISTICS OF FUNCTIONAL MAGNETIC-RESONANCE-IMAGING OF THE BRAIN

In this review we discuss various recent topics that characterize func tional magnetic resonance imaging (fMRI). These topics include a brief description of MRI image acquisition, how to cope with noise or signa l fluctuation, the basis of fMRI signal changes, and the relation of M RI signal to neuronal events. Several observations of fMRI that show g ood correlation to the neurofunction are referred to. Temporal charact eristics of fMRI signals and examples of how the feature of real time measurement is utilized are then described. The question of spatial re solution of fMRI, which must be dictated by the vascular structure ser ving the functional system, is discussed based on various fMRI observa tions. Finally, the advantage of fMRI mapping is shown in a few exampl es. Reviewing the vast number of recent fMRI application that have now been reported is beyond the scope of this article.