核磁気共鳴法を用いた脳機能測定法 (fMRI) の方法論入門

抄録

Functional magnetic resonance imaging (fMRI) is a new tool to evaluate the brain activities by analyzing the time-series of the images obtained by magnetic resonance imaging (MRI) scanners. In the typical fMRI experiments, the dynamic response of the regional cerebral blood flow (rCBF) to the task performed by the subject is detected. The fluctuation of the regional blood oxygenation level induced by the rCBF changes raise the contrast of each pixel of the images between the two or more conditions in the time-series, and the difference is statistically evaluated to represent the brain activation. The role of fMRI is to test the hypothesis of the neurological or cognitive network models. In this paper, the fundamentals of fMRI, history of the technical development, the physiological backgrounds, the basic experiment designs, the methods of data acquisition, statistical data analysis, some recent topics and the limitations of fMRI are reviewed from the view points of medical physics.