Fig 2. Representative regions of interest. A, Regions of interest for gray matter obtained from the frontal and temporal lobes (arrows). An average of the measurements was calculated. B, Region of interest for white matter obtained from the genu of the corpus callosum (arrow). C, Region of interest for CSF obtained from the frontal horn of the left ventricle (arrow). D, Region of interest for the SD of noise obtained from the noise in the upper left quadrant of the image.