Fig. 2.

fDM scatter plots with direction of first principal component (solid line). Left: fDM for a responding MB, showing a first principal component with high slope, compared with the diagonal (dotted line). Middle: fDM for a responding GBM, showing a first principal component with high slope, and conventional fDM analysis shows a substantial volume of decreased diffusion (dark grey pixels). Right: fDM for a nonresponding PNET, showing a first principal component with low slope. Light gray voxels indicate an increase in diffusion, dark gray voxels indicate a decrease in diffusion, and medium gray voxels indicate no change.