FIGURE 2. Correlations between regional DVt estimates by voxelwise graphical analysis and VOI-based graphical analysis without blood-volume correction (reference method). BVC = blood-volume correction; GA = graphical analysis; PI GA and PI smoothed GA = parametric images generated by voxelwise graphical analysis without spatial gaussian smoothing and with spatial gaussian smoothing (filter kernel of 5 mm FWHM), respectively; solid line is line of identity.