Figure 4. Frequency distributions (histograms) of voxel values of the volume transfer between blood plasma and interstitial tissue (k_fp) (upper row) and relative cerebral blood volume calculated from T₁ weighted dynamic images and corrected for contamination by contrast agent (CA) leakage () (bottom row) in five gliomas measured on day 0 (solid line) and day 2 (dashed line). One-sided significance levels (p) from the Wald–Wolfowitz runs tests are also given for each pair of histograms. There is no significant difference between the repeated measurements of k_fp or in any subject (p>0.05). C.U. is a unit of accumulated CA concentration (mmol xs l^-1).