Figure e: Rectal cancer, stage T3N1 (staged with endorectal US). (a) One section of the dynamic CT scan obtained before neoadjuvant chemoradiation therapy shows the tumor as thickening of the right lateral rectal wall. An 869-mm2 ROI was manually drawn along the margins of the rectal cancer for perfusion parameters calculation. (b) On the same section shown in a, a functional map of BF is designed by the software, showing the BF value calculated in each pixel of the image on a color scale. (c) CT scan obtained in the same patient after completion of neoadjuvant chemoradiation therapy shows a great reduction in the tumor; only a mild thickening of rectal wall can be seen and is outlined by the ROI, which is used to calculate perfusion CT values. (d) On the same section shown in c, the functional map of BF shows in a color scale the reduction in BF compared with b. (e) Pathologic surgical specimen shows thickening of the right lateral rectal wall due to inflammatory and cicatritial changes induced by therapy; no tumor cells were found at histologic examination, and the final pathologic stage was T0N0.