Figure 1.

(a) The figure shows two unbowed lines, one from the anal verge to the upper ending of the anal canal (yellow) and the other beginning at the upper ending of the anal canal to the lower border of the tumor (purple) on a high-resolution T2w sagittal scan. The green line indicates the length of the tumor. (b) The figure shows one straight line (in purple) from the anal verge to the lower border of the tumor on a high-resolution T2w sagittal scan. The green line indicates the length of the tumor. (c) The figure shows a curved line beginning at the anal verge and following course of the rectum wall ending at the lower border of the tumor (purple) on a high-resolution T2w sagittal scan. The green line indicates the length of the tumor.