The small rectal cancer dataset only consists of 190 MR images (including ADC, DCE, DWI and T2WI images), which can be categorized into 2 classes, i.e., T2 and T3. Fig. 2 illustrates some of the original MR images about T2 and T3 in the rectal cancer dataset. The ground-truth labels about tumor and rectum for all MR images are defined by one gastrointestinal radiologist.