Imaging examinations performed before surgery. Enhanced CT scans on March 21, 2020 of abdomen revealed that occupying lesions in the middle and upper rectum, the intestinal lumen was narrowed, and the serosal layer was hairy. After enhancement, the lesion was uneven and enhanced, and the length of the lesion was about 5.7 cm, considering that was rectal cancer (T4aN1M0).