“…Magnetic resonance imaging (MRI) has not been shown to be superior to CT in differentiating tumor from scar tissue, although use of an endorectal coil may improve accuracy (31,32). Transrectal or transvaginal ultrasonography shows great promise in the detection of tumor recurrence, provided a baseline reading is taken about 2 to 3 months after primary surgery to establish the position of organs such as the uterus and loops of bowel, which may fall to either side of the neorectum and may otherwise be mistaken for recurrent pelvic rumor (33). However, this modality is highly operator dependent, and, like CT, is limited to detection of lymph node metastases based on the size of the nodes.…”