The appearances on computed tomography after abdominoperineal resection for carcinoma of the rectum: a comparison between the normal appearances and those of recurrence.

Computed tomography is well recognised as a means of showing recurrent tumour in patients who have undergone abdominoperineal resection for carcinoma of the rectum. The appearance of recurrent tumour has to be distinguished from that of normal postoperative fibrous tissue. To define the normal postoperative appearances CT was carried out on 15 patients at various intervals up to 18 months after the operation. All the patients were clinically free of recurrence at the time of the scan and for at least six months afterwards. The appearances were compared with those in 19 patients who had local recurrence at the time of scanning. The normal appearances are outlined, pitfalls in diagnosis are described and points of differentiation between the normal appearance and recurrent tumour are discussed.