A radiological and pathological correlation of the mucosal changes in ulcerative colitis.

The double contrast barium enema, in most cases performed by the 'instant' technique without bowel preparation, has been compared with the pathological examination of the colon following resection in 37 patients with ulcerative colitis. Radiology has been found to underestimate the histological extent of disease. This supports the use of the term 'extensive colitis' to denote total histological involvement even if the abnormal mucosa seen radiologically extends proximally only to the hepatic flexure. Ulceration is clearly distinguished from a granular mucosa, and implies severe active disease histologically. Subdividing the granular appearance did not prove useful. Polypoid change may occur in the acute stage from ulceration or in the healed state from mucosal tags. Guidelines are suggested to differentiate these, however intermediate stages are commonly found. It is suggested that the radiologist reports polypoid change and tries to assess the state of the background mucosa separately. It is concluded that with qualifications radiology can usefully fulfil its clinical role in assessing the extent and severity of ulcerative colitis.