The radiology of colonic and rectal polyps

The bowler hat: a valid sign of colonic polyps?

This report briefly describes several cases of diverticula simulating colonic mucosal lesions. We have found that the bowler hat configuration, in particular, frequently occurs in the presence of diverticular disease. In our series, no polyp was found to exhibit the bowler hat sign, while 12 cases of diverticular disease displayed 1 or more "bowler hats." Differentiation between polyps and diverticula displaying the bowler hat sign may be possible, but we conclude that the bowler hat sign per se is a nonspecific finding and that additional views may be necessary to confirm the presence of polyps.

Width of the presacral space in Nigerian adults

The width of the presacral space and the thickness of the rectal valve were measured on lateral radiographs obtained during barium enema examinations performed on 182 Nigerian adult patients over a 5-year period (1980-1984). The mean width of the presacral space was 0.78 cm, the value in men being significantly higher than in women (p less than 0.01). Although these values are similar to those reported among Caucasians, a wider range of normal values was obtained in this study. There is also no significant difference between the mean value of the rectal valve thickness of 4.3 mm obtained in this study and that obtained from previous studies.

Reliability of routine double-contrast examination (DCE) of the large bowel in polyp detection: a prospective clinical study

A total of 2,118 consecutive patients, examined with double-contrast examination of the large bowel (DCE), were evaluated radiographically, clinically, and endoscopically for up to 48 months. A total of 402 polyps were diagnosed during the follow-up period. Of these, 307 were revealed at the first DCE and 95 at subsequent endoscopy or autopsy. The accuracy of the DCE for demonstrating or excluding patients with polypoid lesions of the colon was 97%, whereas the predictive value of a positive DCE report was 96% and a negative one, 97%. However, the ability to demonstrate every known polyp at DCE was only 63%, although the probability of a polypoid lesion demonstrated at DCE being a true polyp was 92%.

The double-contrast enema: myths and misconceptions

The role of the double-contrast enema (DCE) remains contraversial since no controlled comparison between the barium enema (BE) and the DCE has been performed. As a result of our experience with routine use of the DCE, we believe that it is the most sensitive technique for the detection of polypoid, annular, and inflammatory lesions in the colon. There are many commonly held myths and misconceptions regarding the DCE and these are discussed and refuted. The advantages of the DCE over the BE are discussed and illustrated.

Villous adenoma of the large bowel; benign and malignant

The radiological appearances on double contrast barium enema examination of 14 cases of villous adenoma are described and illustrated. Problems of diagnosis and detection of malignancy are discussed. It is concluded that in the majority of cases a confident radiological assessment of benignancy or malignancy cannot be made. The importance of villous adenoma as a pre-cancerous condition and the high incidence of associated large bowel carcinoma are emphasized.

The lateral view in the radiology of the rectum and rectosigmoid

Twenty-seven cases of rectal and rectosigmoid abnormality which had been demonstrated radiologically were reviewed in order to assess the value of the lateral projection. Twenty-one of these cases were derived from a consecutive series of 2500 bariumenema examinations in symptomatic patients. The value of the projection is emphasized as part of a routine barium-enema examination, but it is appreciated that other views may also be necessary and should be included whenever indicated. It is felt that examination of this area not only is a clinical responsibility but also merits meticulous radiological attention.