Abdominal ultrasonography in the diagnosis of colonic cancer.

BACKGROUND

Colonic cancer is normally diagnosed by barium enema or colonoscopy. Neither investigation is ideal, especially in the elderly patient. This study investigates the potential role of abdominal ultrasonography in the diagnosis of colorectal carcinoma.

METHODS

Fifty-four patients with known or suspected colonic carcinoma were referred for abdominal ultrasonography. A single radiologist performed scans on these patients and the site of any colonic mass or wall thickening considered to be consistent with a colonic carcinoma was reported. All carcinomas were confirmed by histology on tissue obtained at colonoscopy or surgery against which the ultrasonographic diagnosis was compared. Colonic masses detected in patients undergoing routine abdominal ultrasonography for abdominal symptoms were also reported.

RESULTS

Forty-five of the 54 patients referred had colonic carcinoma and abdominal ultrasonography detected 43 of the tumours and correctly identified the site of 41. The sensitivity, specificity and accuracy of abdominal ultrasonography in the detection of colonic tumours considered to be consistent with a colonic carcinoma was 96, 67 and 91 per cent respectively. Seven tumours were identified in patients referred before any other investigation had been carried out.

CONCLUSION

Abdominal ultrasonography may detect a colonic mass or wall thickening consistent with a colonic carcinoma with a high degree of accuracy and may be useful when barium enema or colonoscopy is not possible.