DIAGNOSIS OF TUMORS OF THE COLON AND INFL AMMATORY LARGEBOWEL DISEASEBY HYDROCOLONIC SONOGRAPHY

Retrograde instillation of water into the colon makes it possible to v isualize the colon sonographically from the rectosigmoid transition to the cecum in 97 % of the patients examined. The sonographic views obt ained using this technique, which is called hydrocolonic sonography, s how the echofree intestinal lumen, the five individual layers of the c olon wall and the connective tissue surrounding the colon. Colonic pol yps and carcinomas appear sonographically as echogenic structures proj ecting from the intestinal wall into the lumen. Colonic polyps larger than 7 mm diameter can be identified in 91 % of cases, and the sensiti vity of the technique in the detection of carcinomas of the colon is 9 7 %. In addition, detailed evaluation of the structure of the bowel wa ll permits more precise staging of tumors of the colon. Aside from suc h localized changes, hydrocolonic sonography can also demonstrate typi cal changes in the wall structure in chronic inflammatory large-bowel diseases. In acute Crohn's disease the normal stratified appearance of the colonic wall is no longer in evidence and the wall appears visibl e thickened. In contrast, in patients with acute ulcerative colitis th e normal sonographic stratified appearance of the colonic wall is main tained. Hydrocolonic sonography enables a detailed sonographic examina tion of the colonic lumen and the colon wall, thus providing additiona l information and allowing more precise diagnosis of many diseases of the colon.