Gastrointestinal imaging with hydrosonography and hydro-CT. Pt. 2. Colorectal carcinoma

74 patients in whom colorectal carcinoma was suspected were examined. At HUS the colonic wall ist distended by a methylcellulose/water suspension and the carcinoma is enlarged to perform staging of the tumour. HCT is a spiral-CT optimised for parenchymal and vessel contrast. Before the scan is started, up to two litres of fluid are given rectally and spasmolytics are administered to reduce peristalsis. Colorectal carcinomas were classified according to the TNM system and histopathologic correlation was achieved. Out of 43 (HUS) and 39 (HCT) colonic lesions 33 (77%) and 36 (92%), respectively, were diagnosed. T-stage accuracy was 88% (HUS) and 66% (HCT), N-stage accuracy 33% and 46% and M-stage accuracy 88% and 85%, respectively. The T-stage of sonographically visible tumours of the colon is determined precisely by HUS. In contrast to predicting lymph node involvement distant metastases are reliably detected by both methods. If performed together, HUS and HCT achieve high diagnostic accuracy for staging carcinoma of the colon. (orig./MG)