Use of modified multidetector CT colonography for the evaluation of acute and subacute colon obstruction caused by colorectal cancer: a feasibility study.

PURPOSE: This study was designed to evaluate the feasibility of using CT colonography with a modified procedural protocol for diagnosis and cancer staging in patients with suspected acute or subacute colon obstruction caused by colorectal cancer. METHODS: Following colonic cleansing with lukewarm water enemas, thin-collimation CT colonography was performed on 47 patients (15 women and 32 men, mean age, 68 years) in the precontrast prone position and in the supine position after the intravenous administration of a contrast agent. The surgical and pathologic findings served as a reference standard. RESULTS: In 44 of 47 patients, colon distention was caused by obstruction, and pathologic examination confirmed colorectal cancer in 41 of these 44 patients. CT colonography correctly located all tumors and successfully identified noncancerous causes of colon distention in five patients. The overall accuracy of staging was 97.6 percent for the T category, 73.2 percent for N, and 100 percent for M. Two synchronous colorectal cancers were correctly identified. CONCLUSIONS: When appropriate protocol modifications regarding colon cleansing and air insufflation are made to take the clinical situation into account, CT colonography is a technically feasible, accurate, and well-tolerated method for tumor evaluation and cancer staging in patients with acute and subacute colon obstruction.