Computed tomographic colonography is a minimally invasive technique that provides information about the lumen of the colon, like a colonoscopy or double-contrast barium enema, but also about the colon wall, pericolic tissue, lymph nodes, and other extracolonic pathology. In cases of acute and subacute colon obstruction, a plain abdominal radiograph, a contrast enema, a standard abdominal CT, and a colonoscopy have been reported as valuable diagnostic tools. The role of CT colonography in cases of acute or subacute colonic obstruction has yet to be evaluated. PURPOSE: The purpose of the study was to prospectively evaluate the technical feasibility of the multidetector computed tomographic colonography (MDCTC) in patients in whom acute or subacute colon obstruction caused by colorectal cancer was suspected, using a modified procedure protocol, and also to establish the accuracy of MDCTC regarding the presence, location, size, and staging of the cancer, as well as colon evaluation proximal and distal to obstruction. METHODS: This prospective study was approved by Ethic Commitee of University Hospital Center Split; all participants gave written informed consent. On the basis of the clinical symptoms and a plain x-ray film of the abdomen, a 16 row CT colonography was performed in 50 patients (14 women, 36 men; range, 31-93 years; mean age, 70 years) if acute or subacute bowel obstruction was suspected. The colon was cleansed with lukewarm water enemas. Scans were performed in precontrast prone-position and in supine position after the administration of 100-140 ml of contrast agent intravenously in a single portal venous phase. Computed tomography parameters were: slice collimation, 16 x 0.75 mm; kV, 120; mAs, 100-250; rotation time of 0.5 s; reconstructed thickness 1.0 mm at intervals of 0.7 mm. The surgical and pathologic findings served as standards of reference. The accuracy of the method was assessed for T (tumor invasion of colon wall), N (nodal involvement), and M (metastases) staging. RESULTS: In 48 of 50 patients, colon distention was caused by obstruction, and in 44 (13 women, 31 men; range 31-87 years; mean age, of 71 years) of these 48 patients (91%) obstruction was caused by colorectal cancer. MDCTC correctly located all the tumors and successfully revealed all noncancer causes of colon distention. The overall accuracy for T, N and M staging was 91,5%, 72,7% and 90%, respectively. Three (6.8%) synchronous colorectal cancers were correctly revealed by MDCTC. CONCLUSION: MDCTC is a technically feasible and noninvasive method applied in cases of acute and subacute bowel obstruction, with a high accuracy in colon evaluation and in colorectal cancer staging, which allows the planning of the optimal surgical procedure.