Prospective Study of CT Angiography of Superior Mesenteric Artery and Vein Using 16-slice Helical CT in Diagnosing Small Bowel Volvulus

Objective To prospectively assess the accuracy of CT angiography (CTA) of superior mesenteric artery (SMA) and superior mesenteric vein (SMV) in diagnosing small bowel volvulus (SBV). Materials and Methods 16 patients suspected of SBV according to clinical and plain CT manifestations were examined with CTA of SMA and SMV using Siemens 16-slice helical CT. Maximum intensity projection (MIP) and volume rendering (VR) images of SMA and SMV were acquired. The accuracy of CTA in diagnosing SBV was evaluated and compared with surgery or follow-up as the standards of reference. Results Tortuosity of distal SMV was seen in 2 cases and tortuous SMA branches was seen in 1 case. Tortuosity of various tributaries of SMV was seen in other 3 cases and axial torsion of SMV observed in 1 case. There was a correlation between abnormal vascular and location of dilated small bowel loops. SBV was confirmed in 5 patients by surgery. In the diagnosis of SBV, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 100%, 90.9%, 83.3%, 100%, and 93.8%, respectively, for CTA of SMA and SMV. Conclusion CTA of SMV and SMA is a valuable method for the diagnosis of SBV, tortuosity of SMV or its tributaries is the main CTA findings.