64-slice spiral CT appearance of congenital anomalies of the inferior vena cava

Objective: To evaluate the imaging findings of congenital anomalies of inferior vena cava (IVC) with 64-slice spiral CT. Methods: Between January 2008 and May 2009, 6986 patients who had routine abdominal 64-row multi-detector computed tomography were retrospectively analyzed for congenital anomalies of IVC. Results: Among 6896 cases, 25 cases with congenital anomalies of IVC were identified. Six case were left IVC, showing IVC left to the aorta inferior to the renal hilum, Ten cases were double IVC, showing two IVC besides the aorta inferior to the renal hilum. Five cases were abnormal renal vein, showing retroaortic and circumaortic left renal vein. Two cases were IVC interruption with collateral circultion by azygous or hemiazygous vein, contrast-enhanced CT scan showing deficiency of t he IVC between hepatic and renal hilums, the enlarged azygos vein communicating with IVC at renal level and the hepatice vein draining into the right atrium. Venography showed that IVC draining into the superior vena cava through azygous or hemiazygous veins. One case was interruption of the IVC with portal vein continuation, contrast-enhanced CT scan showing the communication between the IVC and portal vein. One case was hemiazygos continuation of a left IVC, contrast-enhanced CT scan demonstrating dilatation hemiazygos continuation of a left IVC and jointed the azygos vein. Conclusiong: The 64-slice spiral CT can be a diagnostic standard for congenital anomalies of inferior vena cava. (authors)