Roentgenologic appearance of left-sided inferior vena cava

2 Cases of left-sided inferior vena cava, and 2 cases of left-sided inferior vena cava with azygos and hemiazygos continuation were evaluated with computed tomography and other roentgenologic procedures and discussed thier clinical and radiological significance. Left-sided inferior vena cava with azygos (hemiazygos) continuation is often associated with cyanotic or acyanotic congenital heart disease and abnormalities of cardiovascular position, abdominal situs and polysplenia. But, single left-sided inferior vena cavas have little tendency having associated anomalies. Both venous anomalies also shuld be embryologically differentiated, namely, failure of development of the lower portion of the supracardinal veins results in infrahepatic interruption of inferior vena cava with azygos continuation, persistence of the left cardinal system and atrophy of the right system lead to the left-side inferior vena cava. Knowledge of inferior vena cava anomalies is important to the radiologist in order to differentiate between venous anomalies and an enlarged lymph nodes in a patient with malignant tumor. (author)