[Congenital anomalies of the inferior vena cava: role of imaging].

In recent years, clinics and radiology of congenital anomalies of the inferior vena cava have increased in importance in planning abdominal surgery, liver or kidney transplantation, or new interventional or diagnostic procedures such as the positioning of inferior vena cava filters to prevent pulmonary embolism, varicocel sclerotherapy and renal venous sampling. In the past, the radiologic assessment of these rare anomalies was performed only with angiography, which remains the most accurate diagnostic method. Today, besides angiography, less invasive examinations can be performed, e.g., US, CT and MRI, with MRA. In the last two years, 5 patients with inferior vena cava anomalies were examined: 3 had double inferior vena cava and 2 azygos continuation. All of them were submitted to US, CT, MRI and MRA and 3 patients underwent also angiography, two of them with double puncture. US can suggest the diagnosis but may be limited by technical factors and in the assessment of the whole inferior vena cava. Enhanced CT can depict anomaly extent, but uses contrast agents and ionizing radiations. Angiography better depicts craniocaudal spread and collateral networks but is an invasive procedure and sometimes needs a double puncture (double inferior vena cava). MRI, with MRA, yields the same information as the other modalities, but without contrast agents or ionizing radiations. The development of velocity encoded sequences will probably make this technique the method of choice in the study of inferior vena cava anomalies. Our study was aimed at reviewing the embryo-genesis of inferior vena cava anomalies and to assess the relative importance of different diagnostic procedures in the diagnosis and staging of these anomalies.