[The superior and inferior venae cavae: angiography by TOF 2D magnetic resonance versus spin-echo sequences].

This work was aimed at assessing the usefulness of magnetic resonance angiography (MRA) in the investigation and diagnosis of vena cava conditions. Forty-five subjects that is 20 volunteers and 25 patients, were examined with MRA using a 1.5 T superconductive system (SE and angiography pulse sequences). In the 25 patients, 8 cases of thrombosis were diagnosed, together with 4 cases of suspected tumor spread into either the superior or the inferior vena cava, 2 cases of inferior vena cava agenesis, 5 cases of retroaortic left renal vein and 5 cases of abdominal aortic aneurysm. MRA was performed with the 2D time-of-flight (TOF) technique (FA 18 degrees, TR 30-40 ms, TE 10 ms); the images were acquired on the coronal, sagittal and axial planes with and without presaturation pulse and rotated in the post-processing according to the maximum intensity projection. In all volunteers MRA identified jugular veins, subclavian veins, anonymous veins, superior vena cava, inferior vena cava and common iliac veins. The main limitation of MRA was its spatial resolution. MRA proved to be less accurate than SE sequences in the assessment of tumor spread. As for thrombotic conditions, MRA provided useful additional information and is therefore considered a complementary technique to SE MRI. As for venous anomalies (double inferior vena cava, vena cava agenesis and retroaortic left renal vein) and in the study of the relationships with abdominal aortic aneurysms, MRA proved to be the more accurate of the two techniques.