[Magnetic resonance angiography of the portal vein in liver transplant recipients].

This work was aimed at investigating the diagnostic accuracy of Magnetic Resonance Angiography (MRA) in the study of the portal vein in liver transplant recipients. Ten patients (7 men and 3 women; mean age: 45 years) were examined 7-180 days after transplantation. The indications to liver transplant follow: post-infective active chronic hepatitis (4 patients), post-alcoholic chronic hepatitis (2 patients), HCC (2 patients), sclerosing cholangitis (1 patient) and primary biliary cirrhosis (1 patient). MRA images were acquired with the 2D TOF technique (TR 50 ms, TE 6.9 ms; FA 30 degrees, 40 slices; 6-mm thickness with 1-mm overlapping; 2 averages; 7.06 TA; matrix: 192 x 256). Axial scans were reconstructed with the MIP technique. Phase contrast sequences with retrospective cardiac triggering were also acquired for flow quantitation (TR/TE/FA: 26/9.3/20 degrees; FOV 150; matrix: 96 x 128; 4 averages, VENC = 20 cm/s). MRA yielded good quality images of the anatomy of the main portal vein and of the bifurcation in all cases, while a signal loss was observed in the peripheral branches. In all cases, the anastomosis could be studied at the portal vein. On MIP reconstructed images, the anastomosis appeared as a relative stenosis (4), while on 2D images it appeared as a small hypodense area on the vessel margin, because of the slight paramagnetic effect of the vascular suture. No thrombi were depicted in any patient and flow was hepatopetal in all cases. In conclusion, MRA is a useful tool for portal system studies in liver transplant recipients, because it permits the panoramic depiction of the portal system and the quantitation of flow (10).