TIME-OF-NIGHT MR-ANGIOGRAPHY OF KIDNEY-TRANSPLANTS

The aim of the study was to apply time-of-flight MR angiography to ren al transplant arteries with comparison of two- and three-dimensional ( 2D and 3D) sequences and to correlate the findings with colour flow so nography (CFS) and digital substraction angiography (DSA). A total of 102 MR studies were performed in 101 patients: 87 with the 2D-FLASH se quence (18 repeated after Gd-DOTA administration), 49 with the 3D-FISP (both in 34). All patients were also studied with CFS and 15 with int ra-arterial DSA. The 3D sequence produced good quality MR angiograms i n 94% of cases (82% in 2D). Gd-DOTA infusion improved the quality of t he 2D angiograms in 7 of 18 cases. Only these patients were included i n the remainder of the evaluation (90 patients with 103 arteries). CFS showed 72 normal and 10 abnormal arteries. In this group, the 2D sequ ence led to 7 (12%) false positives of stenosis and the 3D sequence yi elded 1 (3%). Correlation between MR angiography and DSA was obtained for 21 arteries (15 patients) with suspicion of arterial complications . The 2D-FLASH (n = 13) and the 3D-FISH (n = 12) MR sequence allowed t he correct diagnosis of all main artery complications (14 stenoses and 4 thromboses) without any false negatives and without discordance whe n both sequences were performed (n = 4). In the 3 other cases with a n ormal main artery, 2 segmental thrombosis were correctly identified by both sequences and 1 stenosis of a segmental branch was correctly ide ntified by the 2D sequence only but misdiagnosed as a thrombosis with the 3D sequence. Grading of the severity of stenoses was inaccurate wi th both sequences. It is concluded that the 3D time-of-flight MR seque nce provides better MR sequence provides better MR angiograms than the 2D, with fewer false positives for stenosis. No false-negative arteri al complications were noted.