MAGNETIC-RESONANCE ANGIOGRAPHY IN THE DIAGNOSIS OF THORACIC VENOUS OBSTRUCTION

The aims af this study were ro ;evaluate the diagnostic value of ortho gonal magnetic resonance angiography! (MRA) and to compare the results of MRA with those: of digital, subtraction venography! (DSV) in thora cic venous diseases. Ten normal volunteers were evaluated using two-di mensional time-of-flight MRA in three orthogonal planes ro determine t ile image quality of each venous segment. Twelve consecutive patients suspected of having thoracic venous disease were studied with both MRA and DSI;I Iu rile normal: subjects!, the plane perpendicular to the t arget vein provided tile most consistent visualization,. Using three o rthogonal MRA images, a diagnostic-quality! image was obtained ill 175 (83%) of 210 venous segments in normal volunteers. In patients with t horacic; venous obstructive disease, MRA was more effective than DSV i n detecting total (84 rs 54), patent (56 vs 36), stenotic in (13 vs 10 ), and obstructive (15 vs fi) venous segments, poststenotic ol postobs tructive reins (15 vs 10), thrombosis, of the internal jugular vein (7 vs 2), intraluminal thrombus (5 vs 3), and azygos veins (12 vs 2). Us ing venous segments visible an DVS (II = 54) as the standard, the sens itivity and specificity! of MRA were 94% and 100%, respectively, in de tecting venous patency, and 100%; and 98% in detecting complete venous obstruction. In the shoulder region, the sensitivity and specificity of MRA were 93% and 100%, respectively?, in detecting venous patency, and 100% and. 97% ill detecting venous ai?obstruction. We conclude tha t MRA with three orthogonal planes call provide relatively! complete a nd reliable venous mapping, without tile need for contrast medium.