PHASE-CONTRAST MR-ANGIOGRAPHY OF THE LOWE R-EXTREMITY - COMPARISON OFMETHODS AND CLINICAL-APPLICATION

Purpose: To investigate whether phase-contrast MRA is a clinically sui ted approach to examine arteries of the pelvis and lower extremities. Methods: The study was divided into two parts, a volunteer study and p atient study. Three MRA techniques - 2D TOF with venous saturation, 3D magnitude contrast and 2D phase contrast with EGG triggering were int raindividually compared in 15 volunteers and evaluated by three blinde d readers. Subsequently, a total of 230 vessel segments of 45 MRA stud ies using EGG-triggered phase contrast were compared with intraarteria l DSA. All vessel segments were scored by three blinded readers using a five-point scale with DSA serving as the gold standard. Results: EGG -triggered phase contrast provided better image quality than the other MRA techniques as assessed by the Friedman test. Clinical studies dem onstrated a significant correlation of DSA and MRA as assessed by the Spearman correlation and kappa statistics for individual readers. Conc lusion: MRA of the pelvis and lower extremities may be performed with 2D ECG-triggered phase-contrast MRA within a reasonable time frame (< 30 min). MRA slabs provide orientation similar to that with DSA projec tions and good to very good correlation of vessel pathology as shown b y kappa statistics.