[MR aortofemorography versus DSA: prospective evaluation].

Purpose: To determine how far MRA of lower limbs obviates the need for pre-therapeutic DSA.

Materials And Method: Three-step 3-D gadolinium enhanced aortofemorography with a moving bed was prospectively compared to DSA in 49 consecutive patients (40 males, 9 females; age range 38-80 years; mean age 64 years). According to Leriche and Fontaine's clinical gradation of lower limb ischemia, 5 patients were graded I, 37 graded II, 4 graded III, and 3 graded IV. Two observers graded stenoses for DSA and three for MRA. Cohen's kappa statistics were used to evaluate interobserver variability using MRA, as well as to compare MRA to DSA. In addition, sensitivity, specificity, positive and negative predictive values of MRA for the assessment of stenosis superior to 80% were calculated by using DSA as a gold standard, respectively for arterial trunks above and below the level of the knees.

Results: Overall accuracy of MRA was 92%. Comparison of DSA and MRA yielded a kappa value of 0.87 (0.95 for arterial trunks located above the level of the knees and 0.75 below). Interobserver agreement was very good. Sensitivity, specificity, positive and negative predictive values of MRA for the diagnosis of > 80% stenosis were respectively 98, 98, 85 and 99% above the level of the knees and 87, 91, 77 and 96% below the knees.

Conclusion: MRA can be considered as valuable technique for the evaluation of peripheral arterial obstructive disease, especially for stenosis located above the level of the knees.