DYNAMIC CONTRAST-ENHANCED SUBTRACTION MR-ANGIOGRAPHY OF THE LOWER-EXTREMITIES - INITIAL EVALUATION WITH A MULTISECTION 2-DIMENSIONAL TIME-OF-FLIGHT SEQUENCE

PURPOSE: To determine the clinical feasibility of a contrast material- enhanced two-dimensional (2D) magnetic resonance (MR) angiographic seq uence in lower extremity arteries. MATERIALS AND METHODS: Four healthy volunteers and 12 patients underwent dynamic contrast-enhanced MR ang iography; all patients also underwent conventional angiography. A 2D m ultisection gradient-echo sequence with image subtraction was used for all MR imaging examinations. RESULTS: Oblique-coronal contrast-enhanc ed MR angiography was completed in less than 4 minutes, with a 256 x 5 12 matrix. The arterial contrast enhancement ratio was 2.0 +/- 0.8 (st andard deviation), and the pre- and postcontrast contrast-to-noise rat ios were 2.1 +/- 13.8 and 46.2 +/- 18.7, respectively. The sensitivity for MR angiography was 100% and specificity was 69% for distinction o f vessels with greater than 50% stenoses from normal or mildly stenoti c vessels. CONCLUSION: Dynamic contrast-enhanced 2D MR angiography is capable of increasing intraarterial signal intensity and depicting sma ll vessel anatomy of the lower extremities over a large field of view in a short imaging time.