MAGNETIC-RESONANCE ANGIOGRAPHY OF THE DISTAL LOWER-EXTREMITY

Objective: To assess magnetic resonance angiography (MRA) for demonstr ation of arterial patency in the ankle and foot of patients with perip heral vascular disease. Methods: Peripheral MRA of the ankle and foot was performed on 34 limbs of 31 insulin-dependent diabetics. 2-D time- of-flight MRA (TR 33 ms/TE 7.7 ms/inferior saturation band) was perfor med with 16cm held of view. Pre- or intra-operative angiographic corre lation was available in all cases. Results: In 24 limbs MRA was compar ed to conventional angiography. MRA showed more patent run-off vessel segments (120) than angiography (100). In 10 limbs MRA was compared to intraoperative angiography and for the detection of patent vessel seg ments showed a sensitivity of 87.5% (42/48) with a 95% confidence inte rval of 75% to 95% and a specificity of 95% (38/40) with a 95% confide nce interval of 83% to 99%. Pitfalls included difficulty in visualizin g flow at the bifurcation of the peroneal artery, in the plantar arch and retrograde how in the lateral plantar artery. Conclusions: MRA is sensitive for the detection of patent arteries in the ankle and foot b ut artefacts may cause overdiagnosis of focal stenoses or occlusions.