Diagnostic accuracy of contrast-enhanced magnetic resonance angiography and duplex ultrasound in patients with peripheral vascular disease.

INTRODUCTION: Noninvasive techniques such as duplex ultrasound (DU) and contrast-enhanced magnetic resonance angiography (CE-MRA) are valid alternatives in the preoperative evaluation of such patients. Our aim is to assess the diagnostic accuracy of CE-MRA and DU in patients with peripheral arterial disease (PAD).

METHODS: Forty consecutive patients underwent DU, hybrid CE-MRA, and digital subtraction angiography (DSA). Magnetic resonance angiography and DSA images were evaluated independently and in a blinded fashion. Every segment was graded as normal, stenosed less than 50%, stenosed more than 50%, or occluded.

RESULTS: There were 1720 segments for analysis. Duplex ultrasound depicting stenosis >50% demonstrated a sensitivity (S) 81.4%, specificity (E) 99%, positive predictive value (PPV) 96.2%, and negative predictive value (NPV) 94.8%. Occlusions showed S 90%, E 97%, PPV 98.1%, and NPV 88.4%. Magnetic resonance angiography depicting stenosis >50% demonstrated a S 91%, E 99%, PPV 96.7%, and NPV 97.6%. Occlusions showed S 95.4%, E 98%, PPV 98.4%, and NPV 94.7%.

CONCLUSION: Combined CE-MRA and DU is the first diagnostic approach in the preoperative assessment of PAD, leading to the use of DSA for selected cases.