Diagnostic performance of non-contrast magnetic resonance angiography in patients with lower extremity arterial disease

Introduction: Lower extremity arterial disease (LEAD) is often associated with chronic renal failure, so the use of nephroprotective modalities is essential. Objectiv: We compared the diagnostic performance of non-contrast quiescent-interval single-shot magnetic resonance angiography (QISS MRA) and digital subtraction angiography (DSA). Methods: QISS MRA and DSA images of LEAD patients were compared. A 19-segment model was used to grade the degree of stenosis (none, <50%, 50-70%, >70%) and image quality (5-point Likert scale; 1: non-diagnostic, 5: excellent image quality). The diagnostic accuracy and interpretability were calculated in terms of obstructive (>70%) stenosis; DSA was the reference standard. Intraclass correlation coefficient (ICC) was calculated for interobserver reproducibility of image quality and stenosis assessment. Results: 623 segments were evaluated in 34 patients (10 women, mean age: 67 +/- 9 years). Image quality of QISS MRA was at least equivalent to DSA in all regions (all regions: 4 [4-5] vs. 4 [3-5]; aorto-iliac: 4 [4-4] vs. 4 [4-5]; femoro-popliteal: 4 [4-4] vs. 4 [4-5]; tibio-peroneal: 4 [4-5] vs. 3.5 [3-4]; all p=0.01). The interpretability of QISS MRA was superior to DSA in all regions (99.0% vs. 96.1%, p<0.001). The proportion of non-diagnostic segments was six times higher for DSA than for QISS MRA (24 vs. 4). The diagnostic accuracy of QISS MRA was 91.3%, sensitivity 84.8%, specificity 93.0%, positive predictive value 76.3%, negative predictive value 95.8%. In stenosis grading, the ICC for all regions was 0.94 for QISS MRA and 0.88 for DSA. Conclusion: QISS MRA proved to be a reliable alternative to DSA in the diagnosis of lower extremity arterial disease.