Diagnostic accuracy of non-contrast quiescent-interval slice-selective (QISS) MRA combined with MRI-based vascular calcification visualization for the assessment of arterial stenosis in patients with lower extremity peripheral artery disease

Objectives The proton density-weighted, in-phase stack-of-stars (PDIP-SOS) MRI technique provides calcification visualization in peripheral artery disease (PAD). This study sought to investigate the diagnostic accuracy of a combined non-contrast quiescent-interval slice-selective (QISS) MRA and PDIP-SOS MRI protocol for the detection of PAD, in comparison with CTA and digital subtraction angiography (DSA). Methods Twenty-six prospectively enrolled PAD patients (70 +/- 8 years) underwent lower extremity CTA and 1.5-T or 3-T PDIP-SOS/QISS MRI prior to DSA. Two readers rated image quality and graded stenosis (>= 50%) on QISS MRA without/with calcification visualization. Sensitivity, specificity, and area under the curve (AUC) were calculated against DSA. Calcification was quantified and compared between MRI and non-contrast CT (NCCT) using pairedttest, Pearson's correlation, and Bland-Altman analysis. Results Image quality ratings were significantly higher for CTA compared to those for MRA (4.0 [3.0-4.0] and 3.0 [3.0-4.0];p = 0.0369). The sensitivity and specificity of QISS MRA, QISS MRA with PDIP-SOS, and CTA for >= 50% stenosis detection were 85.4%, 92.2%, and 90.2%, and 90.3%, 93.2%, and 94.2%, respectively, while AUCs were 0.879, 0.928, and 0.923, respectively. A significant increase in AUC was observed when PDIP-SOS was added to the MRA protocol (p = 0.0266). Quantification of calcification showed significant differences between PDIP-SOS and NCCT (80.6 +/- 31.2 mm(3)vs. 88.0 +/- 29.8 mm(3);p = 0.0002) with high correlation (r = 0.77,p < 0.0001) and moderate mean of differences (- 7.4 mm(3)). Conclusion QISS MRA combined with PDIP-SOS MRI provides improved, CTA equivalent, accuracy for the detection of PAD, although its image quality remains inferior to CTA.

Automated summary

The study found that the combination of QISS MRA and PDIP-SOS MRI has higher sensitivity and specificity in detecting PAD, with a significant increase in AUC when PDIP-SOS is added. Quantitative analysis of calcification showed significant differences between PDIP-SOS and NCCT but high correlation.