Accuracy of Noncontrast QISS MR Angiography Versus CT Angiography for Peripheral Artery Disease

This comparative diagnostic study enrolled 30 patients with suspected peripheral artery disease (PAD) and performed both noncontrast quiescent-interval single-shot MR angiography (QISS-MRA) and CT angiography (CTA), using digital subtraction angiography (DSA) as the reference standard.

QISS-MRA and CTA demonstrated similar diagnostic accuracy for PAD detection: sensitivity and specificity of 84.9%/97.2% and 87.3%/95.4%, respectively. QISS-MRA showed fewer inconclusive segments and better performance specifically in heavily calcified vessel segments where CTA artifact from calcium blooming limits interpretability.

The clinical context for this comparison: PAD affects approximately 230 million people globally and shares atherosclerotic risk factors with coronary artery disease — its presence substantially increases cardiovascular mortality independent of symptoms. Imaging is used to characterize disease severity, guide revascularization decisions, and monitor progression.

QISS-MRA’s key advantage is the elimination of iodinated contrast — allowing vascular imaging in patients with renal impairment, contrast allergy, or hemodynamic instability who cannot receive contrast agents. Its performance in calcified segments — where CTA calcium artifact degrades luminal assessment — adds further diagnostic utility in elderly or diabetic patients with extensive vascular calcification.

At n=30, this study establishes the principle but lacks the scale for definitive guideline-level evidence. The finding is consistent with other noncontrast MRA validation studies in peripheral vascular imaging.

We rate the evidence moderate. A well-designed comparative diagnostic study demonstrating that noncontrast QISS-MRA achieves diagnostic accuracy comparable to CTA for PAD assessment — particularly valuable in patients contraindicated for iodinated contrast agents.