Non-contrast-enhanced MR angiography in critical limb ischemia: performance of quiescent-interval single-shot (QISS) and TSE-based subtraction techniques

Purpose: The aim of this study was to evaluate diagnostic performance of non-contrast-enhanced 2D quiescent-interval single-shot (QISS) and 3D turbo spin-echo (TSE)-based subtraction magnetic resonance angiography (MRA) in the assessment of peripheral arteries in patients with critical limb ischemia (CLI).

Materials and methods: Nineteen consecutive patients (74 % male, 72.8 ± 9.9 years) with CLI underwent 2D QISS and 3D TSE-based subtraction MRA at 1.5 T. Axial-overlapping QISS MRA (3 mm/2 mm; 1 × 1 mm²) covered from the toes to the aortic bifurcation while coronal 3D TSE-based subtraction MRA (1.3 × 1.2 × 1.3 mm³) was restricted to the calf only. MRA data sets (two readers) were evaluated for stenosis (≥50 %) and image quality. Results were compared with digital subtraction angiography (DSA).

Results: Two hundred and sixty-seven (267) segments were available for MRA-DSA comparison, with a prevalence of stenosis ≥50 % of 41.9 %. QISS MRA was rated as good to excellent in 79.5-96.0 % of segments without any nondiagnostic segments; 89.8-96.1 % of segments in 3D TSE-based subtraction MRA were rated as nondiagnostic or poor. QISS MRA sensitivities and specificities (segmental) were 92 % and 95 %, respectively, for reader one and 81-97 % for reader two. Due to poor image quality of 3D TSE-based subtraction MRA, diagnostic performance measures were not calculated.

Conclusion: QISS MRA demonstrates excellent diagnostic performance and higher robustness than 3D TSE-based subtraction MRA in the challenging patient population with CLI.

Key points: • QISS MRA allows reliable diagnosis of peripheral artery stenosis in critical limb ischemia. • Robustness of TSE-based subtraction MRA is limited in critical limb ischemia. • QISS MRA allows robust therapy planning in PAD patients with resting leg pain.