Novel Ultrasound Parameters for the Stratification of Femoropopliteal Artery Lesions: A B-Mode and Acceleration Rate Approach

Objective To identify hemodynamic and morphological parameters on duplex ultrasound (DUS) that may improve the accuracy of differentiating between moderate and severe stenosis of the femoropopliteal arteries. Methods Seventy-nine patients (85 limbs) with known peripheral artery disease from two institutions were selected retrospectively and prospectively. Duplex ultrasound (DUS) hemodynamic and morphological (B-mode) parameters were collected at pre-stenotic, stenotic, and post-stenotic segments. Duplex data were compared with contrast-enhanced computed tomography angiography (CTA) or digital subtraction angiography (DSA) as reference standards. Results DUS parameters showing the strongest correlations with the reference-standard examinations were direct lesion estimation using B-mode (R = 0.893), post-stenotic acceleration rate (R = −0.733), and the PSV ratio (stenotic/pre-stenotic peak systolic velocity [PSV]) (R = 0.667). For ≥50% stenosis, direct stenosis estimation ≥50% using B-mode, post-stenotic acceleration rate <730 cm/s 2 , and a stenotic/pre-stenotic PSV ratio ≥1.93 presented sensitivities of 97.1%, 95.7%, and 91.9%, respectively. For ≥70% stenosis, direct stenosis estimation ≥70% using B-mode, post-stenotic acceleration rate <258 cm/s 2 , and a stenotic/pre-stenotic PSV ratio ≥2.6 presented sensitivities of 95.1%, 80.5%, and 78.8%, respectively. Conclusion Among patients with peripheral artery disease, direct lesion estimation using B-mode and post-stenotic acceleration rate emerged as DUS parameters with good sensitivity for detecting moderate and severe stenosis in the femoropopliteal arteries. However, external validation is required before these thresholds can be recommended for clinical use.