Optimal Ultrasound Criteria for Grading Stenosis of the Superficial Femoral Artery.

This retrospective study determined the duplex ultrasound scanning criteria for detecting 50%-69% and 70%-99% stenosis of the superficial femoral artery (SFA). Examinations of 278 limbs in 185 patients with peripheral arterial disease were performed. Duplex ultrasound scanning was used to measure the diameter of the vascular lumen, the peak systolic velocity (PSV) at the stenotic segment of the SFA (PSV), the segment proximal to the stenosis (PSV) and the popliteal artery (PSV, distal to the stenosis). The ratios PSV/PSV and PSV/PSV were calculated. Receiver operator characteristic curves were plotted, with digital subtraction angiography as the reference. PSV and PSV/PSV had the highest diagnostic value for stenosis. Cut-off thresholds were: for 50%-69% stenosis, PSV ≥ 210 cm/s, PSV/PSV ≥ 2.5, with PSV the better parameter; for 70%-99% stenosis, PSV ≥ 275 cm/s, PSV/PSV ≥ 4.0, with PSV/PSV superior. PSV/PSV may be a better parameter than PSV/PSV for diagnosing SFA stenosis.