Interobserver variation of colour duplex scanning of the popliteal tibial and pedal arteries

Abstract

Objectives: to determine interobserver variation in the measurement of Peak Systolic Velocity (PSV) and grading of disease by means of Duplex scanning (DS) in the popliteal, tibial and pedal arteries. Design: prospective validation study. Materials: twenty-four consecutive patients with severe claudication (n = 6), ischaemic rest pain (n = 11) and tissue loss (n = 7). Methods: two vascular technologists independently examined the popliteal, tibial and pedal arteries. The PSV was recorded in 15 arterial segments that were graded with B-mode and Doppler parameters as fully patent, severely diseased or occluded. Concordance in PSV recordings was expressed as intraclass correlation coefficients (ICC). Agreement in artery assessment was expressed as weighted κ-values. Results: the ICC for PSV measurements was 0.90 (95% CI, 0.86 to 0.93) within the popliteal and tibial arteries and 0.64 (95% CI, 0.37 to 0.81) within the pedal arteries. Agreement for grading disease was good within the popliteal and tibial arteries (κ 0.66, 95% CI, 0.58 to 0.74), and moderate within the pedal arteries (κ 0.54, 95% CI 0.33 to 0.74). The presence of diabetes or stage of disease did not influence interobserver agreement. Conclusion: interobserver agreement of DS is good within the popliteal and tibial arteries and moderate within the pedal arteries.