Ultrasound Imaging of Infrainguinal Arterial Disease has a High Interobserver Agreement

Abstract

Objectives: to evaluate and compare the operator dependency of duplex ultrasound and digital subtraction arteriography (DSA) in patients suffering from chronic lower limb ischaemia.

Design: prospective and blinded validation study.

Material: twenty-six consecutive patients (13 male and 13 females) with severe claudication (n=6, 23%), rest pain (n=7, 27%) or tissue loss (n=13, 50%).

Methods: two physicians independently performed a duplex scan of the lower limb from groin to foot (15 segments). Segments were classified as insignificantly (<50% stenosis) or significantly (>50% stenosis or occlusion) diseased. DSA was performed within 24 h of the duplex scanning and was independently reported by two radiologists in the same manner. Interobserver agreement was assessed for both diagnostic methods. After 10 months the arteriograms were reassessed and the intraobserver agreement calculated.

Results: for the limb as a whole the interobserver agreement was good and similar for both duplex and DSA, with kappa-values of 0.79 (95%-CI: 0.72–0.86) and 0.80 (0.74–0.87). In the femoral, crural and pedal segments the interobserver agreement was similar for both methods. The intraobserver agreement between the two DSA readings was 0.84 (0.79–0.90).

Conclusion: ultrasound is comparable to arteriography when visualising arterial occlusive disease in patients with chronic lower limb ischaemia.