Interobserver variation in duplex sonographic scanning in the femoropopliteal tract

The diagnostic value of duplex sonographic scanning was demonstrated in a number of studies, but there is lack of consensus on which characteristic of the Doppler spectrum correlates best with the severity of peripheral vascular disease. In a prospective study we quantified the interobserver variation in duplex scanning for the diagnosis of peripheral vascular disease. Forty-one patients with intermittent claudication were independently examined by two observers. The observers were unaware of the angiographic findings. Reproducibility of classification and separate characteristics of the Doppler spectrum were expressed as kappa coefficients, Pearson correlation coefficients, and repeatability coefficients. PSV was the most reproducible characteristic of the Doppler spectrum. The classification of peripheral disease in 0 to 19%, 20 to 49%, 50 to 99%, and 100% diameter reduction was highly reproducible (kappa 0.68). The other characteristics of the Doppler spectrum were moderately to poorly reproducible; wave form contour, spectral broadening, and end diastolic velocity had kappa values of 0.56, 0.20, and 0.56, respectively. Our findings justify a simplification of the criteria for duplex sonographic scanning for diagnosis of peripheral vascular disease.