VALIDATION OF INTRAVASCULAR ULTRASOUND IN ARTERIOSCLEROTIC PERIPHERAL VESSELS

In this in vitro-study, we validated intravascular ultrasound for the detection of irregular luminal contours, intraarterial structures, intimal thickening in peripheral arteriosclerotic human vessel segments and we compared sonographic criteria to the composition of arteriosclerotic lesions. Sixty-nine post-mortem segments of human peripheral arteries (6 patients) were fixed in formalin, examined with intravascular ultrasound and morphologically evaluated. Specificity, sensitivity, both positive and negative predictive value and accuracy of intravascular ultrasound for the detection of irregular luminal contours, intra-arterial structures and intimal thickening were determined for each of four quadrants. Ultrasonic features (echogeneity, homogeneity, shadowing of echoes) were also compared to the composition of lesions. Intravascular ultrasound detected regular (normal) luminal contours with a high specificity of 96.5%, a sensitivity of 65.0% and an accuracy of 88.4%. Intra-arterial structures were detected with a sensitivity of 88.6%, a specificity of 97.8% and an accuracy of 96.4%. Arteriosclerotic lesions could be localized with a sensitivity of 86.1%, a specificity of 99.1% and an accuracy of 86.9%. Intimal thickening was detectable with a sensitivity of 85.9%, a specificity of 87.8% and an accuracy of 86.2%. Meanwhile, fibrous, atheromatous and combined lesions without calcification did not show shadowing of echoes. The majority of fibrous or atheromatous lesions presented with homogeneous echoes showing hypo-, hyper- and normal density echoes. Using a 20-MHz transducer, homogeneity and echogeneity of echo patterns cannot accurately predict the different components of combined arteriosclerotic lesions.