Noninvasive quantification of atherosclerotic lesions. Reproducibility of ultrasonographic measurement of arterial wall thickness and plaque size.

A noninvasive method based on high-resolution B-mode ultrasonography and a computerized image-analyzing system were used for the quantification of early (thickening of the intima-media complex) and late (plaque) atherosclerosis in the carotid and the femoral artery. The difference between repeated measurements was assessed to estimate intraobserver and interobserver differences. The results were satisfactory, with a coefficient of variation for measurement of lumen diameter in the common carotid artery of 3.8 +/- 4.1% (r = 0.91) and for the femoral artery of 4.8 +/- 4.1% (r = 0.93). Corresponding figures for intima-media thickness in the common carotid artery and the femoral artery were 10.0 +/- 8.5% (r = 0.86) and 16.2 +/- 12.6% (r = 0.91), respectively. The coefficient of variation for measurements of maximal intima-media thickness at the site of the plaque was 14.6 +/- 10.5% (r = 0.88); for plaque base, 13.1 +/- 9.0% (r = 0.91); and for plaque area, 16.3 +/- 12.6% (r = 0.90). The method seems promising for the detection and quantification of early and late atherosclerotic lesions in the carotid and femoral arteries.