Determination of Arterial Diameters, Length and Mass of the Plaque, and Theoretical Volume in the Internal Carotid Artery by Quantitative Vascular Echography

Abstract

To study the evolution of atherosclerosis, the consensual changes that occur in the arterial wall, lumen, and atheroma must be evaluated. The authors propose a new, noninvasive method of obtaining arterial diame ters, length and mass of plaque, and theoretical volume in the internal carotid artery. The study was performed in 37 patients with different degrees of athero sclerosis (from 20% to 50%). All patients underwent echo examination. Long- axis tomographic planes were recorded with the same angle of incidence by placing a goniometer around the neck. Furthermore, the arterial diameters and the plaque length were measured from photorecordings, and theoretical arterial volume (sum of two bitruncated semiellipsoids), residual volume (Simpson's in tegral rule), and plaque mass (difference between theoretical vascular volume and residual volume) were calculated. Intraobserver and interobserver variabil ity and reproducibility were tested in all the measurements and calculations. Intraobserver/interobserver variability and reproducibility were found to be less than 8% according to all measurements and calculations. These results indicate that the method is reproducible and allows noninva sive, quantitative assessments of vascular geometry in evolving atherosclerosis.