Estimation of Arterial Stiffness, Compliance, and Distensibility From M-Mode Ultrasound Measurements of the Common Carotid Artery

early vascular changes that predispose to the development of major vascular disease. The repeatability of a variety of indices of arterial stiffness calculated from a standard carotid arterial M-mode ultrasound image was investigated. Methods Twenty-six asymptomatic normal subjects were imaged and had blood pressure recordings on each of two separate occasions at least 1 day apart. Using a computer-assisted method, the maximum and minimum internal diame-ter and average wall thickness of the right common carotid artery were measured over several cardiac cycles, and the following indices of arterial stiffness and distensibility (com-pliance) were derived: the pressure-strain elastic modulus (Ep), Young's modulus (E), cross-sectional compliance (CC), and the distensibility coefficient (DC). Results The repeatability of these measures, expressed as coefficients of variation, was as follows: Ep, 18%; E, 24%; CC