Direct measurement of wall stiffness for carotid arteries by ultrasound strain imaging.

Objective: The elastic properties of the carotid arterial wall have not been directly characterized in the clinical setting. Strain rate (SR) imaging is a newly developed echocardiographic method developed for imaging the tissue motion of the myocardium. The purpose of this study was to directly estimate the elastic properties of the carotid artery by using SR imaging in patients with coronary artery disease (CAD).
Methods: A total of 135 patients with CAD, 15 age-matched controls, and 35 young healthy subjects had a carotid ultrasound examination for measuring the values of SR and strain of the carotid artery. The intima-media thickness and distensibility coefficient of the carotid artery were estimated.
Results: Age and Framingham risk score were significantly related to SR and strain, respectively (r = 0.62-0.67, all P < .001). These strain measurements were significantly correlated with distensibility coefficient and intima-media thickness, respectively (r = 0.30-0.56, all P < .001). Similar values of the areas under the receiver operating characteristic curves were obtained among Framingham risk score (0.70 +/- 0.05), SR (0.67 +/- 0.05), and strain (0.73 +/- 0.05).
Conclusion: This study demonstrated that the elastic properties of the carotid artery wall were directly characterized by using SR imaging in patients with CAD.