Kinematics parameter extraction of longitudinal movement of common carotid arterial wall in healthy and atherosclerotic subjects based on consecutive ultrasonic image processing

Introduction: In this study, a non-invasive method based on consecutive ultrasonic image processing is introduced to assess time rate changes of the carotid artery wall displacement, velocity and acceleration in the longitudinal direction. The application of these parameters to discriminate healthy and atherosclerotic arteries was evaluated. Methods: Longitudinal displacement rate of common carotid artery wall was extracted with temporal resolution of 33 ms using a block-matching algorithm in three groups of subjects. The 3 groups consisted of 16 healthy men (group 1), as well as 16 men with less than 50% (group 2) and 16 subjects with more than 50% atherosclerotic stenosis in carotid artery (group 3). Differentiating the longitudinal displacement equation resulted in time rate changes of instantaneous velocity and acceleration during three cardiac cycles. Maximum and mean values of displacement and maximum and minimum values of velocity and acceleration were compared among the groups. Results: Maximum longitudinal displacement of the arterial wall was 0.438±0.116, 0.653±0.175 and 1.131±0.376 (mm) in groups 1, 2 and 3, respectively. Results of the statistical analysis (ANOVA), with confidence intervals of 95%, confirmed that there are significant differences (p<0.05) among longitudinal movement, velocity and acceleration of three groups of arteries. Conclusion: In the present study, time rate changes of kinematic parameters of the carotid artery wall motion in the longitudinal direction was evaluated, with temporal resolution of 33 ms. Healthy and atherosclerotic arteries were differentiated using these parameters. Our findings may help understanding the biomechanical behavior of the arteries.