The aim of this study is to understand the effects of different postures and activities on hemodynamics and geometries of carotid artery, by using ultrasound imaging techniques. These findings may be able to improve the understanding of the impact of daily habits on carotid hemodynamics, and the evaluation and progression of carotid plaques, and ultimately contribute to the effectiveness of clinical prediction and prevention strategies.
Different body postures and physical exercises may lead to changes in arterial geometry and hemodynamics. This study was aimed at investigating potential geometric and hemodynamic changes of the carotid bifurcation in different body postures and after high-intensity interval training workouts. Three-dimensional vascular ultrasound (3DVUS) and Doppler ultrasound images were acquired for healthy participants in different body postures (sitting and three sleeping postures [supine, left lateral and right lateral]) and after physical exercises (as shown in the Figure of study procedures). 
3D surface models of the carotid arteries were reconstructed from the acquired 3DVUS images. The velocity waveform generated by Doppler ultrasound was used to extract the flow information near the carotid bifurcation (as shown in Figure of the process of extracting velocity information from ultrasound Doppler images).
