Effect of Head Posture Changes in the Geometry and Hemodynamics of a Healthy Human Carotid Bifurcation

Recent reports have stressed the importance of studying the morphology and hemodynamic changes of peripheral arteries in parts of the body that experience motion and posture change and their relationship to the hemodynamic hypothesis of atherosclerosis development [1, 2]. The carotid arteries may fall into this category since their geometric morphology and hemodyamic conditions may change due to head and neck posture changes. Such changes may alter the hemodynamic variables that are generally associated with the development of atherosclerosis, such as low and oscillating wall shear stress (WSS) and particle residence times. In this study, the carotid bifurcation of a healthy volunteer was imaged in the neutral position and in 3 different posture positions: a) flexion sideways to the right 80°, b) flexion upwards 45°, and c) flexion downwards 45° (Fig. 1). Anatomic and quantitative flow MR data were used to develop computational models to investigate the effect of different postures on arterial geometry and hemodynamic characteristics.