In vivo wall shear stress patterns in carotid bifurcations assessed by 4D MRI

We investigated the distribution of wall shears stress (WSS) within the carotid artery bifurcation of healthy volunteers and patients with internal carotid artery stenosis. WSS was determined by flow-sensitive 4D MRI and correlated with bifurcation angle, vessel tortuosity and the ratio of the diameter of the common (CCA) and internal carotid artery (ICA). Critical WSS occurred at the posterior wall of the physiologically dilated ICA bulb and the incidence of critical WSS values was dependent from individual bifurcation geometry. Moreover, we found that ICA stenosis changed physiological WSS distribution whereas carotid endarterectomy partially restored physiological WSS conditions.