Mathematical Modeling of Blood Flow in a Patientspecific Model of the Middle Cerebral Artery Taking into Account Non-Newtonian Blood Behavior

摘要

According to recent studies hemodynamic conditions play an important role in initiation and development of several disorders of the cerebral circulation, such as atherosclerosis and aneurysm. One of the common sites of the aneurysm formation is the middle cerebral artery (MCA). In the present study, the flow conditions in the individualized model of the MCA aneurysm are investigated in detail and correlated with the aneurysm genesis. A patient-specific model of the saccular aneurysm of MCA was derived from the real clinical imaging data. A realistic physiological pulse curve was scaled to ensure the normal inlet flow rate in the artery. A transient computational fluid dynamics simulation was performed employing the Local viscosity fluid model, which takes into account non-Newtonian blood behavior and increases a precision of hemodynamic parameters evaluation, especially at low shear rate zones. The complex flow pattern was observed in the aneurysm sac, producing a swirling blood flow. A flow impingement zone near the aneurysm fundus was characterized by the high velocity values, about 0.9 m/s, which could potentially affect the endothelial cells at this zone and contribute to further arterial wall degeneration. Moreover, the zone of low wall shear stresses (收起