Measurement of three-dimensional flow field and wall shear stress for wall-deformable cerebral aneurysm under pulsatile flow

Abstract Cerebral aneurysms, which can lead to subarachnoid hemorrhages upon rupture, present challenges in predicting such ruptures due to unclear mechanisms. Prior research highlights the importance of wall shear stress (WSS) in aneurysm rupture. Contradictory findings on the role of high WSS, low WSS, WSS gradient, and oscillatory shear index necessitate further investigation, particularly under pulsatile flow conditions. This study aims to develop a robust method for accurate WSS calculation that accounts for the complex flow structures within aneurysms. Using scanning-stereoscopic particle image velocimetry (SSPIV), we estimated three-dimensional wall positions from particle image captured in a Y-shaped aneurysm model. Moreover, an elastic, patient-specific model under pulsatile flow conditions revealed periodic changes in shape and WSS distribution synchronized with the flow rate. Our method achieved a wall reconstruction accuracy within 0.6%. The results demonstrate the potential of WSS measurement with elastic walls under pulsatile flow to provide insights into aneurysm growth and rupture mechanisms.