Intracranial aneurysms(IAs)are abnormal bulges in a blood vessel in the brain that have a potential to rupture and even causing a stroke,which can lead to lasting brain damage,long-term disability,or even loss of life...Intracranial aneurysms(IAs)are abnormal bulges in a blood vessel in the brain that have a potential to rupture and even causing a stroke,which can lead to lasting brain damage,long-term disability,or even loss of life.It has been widely acknowledged that hemodynamic factors,e.g.,instantaneous wall shear stress,time-averaged wall shear stress,wall shear stress gradient,gradient oscillatory number,oscillatory shear index,pulsatile blood flow waveform(flow rate magnitude and shape,physical flow period),relative residence time/turnover time,blood pressure.展开更多
Objective:To study the hemodynamics of an anatomic internal carotid artery aneurysm derived from a patient-specific model and then manipulate into two phantom morphologies:one growing uniformly by size and the other c...Objective:To study the hemodynamics of an anatomic internal carotid artery aneurysm derived from a patient-specific model and then manipulate into two phantom morphologies:one growing uniformly by size and the other changing shape unevenly.Methods:The computational model of the saccular,internal carotid artery,aneurysm was constructed from 3D rotational,digitally subtracted,catheter angiography images.Computational fluid dynamics simulations were performed under pulsatile cardiac flow conditions.Velocity vectors,streamlines,pressure,and wall shear stress(WSS)and its variance distributions were quantitatively visualized.Results:The maximum pressure and WSS from the time-averaged distribution on the inside saccular surface of the original case are 415.38 and 17.61 Pa.In contrast,the bi-lobed shape gives rise to higher peak values of pressure(461.00 Pa)and WSS(33.20 Pa)on the saccular dome.Conversely,the evenly enlarged aneurysm actually results in a slightly lower peak pressure(399.58 Pa)and drastically decreased WSS(9.81 Pa).Conclusions:The current study indicates that the size of the aneurysm should not be the only determining factor for the rupture risk consideration,the irregularity of the aneurysm shape and the corresponding aberrant hemodynamics might be a more important factor to consider for risk assessment.展开更多
文摘Intracranial aneurysms(IAs)are abnormal bulges in a blood vessel in the brain that have a potential to rupture and even causing a stroke,which can lead to lasting brain damage,long-term disability,or even loss of life.It has been widely acknowledged that hemodynamic factors,e.g.,instantaneous wall shear stress,time-averaged wall shear stress,wall shear stress gradient,gradient oscillatory number,oscillatory shear index,pulsatile blood flow waveform(flow rate magnitude and shape,physical flow period),relative residence time/turnover time,blood pressure.
文摘Objective:To study the hemodynamics of an anatomic internal carotid artery aneurysm derived from a patient-specific model and then manipulate into two phantom morphologies:one growing uniformly by size and the other changing shape unevenly.Methods:The computational model of the saccular,internal carotid artery,aneurysm was constructed from 3D rotational,digitally subtracted,catheter angiography images.Computational fluid dynamics simulations were performed under pulsatile cardiac flow conditions.Velocity vectors,streamlines,pressure,and wall shear stress(WSS)and its variance distributions were quantitatively visualized.Results:The maximum pressure and WSS from the time-averaged distribution on the inside saccular surface of the original case are 415.38 and 17.61 Pa.In contrast,the bi-lobed shape gives rise to higher peak values of pressure(461.00 Pa)and WSS(33.20 Pa)on the saccular dome.Conversely,the evenly enlarged aneurysm actually results in a slightly lower peak pressure(399.58 Pa)and drastically decreased WSS(9.81 Pa).Conclusions:The current study indicates that the size of the aneurysm should not be the only determining factor for the rupture risk consideration,the irregularity of the aneurysm shape and the corresponding aberrant hemodynamics might be a more important factor to consider for risk assessment.
