目的:基于计算流体力学(computational fluid dynamics,CFD)技术对椎基底动脉延长扩张症(vertebrobasilar dolichoectasia,VBD)进行血流动力学分析。方法:使用Mimics软件读取1例VBD患者颅内动脉影像的DICOM(digital imaging and communi...目的:基于计算流体力学(computational fluid dynamics,CFD)技术对椎基底动脉延长扩张症(vertebrobasilar dolichoectasia,VBD)进行血流动力学分析。方法:使用Mimics软件读取1例VBD患者颅内动脉影像的DICOM(digital imaging and communications in medicine)数据,进行三维实体重建,应用Ansys软件对实体模型进行流体力学分析,模拟VBD患者椎基底动脉的血流动力学变化过程,并描述流线、管壁切应力和管壁压力情况。结果:双侧椎动脉汇合为基底动脉后血流仍表现为分层流动,在基底动脉迂曲部出现绕壁血流。椎基底动脉汇合部及基底动脉下段的局部低壁面切应力和高壁面压力区域相吻合。推测VBD的生长初始部位可能位于椎基底动脉汇合部及基底动脉下段,低壁面切应力导致的血管壁退化及相应区域存在的高壁面压力可能与VBD的发生、发展有关。结论:CFD数值仿真可能为进一步研究血流动力学在VBD发生、发展中的作用提供理论基础。展开更多
The extracellular space(ECS) of brain is defined as an irregular channel which is located in the interstitial tissue outside the plasma membranes of neurons,and occupied by interstititial fluid(ISF).Diffusion in ECS i...The extracellular space(ECS) of brain is defined as an irregular channel which is located in the interstitial tissue outside the plasma membranes of neurons,and occupied by interstititial fluid(ISF).Diffusion in ECS is described by a modified diffusion equation from which several parameters can be calculated,such as the diffusion coefficient(D),the tortuosity(λ),the volume fraction(α) and the clearance of molecules.Radiolabeled tracers were used for early diffusion measurements.Presently,the real-time iontophoresis(RTI) method is employed for small ions,whereas the integrative optical imaging(IOI) and the magnetic resonance diffusion weighted imaging(DWI) are developed for macromolecules tracers.Extensive experimental studies with such methods show that in normal brain tissue,the volume fraction of ECS typically is about 20% and the tortuosity is 1.6,although there are regional variations.These parameters change with the brain development and in various pathophysiological states.Knowledge of ECS diffusion properties help us to understand extrasynaptic volume transmission to the development of paradigms for drug delivery in brain.展开更多
目的：评价大脑中动脉成形术治疗皮质下分水岭梗死（subcortex cerebral watershed infarction,S-CWI）导致中、重度残疾的患者的安全性和有效性.方法：2011年6月至2012年5月北京大学第三医院介入血管外科治疗的合并同侧大脑中动脉重度...目的：评价大脑中动脉成形术治疗皮质下分水岭梗死（subcortex cerebral watershed infarction,S-CWI）导致中、重度残疾的患者的安全性和有效性.方法：2011年6月至2012年5月北京大学第三医院介入血管外科治疗的合并同侧大脑中动脉重度狭窄的中、重度残疾的S-CWI患者5例（6处病变）,观察5例患者术前及术后神经系统评分,并评价神经功能的改善情况.结果：5例患者术后第7天神经功能均有改善,美国国立卫生研究院卒中量表（National Institute of Health Stroke Scale,NIHSS）评分下降4～6分,改良Rankin量表（Modified Rankin Scale,mRs）评分下降1分;3个月随访时4例患者mRs评分为1分,1例患者为2分.1年随访时无新发卒中及支架内再狭窄事件.结论：大脑中动脉成形术对因S-CWI所致中重度残疾的患者有益.展开更多
文摘目的:基于计算流体力学(computational fluid dynamics,CFD)技术对椎基底动脉延长扩张症(vertebrobasilar dolichoectasia,VBD)进行血流动力学分析。方法:使用Mimics软件读取1例VBD患者颅内动脉影像的DICOM(digital imaging and communications in medicine)数据,进行三维实体重建,应用Ansys软件对实体模型进行流体力学分析,模拟VBD患者椎基底动脉的血流动力学变化过程,并描述流线、管壁切应力和管壁压力情况。结果:双侧椎动脉汇合为基底动脉后血流仍表现为分层流动,在基底动脉迂曲部出现绕壁血流。椎基底动脉汇合部及基底动脉下段的局部低壁面切应力和高壁面压力区域相吻合。推测VBD的生长初始部位可能位于椎基底动脉汇合部及基底动脉下段,低壁面切应力导致的血管壁退化及相应区域存在的高壁面压力可能与VBD的发生、发展有关。结论:CFD数值仿真可能为进一步研究血流动力学在VBD发生、发展中的作用提供理论基础。
文摘The extracellular space(ECS) of brain is defined as an irregular channel which is located in the interstitial tissue outside the plasma membranes of neurons,and occupied by interstititial fluid(ISF).Diffusion in ECS is described by a modified diffusion equation from which several parameters can be calculated,such as the diffusion coefficient(D),the tortuosity(λ),the volume fraction(α) and the clearance of molecules.Radiolabeled tracers were used for early diffusion measurements.Presently,the real-time iontophoresis(RTI) method is employed for small ions,whereas the integrative optical imaging(IOI) and the magnetic resonance diffusion weighted imaging(DWI) are developed for macromolecules tracers.Extensive experimental studies with such methods show that in normal brain tissue,the volume fraction of ECS typically is about 20% and the tortuosity is 1.6,although there are regional variations.These parameters change with the brain development and in various pathophysiological states.Knowledge of ECS diffusion properties help us to understand extrasynaptic volume transmission to the development of paradigms for drug delivery in brain.
文摘目的：评价大脑中动脉成形术治疗皮质下分水岭梗死（subcortex cerebral watershed infarction,S-CWI）导致中、重度残疾的患者的安全性和有效性.方法：2011年6月至2012年5月北京大学第三医院介入血管外科治疗的合并同侧大脑中动脉重度狭窄的中、重度残疾的S-CWI患者5例（6处病变）,观察5例患者术前及术后神经系统评分,并评价神经功能的改善情况.结果：5例患者术后第7天神经功能均有改善,美国国立卫生研究院卒中量表（National Institute of Health Stroke Scale,NIHSS）评分下降4～6分,改良Rankin量表（Modified Rankin Scale,mRs）评分下降1分;3个月随访时4例患者mRs评分为1分,1例患者为2分.1年随访时无新发卒中及支架内再狭窄事件.结论：大脑中动脉成形术对因S-CWI所致中重度残疾的患者有益.
