Abstract：
OBJECTIVE: Clinical diagnosis of ischemic stroke commonly relies on examining cerebral perfusion changes by using computed tomography perfusion (CTP) techniques. However, the radiation dose in CTP is quite higher in comparison to computed tomography angiography (CTA), with associated costs and time.
METHODS: Hence, this study established a lumped-parameter model (LPM) of brain tissue microcirculation (BTM) based on CTA, aiming to achieve real-time calculation of cerebral perfusion. After validation of calculated flow results with clinical data, the BTM-LPM model was used to examine the changes in cerebral perfusion following ischemic stroke, in which the effects of nine anatomical structures of the Circle of Willis (CoW) together with various distribution patterns of stenosis in the feeding arteries were considered.
RESULTS: When compared the calculated flow results from BTM-LPM with the clinically measured data of literature, the mean squared error (MSE) value for the feeding arteries was 3.9 % and its total value for microcirculatory flow in each region was 0.1 %. Notably, the calculation time was 35.6 s. In the case of the CoW missing the left and right posterior communicating artery, a 60 % stenosis of the basilar artery is likely to cause ischemic damage to some temporal and occipital lobes of the right and left hemispheres. While in the case of the CoW missing the anterior communicating artery and the left posterior communicating artery, ischemic damage to the entire frontal lobe and parts of the temporal and parietal lobes of the left hemisphere was found when 80 % stenosis occurred in the left internal carotid artery.
CONCLUSIONS: The BTM-LPM proposed in this study could accurately calculate cerebral perfusion in real time and demonstrated the importance of CoW anatomy in different ischemic injuries to cerebral tissue. The calculated cerebral perfusion would be a reference value for early diagnosis and preoperative planning of different ischemic injuries to cerebral tissue, thereby the BTM-LPM holds great promising for replacing CTP examination.
METHODS: Hence, this study established a lumped-parameter model (LPM) of brain tissue microcirculation (BTM) based on CTA, aiming to achieve real-time calculation of cerebral perfusion. After validation of calculated flow results with clinical data, the BTM-LPM model was used to examine the changes in cerebral perfusion following ischemic stroke, in which the effects of nine anatomical structures of the Circle of Willis (CoW) together with various distribution patterns of stenosis in the feeding arteries were considered.
RESULTS: When compared the calculated flow results from BTM-LPM with the clinically measured data of literature, the mean squared error (MSE) value for the feeding arteries was 3.9 % and its total value for microcirculatory flow in each region was 0.1 %. Notably, the calculation time was 35.6 s. In the case of the CoW missing the left and right posterior communicating artery, a 60 % stenosis of the basilar artery is likely to cause ischemic damage to some temporal and occipital lobes of the right and left hemispheres. While in the case of the CoW missing the anterior communicating artery and the left posterior communicating artery, ischemic damage to the entire frontal lobe and parts of the temporal and parietal lobes of the left hemisphere was found when 80 % stenosis occurred in the left internal carotid artery.
CONCLUSIONS: The BTM-LPM proposed in this study could accurately calculate cerebral perfusion in real time and demonstrated the importance of CoW anatomy in different ischemic injuries to cerebral tissue. The calculated cerebral perfusion would be a reference value for early diagnosis and preoperative planning of different ischemic injuries to cerebral tissue, thereby the BTM-LPM holds great promising for replacing CTP examination.
摘要：
目的：缺血性卒中的临床诊断通常依赖于使用计算机断层扫描灌注（CTP）技术检查脑灌注变化。然而,与计算机断层扫描血管造影（CTA）相比，CTP中的辐射剂量要高得多，与相关的成本和时间。
方法：因此，本研究建立了基于CTA的脑组织微循环(BTM)的集总参数模型(LPM),目的是实现脑灌注的实时计算。用临床数据验证计算流量结果后，BTM-LPM模型用于检查缺血性卒中后脑灌注的变化，其中考虑了Willis环（CoW）的9种解剖结构以及供血动脉中狭窄的各种分布模式的影响。
结果：将来自BTM-LPM的计算流量结果与文献的临床测量数据进行比较时，供血动脉的均方误差(MSE)值为3.9%,各区域微循环流量的总值为0.1%.值得注意的是,计算时间为35.6s。在CoW缺失左右后交通动脉的情况下，60％的基底动脉狭窄可能会对左右半球的颞叶和枕叶造成缺血性损害。而在CoW缺少前交通动脉和左后交通动脉的情况下，当80％的狭窄发生在左颈内动脉时，发现整个额叶以及左半球颞叶和顶叶的部分缺血性损害。
结论：本研究中提出的BTM-LPM可以实时准确地计算脑灌注，并证明了CoW解剖在不同缺血性脑组织损伤中的重要性。计算的脑灌注量对不同脑组织缺血性损伤的早期诊断和术前规划具有参考价值。因此，BTM-LPM对于替代CTP检查具有很大的希望。
方法：因此，本研究建立了基于CTA的脑组织微循环(BTM)的集总参数模型(LPM),目的是实现脑灌注的实时计算。用临床数据验证计算流量结果后，BTM-LPM模型用于检查缺血性卒中后脑灌注的变化，其中考虑了Willis环（CoW）的9种解剖结构以及供血动脉中狭窄的各种分布模式的影响。
结果：将来自BTM-LPM的计算流量结果与文献的临床测量数据进行比较时，供血动脉的均方误差(MSE)值为3.9%,各区域微循环流量的总值为0.1%.值得注意的是,计算时间为35.6s。在CoW缺失左右后交通动脉的情况下，60％的基底动脉狭窄可能会对左右半球的颞叶和枕叶造成缺血性损害。而在CoW缺少前交通动脉和左后交通动脉的情况下，当80％的狭窄发生在左颈内动脉时，发现整个额叶以及左半球颞叶和顶叶的部分缺血性损害。
结论：本研究中提出的BTM-LPM可以实时准确地计算脑灌注，并证明了CoW解剖在不同缺血性脑组织损伤中的重要性。计算的脑灌注量对不同脑组织缺血性损伤的早期诊断和术前规划具有参考价值。因此，BTM-LPM对于替代CTP检查具有很大的希望。
