Department of Computational Neuroscience, University Medical Center Hamburg-Eppendorf , Hamburg , Germany.
Department of Neurology, University Medical Center Hamburg-Eppendorf , Hamburg , Germany.
Front Neurol. 2014 Dec 5;5:254. doi: 10.3389/fneur.2014.00254. eCollection 2014.
The aim of this study was to investigate the impact of a coexisting internal carotid artery (ICA) stenosis on lesion volumes as well as diffusion and perfusion parameters in acute ischemic stroke resulting from middle cerebral artery (MCA) occlusion.
Magnetic resonance imaging data of 32 patients with MCA occlusion with or without additional ICA stenosis imaged within 4.5 h of symptom onset were analyzed. Both groups consisted of 16 patients. Acute diffusion lesions were semi-automatically segmented in apparent diffusion coefficient (ADC) MRI datasets. Perfusion maps of cerebral blood volume (CBV), cerebral blood flow, mean transit time and T max were calculated using perfusion-weighted MRI datasets. Tissue-at-risk (TAR) volumes were generated by subtracting the ADC lesion from the hypoperfusion lesion defined by T max >6 s. Median ADC and perfusion parameter values were extracted separately for the diffusion lesion and TAR and used for statistical analysis.
No significant differences were found between the groups regarding the diffusion lesion and TAR volumes. Statistical analysis of diffusion and perfusion parameters revealed CBV as the only parameter with a significant difference (p = 0.009) contributing a small effect (η(2) = 0.11) to the group comparison with higher CBV values for the patient group with a coexisting ICA stenosis, while no significant effects were found for the other diffusion and perfusion parameters analyzed.
The results of this study suggest that a coexisting ICA stenosis does not have a strong effect on tissue status or perfusion parameters in acute stroke patients except for a moderate elevation of CBV. This may reflect improved collateral circulation or ischemic preconditioning in patients with a pre-existing proximal stenosis balancing impaired perfusion from the stenosis.
本研究旨在探讨颈内动脉（ICA）狭窄并存对大脑中动脉（MCA）闭塞所致急性缺血性脑卒中患者病灶体积以及弥散和灌注参数的影响。
对 32 例 MCA 闭塞患者的磁共振成像（MRI）数据进行分析，这些患者在症状发作后 4.5 h 内进行了 ICA 狭窄的影像学检查。两组均包括 16 例患者。在表观弥散系数（ADC）MRI 数据集上，急性弥散病变采用半自动分割。使用灌注加权 MRI 数据集计算脑血容量（CBV）、脑血流量、平均通过时间和 T max 的灌注图。通过将 T max >6 s 定义的低灌注病变从 ADC 病变中减去，生成危险组织（TAR）体积。分别提取弥散病变和 TAR 的 ADC 和灌注参数的中位数，用于统计分析。
两组间弥散病变和 TAR 体积无显著差异。弥散和灌注参数的统计学分析显示，CBV 是唯一具有显著差异（p=0.009）的参数，对组间比较的贡献较小（η(2)=0.11），伴有并存 ICA 狭窄的患者组 CBV 值较高，而分析的其他弥散和灌注参数则无显著影响。
本研究结果表明，除了 CBV 中度升高外，ICA 狭窄并存对急性脑卒中患者的组织状态或灌注参数没有强烈影响。这可能反映了存在近端狭窄的患者侧支循环改善或缺血预处理，平衡了狭窄引起的灌注受损。
