School of Biomedical Sciences & Pharmacy and the Centre for Brain & Mental Health Research, University of Newcastle, Callaghan, NSW, Australia.
Int J Stroke. 2011 Aug;6(4):284-9. doi: 10.1111/j.1747-4949.2010.00564.x. Epub 2011 Jan 10.
Brain computed tomography perfusion imaging in acute stroke may help guide therapy. However, the perfusion thresholds defining potentially salvageable (penumbra) and irreversibly injured (infarct core) tissue require further validation. The aim of this study was to validate infarct core and penumbra perfusion thresholds in a rodent stroke model by developing and optimising perfusion computed tomography imaging, performing serial scanning and correlating scans with final histology. Stroke was induced in male Wistar rats (n=17) using the middle cerebral artery thread-occlusion method. Perfusion computed tomography scans were obtained immediately pre- and postocclusion, and every 30 min for 2.5 h. Histological changes of infarction were assessed after 24 h. High-quality maps of cerebral blood flow and cerebral blood volume were generated at multiple coronal planes after optimisation of contrast injection and scanning parameters. The prestroke absolute cerebral blood flow and cerebral blood volume values (mean ± SD) were 158.2 ± 49.94 ml/min per 100 g and 5.6 ± 1.13 ml per 100 g, respectively. Cerebral blood flow was significantly lower in the infarct region of interest than the contralateral hemisphere region of interest at all time points, except the 0.5 h postocclusion time point. However, cerebral blood volume was only significantly lower in the infarct region of interest than the contralateral hemisphere region of interest at the 1 h and the 1.5 h time points (postocclusion). This study has demonstrated for the first time the feasibility of performing perfusion computed tomography in the most commonly used animal model of stroke. The model will allow definitive studies to determine optimal thresholds and the reliability of perfusion computed tomography measures for infarct core and penumbra.
脑计算机断层灌注成像在急性脑卒中的治疗中可能具有指导作用。然而，界定潜在可挽救（半暗带）和不可挽救（梗死核心）组织的灌注阈值还需要进一步验证。本研究旨在通过开发和优化灌注计算机断层扫描成像、进行连续扫描并将扫描与最终组织学相关联，在一种啮齿动物脑卒中模型中验证梗死核心和半暗带的灌注阈值。使用大脑中动脉线栓法在雄性 Wistar 大鼠（n=17）中诱导脑卒中。在闭塞前和闭塞后即刻、闭塞后 2.5 h 内每 30 min 进行一次灌注计算机断层扫描。在 24 h 后评估梗死的组织学变化。在优化对比剂注射和扫描参数后，在多个冠状面上生成了脑血流量和脑血容量的高质量图。在脑卒中之前，绝对脑血流量和脑血容量值（平均值±标准差）分别为 158.2±49.94 ml/min/100 g 和 5.6±1.13 ml/100 g。在所有时间点，除了闭塞后 0.5 h 时间点外，在梗死感兴趣区的脑血流量均显著低于对侧半球感兴趣区。然而，只有在闭塞后 1 h 和 1.5 h 时间点（脑卒中后），脑血容量才显著低于对侧半球感兴趣区。本研究首次证明了在最常用的脑卒中动物模型中进行灌注计算机断层扫描的可行性。该模型将允许进行确定性研究以确定灌注计算机断层扫描测量梗死核心和半暗带的最佳阈值和可靠性。
