急性脑静脉闭塞DWI、CT灌注成像与病理学相关性的对比实验研究

Comparison of DWI,CT perfusion,and pathology in experimental study of acute cerebral venous occlusion

目的：观察脑静脉闭塞模型脑实质损害区MR扩散加权成像（DWI）、CT灌注成像（CTP）及病理学的变化规律，探讨模型在该病研究中的价值。方法：新西兰大白兔28只，随机分为2组（手术组24只，对照组4只）。术后1、3．6、12、24和48h行DWI和CTP检查，观察扩散异常容积、ADC值和血流动力学变化规律，其结果与病理学对照研究。结果：DWI能早期显示脑实质病变，术后3hDWI和T2WI均能显示病变。术后6h前DWI上扩散异常容积明显大于T2WI上异常高信号区的容积（t=13．69，P〈0．01）；术后12h、24h及48hT2WI病变容积与DWI上的扩散异常容积无显著差异（t值分别为1．467、0．996及2．017，P值均〉0．05）。ADC值早期下降随后逐渐回升。CTP示术后6—12h病变中心区CBV和CBF降低，而病变边缘区CBV增加或正常或轻度降低；术后12—24h病变中心区和边缘区CBV和CBF均明显降低。病理学示以血管源性水肿为主，12h后出现脑组织大量坏死。对照组未见上述各种异常表现。结论：DWI和CTP可准确评价急性脑静脉闭塞模型脑实质损害程度和血流动力学改变，指导临床治疗。

Objective： To observe the evolution of lesions on animal model of acute cerebral venous occlusion by DWI. CTP and histopathology, and investigate the value of this model in the disease study. Methods：28 New Zealand white rabbits were randomly divided into 2 groups, including operation group （ n = 24） and control group （n = 4）. DWI and CTP were performed at an interval of 1, 3, 6, 12, 24 and 48h after operation. The evolution of the volume of DWI abnormality, ADC values, and hemodynamic changes were observed in each group. The data were compared with pathological findings. Results： The early pathological changes were only detected with DWI （within lh）, and then the lesions were also detected with T2WI after 3h. The volume of DWI abnormality was bigger than T2WI abhornudity （ t = 13.69, P 〈 0.01）. No obvious difference of the volume on T2WI abnormality and DWI was found after 12h, 24h and 48h （ t = 1.467, 0.996, 2.017 respectively; P 〉 0.05）. The ADC values of the brain parenchymal lesions decreased at the early stage and increased subsequently. Both CBV and CBF decreased in the center of the lesions, while CBV increased, normal or decreased, CBF decreased in the marginal zone after 6 - 12h. CBV and CBF decreased obviously both in the center and marginal zone after 12 - 24h. Brain parenchymal lesions in microscopically were mainly vasogenic edema and followed by necrosis after 12h. No abnormal changes were observed in control group. Conclusion：DWI and CTP are accurate in evaluating brain parenchymal lesions and hemodynamies of acute cerebral venous occlusion , and is useful for early clinic treatment.