Lo E H, Pan Y, Matsumoto K, Kowall N W
Center for Imaging and Pharmaceutical Research, Massachusetts General Hospital, Harvard Medical School, Charlestown 02129.
Magn Reson Imaging. 1994;12(3):403-11. doi: 10.1016/0730-725x(94)92533-x.
The definition of blood-brain barrier (BBB) damage in cerebral ischemia using contrast-enhanced MRI has not been clearly correlated to the spread of edema or other histological measures of barrier disruption. In this study, we used a rabbit model of focal cerebral ischemia to compare GdDTPA-enhanced MRI with spin-echo images of brain injury and immunocytochemical detection of BBB damage and vasogenic edema. After 4 h of transient ischemia followed by 6 h of reperfusion, in vivo T2W and T1W images were obtained in a 1.5 T magnet using a 3-inch surface coil. After MRI, the animals were sacrificed and anti-serum protein (IgG) monoclonal antibodies were used to detect regions of increased BBB permeability to serum proteins. Ischemic neuronal damage was confirmed with cresyl-violet histology. T2W scans showed focal regions of increased signal intensity in the ischemic hemisphere (17.0 +/- 4.1%) that primarily involved the cortex and striatum. T1W scans showed corresponding regions of hypointensity but demonstrated, in general, smaller lesion sizes (10.1 +/- 2.9%). GdDTPA-enhanced images showed variable areas of BBB disruption that included regions of intense leakage as well as lesions that only showed subtle enhancement along the periphery of damaged tissue. It appeared that large and more severe lesions corresponded to peripheral enhancement whereas smaller lesions showed central parenchymal enhancement. The extent of MR contrast enhancement did not correlate well with immunocytochemical images of serum protein leakage. Anti-IgG stains demonstrated widespread regions of BBB damage corresponding with areas of damaged neurons that appeared pyknotic on cresyl-violet sections.(ABSTRACT TRUNCATED AT 250 WORDS)
使用对比增强磁共振成像（MRI）来定义脑缺血中血脑屏障（BBB）损伤，这与水肿的扩散或屏障破坏的其他组织学指标尚未明确相关。在本研究中，我们使用局灶性脑缺血兔模型，将钆喷酸葡胺（GdDTPA）增强MRI与脑损伤的自旋回波图像以及BBB损伤和血管源性水肿的免疫细胞化学检测进行比较。短暂缺血4小时后再灌注6小时，使用3英寸表面线圈在1.5T磁体中获取体内T2加权和T1加权图像。MRI检查后，处死动物，使用抗血清蛋白（IgG）单克隆抗体检测BBB对血清蛋白通透性增加的区域。用甲酚紫组织学确认缺血性神经元损伤。T2加权扫描显示缺血半球信号强度增加的局灶区域（17.0±4.1%），主要累及皮质和纹状体。T1加权扫描显示相应的低信号区域，但总体上显示病变较小（10.1±2.9%）。GdDTPA增强图像显示BBB破坏的区域大小不一，包括渗漏强烈的区域以及仅在受损组织周边显示轻微强化的病变。似乎大的和更严重的病变对应于周边强化，而较小的病变显示中央实质强化。MR对比增强的程度与血清蛋白渗漏的免疫细胞化学图像相关性不佳。抗IgG染色显示BBB广泛受损区域，与甲酚紫切片上出现固缩的受损神经元区域相对应。（摘要截短于250字）
