Lo E H, Rogowska J, Bogorodzki P, Trocha M, Matsumoto K, Saffran B, Wolf G L
Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, USA.
J Cereb Blood Flow Metab. 1996 Jan;16(1):60-8. doi: 10.1097/00004647-199601000-00007.
A novel temporal correlation technique was used to map the first-pass transit of iodinated contrast agents through the brain. Transit profiles after bolus injections were measured with dynamic computed tomography (CT) scanning (1 image/s over 50 s). A rabbit model of focal cerebral ischemia (n = 6) was used, and dynamic CT scans were performed at 30, 60, 90, and 120 min postocclusion. Within the ischemic core, no bolus transit was detectable, demonstrating that complete ischemia was present after arterial occlusion. In the periphery of the ischemic distribution, transit dynamics showed smaller peaks, broadened profiles, and overall delay in bolus transit. A cross-correlation method was used to generate maps of delays in ischemic transit profiles compared with normal transit profiles from the contralateral hemisphere. These maps showed that penumbral regions surrounding the ischemic core had significantly delayed bolus transit profiles. Enlargement of the ischemic core over time (from 30 to 120 min postocclusion) was primarily accomplished by the progressive deterioration of the penumbral regions. These results suggest that (a) temporal correlation methods can define regions of abnormal perfusion in focal cerebral ischemia, (b) peripheral regions of focal cerebral ischemia are characterized by delays in bolus transit profiles, and (c) these regions of bolus transit delay deteriorate over time and thus represent a hemodynamic penumbra.
一种新型的时间相关技术被用于绘制碘化造影剂首次通过大脑的过程。通过动态计算机断层扫描（CT）（在50秒内每秒1张图像）测量团注注射后的通过曲线。使用局灶性脑缺血兔模型（n = 6），在闭塞后30、60、90和120分钟进行动态CT扫描。在缺血核心区内，未检测到团注通过，表明动脉闭塞后存在完全缺血。在缺血分布的周边区域，通过动态显示较小的峰值、变宽的曲线以及团注通过的总体延迟。采用互相关方法生成缺血通过曲线与对侧半球正常通过曲线相比的延迟图。这些图显示，围绕缺血核心的半暗带区域团注通过曲线明显延迟。随着时间推移（从闭塞后30分钟到120分钟），缺血核心区的扩大主要是由半暗带区域的逐渐恶化导致的。这些结果表明：（a）时间相关方法可以定义局灶性脑缺血中异常灌注的区域；（b）局灶性脑缺血的周边区域以团注通过曲线延迟为特征；（c）这些团注通过延迟区域会随时间恶化，因此代表了血流动力学半暗带。
