Schreiber W G, Gückel F, Stritzke P, Schmiedek P, Schwartz A, Brix G
Department of Radiology, German Research Cancer Center, Heidelberg.
J Cereb Blood Flow Metab. 1998 Oct;18(10):1143-56. doi: 10.1097/00004647-199810000-00011.
We have developed a new method for estimation of regional CBF (rCBF) and cerebrovascular reserve capacity on a pixel-by-pixel basis by means of dynamic magnetic resonance imaging (MRI). Thirteen healthy volunteers, 8 patients with occlusion and/or high grade stenosis of the internal carotid artery (ICA), and 2 patients with acute stroke underwent dynamic susceptibility-weighted contrast enhanced MRI. Using principles of indicator dilution theory and deconvolution analysis, maps of rCBF, regional cerebral blood volume, and of the mean transit time (MTT) were calculated. In patients with ICA occlusion/stenosis, cerebrovascular reserve capacity was assessed by the rCBF increase after acetazolamide stimulation. Mean gray and white matter rCBF values in normals were 67.1 and 23.7 mL x 100 g(-1) x min(-1), respectively. Before acetazolamide stimulation, six of eight patients with ICA occlusions showed decreased rCBF values; and in seven patients increased MTT values were observed in tissue ipsilateral to the occlusion. After acetazolamide stimulation, decreased cerebrovascular reserve capacity was observed in five of eight patients with ICA occlusion. In acute stroke, rCBF in the central core of ischemia was less than 8 mL x 100 g(-1) x min(-1). In peri-infarct tissue, rCBF and MTT were higher than in unaffected tissue but rCBF was normal. Dynamic MRI provides important clinical information on the hemodynamic state of brain tissue in patients with occlusive cerebrovascular disease or acute stroke.
我们已经开发出一种新方法，可通过动态磁共振成像（MRI）逐像素估计局部脑血流量（rCBF）和脑血管储备能力。13名健康志愿者、8名患有颈内动脉（ICA）闭塞和/或高度狭窄的患者以及2名急性中风患者接受了动态磁敏感加权对比增强MRI检查。利用指示剂稀释理论和去卷积分析原理，计算出rCBF、局部脑血容量和平均通过时间（MTT）图。对于ICA闭塞/狭窄患者，通过乙酰唑胺刺激后rCBF的增加来评估脑血管储备能力。正常情况下，灰质和白质的平均rCBF值分别为67.1和23.7 mL×100 g⁻¹×min⁻¹。在乙酰唑胺刺激前，8名ICA闭塞患者中有6名rCBF值降低；7名患者在闭塞同侧组织中观察到MTT值升高。乙酰唑胺刺激后，8名ICA闭塞患者中有5名观察到脑血管储备能力下降。在急性中风中，缺血中心核心区域的rCBF小于8 mL×100 g⁻¹×min⁻¹。在梗死周围组织中，rCBF和MTT高于未受影响的组织，但rCBF正常。动态MRI为患有闭塞性脑血管疾病或急性中风的患者提供了关于脑组织血流动力学状态的重要临床信息。
