Kawahara H, Takeda Y, Tanaka A, Nagano O, Katayama H, Hirakawa M, Hiraki Y
Department of Anesthesiology and Resuscitology, Okayama University Medical School, 2-5-1 Shikata-Cho, 700-8558, Okayama, Japan.
J Neurol Sci. 2000 Dec 1;181(1-2):73-81. doi: 10.1016/s0022-510x(00)00433-0.
To examine the usefulness of diffusion-weighted imaging for detecting neuronal damage following ischemia, dynamic changes in diffusion-, T1- and T2-weighted images of rats subjected to 10 min of 4-vessel occlusion and of humans who had suffered 10-20 min of cardiac arrest were observed. In rats, no remarkable alteration was observed on day 1. On day 3, however, diffusion-weighted images showed high signal intensity in the hippocampal area, in which the apparent diffusion coefficient was significantly lower than that of the control (760+/-28x10(-6) mm(2)/s in control vs. 480+/-29x10(-6) mm(2)/s on day 3, P<0.0001). Histological observation revealed microvacuolation in 92+/-4% of pyramidal neurons in the CA1 region. On day 7, the hyperintensity in diffusion-weighted images had disappeared and microvacuolation had also disappeared in the CA1 region, but severely disrupted pyramidal neurons containing pyknotic nuclei had appeared in the CA1 region instead. In humans, diffusion-weighted images did not show any apparent abnormality in the cerebral cortex on the day of resuscitation. On day 3, however, diffusion-weighted images consistently showed hyperintensities in the temporal or occipital cortex, and these hyperintensities had disappeared in images obtained on days 7 and 14. From day 14, T1-weighted images showed laminar hyperintensity, suggesting laminar necrosis, along the cortex, where diffusion-weighted images showed high signal intensity on day 3. These results suggested that diffusion-weighted imaging has a potential for detection of the occurrence of microvacuolation and is useful for detecting the progression of ischemic changes in humans following global ischemia.
为了研究扩散加权成像在检测缺血后神经元损伤中的作用，观察了经历10分钟四血管闭塞的大鼠以及心脏骤停10 - 20分钟的人类的扩散加权图像、T1加权图像和T2加权图像的动态变化。在大鼠中，第1天未观察到明显变化。然而，在第3天，扩散加权图像显示海马区信号强度增高，表观扩散系数显著低于对照组（对照组为760±28×10⁻⁶mm²/s，第3天为480±29×10⁻⁶mm²/s，P<0.0001）。组织学观察显示CA1区92±4%的锥体细胞出现微空泡形成。在第7天，扩散加权图像上的高信号消失，CA1区的微空泡也消失，但CA1区出现了含有固缩核的严重受损锥体细胞。在人类中，复苏当天扩散加权图像在大脑皮层未显示任何明显异常。然而，在第3天，扩散加权图像始终显示颞叶或枕叶皮层有高信号，这些高信号在第7天和第14天的图像中消失。从第14天开始，T1加权图像显示沿皮层有层状高信号，提示层状坏死，而在第3天扩散加权图像在此处显示高信号。这些结果表明，扩散加权成像有检测微空泡形成的潜力，并且对于检测全脑缺血后人类缺血性变化的进展是有用的。
