Correlations between the apparent diffusion coefficient, water content, and ultrastructure after induction of vasogenic brain edema in cats
Correlations between the apparent diffusion coefficient, water content, and ultrastructure after induction of vasogenic brain edema in cats
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DOI：
10.3171/jns.1999.90.3.0499
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发表时间：
1999-03-01
影响因子：
4.1
通讯作者：
Hirakawa, K
中科院分区：
文献类型：
--
作者：
Kuroiwa, T;Nagaoka, T;Hirakawa, K
Object.作者研究了血管源性脑水肿后表观扩散系数、局部含水量和组织超微结构变化之间的相关性。通过皮层冷损伤，在6只猫的白色物质中诱导血管源性水肿。将从磁共振成像获得的用于测量取向平均水扩散率的扩散张量迹线（迹线[D]）与通过重量研究测定的相应组织含水量和超微结构水定位进行比较。损伤后4.5小时，水肿液已扩散至皮质下和深层白色物质。在皮质下和深层白色物质中，痕量（D）的增加与组织含水量的增加呈显著线性相关，如下所示：y = 45.5x - 2367（r = 0.94）和y = 37.0x - 1769（r = 0.93），其中x是含水量（克水/克组织），y是迹线（D）（X 10（-6）mm（2）/秒端）。在组织学检查中，发现神经纤维在白色物质中分离，细胞外间隙明显扩大，充满蛋白质液体。细胞成分未见明显水肿。在体内血管源性脑水肿中，在痕量（D）的增加和细胞外水体积的增加之间观察到线性相关性。皮质下和深层白色物质之间的相似相关性显示神经纤维的不同排列（分别为平行与混合），表明痕量（D）的测量是评价血管源性脑水肿的合适参数。
Object. The authors examined the correlation between changes in the apparent diffusion coefficient, regional water content, and tissue ultrastructure after vasogenic brain edema.Methods. Vasogenic edema was induced in the white matter of six cats by cortical cold lesioning. The trace of diffusion tensor (Trace[D]) obtained from magnetic resonance imaging to measure the orientationally averaged water diffusibility was compared with the corresponding tissue water content determined by gravimetric studies and with ultrastructural water localization. Edema fluid had spread to the subcortical and deep white matter by 4.5 hours postlesioning. The increase in Trace(D) showed a significant linear correlation with the increase in tissue water content, both in the subcortical and deep white matter as follows: y = 45.5x - 2367 (r = 0.94) and y = 37.0x - 1769 (r = 0.93), respectively, where x is the water content (gram water/gram tissue) and y the Trace(D) (X 10(-6) mm(2)/sec end). On histological examination, nerve fibers were found to be dissociated in the white matter and the extracellular space was markedly enlarged with protein-rich fluid. No noticeable hydropic swelling of the cellular components was observed.Conclusions. A linear correlation was observed between increases in Trace(D) and increases in extracellular water volume in in vivo vasogenic brain edema. A similar correlation between the subcortical and deep white matter showing different arrangements of nerve fibers (parallel compared with intermingled, respectively) indicated that measurement of Trace(D) is a suitable parameter for the evaluation of vasogenic brain edema.