目的　观察人脑外伤后急性弥漫性脑肿胀脑CT值和超微结构变化关系。方法　比较 9例急性弥漫性脑肿胀患者伤后和手术前脑组织CT值的变化 ,结合术中所取 3 6份损伤脑组织中毛细血管和脑实质细胞超微结构变化 ,探讨脑组织CT值下降与超微结构损伤的关系。结果　术前脑组织的CT值比伤后首次CT值低 2 .5～ 4.3HU。电镜下见 :毛细血管管腔扩张和狭窄并存 ,血管周围和细胞间出现大片水肿区。神经元细胞核仁边移或消失 ;染色质呈点状或团块状凝集 ,核膜迂曲 ;核周可见大片脂滴及空白区 ;细胞质内线粒体肿胀、嵴模糊或消失 ,粗面内质网扩张、有脱颗粒现象。神经轴索肿胀 ,轴索部分断裂。星形胶质细胞损伤与神经元细胞相似。结论　急性弥漫性脑肿胀脑组织CT值下降与脑血管源性脑水肿、细胞毒性脑水肿和脑组织细胞的超微结构损伤加重有关 Objective To observe the relationship between the CT value and the ultrastructure changes of acute diffuse brain swelling brain after traumatic brain injury. Methods Nine cases of diffuse brain swelling in patients with diffuse brain injury and preoperative CT value changes, combined with 36 intraoperative lesions in the brain capillary and brain parenchyma ultrastructure changes to explore the CT value of brain tissue Decreased relationship with ultrastructural damage. Results The CT value of preoperative brain tissue was 2.5 ~ 4.3HU lower than the first CT value after injury. Electron microscope see: capillary lumen expansion and stenosis coexist, perivascular and intercellular large edema area. Nucleus of neurons migrate or disappear; chromatin was spot-like or mass agglutination, nuclear membrane tortuous; large peritubular lipid droplets and blank area visible; cytoplasm mitochondria swelling, crest or disappear, rough endoplasmic reticulum dilatation , There is degranulation. Axillary swelling, axonal part of the fracture. Astrocyte injury is similar to neuronal cells. Conclusions The decrease of CT value in brain of acute diffuse brain swelling is related to the increase of cerebrovascular brain edema, cytotoxic brain edema and ultrastructural damage of brain cells