重症颅脑损伤后弥漫性脑肿胀的影像诊断

The imaging diagnosis of diffuse brain swelling due to severe brain trauma

目的探讨脑外伤所致的弥漫性脑肿胀临床特点、发病机制及影像类型。方法分析48例脑外伤引起的弥漫性脑肿胀的临床及影像图像资料。结果 48例脑外伤引起的弥漫性脑肿胀中有33例合并脑挫裂伤(包括12例脑弥漫性轴索损伤,1例合并大脑基底节区梗死)、31例合并硬膜外、硬膜下或脑内血肿、27例合并颅骨骨折、10例合并蛛网膜下腔出血。弥漫性脑肿胀影像表现:①双侧大脑半球弥漫性肿胀,双侧脑室、脑池对称性缩小或消失,中线结构无移位;②一侧大脑半球弥漫性肿胀,同侧脑室、脑池受压缩小或消失,中线结构向对侧移位;③可伴蛛网膜下腔出血或皮层下小灶性出血;④脑实质 CT 值可低于、略高于或等于正常脑组织。结论颅脑外伤导致下丘脑和脑干血管运动中枢受损引起脑血管扩张是广泛弥漫性脑肿胀的发病机制之一,弥漫性脑肿胀有4种 CT 表现,非出血性弥漫性脑肿胀可由脑缺氧后再灌注所致。

Objective To discuss the clinical and pathological characteristics and the imaging types of the diffuse brain swelling due to severe brain trauma. Methods The clinical data and CT ＆ MR images on 48 cases with diffuse brain swelling due to severe brain trauma were analyzed. Results Among these 48 cases of the diffuse brain swelling due to severe brain trauma,33 cases were complicated with brain contusions （including 12 cases brain diffuse axonal injury, 1 case infarct of the right basal ganglion）, 31 cases were complicated with hematoma （epidural, subdural or intracerebral）, 27 cases were complicated with skull base fracture, and 10 cases were complicated with subarachnoid hematoma. The CT ＆ MR imaging of the diffuse brain swelling included as followed：① Symmetrically diffuse brain swelling in both cerebral hemispheres with cerebral ventricles decreased or disappeared, without median line shift. ②Diffuse brain swelling in one＂side cerebral hemisphere with cerebral ventricles decreased or disappeared at same side, and median line shift to other side.③ Subarachnoid hematoma or little subcortex intracerebral hematoma were complicated. ④ The CT value of the cerebral could be equal, lower or higher comparing with normal. Conclusion The pathological reason of diffuse brain swelling was the brain vessel expanding resulting from hypothalamus and brainstem injured in severe brain trauma. There were four CT ＆ MR imaging findings in diffuse brain swelling. The diffuse brain swelling without hematoma may be caused by ischemical reperfusion injury.