病史:患者因昏迷入住于重症监护室,目前已苏醒。 Axial noncontrast CT scans demonstrate diffuse cerebral hypodensity, loss of gray-white matter differentiation, effacement of sulci, and increased attenuation within the subarachnoid spaces and the cisterns. 图1-3:横断位非增强 CT 扫描显示大脑弥散性低密度,灰白质分界不清,脑沟模糊,蛛网膜下腔及脑池密度增高。 诊断:假性蛛网膜下腔出血(Pseudo-Subarachnoid Hemorrhage) 通常继发于复苏或严重头部创伤引起的脑水肿之后; 预后较差; 病理生理学:大脑水肿引起的弥散性低密度影,线状高密度表明为充盈的静脉结构,在非增强 CT 扫描上通常表现为相对的高信号。 Key Diagnostic Features: Diffuse hypodensity Loss of gray-white matter differentiation Effacement of sulci and appearance of increased attenuation (attenuation coefficients 25–35 HU) within cisterns and subarachnoid spaces 诊断要点: 弥散性低密度影; 灰白质分界不清; 脑沟模糊,蛛网膜下腔及脑池密度增高(CT衰减系数25–35 HU)。 鉴别诊断:蛛网膜下腔出血;软脑膜疾病。 假性蛛网膜下腔出血病例图片: 图片来源:www.ajnr.org |
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