鼻咽癌放疗后放射性脑病的CT及MRI表现

目的：观察鼻咽癌放疗后放射性脑病(REP)的CT及MRI表现，并探讨其诊断价值。方法：对48例鼻咽癌放疗后REP的CT及MRI资料进行回顾性分析。结果：REP的发生以颞叶最常见，可累及额、顶叶。其CT主要表现为指套状低密度水肿带．增强后无明显强化。而MRI则表现为指套状水肿、脑坏死、囊变，T1WI呈低信号，T2WI呈高信号．增强后呈脑回状或不规则强化．囊变区则呈环状强化。结论：鼻咽癌放疗后REP的CT及MRI具有一定的特征性．诊断价值较大。

CT and MRI findings of radiation encephalopathy after radiotherapy for nasopharyngeal carcinoma

Objective:To observe the CT and MRI findings and evaluate its diagnostic value for radiation encephalopathy after radiotherapy for nasopharyngeal carcinoma.Methods:CT and MRI manifestations of 48 patients with diagnosis of radiation encephalopathy were retrospectively reviewed.Results:The lesions located mainly in the temporal lobes,bilateral or unilateral.The characteristic CT features were ill defined mottled hypo dense patches in the temporal lobes.Most of the lesions showed no enhancement after contrast medium injection.There were typical MRI features:finger like edema and focal necrosis were found.T 1WI showed low signal intensity,and T 2WI showed high signal intensity.T 1WI plus Gd DTPA showed gyrus like or irregular enhancement in the bottom of temporal lobes.Some of them showed enhancement on the cystic wall.Conclusion:The CT and MRI findings are characteristic in radiation encephalopathy observed in nasopharyngeal carcinoma patients.CT and MRI have significant value in diagnosis of radiation encephalopthy.