目 的 探讨脑后部可逆性脑 病综合征 ( p o s t e r i o r r e v e r s i b l e encephalopathy syndrome, PRES)的MRI 的影像表现特征。方法 回顾性分析13例 PRES患者的临床及MRI影像学资料，患者 均行MRI平扫，4例患者同时行MRV扫描，3 例患者行MR增强扫描，其中8例患者经相 关治疗后复查。结果 病灶主要累及双侧 枕叶及顶叶皮层下白质，其次累及概率 依次为额叶、颞叶、小脑半球、基底节 区、胼胝体及丘脑。MRI表现在T1WI像上 呈等信号或低信号，T2WI像呈高信号， T2Flair像呈明显高信号，DWI像大多呈 等或稍高信号，相对应ADC图大多呈高信 号。行MR增强扫描的患者脑实质均未见 明显异常强化的信号。其中8例患者经临 床治疗9-12天后复查MRI，大多患者的图 像显示病变范围缩小或完全消失。结论 PRES的头颅MR影像表现具有一定的特征， MRV及DWI像具有鉴别意义，结合患者的临 床症状和相关病因，有利于提高本病的诊 断率，对患者的治疗具有重要意义。

Objective To explore the MRI features of posterior reversible encephalopathy syndrome (PRES). Methods The clinical material and MRI data of 15 PRES patients were analyzed retrospectively. All the patients were examined by MRI, 4 with MRV examination at the same time, and 3 received contrast enhanced MR scan, 8 with systematic treatment were reviewed by MRI. Results The lesions mainly located in the white matter of bilateral parieto-occipital lobes, followed by frontal lobe, temporal lobe, cerebellum, basal ganglia, callosum and cerebral ganglia. The lesions on MRI appeared as hypointensity or isointensity on T1WI and hyperintense on T2WI, obvious hyperintense on T2Flair, hyperintense or isointensity on DWI mostly, hyperintense on ADC mostly. No obviously abnormal contrast enhancement was found on MRI imagings of patients received contrast enhanced MR scan. 8 received MRI scan 9-12 days after treatment, all the lesions on imagings resolved mostly. Conclusion The MRI findings of PRES have some characteristics. DWI and MRV are helpful to differential diagnosis. And It will be helpful for prognosis if we can made the diagnosis in time.