目的：分析妊娠期高血压脑后循环可逆性脑病综合征（PRES）的MRI特征及诊断价值。方法：回顾性 分析20例妊娠期高血压患者临床及MRI资料。所有患者治疗前行MRI平扫及DWI扫描。结果：本组伴有 PRES 9例（45%），不伴有PRES 11例。MRI显示有PRES组共30个主要病灶，枕叶12个，胼胝体压部3个， 顶叶半卵圆中心5个，颞叶5个，额叶3个。病灶主体位于皮质下白质、部分邻近皮质亦有受累。T1WI等、稍 低信号，T2WI、T2WI/flair稍高信号。DWI以等、稍高信号为主，ADC以等、稍低信号为著。T2WI/flair发现病 灶数最多，2例仅在DWI序列上显示清晰。结论：妊娠期高血压PRES MRI具有一定的特征性，DWI结合 T2WI/flair能发现更多病灶。

To investigate the MRI features and the diagnostic value of posterior reversible encephalopathy syndrome (PRES) caused by pregnancy-induced hypertension (PIH). Methods: Clinical and MRI data of 20 cases of PIH were retrospectively reviewed. All cases were examined by MRI scanning and diffusion weighted imaging (DWI) before drug therapy. Results: There were 9 cases with PRES (45%) and 11 cases without PRES. MRI revealed 30 lesions in the PRES group: 12 in the occipital lobe, 3 in the corpus callosum, 5 in the parietal lobe centrum semiovale, 5 in the temporal lobe, and 3 in the frontal lobe. Lesion location involved sub-cortical white matter and neighboring portions of the cortex. Lesions were mildly hypointense on T1WI and mildly hyperintense on T2WI and T2WI/flair. Lesions were mildly hyperintense on DWI and hypointense on apparent diffusion coefficient (ADC). T2WI/flair detected the highest number of lesions. Two cases were only able to be clearly imaged on the DWI sequence. Conclusion: MRI features of PRES caused by PIH display certain characteristics; DWI combined with T2WI/flair can detect more lesions.