可逆性后部脑病综合征MRI表现与发病机制的相关性分析

目的:探讨可逆性后部脑病综合征（PRES）患者的MRI表现与其发病时血压及血清乳酸脱氢酶（LDH）水平的关系，进一步研究PRES可能的发病机制。方法: 回顾性分析35例PRES患者的影像学与临床资料，评价患者脑水肿部位及程度，并分析脑水肿程度与发病时血压水平、血清LDH 水平的相关性。结果: MRI显示多数病灶位于顶、枕叶脑实质内，T1WI 呈低或稍低信号，T2WI 呈高信号，DWI呈低或稍高信号，ADC呈高或稍高信号，Flair呈高信号；不同血压组之间脑水肿累及部位、程度比较均无统计学意义(P>0.05)，35例患者脑水肿程度评分与患者发病时SBP、DBP、MAP经Spearman相关分析显示均无明显相关性(P>0.05)；血清LDH水平与脑水肿程度评分具有显著相关性（r=0.42，P=0.028）。结论: PRES的典型MRI表现为双侧顶枕叶对称性血管源性水肿,但也有多种不典型表现；MRI表现对其发病机制的研究具有重要价值。

Correlation between pathogenesis and MRI findings in patients with posterior reversible encephalopathy syndrome

Objective： To investigate the correlation between MRI features （degree and location） of posterior reversible encephalopathy syndrome （PRES） and blood pressures at toxicity as well as the level of serum lactate dehydrogenase （LDH） and to further discuss its pathogenesis. Methods： The clinical and radiologic data of 35 PRES patients were retrospectively analyzed.The extent and distribution of brain edema were graded by two observers blinded to patients＇ clinical information. Results： The lesions were demonstrated as slightly hypointensitive on T1WI and slightly hyperintensitive on T2WI. The parietal occipital lobes were the more common sites. The lesions were shown as isomtensitive and slightly hyperintensitive on DWI and Flair. The brain edema affected regions and edema degree scores among three groups had no statistically significant difference （P〉0.05）. No linear correlations were found between the extent of brain edema and degree scores on the levels of SBP,DBP and MAP. The level of serum LDH was significantly correlated with brain edema （r=0.42, P=0.028）. Conclusion： MR imaging is of great importance in investigating the pathogenesis of this clinically inhomogeneous syndrome, which typically shows bilateral signal-intensity alterations in cortical and subeortieal regions of the posterior circulation, indicating vasogenic edema.