MRI和MRV在评价先兆子痫、子痫后脑静脉窦闭塞和可逆性后部脑白质病的价值

MRI and MRV in differentiation of posterior reversible encephalopathy syndrome and venous occlusion inpatients with eclampsia or pre-eclampsia

目的 探讨MR静脉成像（MRV）和MRI对孕产妇特有疾病先兆子痫、子痫的脑部并发症——静脉窦闭塞和可逆性后部脑白质病（PRES）的诊断价值。方法 回顾性分析27例妊娠期间或产后出现癫痫、头痛、视物模糊的先兆子痫、子痫病人的临床及影像学资料，其中6例为顺产后3～5d，4例为剖宫产后1d，5例为妊娠25～34周胎死宫内，12例为足月妊娠。病人均行MRI和MRV检查，检查序列包括：T，WI、T2WI、FLAIR、DWI。结果 14例显示静脉窦闭塞，其中上矢状窦4例，以前部为主。横窦2例、乙状窦1例、深部静脉系统2例、颈内静脉3例、皮质静脉3例。全部静脉窦闭塞2例。MRI显示相应闭塞静脉的引流区呈不规则形长T1、长T2信号影，DWI显示等信号，ADC图呈高信号。4例病人出现DWI高信号，ADC图呈低信号，提示病变为细胞毒性水肿。5例2周后随访MRI及MRV显示静脉窦通畅，而2例并发了脑实质出血。13例PRES病人，MRI显示双侧顶叶（10例）、右侧顶叶（2例）、双侧枕叶（7例）、双侧额叶（6例）、右侧额叶（3例）、双侧颞叶（4例）、左侧颞枕叶交界区（1例）、胼胝体压部（1例）、双侧基底节区（2例）、右侧基底节区（1例）、左侧半卵圆中心（1例）、双侧小脑半球（1例）多发异常信号。病变于T1WI呈等或低信号，T2WI及FLAIR呈高信号，部分病灶DWI及ADC图均表现为高信号。1例病人左侧颞叶发生出血。6例随访MRI显示病灶范围变小，数目减少，甚至病灶消失。结论 静脉窦闭塞好发于上矢状窦，但深静脉和浅静脉均可发生。PRES好发于顶枕叶白质，皮质也可受累。还可见于额叶、基底节区、颞叶、胼胝体、小脑半球。两者病变均为血管源性水肿．但分布的部位和范围不同．MRI和MRV对其可作出明确诊断。

Objective To evaluate the role of MRV and MRI in the diagnosis of posterior encephalopathy syndrome （PRES） and venous sinus occlusion in patients with eclampsia or pre-eclampsia. Methods We respectively studied the clinical and imaging data of 27 pre-eclampsia or eclampsia patients who occurred epilepsy, headache, and vision deficient during pregnancy or post partum. All patients underwent MRI and MRV examinations. The imaging protocol included coronal, sagittal, and axial TmWI, T2WI, FLAIR, DWI, and MRV. Results 14 patients showed evidence of venous occlusion. Among them, 3 occurred in cortical vein, 4 in superior sagittal sinus, 2 in transverse sinus, 1 in sigmoid sinus,2 in deep vein system, 3 in jugular vein, and 2 with complete sinus occlusion. Brain edema distributed in the corresponding area of occlusive sinus and 2 cases combined with secondary hemorrhage. 13 patients suffered from hypertensive encephalopathy. All of the lesions involved arcuate fibre in the bilateral parietal lobe （10 cases）, right parietal lobe （2 cases）, bilateral occipital lobe （7 cases）, bilateral frontal lobe （6 cases）, right frontal lobe （3 cases）, bilateral temporal lobe （4 cases）, left tempro-occipital lobe （1 case）, splenium of corpus callosum （1 case）, bilatral basal ganglia （2 cases）, right basal ganglia （1 case）, left centrum semiovale （1 case）, and bilateral cerebellar hemisphere （1 case）. Both of the lesions of PRES and venous occlusion showed hyperintensity on FLAIR and T2WI images, isointensity on DWI and hyperintensity on ADC, indicating vasogenic edema. Decreased lesion extent or completely disappeared was identified in 12 patients on follow-up scans. Conclusion Lesions of PRES are usually located in the parietal and occipital lobes, especially in white matter. The lesion of venous occlusion usually occurs in the area of corresponding occlusive sinus. The MRV has an important value in diagnosis of PRES and venous sinus occlusion.