RESUMO
Objective To evaluate the role of CT and MR/in the diagnosis of posterior reversible encephalopathy syndrome(PRES).Methods Eight women with PRES(6 pregnant women,1 case after chemotherapy,and 1 patient with hypertension)were enrolled in our study.All of them had MR imaging (T_1WI,T_2WI,FLAIR,DWI),and five cases underwent post-contrast T_1WI and three dimensional contrast enhanced MR angiography(3D CEMRA).Two cases also had CT scan.Results MRV in all 8 patients showed no evidence of stenosis,dilation,or thrombosis in cranial veins and sinuses.MRI demonstrated multiple lesions located in bilateral parieto-occipital lobes(8 cases),bilateral basal ganglia(2 cases),and bilateral frontal lobes(4 cases).The lesions were prominent within white matter,some of them involved gray matter(3 cases).Lesions appeared as hyperintense signals on FLAIR and T_2-weighted images, isointense or mildly hypointense signals on T_1-weighted images,normal or decreased intensity on DWI,and isointensity or hyperintensity on apparent diffusion coefficient(ADC)maps.Post-contrast T_1WI showed mild reversible enhancement and 3D CEMFdisplayed numerous reversible“grape-like”enhancements in terminal arterial branches along the middle cerebral artery(MCA),anterior cerebral artery(ACA)and posterior cerebral artery(PCA).Follow-up scan showed decreased abnormal signals.Conclusion Lesions of PRES are usually located in parieto-occipital lobes,especially in white matter,but they can also be seen in frontal lobes and basal ganglia bilaterally.Post-contrast T_1WI and 3D enhanced MRA can provide useful information in the manifestation of reversible enhancement.MRI has advantages to display lesion in PRES,
