RESUMO
Objective To study the MRI features of primary central nervous system lymphoma (PCNSL)to improve its diagnosis. Methods The MRI data of 1 3 patients with PCNSL confirmed by biopsy or surgical pathology were analyzed retrospectively.All patients underwent nonenhanced and contrast-enhanced MRI examinations.Results Multiple lesions in 8 cases and solitary one in 5 cases were found.Five leisons (38.5%)were located in the cerebral hemispheres.Eight(61.5%)were located in deep structures of the brain including periventricular white matter,basal ganglia,thalami and corpus callosum,6 (46.2%)of whom involved in the ependyma including 1 involved in the ependyma of the 4 th ventricle.One leison(7.7%)was located in the cerebellar hemisphere.The tumor showed isointense or mildly hypointense signal on T1WI,mildly hyperintense signal on T2WI and hyperintense signal on DWI.Mild to moderate perilesional edema was noted.The tumors in 13 cases showed remarkable homogeneous enhancement after the contrast agent was injected with the signs of characteristic notch,butterfly and satellite.Focal necrosis occurred in 1 lesions.Conclusion PCNSL shouldbe first considered when a lesion located in the deep central structeres of the brain,multiple and involve ependymal membrane,showed isointensity on T1WI and T2WI,highintensity on DWI in tumoral parenchyma demonstrated,significantly enhancement in the solid part of the tumor.