Objective The purpose of this study was to investigate the clinical features and the magnetic resonance imaging of brain of children with Japanese encephalitis (JE) and whether this relationship can be used in early diagnosis.MethodsMRI was performed in 145 children with JE.T1-weighted,T2-weighted and FLAIR of brain were obtained in 98 patients with 0.35 T MRI system and conventional MRI and DWI were performed in 47 patients with 1.5 T MRI system.The position,range and MRI features were analyzed.ResultsMR imaging studies of 106 patients showed hyperintensity in the thalamic with 87 patients involved the caudex cerebri,as seen on T2-weighted images.The lesions were also seen in basal ganglia (32 cases),cerebral cortex (43 cases),cerebellum (2 cases),and white matter (15 cases).Lesions showed high intensity signal on T2WI and T2-FLAIR,and iso- or low intensity on T1WI.The number of the lesions in FLAIR were more than T2WI.The positive rate on 1.5 T MRI (87.2%) was higher than that on 0.35 T MRI(66.3%,χ2＝7.06,P＜0.01).ConclusionsMultiple brain tissues can be involved and the thalamic and the caudex cerebri involvement are the conspicuous characteristics in children with JE.T2-FLAIR and DWI are helpful in the early diagnosis of JE.