Adult Japanese encephalitis:conventional MR imaging and early diffusion weighted imaging features / 实用放射学杂志

ABSTRACT

Objective To study the conventional MRI features of adult Japanese encephalitis (JE)and explore the early features of diffusion weighted imaging(DWI).Methods Thirty-two patients with adult JE were included.MR scanning including T1 WI,T2 WI and FLAIR were done in all patients,and DWI in 28 patients.Twenty-three patients received DWI in the early stage (within 1 to 7 days),in which the appearances of DWI were analyzed,ADC graphs were obtained and the signal noise ratio and the ADC values of lesions were calculated.Results Twenty-eight cases were abnormal on MRI,and 4 patients were normal.The lesions of JE involved the thalamus in 22 cases,the substantia nigra of midbrain in 13,kellogg’s seahorse in 9,the basal ganglia in 7,the splenium corpo-ris callosi in 4,the pons in 6 and the insular lobe in 2,extensive cerebral edema in 2.The early features of DWI in 23 patients showed cytotoxic edema in 2,vasogenic edema in 12,both two edemas existing in 5,and normal in 3.DWI were superior to T2 WI in 6 cases,and T2 WI were superior to DWI in 9 cases,DWI was similar to T2 WI in 5 cases on showing the size and signal of the le-sions.Conclusion Adult JE often occurs in the thalamus,substantia nigra of midbrain and kellogg’s seahorse.DWI shows vasogenic edema in the early stage.Comprehensive analysis of DWI,ADC and T2 WI details helps to early detection and qualitative adult JE le-sions.