RESUMEN
Objective To explore the diagnostic value of MR diffusion weighted imaging (DWI) in the differential diagnosis between encephalitis and acute cerebral infarction.Methods The MR DWI appearances of 23 cases of encephalitis including 14 cases with viral encephalitis, 9 cases with demyelinative encephalitis and 30 cases with acute cerebral infarction were retrospectively analyzed.Results The 30 cases of acute cerebral infarction appeared bright signal in DWI with a ADC values of (0.46?0.13)?10 -3mm2/s. 7 cases with viral encephalitis and 9 cases with demyelinative encephalitis appeared slightly high or high signal intensity in DWI with a ADC values of (0. 98?0.18)?10 -3mm2/s and(0. 89?0.07)?10 -3mm2/s respectively. The ADC values of viral encephalitis and demyelinative encephalitis were higher comparing to acute cerebral infarction(?0.05). However, the ADC values showed higher or lower in different areas in 4 cases, and lower ADC values appearing in 3 cases with viral encephalitis comparing normal parenchyma.Conclusion MR DWI is useful in the differential diagnosis between encephalitis and acute cerebral infarction.