The Value of Apparent Diffusion Coefficient in the Differentiation between Peritumoral Edema of Malignant Glioma and Brain Metastasis

[Purpose] To investigate the value of MR diffusion-weighted imaging(DWI)apparent diffusion coefficient(ADC)in the differentiation between peritumoral edema of malignant glioma and brain metastatic tumor.[Methods] MR diffusion-weighted imaging was performed preoperatively in 32 cases with malignant gliomas(≥Ⅲstage)and 24 cases with brain metastasis.Furthermore,The ADC and relative ADC(rADC)values in the peri and distant peritumoral edema of malignant glioma and brain metastasis were analyzed.[Results] The ADC and rADC values in the peri peritumoral edema of malignant glioma were 1.44×10-3±0.15×10-3mm2/s and 2.01±0.24 respectively,while in the distant peritumoral edema were 1.81×10-3±0.21×10-3mm2/s and 2.49±0.33.The ADC and rADC values in the peri peritumoral edema of the brain metastasis were 1.70×10-3±0.22×10-3mm2/s and 2.43±0.44 respectively,while in the distant peritumoral edema were 1.81×10-3±0.18×10-3mm2/s and 2.54±0.41.There was a significant difference between the ADC and rADC values in the peri peritumoral edema(P0.01),and no significant difference in the distant peritumoral edema(P0.05).There was a significant difference between the ADC or rADC in the peri and distant peritumoral edema of the malignant glioma(P0.01).There was no significant difference between the ADC or rADC in the peri and distant peritumoral edema of the brain metastasis(P0.05).[Conclusions] The ADC and rADC in the peri and distant peritumoral edema in DWI and the edge features play an important role in the differentiation between malignant glioma and brain metastatic tumor.