[Value of Minimum Apparent Diffusion Coefficient in Peritumoral Edema in the Differential Diagnosis between Primary Central Nervous System Lymphoma and Glioblastoma].

Objective To evaluate the role of minimum apparent diffusion coefficient(MinADC) values in peritumoral edema based on magnetic resonance diffusion weighted imaging in the differential diagnosis between primary central nervous system lymphoma(PCNSL) and glioblastoma(GBM).Methods ADC values in peritumoral edema were measured in 16 patients with PCNSL(diffuse large B cell lymphoma) and 31 patients with GBM(WHO grade 4) confirmed by pathology.Regions of interests were manually drawn on ADC maps on peritumoral edema regions to obtain the MinADC value.Independent samples t-test and receiver operating characteristic analysis were performed for statistical analysis.Results The MinADC value [(1.20-1.45)×10-3 mm2/s,mean(1.35±0.68)×10-3 mm2/s] in PCNSL was significantly higher than that in GBM [(0.95-1.31)×10-3 mm2/s,mean(1.12±0.09)×10-3 mm2/s](t=9.977,P=0.000).The area under the receiver operating characteristic curve was 0.986,and the cutoff value of MinADC was 1.245×10-3 mm2/s for the differentiation between PCNSL and GBM,with the best combination of sensitivity(94.1%) and specificity(94.1%).Conclusion MinADC value can be a simple and effective measure for the differential diagnosis between PCNSL and GBM.