Diagnostic utility of intravoxel incoherent motion mr imaging in differentiating primary central nervous system lymphoma from glioblastoma multiforme

Purpose: To evaluate the diagnostic performance of intravoxel incoherent motion (IVIM) MR imaging and ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET) in differentiating primary central nervous system lymphoma (PCNSL) from glioblastoma multiforme (GBM). Materials and Methods: Fifty patients, 17 with PCNSL and 33 with GBM, were retrospectively studied. From the 3 Tesla IVIM data, the perfusion fraction (f) and diffusion coefficient (D) were obtained. In addition, the maximum standard uptake value (SUV_max) was obtained from the FDG-PET data. Each of the three parameters was compared between PCNSL and GBM using Mann-Whitney U-test. The performance in discriminating between PCNSL and GBM was evaluated using receiver-operating characteristics analysis and area-under-the-curve (AUC) values for the three parameters. Results: The f_max and D_min values were significantly higher in GBM than in PCNSL (P < 0.01 and P < 0.0001, respectively). In addition, the SUV_max value was significantly lower in GBM than in PCNSL (P < 0.0005). The AUC values for f_max, D_min, and SUV_max were 0.756, 0.905, and 0.857, respectively. The combination of the f_max and D_min increased the diagnostic performance (AUC = 0.936) of f_max (P < 0.05), but this value was not significantly different from the values for D_min (P = 0.30). Conclusion: IVIM-MR imaging noninvasively provides useful quantitative information in distinguishing between PCNSL and GBM. J. Magn. Reson. Imaging 2016;44:1256–1261.