Comparison of the features of MRI of tumefactive demyelinating lesions and glioma

      Objective: To explore the imaging features of tumefactive demyelinating lesions (TDL) and Glioma.
      Methods: The brain MRI and 1H-MRS features in 60 TDLs and 65 Glioma (all patients pathologically diagnosed) were studied.
      Results: (1) The occipital lobes were more rarely involed in Glioma than TDL. The mid line structures were involved in Glioma more frequently than in TDL (ratio of 44.6% in Glioma vs 5.0% in TDL). (2) The lesions of TDL exhibited appearances termed diffusely infiltrating (n = 31), ring-like (n = 24), Balolike (n = 11), megacystic (n = 2). (3) On T2WI the typical characteristics of TDL looked like cloud (n = 23), round with hypointense rim (n = 19). (4) The tissue necrosis were more frequently found in the lesions of Glioma than TDL, especially for higher grade Glioma. (5) On enhanced T1WI:21 of 44 Glioma in mass like enhancement, 14 in ring-shaped enhancement. (6) The features on DWI were as follows: in Glioma group, 33 of 65 showing high signal , 8 with low and 17 with mixed;58 TDLs appeared hyperintense in acute and subacute. (7) 19 of 65 Glioma showed mass effect on MRA , but none of TDL. (8) Most of the patients of the 2 groups showed NAA and increased Cho on MR spectroscopy, but the ratio of Cho/NAA in the Glioma group was far more than 2, and the increased β,γ-Glx was most frequently found in TDL.
      Conclusions: Many characteristics of MRI imagings distinguish Glioma from TDLs, such as the mass effect, intralesional necrosis and sign of swelled callosum for Glioma, the increased β,γ-Glx of MRS, open-ring enhanced sign and the dilated venular structure for TDL.