Differentiation of tumefactive demyelinating lesions from high-grade gliomas with the use of diffusion tensor imaging

Abstract

Background and purpose: TDLs may be indistinguishable from high-grade gliomas on conventional MR imaging. The role of DTI in differentiating TDLs from high-grade gliomas is not clear, and quantitative comparison between the 2 has not been reported. Here we aimed to differentiate TDLs from high-grade gliomas by using DTI.

Materials and methods: DTI was performed in 8 TDLs and 13 high-grade gliomas. The presence of 3 findings (ie, intralesional hyperintensities on the FA map, restricted diffusion in the lesion periphery, and a perilesional hyperintense FA rim) was assessed by visual inspection. The FA and MD values were measured in the central nonenhancing portion, peripheral enhancing portion, and perilesional edema for each lesion and compared between the 2 groups respectively.

Results: TDLs had a significantly higher incidence of intralesional hyperintensities on FA maps (P = .049) but a lower incidence of a perilesional hyperintense FA rim (P < .001), compared with those of high-grade gliomas on visual inspection. TDLs had significantly higher FA (P = .004) and lower MD (P = .001) values in the peripheral enhancing portions of the lesions compared with those of high-grade gliomas. In perilesional edema, FA values were significantly higher in high-grade gliomas (P = .001).

Conclusions: DTI is helpful in differentiating TDLs from high-grade gliomas by using visual inspection and quantitative analysis.

Fig 1.

A 28-year-old woman with a large TDL in the right frontal lobe. A, There is heterogeneous enhancement at the medial margin (arrows) of the lesion on the axial contrast-enhanced T1-weighted image. B and C, On the axial DWI (B) and MD map (C), the peripheral portion of the lesion shows restricted diffusion (arrows). D and E, Intralesional hyperintensities (arrow) are seen in both the lesion center (arrow) and periphery (arrowheads) on axial (D) and coronal (E) FA maps. F, Directional-coded FA map displays the directionality of these intralesional hyperintensities. The FA values are 0.06 for central nonenhancing portion and 0.21 for peripheral enhancing portion. The MD values (× 10⁻³ mm²/s) are 1.966 for central nonenhancing portion and 0.704 for peripheral enhancing portion.

Fig 2.

A, A 68-year-old man with a left frontal glioblastoma, which appears as a rim-enhancing mass on the axial contrast-enhanced T1-weighted image. B and C, On the axial DWI (B) and MD map (C), restricted diffusion is present at the lesion periphery (arrow). D and E, Intralesional hyperintensities (arrow) are seen on axial (D) and coronal (E) FA maps. A red scattered ROI representing a contrast-enhancing rim is overlaid on the FA map (D). F, Note that there is a hyperintense FA rim (arrowheads in D, E, and F) in the perifocal edema, external to the enhancing rim. Directional-coded (F) FA map displays the directionality of hyperintense FA rim and intralesional hyperintensity. The FA values are 0.09 for the central nonenhancing portion and 0.13 for the peripheral enhancing portion. The MD values (× 10⁻³ mm²/s) are 1.530 for the central nonenhancing portion and 1.252 for the peripheral enhancing portion.