White Matter Change Revealed by Diffusion Tensor Imaging in Gliomas

Abstract

BackgroundTumor-related white matter change is detected at late stages with magnetic resonance imaging (MRI), when mass effect or prominent edema is present. We analyzed if diffusion tensor imaging (DTI) white matter change earlier than conventional MRI.MethodsTwenty-six patients with gliomas (World Health Organization grade II, 5; grade III, 12; and grade IV, 9) within 2 cm from the posterior limb of the internal capsule (IC) were studied. Fifteen normal adults were enrolled as controls. Fluid attenuation inversion recovery MRI showed a high signal change at the posterior limb of the IC (HSIC) in 9 patients with grade III or IV gliomas. We classified the gliomas as WHO grade II (gliomas II), grade III or IV without HSIC [gliomas III/IV(-)] and grade III or IV with HSIC [gliomas III/IV(+)], as an indicator of the increase in the severity of the white matter changes. Fractional anisotropy (FA) and apparent diffusion coefficients (ADC) were calculated for the pyramidal tract. Tumor progression along pyramidal tract was evaluated by follow-up MRI in 16 patients at 40±18 months.ResultsFA showed no significant difference between gliomas II and control (p=0.694), but was lower in gliomas III/IV(-) and gliomas III/IV(+) (p<0.001). ADCs were higher in gliomas II, gliomas III/IV(-) and gliomas III/IV(+) than control (p<0.001). Tumor progression was detected in 2/16 patients.ConclusionDTI detected white matter changes that appeared to be normal in MRI. ADC changed even in low grade glioma, indicating ADC may be a better parameter for the early detection of white matter change.

Cerebral Microstructural Alterations after Radiation Therapy in High-Grade Glioma: A Diffusion Tensor Imaging-Based Study

“…There is some evidence that DTI may help in distinguishing between high-grade glioma and brain metastases by the analysis of peritumoral FA and MD values ( 15 ) or may help in differentiating tumor progression from pseudoprogression ( 16 ). On the other hand, DTI is a possible tool to improve radiation therapy target delineation as it has been suggested that DTI detects white matter changes due to tumor tissue itself earlier than standard MRI ( 25 ). With respect to the aim of this study, it has been previously reported that DTI might serve as a tool to assess early radiation-induced injuries to normal-appearing white matter in high-grade glioma patients ( 11 ).…”

Diffusion Tensor Imaging Reveals Microstructural Heterogeneity of Normal-Appearing White Matter and Related Cognitive Dysfunction in Glioma Patients

“…Studies on glioma-induced WM changes in regions remote to the primary tumor site are only sparse, but suggest DTI to allow tracing glioma cell infiltration into brain regions distant to the primary tumor site, which is inapparent in conventional imaging (13–16). Previous studies in this regard were based on region-of-interest (ROI) analyses, in which DTI metrics were determined locally at assumed tumor projections along predefined WM structures such as the corticospinal tract or in peritumoral areas, with restriction to observer-dependent predefined regions.…”

Dissociation of structural and functional connectomic coherence in glioma patients

“…Diffusion-weighted imaging (dMRI) provides estimates of macroanatomic WM tracts, as well as measures for microstructural characterization of WM properties in vivo. dMRI is used for surgical treatment planning by tracking peritumoral eloquent WM tracts, or has been applied to estimate the extent of diffuse tumor infiltration 15 – 17 . dMRI can furthermore be used for mapping whole-brain WM structural connectivity (SC), based on whole-brain parcellation with diffusion based tractography algorithms, estimating the number of all streamlines connecting each parcellated region with one another 18 .…”