Axial diffusivity and tensor shape as early markers to assess cerebral white matter damage caused by brain tumors using quantitative diffusion tensor tractography.
OBJECTIVE
We investigated the usefulness of diffusion tensor tractography (DTT) for differentiating between histological pathologies and evaluating white matter (WM) damage resulting from brain tumors. We also sought to categorize the appearance of brain tumor-related WM tract changes.


METHODS
A total of 18 inpatients with intracranial neoplasms were enrolled. MRI examinations were performed at 3 T using an 8-channel phased array coil. DTT was reconstruction from the raw data of diffusion tensor imaging. WM tract-based analysis of the mean diffusivity (MD), eigenvalues (λ(1) , λ(2) , λ(3) ), and fractional anisotropy (FA) was performed by the manual placement of regions of interest (ROIs) on the color-coded FA maps using DTIStudio software. The axial diffusivity (DA, namely λ(1) ) and the tensor shape (Cl, namely (λ(1) -λ(2) )/3 (λ)) were also compared between groups. P values <0.05 were considered statistically significant.


RESULTS
In cases of low-grade glioma (LGG), the tracts adjacent to the tumors displayed the highest levels of invasion. Tract disruption was mainly observed in cases of high-grade glioma (HGG). We found significant differences regarding the FA, MD, DA, and radial diffusivity between ROIs in patients with LGG or HGG. There were also significant differences in DA and tensor shape (Cl) between patients with LGG and HGG.


CONCLUSIONS
Axial diffusivity and Cl may be useful early markers for differentiating between LGG and HGG.
Department of Neurology, Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University, Nanjing, China.
Fei
F
Chen
Xin
X
Zhang
Ming
M
Li
Rong
R
Wang
Hui-Ting
HT
Wang
Feng
F
Zhu
De-Ji
DJ
Lu
Hui
H
Zhao
Jing-Wei
JW
Li
Yun
Y
Xu
Bin
B
Zhu
Bing
B
Zhang
D000328:Adult; D000368:Aged; D000465:Algorithms; D016880:Anisotropy; D014408:Biomarkers, Tumor; D001921:Brain / Q000473:pathology*; D001932:Brain Neoplasms / Q000473:pathology*; D056324:Diffusion Tensor Imaging; D005260:Female; D005910:Glioma / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D055815:Young Adult
D014408:Biomarkers, Tumor