This study aimed to determine the potential value of intravoxel water diffusion heterogeneity imaging for brain tumor characterization and evaluation of high-grade gliomas, by comparing an established heterogeneity index (α value) measured in human high-grade gliomas to those of normal appearing white and grey matter landmarks. Twenty patients with high-grade gliomas prospectively underwent diffusion-weighted magnetic resonance imaging using multiple b-values. The stretched-exponential model was used to generate α and distributed diffusion coefficient (DDC) maps. The α values and DDCs of the tumor and contralateral anatomic landmarks were measured in each patient. Differences between α values of tumors and landmark tissues were assessed using paired t-tests. Correlation between tumor α and tumor DDC was assessed using Pearson's correlation coefficient. Mean α of tumors was significantly lower than that of contralateral frontal white matter (p = 0.0249), basal ganglia (p < 0.0001), cortical grey matter (p < 0.0001), and centrum semiovale (p = 0.0497). Correlation between tumor α and tumor DDC was strongly negative (Pearson correlation coefficient, -0.8493; p < 0.0001). The heterogeneity index α of human high-grade gliomas is significantly different from those of normal brain structures, which potentially offers a new method for evaluating brain tumors. The observed negative correlation between tumor α and tumor DDC requires further investigation.
- Brain tumor
- Diffusion-weighted magnetic resonance imaging
- Intravoxel water diffusion heterogeneity