Intravoxel water diffusion heterogeneity imaging of human high-grade gliomas

Abstract

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. Copyright © 2009 John Wiley & Sons, Ltd.