Establishing a Correlation between Diffusion Heterogeneity and Tissue Structural Heterogeneity Using Stereotactic Biopsies on Brain Tumors

Non-Gaussian diffusion MRI with a continuous-time random-walk (CTRW) model offers a unique avenue to probing tissue microstructural heterogeneity. The CTRW parameters, α and β, corresponding to temporal and spatial intravoxel diffusion heterogeneities, have empirically been linked to tumor tissue heterogeneity in clinical studies. This study aims at directly establishing the correlation between the CTRW parameters from patients suspected of glioma and tissue microstructural heterogeneity revealed by histology on stereotactic brain biopsies. We developed a practical protocol that integrates quantitative imaging techniques and surgical procedures to perform MR-histology correlation, and demonstrated that lower CTRW parameters correspond to increased tissue microstructural heterogeneity.