Abstract #0287

Intravoxel Water Diffusion Heterogeneity of Human High-Grade Gliomas

Thomas Kwee¹, Craig Galban¹, Marko Ivancevic^1,2, Pia Sundgren¹, Christina Tsien³, Larry Junck⁴, Benjamin Hoff¹, Charles Meyer¹, Brian Ross¹, Thomas Chenevert¹

¹Department of Radiology, University of Michigan, Ann Arbor, MI, USA; ²Philips Healthcare, Cleveland, OH, USA; ³Department of Radiation Oncology, University of Michigan, Ann Arbor, MI, USA; ⁴Department of Neurology, University of Michigan, Ann Arbor, MI, USA

Diffusion-weighted signal decay of brain tissue is multi-exponential due to the presence of multiple intravoxel proton pools (IPPs) with different diffusion coefficients. This study investigated the intravoxel water diffusion heterogeneity (IDWH) of human high-grade gliomas (N=20), using the stretched-exponential model. IDWH was significantly higher in high-grade gliomas than in normal brain tissue, which potentially offers a new method for assessing tumor extent and evaluating therapeutic response. Correlation between tumor IDWH and overall tumor diffusion coefficient was strongly negative, suggesting that highly cellular tumors contain a lower number of distinct IPPs, while cystic/necrotic tumors contain a higher number of distinct IPPs.