Characterization of Brain Tumor Using High Order Diffusion Imaging

Chu-Yu Lee¹, Chris Goettl², Leslie C. Baxter³, John P. Karis³, Josef P. Debbins, ^1,3

Brain neoplasms are typically characterized by contrast enhanced T1 imaging. Depending on the course of treatment, tumor reoccurrence remains a possibility, and can be difficult to distinguish from other enhancing areas, for example post-treatment radiation effects (PTRE), typically necrosis [1]. Further, detailed information about the tumor heterogeneity as detected by standard MR methods is not generally available, but can play a significant role in characterizing and grading the tumor. In this work, a simple multi-b-value DWI sequence has been developed to better understand the heterogeneity and diffusion characteristics of different types of tumors, encountered during routine clinical scanning. The signal decay is fitted with two recently developed diffusion models: a stretched exponential (\-DWI) [2] and a cumulant expansion (DKI) [3] model, where fitted parameters \ and Kapp were shown to correlate the diffusion heterogeneity. We expected to see differences in alpha and K when the multi-b-value DWI sequence directed to the anatomy of interest, primarily due the heterogeneity of the more advanced tumors.