Chu-Yu Lee1, Chris Goettl2,
Leslie C. Baxter3, John P. Karis3, Josef P. Debbins,
1Electrical Engineering, Arizona State
University, Tempe, AZ, United States; 2College of Medicine,
University of Arizona, Phoenix; 3Barrow Neurological Institute,
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
. 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)  and a cumulant expansion (DKI)
 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.