Abstract #3727

Assessing Thermal Tissue Damage with Biexponential Diffusion-Weighted MRI

Valentina Giannini^1,2, Pejman Ghanouni³, Graham Sommer³, Chris Diederich⁴, Andrew Holbrook³, Vasant Salgaonkar⁴, Punit Prakash⁴, Harcharan Gill⁵, Donna Bouley⁶, Kim Butts Pauly³

¹Radiology, FPRC, Candiolo, TO, Italy; ²Radiology, Stanford University, Stanford, Ca, United States; ³Radiology, Stanford University, Stanford, CA, United States; ⁴Radiation Oncology, University of California, San Francisco, San Francisco, Ca, United States; ⁵Urology, Stanford University, Stanford, CA, United States; ⁶Comparative Medicine, Stanford University, Stanford, CA, United States

In this study, we want to assess the use of DWI images to estimate prostate tissue damage during HIFU ablation, by measuring diffusion coefficients of canine prostate pre and post ablated, using multiple b-factors ranging up to 3500 s/mm2. EPI DWI images were collected before and after the ablation, with 12 different b values from 0 to 3500 s/mm2, and with a tetrahedral encoding scheme. This study demonstrates changes in the fast and slow diffusion rates and fractions after thermal ablation. In addition, differences in the diffusion rates in heat fixed vs. non-heat fixed ablated tissue are demonstrated.