Abstract #1793

Characterising the Contribution of Hypoxia to R2* Differences Between Prostate Tumours and Normal Tissue

Amy Johnson¹, Arash Latifoltojar¹, Valentin Hamy¹, Heather Fitzke¹, Shonit Punwani¹, Karin Shmueli²

¹Centre for Medical Imaging, University College London, London, United Kingdom; ²Medical Physics and Bioengineering, University College London, London, United Kingdom

R2* has been proposed to measure hypoxia in prostate cancer but the relative contribution of R2 and R2 to the increased tumour R2* is unknown, although we expect R2 to dominate via static dephasing in hypoxia-induced field inhomogeneities. We measured R2*, R2 and R2 at 1.5T in tumour and healthy tissue ROIs in 50 patients. R2* and R2 were significantly increased in tumours. However, there was no significant difference in R2. Field inhomogeneities probably affected R2 more than R2 due to irreversible diffusive dephasing in the longer SE echo-times used here. Future studies are needed to separate R2 and R2.