Abstract #0441

Monitoring the Effects of Bicarbonate Treatment on Tumor Extracellular pH Using AcidoCEST MRI

Liu Qi Chen¹, Christy M. Howison², Justin J. Jeffery², Ian F. Robey³, Marty Pagel²

¹Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, United States; ²Biomedical Engineering, University of Arizona, Tucson, AZ, United States; ³University of Arizona Cancer Center, University of Arizona, Tucson, AZ, United States

We have developed a non-invasive MRI method that can accurately measure pHe to assess tumor acidosis, termed “acidoCEST MRI”. This method measures a ratio of the Chemical Exchange Saturation Transfer (CEST) effects of Iopromide (Ultravist®), a FDA approved contrast agent for X-ray/CT. We have applied acidoCEST MRI to monitor the effects of bicarbonate treatment on tumors of mammary carcinoma. Our method has strong clinical translation potential because it uses low saturation powers, incomplete saturation, and a clinically approved contrast agent.