Nirbhay Yadav1, 2, Amnon Bar-Shir1, Craig Jones1, 2, Chien-Yuan Lin, 23, Jun Hua1, 2, Assaf Gilad1, Michael McMahon1, 2, Peter v
1Johns Hopkins University, Baltimore, MD, United States; 2KKI, Baltimore, MD, United States; 3UT Southwestern Medical Center, Dallas, TX, United States
In Vivo CEST studies are complicated by multiple groups of protons that contribute to the exchange contrast. Here, we used the recently reported FLEX approach to measure the exchange-based proton-transfer ratio (PTR) from the imino protons of thymidine under conditions of different exchange rate due to a change in pH of the solution. Our results show that it is possible to weight exchange contrast in FLEX based on exchange rate. These methods can then be used to filter the contrast from protons with certain exchange rates.