Jochen Keupp1, Ivan Dimitrov2,3, Sander Langereis4, Osamu Togao3, Masaya Takahashi3, A. Dean Sherry3
1Philips Research Europe, Hamburg, Germany; 2Philips Healthcare, United States; 3Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, United States; 4Philips Research Europe, Eindhoven, Netherlands
Clinical MR techniques to report on local pH would be of high interest, because several pathologies are associated with pH changes like in renal diseases. Fortuitously, a clinically approved CT agent, Iopamidol, has been shown to have exchangeable protons that generate pH-dependent CEST (chemical exchange saturation transfer)-MRI contrast. It provides two proton pools, which allow a ratiometric pH measure independent from the local agent concentration, as recently demonstrated pre-clinically. In the present study it is shown, that Iopamidol can be used for in vivo human pH measurement in the renal pelvis using breathing triggered CEST-MRI on a clinical 3T scanner.