Luca Frullano1, Ciprian Catana1, Thomas Benner1, A. Dean Sherry2,3, Peter Caravan1,4
1A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States; 2Chemistry, University of Texas at Dallas, Dallas, TX, United States; 3Advanced Imaging Research Center, UT Southwestern, Dallas, TX, United States; 4Radiology, Harvard Medical School, Charlestown, MA, United States
In vivo application of activatable contrast agents is limited by the inability to determine both probe concentration and relaxivity. One approach to this problem is simultaneous MR-PET using a dual MR-PET probe, where PET provides quantification of probe concentration and MR signal can then be related to relaxivity. We describe synthesis and characterization of a fluorine-18 labeled, gadolinium-based probe with pH dependent relaxivity. Simultaneous MR-PET imaging indicates a strong correspondence between pH calculated from the joint image analysis and pH measured by electrode.