Ivan E. Dimitrov1, 2, Masaya Takahashi2, Koji Sagiyama2, A. Dean Sherry2, 3, Jochen Keupp4
1Philips Medical Systems, Cleveland, OH, United States; 2Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States; 3Chemistry, University of Texas Dallas, Richardson, TX, United States; 4Philips Research Europe, Hamburg, Germany
A parallel transmission CEST method is presented for ratiometric, concentration-independent pH mapping of human kidneys at 3T using clinically approved contrast agent, Iopamidol. The method combines respiratory triggered single-shot turbo-spin echo that runs in time-interleaved mode of an MR scanner with parallel RF transmission system. Triggering was made such that to lower the acquisition duty cycle and SAR by skipping pre-defined number of respiratory cycles to enable longer and more powerful RF saturation. CEST effects of up to 20% were recorded in the pelvic and medullar regions of the kidney, allowing for generating pixel-wise pH maps.