1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States; 2Siemens AG, Erlangen, Bavaria, Germany; 3Siemens Medical Solutions USA, Inc., Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States
Cardiac MRI may greatly benefit from ultra-high field (UHF) providing higher SNR and intrinsic contrast. However, shorter RF wavelength at UHF results in transmit B1 (B1+) and contrast variations through the heart. This problem has been addressed using multi-channel transmit coils and B1-shimming, but further improvements are expected by using parallel transmission (pTX) with multi-spoke RF-pulses as shown in brain and liver at 7T. However, this involves additional challenges, including rapid and robust multi-channel ECG-triggered B1+ calibration, and sensitivity to motion. Here, we investigate the impact of 2-spoke RF-pulse design on 7T cardiac imaging using a 16-channel pTX system.