Designing a new T ₂ -preparation (T ₂ -Prep) module to simultaneously provide robust fat suppression and efficient T ₂ preparation without requiring an additional fat-suppression module for T ₂ -weighted imaging at 3T.
The tip-down radiofrequency (RF) pulse of an adiabatic T ₂ -Prep module was replaced by a custom-designed RF-excitation pulse that induces a phase difference between water and fat, resulting in a simultaneous T ₂ preparation of water signals and the suppression of fat signals at the end of the module (a phaser adiabatic T ₂ -Prep). Numerical simulations and in vitro and in vivo electrocardiogram (ECG)-triggered navigator-gated acquisitions of the human heart were performed. Blood, myocardium, and fat signal-to-noise ratios and right coronary artery vessel sharpness were compared against previously published adiabatic T ₂ -Prep approaches.
Numerical simulations predicted an increased fat-suppression bandwidth and decreased sensitivity to transmit magnetic field inhomogeneities using the proposed approach while preserving the water T ₂ -Prep capabilities. This was confirmed by the tissue signals acquired in the phantom and the in vivo images, which show similar blood and myocardium signal-to-noise ratio, contrast-to-noise ratio, and significantly reduced fat signal-to-noise ratio compared with the other methods. As a result, the right coronary artery conspicuity was significantly increased.
A novel fat-suppressing T ₂ -Prep method was developed and implemented that showed robust fat suppression and increased vessel sharpness compared with conventional techniques while preserving its T ₂ -Prep capabilities.