Purpose: Designing a new T2 preparation (T2-Prep) module in order to
simultaneously provide robust fat suppression and efficient T2 preparation
without requiring an additional fat suppression module for T2-weighted imaging
at 3T. Methods: The tip-down RF pulse of an adiabatic T2 preparation (T2-Prep)
module was replaced by a custom-designed RF excitation pulse that induces a
phase difference between water and fat, resulting in a simultaneous T2
preparation of water signals and the suppression of fat signals at the end of
the module (now called a phaser adiabatic T2-Prep). Using numerical
simulations, in vitro and in vivo ECG-triggered navigator gated acquisitions of
the human heart, the blood, myocardium and fat signal-to-noise ratio and right
coronary artery (RCA) vessel sharpness using this approach were compared
against previously published conventional adiabatic T2-Prep approaches Results:
Numerical simulations predicted an increased fat suppression bandwidth and
decreased sensitivity against transmit magnetic field inhomogeneities using the
proposed approach, while preserving the water T2 preparation capabilities. This
was confirmed by the tissue signals acquired on the phantom and the in vivo
MRA, which show similar blood and myocardium SNR and CNR and significantly
reduced fat SNR compared to the other methods tested. As a result, the RCA
conspicuity was significantly increased and the motion artifacts were visually
decreased. Conclusion: A novel fat-suppressing T2-preparation method was
developed and implemented that demonstrated robust fat suppression and
increased vessel sharpness compared with conventional techniques, while
preserving its T2 preparation capabilities.Comment: 23 pages, 5 figures, submitted to Magnetic Resonance in Medicin
