Fat signal suppression for coronary MRA at 3T using a water‐selective adiabatic T 2 ‐preparation technique

Purpose To improve fat saturation in coronary MRA at 3T by using a spectrally selective adiabatic T 2 ‐Prep (WSA‐T 2 ‐Prep). Methods A conventional adiabatic T 2 ‐Prep (CA‐T 2 ‐Prep) was modified, such that the excitation and restoration pulses were of differing bandwidths. On‐resonance spins are T 2 ‐Prepared, whereas off‐resonance spins, such as fat, are spoiled. This approach was combined with a CHEmically Selective Saturation (CHESS) pulse to achieve even greater fat suppression. Numerical simulations were followed by phantom validation and in vivo coronary MRA. Results Numerical simulations demonstrated that augmenting a CHESS pulse with a WSA‐T 2 ‐Prep improved robustness to B 1 inhomogeneities and that this combined fat suppression was effective over a broader spectral range than that of a CHESS pulse in a conventional T 2 ‐Prepared sequence. Phantom studies also demonstrated that the WSA‐T 2 ‐Prep+CHESS combination produced greater fat suppression across a range of B 1 values than did a CA‐T 2 ‐Prep+CHESS combination. Lastly, in vivo measurements demonstrated that the contrast‐to‐noise ratio between blood and myocardium was not adversely affected by using a WSA‐T 2 ‐Prep, despite the improved abdominal and epicardial fat suppression. Additionally, vessel sharpness improved. Conclusion The proposed WSA‐T 2 ‐Prep method was shown to improve fat suppression and vessel sharpness as compared to a CA‐T 2 ‐Prep technique, and to also increase fat suppression when combined with a CHESS pulse. Magn Reson Med 72:763–769, 2014. © 2013 Wiley Periodicals, Inc.