Quiet Fat-suppressed T1-weighted MRI by Dual-IR PETRA

Motivation: MRI produces considerable acoustic noise. PETRA sequence can solve this problem but has limited contrast. Goal(s): This study improves PETRA sequence by magnetization preparation to achieve widely used T1-weighted imaging with fat suppression and sound reduction. Approach: Double asymmetric adiabatic RF pulses are designed to invert aqueous tissues for T1-weighted contrast creation and invert lipidic tissues for fat suppression and combined with PETRA gradient trajectories. Results: The brain and knee experiments are conducted to verify the feasibility of the proposed sequence. The fat is decreased by above 70%. The gray-to-white matter contrast and knee cartilage visualization are enhanced compared with non-prepared PETRA sequence. Impact: The significantly reduced SPL of 67.4 dBA using limited gradient switching, providing better patient scanning comfort, can promote its acceptance to pediatric imaging. The double RF preparation design improves the limited contrast of PETRA.