Multi-echo EPI more effectively boosts BOLD sensitivity than sequence optimization in orbitofrontal cortex

Multi-echo fMRI can boost BOLD sensitivity relative to conventional single-echo fMRI, especially in high-susceptibility brain regions like orbito-frontal cortex (OFC). Another option is to optimise slice-tilts, z-shimming and k-space traversal to minimise susceptibility effects. In this study, we sought to determine if multi-echo EPI, which requires the use of parallel imaging to achieve reasonable echo times, would remain optimal in OFC when compared to an OFC-optimised single echo alternative. The relative performance is quantified via BOLD contrast-to-noise ratio and an additional comparison is made by incorporating the TE Dependent ANAlysis (TEDANA) denoising approach. Multi-echo increased BOLD CNR, particularly following denoising.