Towards ultrafast submillimeter T2* and QSM quantification at 3T using spherical Echo Planar Time Resolved Imaging (sEPTI)

Motivation: To further improve the image quality, SNR, and reduce scan time by reducing averages for submillimeter T2* and QSM at 3T Goal(s): To achieve whole-brain 0.75-mm T2* and QSM quantification using sEPTI within a single average scanApproach: We developed: (1) an iterative data-driven B0 update pipeline for accurate and high SNR B0 map; (2) data-driven eddy-current correction approach to reduce artifacts; (3) a physics-informed unrolled network to boost the SNR of the reconstructed image to achieve 2X acceleration by reducing the need of averages. Results: sEPTI achieved whole-brain 0.75-mm T2* and QSM quantification within 84 seconds with the potential for wide applicationsImpact: The work presented synergetic improvements in B0 update, eddy-current correction, and unrolled-network based SNR-boosted reconstruction for sEPTI, which achieves whole-brain 0.75-mm distortion-free and blurring-free T2* and QSM quantification at 3T in 84 seconds with the potentials for wide applications.