Functional quantitative susceptibility mapping for layer specific activation

Motivation: The feasibility of high-resolution fQSM at ultra-high field and the good localization properties of fQSM as well as its quantitative nature motivated this study which aims to use fQSM for investigating layer-dependent activation. Goal(s): To investigate the feasibility to study layer-dependent activation with fQSM. Approach: Data were acquired with a segmented multi-shot 3D EPI sequence at 7 Tesla, high-resolution data were denoised prior to fQSM computation. Layer-dependet fMRI and fQSM signals were extracted from 20 layers. Results: fQSM shows distinctively different activation patterns across cortical layer compared to fMRI. Impact: High-resolution fQSM acquired at 7 Tesla is used to study layer dependence of fQSM in comparison with BOLD fMRI. fQSM quantifies the underlaying susceptibility change more directly, therefore it might be feasible to use fQSM to study layer-dependent activation.