Jonathan Rizzo Polimeni1, Douglas N. Greve1,
1Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA, United States; 2Computer Science and AI Lab (CSAIL), Massachusetts Institute of Technology, Cambridge, MA, United States; 3Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, United States
While voxels as small as 0.75 mm isotropic provide sufficient SNR for high-field fMRI, voxels falling within cortical gray matter voxels are still influenced by partial-volume contamination with white matter and CSF, which contribute different levels of physiological noise. Here we characterize the impact of partial-volume effects as a function of cortical depth on the resting-state fluctuation amplitudes at 7T. Even after partial-volume effects are taken into account, the magnitude of resting state fluctuations increases with proximity to the pial surface. This suggests that laminar differences in the resting-state fluctuations exist and may reflect increasing dominance of extravascular BOLD signal changes surrounding large pial vessels.