Christina Triantafyllou1, Jonathan R. Polimeni1, Boris Keil1, Lawrence L. Wald1, 2
1A.A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, United States; 2Health Science and Technology, MIT, Cambridge, MA, United States
Sensitivity in BOLD fMRI is characterized by the time-series SNR, which contains fluctuations from thermal and physiological noise sources. In this work we investigate the need for a modified model describing the behavior of physiological noise in the fMRI time-series in multi-channel acquisitions and assess the new models dependence on the physiological noise correlations, tissue class and coil combination methods across field strengths of 3T and 7T. Our findings demonstrate that the proposed model could be used to characterize multi-channel array acquisitions at high and ultra-high field strengths and ultimately to optimize fMRI protocols towards maximizing tSNR.