Physiological Noise Characteristics in FMRI of the Rodent at 11.7T

Daniel Kalthoff¹, Jrg Ulrich Seehafer¹, Dirk Wiedermann¹, Mathias Hoehn¹

Temporal SNR (tSNR) in fMRI studies can be compromised by physiological noise, which prevents SNR gains from higher field strength or improved hardware to be translated into fMRI sensitivity. In this study we investigated the presence of physiological noise in BOLD fMRI protocols for the rodent at very high field strength of 11.7 Tesla. Physiological Noise contributions were spatially mapped and analyzed for various voxel sizes in rats (n=5) under Isoflurane anesthesia. Results indicate that physiological noise contribution may be on the level of thermal noise or even the dominant source of noise for common fMRI protocols in this application.