Odor specific activation patterns in the human olfactory bulb detected by high resolution BOLD fMRI on 7T

Motivation: Functional organization of olfactory-bulb (OB) may be fundamentally different between humans and rodents. The spatial pattern of functional activation in human OB has not been studied mainly due to the lack of validated neuroimaging methods for visualizing OB. Goal(s): T2prep-BOLD-fMRI can measure activation in the human OB with excellent intra-subject reproducibility. Here, we further evaluate if T2prep-BOLD-MRI can detect odor specific activation patterns in the human OB. Approach: T2prep-BOLD-fMRI was performed in 5 subjects exposed to two distinct odorants. Results: The spatial and temporal characteristics of fMRI signals in the OB were substantially different between the two odors. Impact: Imaging human olfactory bulb function is notoriously difficult for fMRI. We proposed methodology that has the potential to provide a tool for mapping functional activation patterns in the human olfactory bulb on an individual level.