Resting-State FMRI at 7T

Resting-state Functional Magnetic Resonance Imaging (RS-FMRI) is a method for non-invasively investigating brain functional connectivity when a subject is at rest. The brain is never really at rest and therefore the Blood Oxygen Level Dependent (BOLD) MRI signal which detects the metabolism and hemodynamics that underlie brain function can be detected even when no stimulus is present. By sampling hundreds of consecutive time-points and looking for correlations between the time-course in a given voxel(s) and the rest of the voxels of the brain, it is possible to identify component brain-networks. The fundamental principle is that neurons that work together to perform a specific cognitive function tend to be activated in synchrony.

Benefits of Ultra-High Field MRI (7T) for RS-FMRI: The increased SNR and T2* contrast provided by a 7T MR scanner offers the potential to acquire resting-state FMRI data with higher spatial resolution and to employ under-sampling techniques that improve temporal resolution. Improved spatial and temporal resolution for resting-state FMRI can provide a better anatomical delineation of the resting-state networks and this could be critical to improving our understanding and application of this relatively new methodology.

Analysis of Hemorrhagic Traumatic Axonal Injury Lesions Using Seed-Based Resting-State FMRI at 7T.

Lee S, Polimeni JR, Witzel T, Price CM, Greicius MD, Edlow BL, McNab JA.

International Society for Magnetic Resonance in Medicine Annual Scientific Meeting: Toronto, Canada, June 2015.