Bebop-EPI (BEeping BOld Pulse sequence) – employing inherent acquisition acoustics to generate auditory stimuli for auditory fMRI

Motivation: With improved scanning methods and SNR, auditory response studies in functional MRI require well-defined stimuli but are encumbered by the acoustic noise from the acquisition gradients and by the temporal inaccuracy of the external audio source. Goal(s): Our goal was to use the acoustic noise generated by the MRI gradients to circumvent an external source for auditory fMRI. Approach: We implemented BEBOP (BEeping BOld Pulse sequence) EPI which enables varying the echo spacing, and thus pitch, per slice and per repetition and so provides a platform for auditory fMRI. Results: An fMRI feasibility study at 7T was successfully implemented, measuring auditory-motor responses. Impact: We demonstrated a new approach that simultaneously generates auditory stimuli and measures their BOLD response. The new approach offers high temporal accuracy of the auditory tasks due to the MRI gradients’ high temporal precision.