Spiral Keyhole (SpiralK) Imaging: an in silico investigation

Motivation: Achieving submillimetre imaging for applications such as laminar fMRI requires balancing temporal resolution with slice coverage and demands additional in-plane acceleration. Goal(s): Characterize and validate SpiralK in the context of submillimetre spiral fMRI. Approach: SpiralK simulations were conducted with varying keyhole sizes and accelerations while keeping the acquisition readout time. Results: SpiralK activation maps demonstrated improved specificity at elevated t-thresholds. Increasing keyhole size was found to decrease the specificity of the activation maps. Improved tSNR and t-value metrics were found for SpiralK compared to the other simulated acquisitions. Impact: SpiralK shows promise for achieving submillimetre resolutions with whole-brain coverage while maintaining appropriate temporal resolution.