Multi-echo EPI for improving temporal resolution in task-based fMRI at 7T- a dynamic phantom study

Ultra-high field MRI provides increased sensitivity, which we aim to utilize for improving the temporal resolution in functional studies. To investigate the achievable resolution at 7T MRI, a dynamic phantom that can generate an fMRI-like time-series was used. A dataset based on block-design with defined time shifts and a range of contrast-to-noise values was used to characterize the effective temporal resolution. Estimated temporal resolution was x1.7 times better for multi-echo compared to single-echo EPI, estimated as 146ms for a scan with TR of 600ms. This study offers a novel approach of optimizing protocols and new insights into fMRI temporal resolution.