Evaluating the reproducibility of parallel transmission in fMRI at 7T

Motivation: While pTx has been shown to improve the temporal signal-to-noise ratio (tSNR) in fMRI, it is not clear how variations in pulse fidelity between scans modulate tSNR and how this impacts fMRI studies using pTx. Goal(s): To study whether the improved tSNR obtained with pTx in fMRI is reproducible across multiple scans of the same subject. Approach: We scanned and rescanned two subjects using both traditional and pTx excitations, and examined the variation in tSNRs between the scans. Results: Traditional and pTx excitations demonstrated comparable reproducibility in tSNR. Impact: The improved tSNRs obtained using pTx were consistent across scans of the same subject, demonstrating inter-scan variations comparable with traditional single channel excitations. Collectively, these preliminary results suggest that pTx can be used with reproducibility confidence in fMRI studies.