Correction of the post-irradiation T1 relaxation effect for chemical exchange-sensitive MRI: A phantom study

Purpose: In many pulse sequences of chemical exchange-sensitive MRI including multi-slice exchange saturation transfer (CEST) or sensitive spin-lock (CESL), there is a finite time delay between the irradiation preparation and imaging acquisition, during which T 1 -relaxation reduces contrast affects accuracy for volumetric imaging. We propose simple post-acquisition method to correct this contamination. Methods: A formula was derived evaluate cross-slice contamination in echo-planar (EPI) after preparation. CEST CESL experiments were performed on phantoms examine approach. Results: Theoretical derivation showed that EPI can be corrected by signals each slice at parameter suppresses signal, e.g., water frequency CEST, with very long CESL. This confirmed results phantom experiments, both short durations without steady-state, respectively. To minimize effect B 0 inhomogeneity experiment, more accurate measurement signal achieved higher power shorter duration. Conclusion: proposed validated approach effect, applied studies acquired EPI, other modalities similar