Jing Yuan1, Qinwei Zhang1, Anil T. Ahuja1, Yi-Xiang Wang1
1Department of Imaging and Interventional Radiology, Chinese University of Hong Kong, Shatin, NT, Hong Kong
Spin-lock technique, which is traditionally used to measure T1l relaxation time, can also be used for chemical exchange (CE) imaging. This study theoretically investigates the optimization of spin-lock frequency (FSL) and spin-lock time (TSL) to maximize the asymmetric magnetization transfer ratio for different proton exchange rates, by numerical simulations based on a two-pool R1l relaxation model derived from the Bloch-McConnell equations. Results show that spin-lock pulse with low FSL and long TSL is sensitive to detect slow CE processes while spin-lock pulse with high FSL and short TSL is useful for fast CE process study.