A Comparative Analysis of CEST Techniques for Mapping Muscle Creatine and Phosphocreatine at 3T

Motivation: Creatine and phosphocreatine metabolites imaging at 3T are essential for related disease in muscle. Goal(s): Estimate creatine proton exchange rate in muscle; Simultaneous mapping of PCr and Cr by PLOF CEST method at 3T. Approach: Antemortem and postmortem animal study was to validate PCr/Cr CEST peak position and creatine exchange rate. Three types of CEST acquisition methods were compared on human leg muscle. Results: Z-spectra in mouse hindlimb before and after euthanasia indicated CrCEST is a slow-exchanging process (<150 s-1). This allowed us to simultaneously extract PCr/CrCEST signals and mapping in muscle at 3T using the PLOF method on both human and animal. Impact: Amide, Cr, and PCr CEST in the skeletal muscle can be mapped simultaneously at 3T by PLOF CEST within a clinically feasible acquisition duration, which has potential to assist in the diagnosis of related diseases.