Kenya Murase1, Shigeyoshi Saito1
1Department of Medical Physics and Engineering, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
We present a simple and fast method for solving the time-dependent Bloch equations in spin-locked chemical exchange saturation transfer (CESTrho) MRI using the 2-pool CEST model, and for calculating the longitudinal relaxation time in the rotating frame (T1ρ). When using the population-averaged longitudinal (R1) and transverse relaxation rates (R2), the T1ρ values obtained by our method agreed with the approximate solutions given by Trott and Palmer, except for the on-resonance SL case. When the population-averaged R1 and R2 were not used, some differences were observed between them. Our method will be useful for better understanding and optimization of CESTrho MRI.