Abstract #4261

A Simple and Fast Method for Solving the Time-Dependent Bloch Equations in Spin-Locked Chemical Exchange Saturation Transfer (CESTrho) Magnetic Resonance Imaging

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 (T_1ρ). When using the population-averaged longitudinal (R₁) and transverse relaxation rates (R₂), the T_1ρ 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.