Fig. 1
Illustration of a simple T1ρ spin-lock experiment. A first 90º “tip-down” radiofrequency (RF) pulse is applied along the x-axis (transverse plane) to rotate the magnetization, followed by two spin-lock pulses, with alternating phases (SL±y) and fixed duration, that are separated by an adiabatic 180º pulse. An additional 90º “tip-up” pulse is played out to flip back the magnetization to the z-axis (longitudinal direction). After the T1ρ preparation module, a crusher gradient is used to eliminate any residual magnetization in the transverse plane. SL spin-lock, TSL spin-lock time, M0 longitudinal magnetization, Mxy transverse magnetization