The Role of the Chemical Shift Difference in a Two-Site Exchange Model Under an On-Resonance Spin-Lock RF Field

The manuscript investigates the role of the chemical shift difference between two exchanging pools under a spin-lock RF field. The results demonstrate that the width of the dispersion of R1rho is determined mainly by the chemical shift difference when the exchange is slow. This work may give a new insight into the spin dynamics under a spin-lock condition and the results may be relevant to the fields using the spin-lock technique, such as protein NMR and MRI contrast.