A model of the inversion process in an arterial inversion experiment.

A model of the behavior of spins moving through spatially varying gradient and B1 fields is presented. The model simulates the adiabatic behavior of flowing arterial water during a two-coil arterial inversion experiment. Predictions of the degree of inversion generated by the model are compared with flow phantom results for a wide range of gradient magnitudes, nominal B1 magnitudes, and flow velocities. The high level of agreement between the model and the flow phantom results indicates that the model can be used to help select efficient pulse sequence parameters when setting up an in vivo arterial inversion experiment. In addition, the model provides valuable insights into the adiabatic behavior of arterial spins. These insights could be useful in selecting an efficient surface coil geometry which achieves maximum inversion with a minimum B1 magnitude.