Surface coil cardiac tagging and ³¹P spectroscopic localization with B₁‐insensitive adiabatic pulses

A technique is presented for MRI tagging in the presence of inhomogeneous B₁ fields. A rectangular tagging grid is produced with B₁‐insensitive adiabatic pulses in a magnetization preparation period that precedes image acquisition. Phantom results demonstrate that the method is well‐suited to surface coil experiments. The technique is applied to a canine model of myocardial ischemia to track the spatially dependent wall motion of the left ventricle during the cardiac cycle. Transmural ³¹P spectra are acquired from the same double‐tuned surface coil, with tagging and spectroscopy performed for the first time, during normal, ischemic, and recovery conditions for the same animal.