B1 VOXEL SHIFTING OF PHASE-MODULATED SPECTROSCOPIC LOCALIZATION TECHNIQUES

Localization techniques based on B1 gradients have generally been implemented as amplitude-modulated experiments. Recent introduction of adiabatic plane-rotation pulses has permitted the execution of B1-based localization in a phase-modulated form using a single surface coil, resulting in gains in signal-to-noise ratio with multivoxel capabilities. In this phase-modulated form, the voxel positions can also be shifted arbitrarily to desired regions in B1 with appropriate postacquisition data processing. The resultant "voxel-shifted" spectra are identical to spectra acquired with parameters optimized for the desired B1 region. This technique of B1 voxel shifting is presented and demonstrated on both phantoms and in vivo data sets. © 1992.