T2*-weighted acquisitions used for functional
neuroimaging can suffer from through-slice dephasing. Additional, so-called z-shim
gradient pulses can be applied in the slice direction to minimize related signal
losses. Thereby, a single, slice-specific gradient moment may be sufficient for
small target regions like the spinal cord. To combine this z-shimming approach
with multi-band acceleration, the individual bands must provide different
dephasing moments in the slice direction. This can be realized with appropriate
temporal shifts of the individual envelopes as is demonstrated for conventional
slice-selective RF excitations and 2D-selective RF excitations for
inner-field-of-view imaging.
