Figure 6.

Use of a low slice-selection bandwidth results in substantial slice distortion or “potato-chipping” in the presence of frequency variations (a). Use of a higher excitation pulse bandwidth decreases the disotortion (b), but at a cost of higher RF power. An option to reduce image distortion is to use unmatched bandwidths on the excitation and refocusing pulses so that only the overlapped region is imaged (c). This may reduce some artifact, but can also result in signal loss.