Slice profile optimization for a nuclear magnetic resonance tomography apparatus operated with a gradient echo sequence

摘要

In a nuclear magnetic resonance tomography apparatus, for slice profile optimization, a pre-saturation RF pulse is generated in the presence of a slice selection gradient before the excitation RF pulse in a gradient echo sequence. The frequency spectrum of the pre-saturation RF pulse is defined so that it excites regions of the slice which correspond to the edges of the excitation RF pulse. A spoiler gradient in the z-direction is generated between the pre-saturation RF pulse and the excitation RF pulse. As a result of the pre-saturation RF pulse, the dependency of the slice profile on the flip angle of the excitation RF pulse and on the relationship TR/T1 is reduced.