5422572 Method and apparatus for substantially simultaneously exciting a plurality of slices in NMR imaging

An NMR parallel imaging method and apparatus in a single sequence has a plurality of RF pulses (RF EXCITE 90°) applied substantially simultaneously, each having a different frequency, in the same contiguous time period in a subinterval of time (τ) during which the select slice magnetic gradient (SS) is applied, to activate a plurality of different physical slices. The refocusing RF pulses also comprise a plurality of RF pulses (RF EXCITE 180°) each having a different frequency, applied non-simultaneously but within the same slice select magnetic gradient (SS) in the same subinterval time (τ). A plurality of echo signals (RF RECEIVE) from the plurality of different excited slices then read out during the same single read out magnetic pulse (RO) in the same subinterval. The method and apparatus of the present invention can be applied in MRI spin echo, pre-saturation or inversion.