Magnetic resonance imaging method and apparatus with application of the truefisp sequence and sequential acquisition of the MR images of multiple slices of a measurement subject

摘要

In a method and apparatus for generation of magnetic resonance (MR) images based on the TrueFISP sequence with simultaneous acquisition of the MR images of a number of parallel slices of a measurement subject the number of the slices N to be acquired in the measurement subject is established whereby N is at least, the number of the phase coding lines MA per raw data matrix and slice N are established, with the requirement that the quotient of MA and N is a natural number, the repetition time TR, the radio-frequency pulse duration RF and the flip angle α are established, of each raw data matrix is sub-divided into S separate segments to be measured, whereby S is equal to N or a whole-number multiple of N, with the requirement that the quotient Q of MA and S that corresponds to the number of the phase coding lines per segment is a natural number, data are acquired for all segments S of all slices N, whereby the time duration, in msec, T_Seg for the acquisition of the data of each segment is; $$ T_{\mathrm{Seg}}=\mathrm{TR}+\mathrm{RF}+\frac{\mathrm{MA}}{S}·\mathrm{TR},$$and the measurement of all segments S of all slices N is implemented such that the time duration T_Relax is T_Relax=(N−1)·T_Seg [msec] for the relaxation of the magnetization M_Z with the relaxation constant T₁ in a slice N that corresponds to the time span from the end of the measurement of a first segment up to the beginning of the measurement of a second segment of the same slice.