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

Method for generation of magnetic resonance images based on a TrueFISP sequence with simultaneous acquisition of the MR images of a plurality of volumes of a measurement subject with raw data for the respective volumes being entered into a respective raw data matrices, comprising the steps of:

• a) establishing a number of the volumes N to be acquired in a measurement subject, wherein N is at least 2;
• b) establishing a number of phase coding lines MA per raw data matrix per volume, with a requirement that a quotient of MA and N is a natural number;
• c) establishing a repetition time TR, a radio-frequency pulse duration RF and a flip angle α for acquiring said volumes;
• d) sub-dividing each raw data matrix into S separate segments to be measured, wherein S is equal to N or a whole-number multiple of N, with a requirement that a quotient Q of MA and S, that corresponds to a number of the phase coding lines per segment, is a natural number;
• e) acquiring data for all segments S of all volumes N, with the time duration, in msec, TSeg for the acquisition of the data of each segment being
• TSeg=P·TR
• and wherein the acquisition of said data for all segments D of all volumes N is implemented with a time duration, in msec,
• TRelax=(N−1)·TSeg
• for relaxation of the magnetization Mz with a relaxation constant T1 in a volume N that corresponds to a time duration from an end of a measurement of a first segment up to a beginning of a measurement of a second segment of the same volume, and incrementing a phase coding gradient P times in an internal loop with a requirement that a quotient P/N, corresponding to a number of phase coding steps per segment, is a natural number, and terminating said phase coding in a further external loop after MA increments in said further external loop, thereby obtaining a plurality of raw data matrices filled with raw data respectively for said N volume;
• and
• (f) processing each of said raw data matrices by multi-dimensionally Fourier transforming the raw data thereof to obtain image data for each of said volumes in a form suitable for visual display, and making said image data available as an output.

A magnetic resonance tomography apparatus comprising:

• a magnetic resonance scanner adapted to interact with an examination subject to acquire data therefrom;
• and
• a control unit connected to said magnetic resonance scanner that operates said magnetic resonance scanner to acquire said data based on a TrueFISP sequence with simultaneous acquisition of MR images of a plurality of parallel slices of the examination subject, by establishing a number of the slices N to be acquired in a measurement subject, wherein N is at least 2, establishing a number of phase coding lines MA per raw data matrix per slice, with a requirement that a quotient of MA and N is a natural number, establishing a repetition time TR, a radio-frequency pulse duration RF and a flip angle α for acquiring said slices, sub-dividing each raw data matrix into S separate segments to be measured, wherein S is equal to N or a whole-number multiple of N, with a requirement that a quotient Q of MA and S, that corresponds to a number of the phase coding lines per segment, is a natural number acquiring data for all segments S of all slices N, with the time duration, in msec, TSeg for the acquisition of the data of each segment being TSeg =TR+RF+MA/S·TR and wherein the acquisition of said data for S all segments S of all slices N is implemented with a time duration, in msec, TRelax =(N−1) ·TSeg for relaxation of the magnetization Mz with a relation, constant T1 in a slice N that corresponds to a time duration from an end of a measurement of a first segment up to a beginning of a measurement of a second segment of the same slice.

A magnetic resonance tomography apparatus comprising:

• a magnetic resonance scanner adapted to interact with an examination subject to acquire data therefrom;
• and
• a control unit connected to said magnetic resonance scanner that operates said magnetic resonance scanner to acquire said data based on a TrueFISP sequence with simultaneous acquisition of MR images of a plurality of parallel slices of the examination subject, by establishing a number of the volumes N to be acquired in a measurement subject, wherein N is at least 2, establishing a number of phase coding lines MA per raw data matrix per volume, with a requirement that a quotient of MA and N is a natural number, establishing a repetition time TR, a radio-frequency pulse duration RF and a flip angle α for acquiring said volumes, sub-dividing each raw data matrix into S separate segments to be measured, wherein S is equal to N or a whole-number multiple of N, with a requirement that a quotient Q of MA and S, that corresponds to a number of the phase coding lines per segment, is a natural number acquiring data for all segments S of all volumes N, with the time duration, in msec, TSeg for the acquisition of the data of each segment being TSeg =P·TR and wherein the acquisition of said data for all segments S of all volumes N is implemented with a time duration, in msec, TRelax =(N−1) ·TSeg for relaxation of the magnetization Mz with a relaxation constant T1 in a volume N that corresponds to a time duration from an end of a measurement of a first segment up to a beginning of a measurement of a second segment of the same volume, and incrementing a phase coding gradient P times in an internal loop with a requirement that a quotient P/N, corresponding to a number of phase coding steps per segment, is a natural number, and terminating said phase coding in a further external loop after MA increments in said further external loop, thereby obtaining a plurality of raw data matrices filled with raw data respectively for said N volume, and processing each of said raw data matrices by multi-dimensionally Fourier transforming the raw data thereof to obtain image data for each of said volumes in a form suitable for visual display, and making said image data available as an output.