Magnetic resonance apparatus and multi-slice data acquisition method with preparation pulses for slices being set dependent on the slice position within a target volume

A magnetic resonance apparatus comprising:

• a magnetic resonance data acquisition scanner;
• and
• a control computer configured to:
• operate said a magnetic resonance data acquisition scanner to acquire magnetic resonance data from a slice stack, comprising a plurality of measurement slices that collectively form a target volume, by executing a measurement sequence comprising a plurality of scans, with each acquisition of magnetic resonance data from each individual measurement slice of the plurality of measurement slices constituting a respective scan in said plurality of scans;
• operate said magnetic resonance data acquisition scanner to radiate, prior to each scan of each individual measurement slice of the plurality of measurement slices, a preparation pulse in said measurement sequence that is associated with the respective individual measurement slice of the plurality of measurement slices from which magnetic resonance data are acquired in the respective scan, but said preparation pulse acting on all of said measurement slices of the plurality of measurement slices in said target volume, said preparation pulse suppressing a magnetic resonance signal, which originates from a type of saturation molecule, in the magnetic resonance data acquired from the respective measurement slice of the plurality of measurement slices in the respective scan;
• divide said slice stack into a plurality of measurement slice groups that each comprise at least one of said measurement slices of the plurality of measurement slices, with each measurement slice group of the plurality of measurement slice groups covering a contiguous partial volume of said target volume that is smaller than an entirety of said target volume;
• select a time order in which to scan said plurality of measurement slice groups so that, when target molecules of each measurement slice group of the plurality of measurement slice groups are excited outside of the scan of each measurement slice group of the plurality of measurement slice groups, the excitation of said target molecules of each measurement slice group has decayed before a start of a scan of said further another measurement slice group in said plurality of measurement slice groups, or said magnetic resonance data from each measurement slice group have already been acquired;
• operate said magnetic resonance data acquisition scanner to select at least one of a pulse frequency and a pulse bandwidth as at least one pulse parameter of said preparation pulse for a measurement slice group in said plurality of measurement slice groups, dependent on resonance information of the contiguous partial volume covered by said respective measurement slice group, said resonance information describing at least respective, different resonance frequencies of said type of said saturation molecule and a type of target molecule from which said magnetic resonance data are to be acquired in said contiguous partial volume of said target volume covered by said respective measurement slice group;
• and
• provide said magnetic resonance data to a processor and make the magnetic resonance data available from the processor in electronic form, as a data file.

A non-transitory, computer-readable data storage medium encoded with programming instructions, said storage medium being loaded into a control computer of a magnetic resonance apparatus, that comprises a magnetic resonance data acquisition scanner, said programming instructions causing said control computer to:

• operate the magnetic resonance data acquisition scanner to acquire magnetic resonance data from a slice stack, comprising a plurality of measurement slices that collectively form a target volume by executing a measurement sequence comprising a plurality of scans, with each acquisition of magnetic resonance data from each individual measurement slice of the plurality of measurement slices constituting a respective scan in said plurality of scans;
• operate the magnetic resonance data acquisition scanner to radiate, prior to each scan of each individual measurement slice of the plurality of measurement slices from which magnetic resonance data are acquired in the respective scan, but said preparation pulse acting on all of said measurement slices of the plurality of measurement slices in said target volume, a preparation pulse in said measurement sequence that is associated with the respective individual measurement slice of the plurality of measurement slices, said preparation pulse suppressing a magnetic resonance signal, which originates from a type of saturation molecule in the magnetic resonance data acquired from the respective measurement slice of the plurality of measurement slices in the respective scan;
• divide said slice stack into a plurality of measurement slice groups that each comprise at least one of said measurement slices of the plurality of measurement slices, with each slice group of the plurality of measurement slice groups covering a contiguous partial volume of said target volume that is smaller than an entirety of said target volume;
• select a time order in which to scan said plurality of measurement slice groups so that, when target molecules of each measurement slice group of the plurality of measurement slice groups are excited outside of the scan of each measurement slice group of the plurality of measurement slice groups, the excitation of said target molecules of each measurement slice group has decayed before a start of a scan of said further another measurement slice group in said plurality of measurement slice groups, or said magnetic resonance data from each measurement slice group have already been acquired;
• operate said magnetic resonance data acquisition scanner to select at least one of a pulse frequency and a pulse bandwidth as at least one pulse parameter of said preparation pulse for a respective measurement slice group in said plurality of measurement slice groups, dependent on resonance information of the contiguous partial volume covered by said measurement slice group, said resonance information describing at least respective, different resonance frequencies of said type of said saturation molecule and a type of target molecule from which said magnetic resonance data are to be acquired in said contiguous partial volume of said target volume covered by said respective measurement slice group of the plurality of measurement slice groups;
• and
• provide said magnetic resonance data to a processor and making the magnetic resonance data available from the processor in electronic form, as a data file.

A method for acquiring magnetic resonance data from a slice stack, said method comprising:

• operating a magnetic resonance data acquisition scanner to acquire magnetic resonance data from a slice stack, comprising a plurality of measurement slices that collectively form a target volume by executing a measurement sequence comprising a plurality of scans, with each acquisition of magnetic resonance data from each individual measurement slice of the plurality of measurement slices constituting a respective scan in said plurality of scans;
• operating the magnetic resonance data acquisition scanner to radiate, prior to each scan of each individual measurement slice, a preparation pulse in said measurement sequence that is associated with the respective individual measurement slices of the plurality of measurement slices from which magnetic resonance data are acquired in the respective scan, but said preparation pulse acting on all of said measurement slices of the plurality of measurement slices in said target volume, said preparation pulse suppressing a magnetic resonance signal, which originates from a type of saturation molecule, in the magnetic resonance data acquired from the respective measurement slice of the plurality of measurement slices in the respective scan;
• dividing said slice stack into a plurality of measurement slice groups that each comprise at least one of said measurement slices of the plurality of measurement slices, with each slice group covering a contiguous partial volume of said target volume that is smaller than an entirety of said target volume;
• operating said magnetic resonance data acquisition scanner to select at least one of a pulse frequency and a pulse bandwidth as at least one pulse parameter of said preparation pulse for a respective measurement slice group in said plurality of measurement slice groups, dependent on resonance information of the contiguous partial volume covered by said respective measurement slice group, said resonance information describing at least respective, different resonance frequencies of said type of said saturation molecule and a type of target molecule from which said magnetic resonance data are to be acquired in said contiguous partial volume of said target volume covered by said respective measurement slice group, wherein said at least one pulse parameter is selected for said respective measurement slice group of the plurality of measurement slice groups based on resonance information of another measurement slice group of said plurality of measurement slice groups, said other measurement slice group being adjacent to the respective measurement slice group;
• and
• providing said magnetic resonance data to a processor and making the magnetic resonance data available from the processor in electronic form, as a data file.