Method for ascertaining flip angles, magnetic resonance apparatus, and computer program product
AssigneeSiemens Healthineers AG
InventorsDominik Paul, Mario Zeller, Flavio Carinci, Max Müller
Life of this patent
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Abstract
A computer-implemented method for ascertaining flip angles of a magnetic resonance sequence with variable flip angles, a magnetic resonance apparatus, and a computer program product are disclosed. In this case, the magnetic resonance sequence includes at least one echo train with an excitation pulse and a plurality of refocusing pulses. In each case, an adapted flip angle is ascertained for at least one part of the plurality of refocusing pulses.
Claims20
A computer-implemented method for ascertaining flip angles of a magnetic resonance sequence with variable flip angles, wherein the magnetic resonance sequence comprises at least one echo train with an excitation pulse and a plurality of refocusing pulses, the method comprising:
- ascertaining in each case an adapted flip angle for at least one part of the plurality of refocusing pulses comprising:
- providing in each case an initial flip angle for each refocusing pulse of the at least one part of the plurality of refocusing pulses;
- providing a magnitude integral of the excitation pulse, wherein the magnitude integral is a temporal integral over an amount of an amplitude of the excitation pulse;
- providing a respective magnitude integral of the plurality of refocusing pulses, wherein the respective magnitude integral is a temporal integral over an amount of an amplitude of the respective refocusing pulse;
- and
- ascertaining a respective adapted flip angle for at least one part of the plurality of refocusing pulses based on:
- (1) the magnitude integral of the excitation pulse, (2) the respective magnitude integral of the plurality of refocusing pulses, and (3) the respective initial flip angle for each refocusing pulse of the at least one part of the plurality of refocusing pulses,
- wherein the respective initial flip angle for the respective refocusing pulse of the at least one part of the plurality of refocusing pulses is adapted such that at least one specified boundary condition is met to provide the respective adapted flip angle, and
- wherein the at least one specified boundary condition comprises a performance limit of a radio-frequency amplifier of a magnetic resonance apparatus and/or a maximum specific absorption rate of a patient.
A magnetic resonance apparatus comprising:
- a control unit configured to:
- receive a magnetic resonance sequence having variable flip angles, wherein the magnetic resonance sequence comprises at least one echo train with an excitation pulse and a plurality of refocusing pulses;
- and
- ascertain in each case an adapted flip angle for at least one part of the plurality of refocusing pulses comprising:
- providing in each case an initial flip angle for each refocusing pulse of the at least one part of the plurality of refocusing pulses;
- providing a magnitude integral of the excitation pulse, wherein the magnitude integral is a temporal integral over an amount of an amplitude of the excitation pulse;
- providing a respective magnitude integral of the plurality of refocusing pulses, wherein the respective magnitude integral is a temporal integral over an amount of an amplitude of the respective refocusing pulse;
- and
- ascertaining a respective adapted flip angle for at least one part of the plurality of refocusing pulses based on:
- (1) the magnitude integral of the excitation pulse, (2) the respective magnitude integral of the plurality of refocusing pulses, and (3) the respective initial flip angle for each refocusing pulse of the at least one part of the plurality of refocusing pulses,
- wherein the respective initial flip angle for the respective refocusing pulse of the at least one part of the plurality of refocusing pulses is adapted such that at least one specified boundary condition is met to provide the respective adapted flip angle, and
- wherein the at least one specified boundary condition comprises a performance limit of a radio-frequency amplifier of the magnetic resonance apparatus and/or a maximum specific absorption rate of a patient.
Dependencies are inferred from the claim text.