Method and apparatus for optimization of a pulse sequence for a magnetic resonance system

A method to operate a magnetic resonance system, comprising:

• providing a pulse sequence, as an input, to a processor, said pulse sequence including at least one refocusing pulse, one slice selection gradient pulse, and one gradient spoiler pulse;
• in said processor, automatically shortening a pulse duration of said refocusing pulse;
• in said processor, automatically adapting a pulse duration of the slice selection gradient pulse to the shortened pulse duration of the refocusing pulse;
• in said processor, increasing an amplitude of the slice selection gradient pulse to cause a same slice thickness to be selected by the slice selection pulse as before shortening of the pulse duration of the refocusing pulse;
• in said processor, adapting a pulse shape of the gradient spoiler pulse, without changing a total spoiler moment of the gradient spoiler pulse, so as to produce an optimally shortened pulse duration of the focusing pulse that occurs when, by adapting the pulse shape of the gradient spoiler pulse, a maximum amplitude of the gradient spoiler pulse equals the amplitude of the slice selection gradient pulse and an edge steepness of the gradient spoiler pulse is minimized;
• and
• operating the magnetic resonance system according to the pulse sequence with the refocusing pulse having said optimally short duration, said slice selection gradient pulse with the adapted pulse duration and the adapted amplitude, and the gradient spoiler pulse with the adapted pulse shape.

A pulse sequence determination device to optimize a pulse sequence for a magnetic resonance system, said pulse sequence determination device comprising:

• a processor comprising am input interface provided with a pulse sequence as an input to the processor, said pulse sequence including at least one refocusing pulse, one slice selection gradient pulse, and one gradient spoiler pulse;
• said processor being configured to automatically shorten a pulse duration of said refocusing pulse;
• said processor being configured to automatically adapt a pulse duration of the slice selection gradient pulse to the shortened pulse duration of the refocusing pulse;
• said processor being configured to increase an amplitude of the slice selection gradient pulse to cause a same slice thickness to be selected by the slice selection pulse as before shortening of the pulse duration of the refocusing pulse;
• said processor being configured to adapt a pulse shape of the gradient spoiler pulse, without changing a total spoiler moment of the gradient spoiler pulse, so as to produce an optimally shortened pulse duration of the focusing pulse that occurs when, by adapting the pulse shape of the gradient spoiler pulse, a maximum amplitude of the gradient spoiler pulse equals the amplitude of the slice selection gradient pulse and an edge steepness of the gradient spoiler pulse is minimized;
• and
• said processor being configured to make the pulse sequence with the refocusing pulse having said optimally short duration, said slice selection gradient pulse with the adapted pulse duration and the adapted amplitude, and the gradient spoiler pulse with the adapted pulse shape, available at an output interface of the processor in electronic form in a format configured to use said pulse sequence to operate said magnetic resonance system.

A magnetic resonance apparatus comprising:

• a magnetic resonance data acquisition unit;
• a pulse optimization device comprising:
• a processor having an input interface provided with a pulse sequence as an input to the processor, said pulse sequence including at least one refocusing pulse, one slice selection gradient pulse, and one gradient spoiler pulse;
• said processor being configured to automatically shorten a pulse duration of said refocusing pulse;
• said processor being configured to automatically adapt a pulse duration of the slice selection gradient pulse to the shortened pulse duration of the refocusing pulse;
• said processor being configured to increase an amplitude of the slice selection gradient pulse to cause a same slice thickness to be selected by the slice selection pulse as before shortening of the pulse duration of the refocusing pulse;
• said processor being configured to adapt a pulse shape of the gradient spoiler pulse, without changing a total spoiler moment of the gradient spoiler pulse, so as to produce an optimally shortened pulse duration of the focusing pulse that occurs when, by adapting the pulse shape of the gradient spoiler pulse, a maximum amplitude of the gradient spoiler pulse equals the amplitude of the slice selection gradient pulse and an edge steepness of the gradient spoiler pulse is minimized;
• and
• said processor being configured to make the pulse sequence with the refocusing pulse having said optimally short duration, said slice selection gradient pulse with the adapted pulse duration and the adapted amplitude, and the gradient spoiler pulse with the adapted pulse shape, available at an output interface of the processor in electronic form in a format configured to use said pulse sequence to operate said magnetic resonance system.
• a control unit supplied with said pulse sequence from said output interface of said processor of said pulse sequence optimization device, said control unit being configured to operate said data acquisition unit according to said pulse sequence from the output interface of the processor.

A non-transitory, computer-readable data storage medium encoded with programming instructions, said data storage medium being loaded into a computerized processor and said programming instructions causing said processor to:

• receive a pulse sequence as an input to the processor, said pulse sequence including at least one refocusing pulse, one slice selection gradient pulse, and one gradient spoiler pulse;
• automatically shorten a pulse duration of said refocusing pulse;
• automatically adapt a pulse duration of the slice selection gradient pulse to the shortened pulse duration of the refocusing pulse;
• increase an amplitude of the slice selection gradient pulse to cause a same slice thickness to be selected by the slice selection pulse as before shortening of the pulse duration of the refocusing pulse;
• adapt a pulse shape of the gradient spoiler pulse, without changing a total spoiler moment of the gradient spoiler pulse, so as to produce an optimally shortened pulse duration of the focusing pulse that occurs when, by adapting the pulse shape of the gradient spoiler pulse, a maximum amplitude of the gradient spoiler pulse equals the amplitude of the slice selection gradient pulse and an edge steepness of the gradient spoiler pulse is minimized;
• and
• make the pulse sequence with the refocusing pulse having said optimally short duration, said slice selection gradient pulse with the adapted pulse duration and the adapted amplitude, and the gradient spoiler pulse with the adapted pulse shape, available at an output of the processor in electronic form in a format configured to use said pulse sequence to operate said magnetic resonance system.