Method and device for a magnetic resonance system control sequence

A method for operating a magnetic resonance system with a plurality of independent radio-frequency transmit channels, the method comprising:

• calculating, in an RF pulse optimization method, a control sequence comprising a multichannel pulse train based on a prespecified k-space gradient trajectory and a prespecified target magnetization;
• transmitting, by the magnetic resonance system, the multichannel pulse train with a plurality of individual RF pulse trains, the plurality of individual RF pulse trains being transmitted in parallel over the plurality of independent radio-frequency transmit channels;
• and
• operating the magnetic resonance system using the control sequence,
• wherein the k-space gradient trajectory is optimized using a parameterizable function in an RF exposure optimization method, the parameterizable function being parameterizable at least with respect to an RF exposure value of an object under examination.

A control sequence determination device for determining a magnetic resonance system control sequence, the magnetic resonance system control sequence comprising a multichannel pulse train with a plurality of individual RF pulse trains to be sent out by the magnetic resonance system over different independent radio-frequency transmit channels in parallel, the control sequence determination device comprising:

• an input interface for detecting a k-space gradient trajectory and a target magnetization;
• an RF pulse optimization unit configured to calculate the multichannel pulse train in an RF pulse optimization method based on a prespecified k-space gradient trajectory and a prespecified target magnetization;
• and
• a control sequence output interface,
• wherein the control sequence determination device is configured to optimize the k-space gradient trajectory using a parameterizable function in an RF exposure optimization method, the parameterizable function being parameterizable at least with respect to an RF exposure value of an object under examination.

A magnetic resonance system comprising:

• a plurality of independent radio-frequency transmit channels;
• a gradient system;
• a control device that is configured to:
• carry out a desired measurement based on a prespecified control sequence;
• send out a multichannel pulse train comprising a plurality of parallel individual RF pulse trains over the plurality of independent radio-frequency transmit channels;
• and
• send out a gradient pulse train coordinated to the plurality of parallel individual RF pulse trains over the gradient system;
• and
• a control sequence determination device comprising:
• an input interface for detecting a k-space gradient trajectory and a target magnetization;
• an RF pulse optimization unit configured to calculate the multichannel pulse train in an RF pulse optimization method based on a prespecified k-space gradient trajectory and a prespecified target magnetization;
• and
• a control sequence output interface,
• wherein the control sequence determination device is configured to optimize the k-space gradient trajectory using a parameterizable function in an RF exposure optimization method, the parameterizable function being parameterizable at least with respect to an RF exposure value of an object under examination, and
• wherein the control sequence determination device is configured to determine a control sequence and to transfer the control sequence to the control device, the control sequence comprising the multichannel pulse train, the control sequence being the prespecified control sequence.

A non-transitory computer readable medium comprising computer executable instructions that, when executed by a control sequence determination device, cause the control sequence determination device to determine a magnetic resonance system control sequence, the instructions comprising:

• calculating, in an RF pulse optimization method, a multichannel pulse train based on a prespecified k-space gradient trajectory and a prespecified target magnetization;
• and
• transmitting, by the magnetic resonance system, the multichannel pulse train with a plurality of individual RF pulse trains, the plurality of individual RF pulse trains being transmitted in parallel over different independent radio-frequency transmit channels,
• wherein the k-space gradient trajectory is optimized using a parameterizable function in an RF exposure optimization method, the parameterizable function being parameterizable at least with respect to an RF exposure value of an object under examination.