Method for detection of a number of pilot tone signals, magnetic resonance apparatus, and computer program product

A non-transitory computer readable medium comprising a computer program product and is configured to be loaded directly into a memory of a programmable system control unit of a magnetic resonance apparatus, wherein the program, when executed by the programmable system control unit, is configured to cause the magnetic resonance apparatus to:

• receive, by a radio frequency receive unit of the magnetic resonance apparatus, receive signals in accordance with a magnetic resonance sequence, wherein the receive signals comprise a magnetic resonance signal and a number of pilot tone signals, wherein the number of pilot tone signals have a different pilot tone frequency in each case, and wherein the number of pilot tone signals are received according to the magnetic resonance sequence in a number of pilot tone receive time segments interrupted by pauses, which each have a duration;
• digitize the receive signals by sampling with a first sampling frequency f1;
• detect the number of pilot tone signals from the digitized receive signals by sampling the digitized receive signals with a second sampling frequency f2, wherein f2≥2/tm, wherein tm is a shortest duration of the number of pilot tone recording time segments;
• and
• separate the number of pilot tone signals by a bandpass filter or by a frequency conversion of a respective pilot tone signal to 0 Hz and a subsequent lowpass filtering;
• and/or
• interpolate over the pauses interrupting the pilot tone receive time segments of the receipt of the number of pilot tone signals.

A magnetic resonance apparatus comprising:

• a radio frequency receive unit configured to receive, in accordance with a magnetic resonance sequence, receive signals, wherein the receive signals comprise a magnetic resonance signal and a number of pilot tone signals, wherein the number of pilot tone signals have a different pilot tone frequency in each case, and wherein the number of pilot tone signals are received according to the magnetic resonance sequence in a number of pilot tone receive time segments interrupted by pauses, which each have a duration;
• and
• a control unit configured to:
• digitize the receive signals by sampling with a first sampling frequency f1;
• and
• detect the number of pilot tone signals from the digitized receive signals by sampling the digitized receive signals with a second sampling frequency f2, wherein f2≥2/tm, wherein tm is a shortest duration of the number of pilot tone recording time segments.