Magnetic resonance system and method for frequency calibration of the magnetic resonance system

摘要

In a method for frequency calibration in a magnetic resonance system in a volume section containing an unknown number of determined substances, the predetermined volume section is excited with RF pulses and subsequent echo signals are recorded at different times and spectral information is determined for each of the echo signals, from which a peak value in the spectral information and an associated relaxation time are determined. Dependent on the relaxation time, a substance is determined for each peak value. A frequency adjustment substance dependent of the magnetic resonance system is then implemented. Multiple peak values in the spectral information of the echo signals can be determined.

主权项

1. A method for frequency calibration of a magnetic resonance system with respect to a volume section of an examination subject containing an unknown number of substances, said method comprising:
operating a plurality of components of a magnetic resonance data acquisition unit in order to excite nuclear spins in a volume section of an examination subject by irradiating said volume section with radio-frequency (RF) pulses; detecting, at respectively different times after exciting said nuclear spins, a plurality of echo signals from the volume section that arise in said volume section due to said excitation of said nuclear spins; supplying said echo signals to a computerized processing system and, in said computerized processing system, automatically determining, for each of said echo signals, spectral information; in said computerized processing system, detecting at least one peak value in the respective spectral information for each of the echo signals; in said computerized processing system, automatically determining, for each peak value, a relaxation time of the nuclear spins that produced the respective echo signals from which the respective peak volume was detected; in said computerized processing system, for each peak value, determining a substance associated therewith dependent on the relaxation time identified for the respective peak value; and from said computerized processing system, implementing a frequency adjustment of at least one of said plurality of components of said magnetic resonance data acquisition unit operated to excite said nuclear spins, dependent on the peak value determined for at least one of said substances, for implementing another excitation of said nuclear spins in said volume section of said examination subject.