Abstract: A magnetic resonance imaging system includes a gradient system and a processor for controlling the magnetic resonance imaging system.

Abstract: The invention relates to a magnetic resonance imaging system (100). The magnetic resonance imaging system (100) comprises a gradient system and a processor (124) for controlling the magnetic resonance imaging system (100). Execution of machine executable instructions causes the magnetic resonance imaging system (100) to: acquire by coil elements (114) first magnetic resonance data simultaneously from a group of passive local probes 5 (302, 312, 402, 702, 901), wherein the first group of passive local probes (302, 312, 402, 702, 901) comprises a plurality of passive local probes (302, 312, 402, 702, 901) located spaced apart from each other; disentangle contributions to the first magnetic resonance data from the individual local probes, calculate for the magnetic resonance imaging system (100) a gradient impulse response function of the gradient system using the first magnetic resonance data 10 from the local probes; determine correction factors using the gradient impulse response function.

Abstract: A method of determining an actual gradient impulse response function during execution of a magnetic resonance (MR) imaging or spectroscopy sequence, wherein a main magnetic field is generated in a sample region of an MR apparatus by means of a main magnet and wherein superimposed time dependent gradient fields and radiofrequency fields in a first RF band are generated in the sample region according to a first MR sequence for forming images or spectra, the gradient fields being generated by gradient forming means of the MR apparatus operated according to a gradient forming sequence part of said first MR sequence, the MR apparatus further comprising at least one magnetic field probe.

Abstract: A method of determining an actual gradient impulse response function during execution of a magnetic resonance (MR) imaging or spectroscopy sequence, wherein a main magnetic field is generated in a sample region of an MR apparatus by means of a main magnet and wherein superimposed time dependent gradient fields and radiofrequency fields in a first RF band are generated in the sample region according to a first MR sequence for forming images or spectra, the gradient fields being generated by gradient forming means of the MR apparatus operated according to a gradient forming sequence part of said first MR sequence, the MR apparatus further comprising at least one magnetic field probe.

Abstract: A dynamic field camera arrangement for monitoring electromagnetic field behavior in a spatial region comprises a main magnetic field and a radiofrequency (RF) field limited to a first RF band, particularly in an MRI or NMR apparatus. The arrangement comprises a magnetic field detector set comprising a plurality of low-frequency magnetic field detectors, each one of said magnetic field detectors comprising a magnetic resonance (MR) active substance, means for pulsed MR excitation of said substance and means for receiving an MR signal generated by said substance, wherein said pulsed excitation and said MR detector signal is in a second RF band that does not overlap said first RF band. The MR signal receiving means comprise a first RF filter which suppresses RF signal from said first RF band and transmits RF signal from said second RF band.

Abstract: A dynamic field camera arrangement for monitoring electromagnetic field behavior in a spatial region comprises a main magnetic field and a radiofrequency (RF) field limited to a first RF band, particularly in an MRI or NMR apparatus. The arrangement comprises a magnetic field detector set comprising a plurality of low-frequency magnetic field detectors, each one of said magnetic field detectors comprising a magnetic resonance (MR) active substance, means for pulsed MR excitation of said substance and means for receiving an MR signal generated by said substance, wherein said pulsed excitation and said MR detector signal is in a second RF band that does not overlap said first RF band. The MR signal receiving means comprise a first RF filter which suppresses RF signal from said first RF band and transmits RF signal from said second RF band.