In a method and a control device for operating a magnetic resonance system by a pulse sequence that includes an excitation phase, material in an examination volume is excited by emission of an RF excitation pulse during a selection gradient pulse in a first gradient direction. RF refocusing pulses are then emitted and readout gradient pulses are activated in a second gradient direction for spatially coded acquisition of raw data of the examination volume along the second gradient direction. A prephasing gradient pulse is switched before a first RF refocusing pulse in the second gradient direction, and/or a rephaser gradient pulse is switched before an RF restore pulse, following the RF refocusing pulses, in the second gradient direction. The prephaser gradient pulse and/or the rephaser gradient pulse have lower slew rates than the readout gradient pulses.

A method and apparatus for limiting an RF alternating magnetic field in MRI. The method includes: measuring a perpendicular distance between a local coil placed on a scanned part of a patient and the center of a detection hole of a magnetic resonance (MR) scanner; based on the perpendicular distance, determining a deviation between the B1 field strength at the position of the local coil during an MR scan and the B1 field strength at the center of the detection hole; based on the deviation, computing a conversion coefficient for conversion between the B1 field strength at the position of the local coil and the B1 field strength at the center of the detection hole; based on the B1 field strength required when the surface temperature of the local coil is equal to a safe temperature upper limit and the conversion coefficient, computing a maximum permissible field strength of the B1 field at the center of the detection hole. The B1 field may be limited to a smaller but still effective field strength range, reducing wastage of B1 field performance while ensuring patient safety and MR imaging quality

A method and apparatus for limiting an RF alternating magnetic field in MRI. The method includes: measuring a perpendicular distance between a local coil placed on a scanned part of a patient and the center of a detection hole of a magnetic resonance (MR) scanner; based on the perpendicular distance, determining a deviation between the B1 field strength at the position of the local coil during an MR scan and the B1 field strength at the center of the detection hole; based on the deviation, computing a conversion coefficient for conversion between the B1 field strength at the position of the local coil and the B1 field strength at the center of the detection hole; based on the B1 field strength required when the surface temperature of the local coil is equal to a safe temperature upper limit and the conversion coefficient, computing a maximum permissible field strength of the B1 field at the center of the detection hole. The B1 field may be limited to a smaller but still effective field strength range, reducing wastage of B1 field performance while ensuring patient safety and MR imaging quality

In a magnetic resonance method and apparatus to determine a subject-specific B1 distribution of an examination subject in a measurement volume in the magnetic resonance apparatus, a first measurement data set of the examination subject is acquired using a first pulse sequence, a second measurement data set of the examination subject is acquired using a second pulse sequence, and a third measurement data set of the examination subject is acquired using a third pulse sequence. A first phase is determined from the first measurement data set, a second phase from the second measurement data set and a third phase from the third measurement data set. A relevant phase shift is calculated from the first phase, the second phase and the third phase, and the B1 distribution are determined from the calculated relevant phase shift.

In a magnetic resonance method and apparatus to determine a subject-specific B1 distribution of an examination subject in a measurement volume in the magnetic resonance apparatus, a first measurement data set of the examination subject is acquired using a first pulse sequence, a second measurement data set of the examination subject is acquired using a second pulse sequence, and a third measurement data set of the examination subject is acquired using a third pulse sequence. A first phase is determined from the first measurement data set, a second phase from the second measurement data set and a third phase from the third measurement data set. A relevant phase shift is calculated from the first phase, the second phase and the third phase, and the B1 distribution are determined from the calculated relevant phase shift.

A method is for measuring phase currents of a device under test, in particular of an inverter, in which a sensor arrangement, which has a component including a crystal lattice with a defect, is arranged in a region of the device under test. The method includes using the sensor arrangement to detect a magnetic field formed by a vector of magnetic fields, the magnetic fields each in turn being brought about by one of the phase currents of the device under test, and calculating a vector of the phase currents from the vector of the magnetic fields based on a coefficient matrix.

In order to determine the position of a reception coil in a magnetic resonance (MR) scanner of an MR apparatus, wherein the instrument has a reception coil, MR data are acquired from the reception coil along one direction in the scanner, and are provided to a processor that determines a position specification from the acquired MR data. The processor determines the position specification by initially executing a training period, using a first position specification establishment method, in order to produce a training period dataset, and then the training period dataset is used to establish a final position specification with a second position specification establishment method that differs from the first position specification establishment method.

In order to determine the position of a reception coil in a magnetic resonance (MR) scanner of an MR apparatus, wherein the instrument has a reception coil, MR data are acquired from the reception coil along one direction in the scanner, and are provided to a processor that determines a position specification from the acquired MR data. The processor determines the position specification by initially executing a training period, using a first position specification establishment method, in order to produce a training period dataset, and then the training period dataset is used to establish a final position specification with a second position specification establishment method that differs from the first position specification establishment method.

Methods and systems for Nuclear Magnetic Resonance (NMR) spectra of complex chemical mixtures are described. The methods and systems allow undesired NMR spectral background to be removed or suppressed and target spectral peaks to be uncovered, for example, when strong background signals overlap weaker peaks. In some embodiments, the methods and systems employ a quantum filter utilizing nuclear spin singlet states.

Methods and systems for Nuclear Magnetic Resonance (NMR) spectra of complex chemical mixtures are described. The methods and systems allow undesired NMR spectral background to be removed or suppressed and target spectral peaks to be uncovered, for example, when strong background signals overlap weaker peaks. In some embodiments, the methods and systems employ a quantum filter utilizing nuclear spin singlet states.