摘要:
A method for monitoring a temporal change in a magnetic field in a magnetic resonance device, as well as an evaluation unit, a magnetic resonance device, and a computer program product for performing the method are provided. The method provides that a position-dependent magnetic field distribution that is produced by the plurality of gradient coils is provided with a plurality of monitoring points. In addition, time-dependent gradient values of the plurality of gradient coils are ascertained. Based on position-dependent magnetic field distribution and the time-dependent gradient values, the temporal change in the magnetic field is ascertained. The temporal change in the magnetic field is monitored by comparing the temporal change in the magnetic field with at least one limit value.
摘要:
A method for operating a magnetic resonance apparatus by a safety unit, taking into account persons fitted with an implant, a safety unit, a safety system, a magnetic resonance apparatus, and a computer program product are provided. The magnetic resonance apparatus includes a first part and a second part. The first part is operated separately from the second part and includes the safety unit. During an examination of a person fitted with an implant, the safety unit checks that the magnetic resonance apparatus, in a restricted operating mode, is complying with implant-conformant limit values.
摘要:
A method for monitoring a temporal change in a magnetic field in a magnetic resonance device, as well as an evaluation unit, a magnetic resonance device, and a computer program product for performing the method are provided. The method provides that a position-dependent magnetic field distribution that is produced by the plurality of gradient coils is provided with a plurality of monitoring points. In addition, time-dependent gradient values of the plurality of gradient coils are ascertained. Based on position-dependent magnetic field distribution and the time-dependent gradient values, the temporal change in the magnetic field is ascertained. The temporal change in the magnetic field is monitored by comparing the temporal change in the magnetic field with at least one limit value.
摘要:
A method for operating a magnetic resonance apparatus by a safety unit, taking into account persons fitted with an implant, a safety unit, a safety system, a magnetic resonance apparatus, and a computer program product are provided. The magnetic resonance apparatus includes a first part and a second part. The first part is operated separately from the second part and includes the safety unit. During an examination of a person fitted with an implant, the safety unit checks that the magnetic resonance apparatus, in a restricted operating mode, is complying with implant-conformant limit values.
摘要:
In a magnetic resonance system according to a measurement protocol defined in advance and comprising multiple acquisition parameters, wherein given a non-compliance with at least one limit value (which is automatically established before the beginning of a subject-specific measurement data acquisition)—in particular a SAR limit value and/or a magneto-stimulation limit value and/or a hardware limit value—by the measurement protocol, an adaptation of at least one acquisition parameter ensues using at least one (in particular user-defined) protocol-specific rule for compliance with the limit value, and the measurement data acquisition ensues automatically according to the adapted acquisition parameters.
摘要:
The disclosure relates to a method for monitoring an absorption rate when using a primary coil of a magnetic resonance device and a secondary coil inductively coupled to the primary coil and to a monitoring unit, a magnetic resonance device and a computer program product. According to the method a maximum admissible absorption rate is provided, using which a maximum admissible B1 field strength of the secondary coil is determined. Furthermore, an actual B1 field strength of the secondary coil is determined. The absorption rate is monitored using the actual B1 field strength of the secondary coil and the maximum admissible B1 field strength of the secondary coil.
摘要:
The disclosure relates to a method for monitoring an absorption rate when using a primary coil of a magnetic resonance device and a secondary coil inductively coupled to the primary coil and to a monitoring unit, a magnetic resonance device and a computer program product. According to the method a maximum admissible absorption rate is provided, using which a maximum admissible B1 field strength of the secondary coil is determined. Furthermore, an actual B1 field strength of the secondary coil is determined. The absorption rate is monitored using the actual B1 field strength of the secondary coil and the maximum admissible B1 field strength of the secondary coil.
摘要:
In a method and a device for specific absorption rate monitoring in a magnetic resonance system wherein multiple transmit coils are independently charged with respective currents, a primary model point voxel and at least one auxiliary model point voxel are automatically selected from among multiple voxels that model a modeled examination subject. The primary model point voxel is that voxel in which an absolute maximum of a total field variable occurs that is produced by the respective electrical fields emitted by the transmit coils. The at least one auxiliary model point voxel is that voxel in which a relative maximum of the variable occurs. The primary model point voxel and the at least one auxiliary model point voxel are stored, and specific absorption rate monitoring of an actual examination subject in the magnetic resonance system is implemented during the acquisition of magnetic resonance data in respective voxels of the actual examination subject corresponding to the stored primary model point voxel and the stored at least one auxiliary model point voxel.
摘要:
In a method and a device for specific absorption rate monitoring in a magnetic resonance system wherein multiple transmit coils are independently charged with respective currents, a primary model point voxel and at least one auxiliary model point voxel are automatically selected from among multiple voxels that model a modeled examination subject. The primary model point voxel is that voxel in which an absolute maximum of a total field variable occurs that is produced by the respective electrical fields emitted by the transmit coils. The at least one auxiliary model point voxel is that voxel in which a relative maximum of the variable occurs. The primary model point voxel and the at least one auxiliary model point voxel are stored, and specific absorption rate monitoring of an actual examination subject in the magnetic resonance system is implemented during the acquisition of magnetic resonance data in respective voxels of the actual examination subject corresponding to the stored primary model point voxel and the stored at least one auxiliary model point voxel.
摘要:
A method for evaluating positioning of an examination object on a patient-positioning apparatus in a magnetic resonance unit, a magnetic resonance unit, and a computer program product are provided. The method includes acquiring positioning data relating to the examination object using an acquisition unit. Using the acquired positioning data, positioning information relating to the examination object is determined using an analysis unit. Evaluation information is determined using the positioning information, using an evaluation unit. Using the evaluation information, an evaluation signal is transmitted using an output unit. Monitoring of a specific absorption rate may be adjusted using the evaluation signal.