Magnetic resonance imaging method and apparatus with adherence to SAR limits in a scan using data from a previous scan

摘要

In a method and apparatus for magnetic resonance imaging with adherence to SAR limits, a patient is exposed to a radio-frequency pulse sequence via at least one transmission antenna for the implementation of a measurement and the magnetic resonance signals that are generated are acquired in a spatially resolved manner via at least one reception antenna and are further-processed for generating magnetic resonance images or spectra, with current SAR values for planned parameters of the measurement being identified before the implementation of the measurement and the parameters being modified as needed until the current SAR values lie within the SAR limits. The determination of the current SAR values ensues employing stored data that contain the time curve of the RF stressing of the patient during one or more preceding measurements, as well as information from which the temporal spacing of the RF stress of the preceding measurements from the planned measurement can be determined. Better utilization of the performance capability of the magnetic resonance tomography apparatus is achieved by the patient throughput, which is of particular interest for economic feasibility, being increased with adherence to the SAR limit values.