Patent ID: 8638099

Claim:
A method of reducing magnetic resonance temperature measurement errors in a treatment of a patient with high-intensity focused ultrasound (HIFU), produced by an ultrasound transducer of a HIFU device, while monitoring said treatment by magnetic resonance (MR) imaging, comprising: operating an MR data acquisition unit, in which a patient is located in a basic magnetic field generated by the MR data acquisition unit, in order to obtain an MR phase diagram of an area of the patient, as a reference image, with the ultrasound transducer located at a start position in the MR data acquisition unit, before heating the area with HIFU from said ultrasound transducer; operating said MR data acquisition unit, also with said patient located in said basic magnetic field, in order to obtain a plurality of further MR phase diagrams of said area, as heating images, during or after heating said area with HIFU produced by said ultrasound transducer, while moving said ultrasound transducer to respectively different positions in a grid in said MR data acquisition unit, so that each of said plurality of additional MR phase diagrams is acquired with said ultrasound transducer located at a different one of said positions in said grid; providing a processor with said reference image and said heating images and, in said processor, automatically calculating, from differences in said MR phase diagrams that form said heating images and from the MR phase diagram that forms said reference image, changes in said basic magnetic field caused by said ultrasound transducer being moved onto said respectively different positions in said grid; in said processor, also calculating, from differences in said MR phase diagrams that form said heating images with respect to said MR phase diagram that forms said reference image, temperature changes in said area caused by said heating of said area with HIFU; and in said processor, automatically correcting said temperature changes dependent on said changes to said basic magnetic field, thereby producing corrected temperature changes, and making said corrected temperature changes available at an output of said processor in an electronically displayable form.