Patent ID: 8401614

Claim:
A method for reducing errors in a measurement of temperature by magnetic resonance in a high intensity focused ultrasound (HIFU) procedure using magnetic resonance imaging-guide HIFU equipment, comprising: before heating, with said HIFU equipment, an area of a subject located within a magnetic resonance imaging apparatus, operating said magnetic resonance imaging apparatus to acquire a magnetic resonance phase image, as a reference image, of a region of the subject comprising said area, the operation of said magnetic resonance imaging apparatus including generating a static magnetic field therein, and said HIFU equipment comprising an ultrasonic transducer comprised of a material that causes a change in said static magnetic field when a position of said ultrasonic transducer changes within said magnetic resonance imaging apparatus; operating said magnetic resonance imaging apparatus to acquire another magnetic resonance phase image of said region of said patient, as a heated image, during or after heating of said area by said HIFU equipment; supplying said reference image and said heated image to a processor and, in said processor, automatically calculating a temperature change in the heated area from said heated image and said reference image; and in said processor, automatically making compensation to said temperature change by identifying and using said change in said static magnetic caused by a position change of said ultrasonic transducer in said magnetic resonance apparatus.