Patent ID: 8436617
Filing Date: 2013-05-07
Classification: A61B,G01R

Abstract:
1. In a magnetic resonance (MR) apparatus comprising a radiofrequency (RF) transmitter connected with an RF oscillator and configured to radiate RF signals that excite nuclear spins in a subject located in an MR data acquisition volume of the MR apparatus, and an interventional device having at least a portion thereof located in said MR acquisition region and the interventional device being configured to interact with the subject during radiation of said RF signals, the improvement of a compensation device comprising: a control device having an RF input and an RF output, said RF input being configured for connection with said RF oscillator; an RF power injection device connected to said RF output of said control device, said RF power injection device being configured to inject RF power delivered by said control device into said interventional apparatus; a measurement device configured to measure at least one electrical variable at said interventional device, said electrical variable changing dependent on said RF signals radiated by said RF transmitter; and a regulator connected to said control device and to said measurement device, said regulator being configured to adjust said control device to adjust delivery of said RF power in order to reduce said electrical variable at said interventional apparatus and, by reducing said electrical variable, said regulator also reducing an electromagnetic field load on the subject caused by interaction of the interventional device in the subiect with the radiated RF signals.