Abstract #2636

A Digital Cartesian Feedback Loop for the MRI Transmitter

Klaus M. Huber¹, Wnsch Christian², Seisenberger Claus³, Nisznansky Martin², Demharter Nikolaus², Vester Markus²

¹Siemens Corporate Technology, Erlangen, Germany; ²Siemens Healthcare, Erlangen, Germany; ³Siemens Corporate Technology, Munich, Germany

Functional MRI (fMRI) and Diffusion-weighted MRI (DWI/DTI) are two important MR applications which are known to be sensitive to random system instabilities. The RF power amplifier and the transmit path usually are major contributors to this non-perfect system behavior. We implemented a feedback loop in the digital part of the transmitter hardware which can be configured flexibly according to application-specific needs. The configuration is done by choosing the appropriate linear combination of the measured and digitized complex wave parameters as an actual value for the control loop. Results for both control of the forward power and control of the actual B1-field are presented.