Florian Maier1, Axel Joachim Krafft1, Jrgen W. Jenne2,3, Rdiger Dillmann4, Wolfhard Semmler1, Michael Bock1
1Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany; 2Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany; 3Mediri GmbH, Heidelberg, Germany; 4Institute of Anthropomatics, Karlsruhe Institute of Technology, Karlsruhe, Germany
Proton resonance frequency shift thermometry is sensitive to motion. Artifacts are caused by tissue displacement and susceptibility changes. In this work, a novel navigator technique for triggering MR thermometry image acquisition is presented. Non-velocity and velocity encoded navigator signals were acquired without lengthening of TR. Based on the phase variation of non-encoded values and the estimated velocity, trigger events were generated. The measurements indicate that the proposed triggered segmented EPI pulse sequence allows for motion compensated thermometry of periodically moving tissue.