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.
Keywords