Christopher M Rank1, Thorsten Heußer1, Andreas Wetscherek1, Martin T Freitag2, Heinz-Peter Schlemmer2, and Marc Kachelrieß1
1Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
To
allow for MR acquisition times as short as 1 minute per bed, we propose a new
method for PET/MR respiratory motion compensation (MoCo), which is based on
strongly undersampled radial MR data. We acquired simultaneous PET/MR data of
the thorax of three patients. Motion vector fields were estimated with a
newly-developed algorithm, which alternates between MR image reconstruction and
motion estimation. Subsequent 4D MoCo PET reconstructions employing
the motion vector field derived from strongly undersampled MR data yielded a considerable
visual and quantitative improvement compared to standard 3D PET and 4D gated PET
reconstructions.
