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@ARTICLE{Baran:861490,
      author       = {Baran, Jakub and Chen, Zhaolin and Sforazzini, Francesco
                      and Ferris, Nicholas and Jamadar, Sharna and Schmitt, Ben
                      and Faul, David and Shah, N. J. and Cholewa, Marian and
                      Egan, Gary F.},
      title        = {{A}ccurate hybrid template–based and {MR}-based
                      attenuation correction using {UTE} images for simultaneous
                      {PET}/{MR} brain imaging applications},
      journal      = {BMC medical imaging},
      volume       = {18},
      number       = {1},
      issn         = {1471-2342},
      address      = {London},
      publisher    = {BioMed Central},
      reportid     = {FZJ-2019-01951},
      pages        = {41},
      year         = {2018},
      abstract     = {BackgroundAttenuation correction is one of the most crucial
                      correction factors for accurate PET data quantitation in
                      hybrid PET/MR scanners, and computing accurate attenuation
                      coefficient maps from MR brain acquisitions is challenging.
                      Here, we develop a method for accurate bone and air
                      segmentation using MR ultrashort echo time (UTE)
                      images.MethodsMR UTE images from simultaneous MR and PET
                      imaging of five healthy volunteers was used to generate a
                      whole head, bone and air template image for inclusion into
                      an improved MR derived attenuation correction map, and
                      applied to PET image data for quantitative analysis. Bone,
                      air and soft tissue were segmented based on Gaussian Mixture
                      Models with probabilistic tissue maps as a priori
                      information. We present results for two approaches for bone
                      attenuation coefficient assignments: one using a constant
                      attenuation correction value; and another using an estimated
                      continuous attenuation value based on a calibration fit.
                      Quantitative comparisons were performed to evaluate the
                      accuracy of the reconstructed PET images, with respect to a
                      reference image reconstructed with manually segmented
                      attenuation maps.ResultsThe DICE coefficient analysis for
                      the air and bone regions in the images demonstrated
                      improvements compared to the UTE approach, and other
                      state-of-the-art techniques. The most accurate whole brain
                      and regional brain analyses were obtained using constant
                      bone attenuation coefficient values.ConclusionsA novel
                      attenuation correction method for PET data reconstruction is
                      proposed. Analyses show improvements in the quantitative
                      accuracy of the reconstructed PET images compared to other
                      state-of-the-art AC methods for simultaneous PET/MR
                      scanners. Further evaluation is needed with
                      radiopharmaceuticals other than FDG, and in larger cohorts
                      of participants.},
      cin          = {INM-4 / JARA-BRAIN / INM-11},
      ddc          = {610},
      cid          = {I:(DE-Juel1)INM-4-20090406 / $I:(DE-82)080010_20140620$ /
                      I:(DE-Juel1)INM-11-20170113},
      pnm          = {573 - Neuroimaging (POF3-573)},
      pid          = {G:(DE-HGF)POF3-573},
      typ          = {PUB:(DE-HGF)16},
      pubmed       = {pmid:30400875},
      UT           = {WOS:000449349600002},
      doi          = {10.1186/s12880-018-0283-3},
      url          = {https://juser.fz-juelich.de/record/861490},
}