% IMPORTANT: The following is UTF-8 encoded.  This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.

@ARTICLE{Dietrich:289789,
      author       = {K. Dietrich$^*$ and S. Klüter and F. Dinkel$^*$ and G.
                      Echner$^*$ and S. Brons and S. Orzada$^*$ and J. Debus$^*$
                      and M. E. Ladd$^*$ and T. Platt$^*$},
      title        = {{A}n essentially radiation-transparent body coil integrated
                      with a patient rotation system for {MR}-guided particle
                      therapy.},
      journal      = {Medical physics},
      volume       = {51},
      number       = {6},
      issn         = {0094-2405},
      address      = {College Park, Md.},
      publisher    = {AAPM},
      reportid     = {DKFZ-2024-00868},
      pages        = {4028-4043},
      year         = {2024},
      note         = {#EA:E020#EA:E050#LA:E020#LA:E050# / 2024
                      Jun;51(6):4028-4043},
      abstract     = {The pursuit of adaptive radiotherapy using MR imaging for
                      better precision in patient positioning puts stringent
                      demands on the hardware components of the MR scanner.
                      Particularly in particle therapy, the dose distribution and
                      thus the efficacy of the treatment is susceptible to beam
                      attenuation from interfering materials in the irradiation
                      path. This severely limits the usefulness of conventional
                      imaging coils, which contain highly attenuating parts such
                      as capacitors and preamplifiers in an unknown position, and
                      requires development of a dedicated radiofrequency (RF) coil
                      with close consideration of the materials and components
                      used.In MR-guided radiation therapy in the human torso,
                      imaging coils with a large FOV and homogeneous B1 field
                      distribution are required for reliable tissue
                      classification. In this work, an imaging coil for MR-guided
                      particle therapy was developed with minimal ion attenuation
                      while maintaining flexibility in treatment.A birdcage coil
                      consisting of nearly radiation-transparent materials was
                      designed and constructed for a closed-bore 1.5 T MR system.
                      Additionally, the coil was mounted on a rotatable patient
                      capsule for flexible positioning of the patient relative to
                      the beam. The ion attenuation of the RF coil was
                      investigated in theory and via measurements of the Bragg
                      peak position. To characterize the imaging quality of the RF
                      coil, transmit and receive field distributions were
                      simulated and measured inside a homogeneous
                      tissue-simulating phantom for various rotation angles of the
                      patient capsule ranging from 0° to 345° in steps of 15°.
                      Furthermore, simulations with a heterogeneous human voxel
                      model were performed to better estimate the effect of real
                      patient loading, and the RF coil was compared to the
                      internal body coil in terms of SNR for a full rotation of
                      the patient capsule.The RF coil (total water equivalent
                      thickness (WET) ≈ 420 µm, WET of conductor ≈ 210 µm)
                      can be considered to be radiation-transparent, and a
                      measured transmit power efficiency (B1 +/ P $\sqrt
                      {\mathrm{P}} $ ) between 0.17 µT/ W $\sqrt {\mathrm{W}} $
                      and 0.26 µT/ W $\sqrt {\mathrm{W}} $ could be achieved in a
                      volume (Δz = 216 mm, complete x and y range) for the 24
                      investigated rotation angles of the patient capsule.
                      Furthermore, homogeneous transmit and receive field
                      distributions were measured and simulated in the transverse,
                      coronal and sagittal planes in a homogeneous phantom and a
                      human voxel model. In addition, the SNR of the
                      radiation-transparent RF coil varied between 103 and 150, in
                      the volume (Δz = 216 mm) of a homogeneous phantom and
                      surpasses the SNR of the internal body coil for all rotation
                      angles of the patient capsule.A radiation-transparent RF
                      coil was developed and built that enables flexible patient
                      to beam positioning via full rotation capability of the RF
                      coil and patient relative to the beam, with results
                      providing promising potential for adaptive MR-guided
                      particle therapy.},
      keywords     = {MR‐guided particle therapy (Other) / interventional MRI
                      (Other) / rotatable body coil (Other)},
      cin          = {E020 / E050 / HD01 / E040},
      ddc          = {610},
      cid          = {I:(DE-He78)E020-20160331 / I:(DE-He78)E050-20160331 /
                      I:(DE-He78)HD01-20160331 / I:(DE-He78)E040-20160331},
      pnm          = {315 - Bildgebung und Radioonkologie (POF4-315)},
      pid          = {G:(DE-HGF)POF4-315},
      typ          = {PUB:(DE-HGF)16},
      pubmed       = {pmid:38656549},
      doi          = {10.1002/mp.17065},
      url          = {https://inrepo02.dkfz.de/record/289789},
}