@article{ChoiFelderFelderetal.2020,
  author    = {Choi, Chang-Hoon and Felder, Tim and Felder, J{\"o}rg and Tellmann, Lutz and Hong, Suk-Min and Wegener, Hans-Peter and Shah, N Jon and Ziemons, Karl},
  title     = {Design, evaluation and comparison of endorectal coils for hybrid MR-PET imaging of the prostate},
  series = {Physics in Medicine \& Biology},
  volume    = {65},
  journal   = {Physics in Medicine \& Biology},
  number    = {11},
  publisher = {IOP},
  address   = {Bristol},
  issn      = {0031-9155},
  doi       = {10.1088/1361-6560/ab87f8},
  year      = {2020},
  abstract  = {Prostate cancer is one of the most common cancers among men and its early detection is critical for its successful treatment. The use of multimodal imaging, such as MR-PET, is most advantageous as it is able to provide detailed information about the prostate. However, as the human prostate is flexible and can move into different positions under external conditions, it is important to localise the focused region-of-interest using both MRI and PET under identical circumstances. In this work, we designed five commonly used linear and quadrature radiofrequency surface coils suitable for hybrid MR-PET use in endorectal applications. Due to the endorectal design and the shielded PET insert, the outer face of the coils investigated was curved and the region to be imaged was outside the volume of the coil. The tilting angles of the coils were varied with respect to the main magnetic field direction. This was done to approximate the various positions from which the prostate could be imaged. The transmit efficiencies and safety excitation efficiencies from simulations, together with the signal-to-noise ratios from the MR images were calculated and analysed. Overall, it was found that the overlapped loops driven in quadrature were superior to the other types of coils we tested. In order to determine the effect of the different coil designs on PET, transmission scans were carried out, and it was observed that the differences between attenuation maps with and without the coils were negligible. The findings of this work can provide useful guidance for the integration of such coil designs into MR-PET hybrid systems in the future.},
  language  = {en}
}
@article{BeerStreunHombachetal.2010,
  author    = {Beer, S. and Streun, M. and Hombach, T. and Buehler, J. and Jahnke, S. and Khodaverdi, M. and Larue, H. and Minwuyelet, S. and Parl, C. and Roeb, G. and Schurr, U. and Ziemons, Karl},
  title     = {Design and initial performance of PlanTIS: a high-resolution positron emission tomograph for plants},
  series = {Physics in Medicine and Biology},
  volume    = {55},
  journal   = {Physics in Medicine and Biology},
  number    = {3},
  publisher = {IOP},
  address   = {Bristol},
  issn      = {1361-6560},
  doi       = {10.1088/0031-9155/55/3/006},
  pages     = {635 -- 646},
  year      = {2010},
  abstract  = {Positron emitters such as 11C, 13N and 18F and their labelled compounds are widely used in clinical diagnosis and animal studies, but can also be used to study metabolic and physiological functions in plants dynamically and in vivo. A very particular tracer molecule is 11CO2 since it can be applied to a leaf as a gas. We have developed a Plant Tomographic Imaging System (PlanTIS), a high-resolution PET scanner for plant studies. Detectors, front-end electronics and data acquisition architecture of the scanner are based on the ClearPET™ system. The detectors consist of LSO and LuYAP crystals in phoswich configuration which are coupled to position-sensitive photomultiplier tubes. Signals are continuously sampled by free running ADCs, and data are stored in a list mode format. The detectors are arranged in a horizontal plane to allow the plants to be measured in the natural upright position. Two groups of four detector modules stand face-to-face and rotate around the field-of-view. This special system geometry requires dedicated image reconstruction and normalization procedures. We present the initial performance of the detector system and first phantom and plant measurements.},
  language  = {en}
}