@conference{bcd5dbf9316c4ef8a56698e8947fc92e,
  title    = "Analytical modeling of inter-crystal scattering in PET with energy information",
  author   = "Jorge Roser and Vo, \{Hong Phuc\} and Rebecca Kantorek and Seeger, \{Steven Sebastian\} and Magdalena Rafecas",
  year     = "2026",
  language = "English",
  note     = "FTMI-TBPET-PSMR ; Conference date: 11-05-2026 Through 14-05-2026",
}

@conference{f93a46b21dfd40739d8e786695e23c89,
  title    = "Fabrication and Evaluation of 3D-Printed 89Zr Image Quality Phantoms for Preclinical Immuno-PET Imaging",
  abstract = "Introduction: Immuno-PET relies on labelling monoclonal antibodies with isotopes with sufficient long half-life times, such as 89Zr. Compared with 18F, 89Zr has a lower positron yield resulting in increased image noise, particularly at late imaging time points; multi-day 89Zr imaging is further complicated by challenges in phantom preparation, as 89Zr solutions are prone to adsorption to phantom walls, tubing, and syringes, leading to unstable and non-uniform activity distributions. These effects limit the reproducibility and accuracy of performance and protocol optimization studies. To address these challenges, we investigate the use of stereolithographic 3D printing of 89Zr-containing structures, enabling wall-less, stable, and reproducible activity distributions for multi-day immuno-PET phantom studies. Methods: 3D printing was performed using an LCD-based Photon Mono printer (Anycubic, China). The printer operates by selectively curing a liquid photopolymer resin using a UV-emitting LCD screen and provides nominal resolutions of 51 × 51 × 10 µm in the X, Y, and Z directions, respectively. A modified resin–radionuclide mixing protocol was developed by combining 89Zr with a water-washable photopolymer resin (density 1.1 g/cm³). Moreover, non-radioactive zirconium diluted in hydrochloric acid was added to promote binding between the resin and 89Zr. The mixture with 0.2 MBq/mL was homogenized by vigorous manual shaking without external heating. A single-point phantom was fabricated by depositing a high-activity resin droplet directly above the LCD screen at predefined locations and was compared with four commercial 22Na point sources to assess spatial precision. CT imaging was used to assess the geometric characteristics of the sources. Additionally, two phantoms, design based on NEMA NU 4-2008 IQ phantoms, were printed with (89Zr 0.2 MBq/mL) and with (18F, 1.8 MBq/mL) and compared to a filled phantom with (89Zr 0.2 MBq/mL). Results: In the CT image of the commercial point sources, three radioactive seeds were identified within a 20 mm diameter area, each with an approximate diameter of 0.8 mm and all skewed toward one side of the disk. This asymmetry implies that, for PET systems with spatial resolution < 1 mm, rotating the source by 180° could lead to different spatial resolution measurements due to altered seed positioning. In contrast, the 3D-printed point source consisted of a single, centrally located seed, providing accurate reproducibility regardless of the source orientation. For the IQ phantoms, uniformity measurements following NEMA NU 4-2008 showed mean activity concentrations of 1.7 MBq/mL (\%STD = 4.6) for the 18F printed phantom, 0.2 MBq/mL (\%STD = 3.4) for the 89Zr printed phantom, and 0.2 MBq/mL (\%STD = 1.5) for the 89Zr filled phantom, indicating comparable values between the 89Zr printed and conventionally filled phantoms. Recovery coefficients for the printed phantoms were similar to those of the filled phantom, as illustrated in Figure 2. Conclusions: This study demonstrates the feasibility of manufacturing 3D-printed image quality phantoms incorporating 89Zr for preclinical PET imaging. The single-point source phantom achieved accurate centering of a 1 mm source seed, eliminating geometric ambiguities observed in commercial multi-seed point sources. While such discrepancies are negligible in clinical PET systems, they may influence measurements in high-resolution preclinical or dedicated scanners. For example, when modeling the point spread function (PSF) for image reconstruction, precise source positioning becomes advantageous. Using a modified mixing protocol, an 89Zr-based IQ phantom was successfully printed and showed comparable performance to conventional fillable phantoms and 18F-printed phantoms. This approach enables stable, reproducible phantom designs suitable for multi-day immuno-PET studies. Future work will focus on translation to clinical scanners and evaluation of multi-day imaging performance. ",
  author   = "Ezzat Elmoujarkach and Pia Linder and Seeger, \{Steven Sebastian\} and Christian Schmidt and Gowthaam Nachimuthu and Julia Mannheim and Fabian Schmidt and Magdalena Rafecas",
  year     = "2026",
  month    = may,
  language = "English",
}

@article{9c2f6724119b4f9585c68972897e8851,
  title     = "Inclusion of Inter-crystal Scattering in PET: Analytical Models and Dedicated Reconstruction",
  abstract  = "Inter-crystal scattering (ICS) in Positron Emission Tomography (PET) is commonly regarded as a degradation effect that might compromise the image spatial resolution. In parallel, the inclusion of ICS events has also been recognized as a potential approach to increase PET sensitivity, which could be especially beneficial in scenarios where the latter is a limiting factor, such as very small animal imaging. Several methods for the recovery of ICS events have been proposed, many of which aim to locate the first interaction, i.e., the Compton scattering site, usually limited by their success rate, computational burden or data and training dependency. Conversely, this work proposes a physics-based model for ICS events, leading to analytical expressions of the sensitivity image and the system matrix (required by statistical reconstruction algorithms), without the need to identify the original line of response. After validating the model, the work shows how ICS events can be integrated into a joint image reconstruction algorithm (based on list-mode MLEM) together with conventional PET events, for which dedicated analytical models are also developed. To assess the performance of the proposed approach, Monte-Carlo simulated and experimental data of an image quality phantom were obtained with the MERMAID small-fish PET scanner prototype. Both simulation and experimental results indicate that, while slightly decreasing the recovery coefficient values, the inclusion of ICS clearly reduces statistical noise and improves uniformity.",
  author    = "Jorge Roser and Vo, \{Hong Phuc\} and Rebecca Kantorek and Seeger, \{Steven Sebastian\} and Magdalena Rafecas",
  note      = "Publisher Copyright: {\textcopyright} 2017 IEEE.",
  year      = "2026",
  doi       = "10.1109/TRPMS.2026.3691192",
  language  = "English",
  journal   = "IEEE Transactions on Radiation and Plasma Medical Sciences",
  issn      = "2469-7311",
  publisher = "IEEE",
}

@techreport{88c4770b36094e2b9e8d4728d4208d14,
  title    = "MERMAID-v1 PET Scanner Prototype: Initial Characterization and First Zebrafish Scans",
  author   = "Seeger, \{Steven Sebastian\} and Vo, \{Hong Phuc\} and Rebecca Kantorek and Kolodziej, \{Magdalena Maria\} and Ezzat Elmoujarkach and Caroline Florack and Jorge Roser and Christian Schmidt and Magdalena Rafecas",
  year     = "2026",
  month    = jun,
  day      = "16",
  doi      = "10.48550/arXiv.2606.18055",
  language = "English",
  type     = "WorkingPaper",
}

@conference{71ef4504a58b489c8521fac6fe9bb860,
  title    = "The MERMAID Project: Current Developments and Future Directions",
  author   = "Rebecca Kantorek and Seeger, \{Steven Sebastian\} and Jorge Roser and Vo, \{Hong Phuc\} and Kolodziej, \{Magdalena Maria\} and Magdalena Rafecas",
  year     = "2026",
  language = "Deutsch",
  note     = "FTMI-TBPET-PSMR ; Conference date: 11-05-2026 Through 14-05-2026",
}

@conference{012e247e964d4acc9ed4e3272610b4b6,
  title    = "First in-Vivo Tests of Zebrafish with Mermaid, a PET Prototype for Small Aquatic Animals",
  author   = "Seeger, \{Steven Sebastian\} and Rebecca Kantorek and Vo, \{Hong Phuc\} and Jorge Roser and Kolodziej, \{Magdalena Maria\} and Christian Schmidt and Magdalena Rafecas",
  year     = "2025",
  month    = dec,
  day      = "18",
  doi      = "10.1109/NSS/MIC/RTSD57106.2025.11287003",
  language = "English",
}

@conference{c6e8fc18b50f44b0b832b8904aff866a,
  title    = "In-vivo 18F-FDG administration in zebrafish and dedicated PET imaging with MERMAID",
  author   = "Seeger, \{Steven Sebastian\} and Nicola Beindorff and Vo, \{Hong Phuc\} and Rebecca Kantorek and Anja Heeren-Hagemann and Sarah Spreckelmeyer and Magdalena Rafecas",
  year     = "2025",
  month    = mar,
  day      = "14",
  language = "Deutsch",
  note     = "European Molecular Imaging Meeting 2025, EMIM 2025 ; Conference date: 11-03-2025 Through 14-03-2025",
  url      = "https://e-smi.eu/meetings/emim/past-meetings/2025-bilbao/",
}

@article{20781e9778a94eb7a2902d9bd42c12fb,
  title     = "Dedicated 3D Printed Radioactive Phantoms With 18F-FDG for Ultra-High Resolution PET",
  author    = "Ezzat Elmoujarkach and Steven Seeger and Luise Morgner and Fabian Schmidt and Julia Mannheim and Schmidt, \{Christian L.\} and Magdalena Rafecas",
  year      = "2024",
  doi       = "10.1109/TRPMS.2024.3483233",
  language  = "English",
  pages     = "1--1",
  journal   = "IEEE Transactions on Radiation and Plasma Medical Sciences",
  issn      = "2469-7311",
  publisher = "IEEE",
}

@conference{fe1d0164e06a4fcfbc0bb8dae37e2e3d,
  title    = "EP-0693 Fabrication of Zirconium-89 solid phantoms for PET using 3D Printing",
  author   = "Steven Seeger and Ezzat Elmoujarkach and Fabian Schmidt and Gowthaam Nachimuthu and Christian Schmidt and Julia Mannheim and Magdalena Rafecas",
  year     = "2024",
  doi      = "10.1007/s00259-024-06838-z",
  language = "English",
  pages    = "1--1026",
}

@conference{e38cd618a50b467891082b769af7e936,
  title    = "EP-0704 The MERMAID Project : Pioneering PET Imaging for Small Aquatics Animals",
  author   = "Steven Seeger and Hong Vo and Ezzat Elmoujarkach and Christian Schmidt and Magdalena Rafecas",
  year     = "2024",
  language = "English",
}