Dr. Jorge Roser

Institut für Medizintechnik
Universität zu Lübeck
Ratzeburger Allee 160
23562 Lübeck
Gebäude 64, Raum 062

Email:	jorge.rosermartinez(at)uni-luebeck.de
Phone:	+49 45131015463
Fax:	+49 451 3101 5404

Roles

Research Scientist

Research

Research Interests

- Emission tomography
- Image reconstruction
- Gamma-ray detection

Teaching

Involved Lectures, Seminars and Courses

Undergraduate Seminar - Medical Imaging

Curriculum Vitae

JORGE ROSER was born in Chiva, Spain in 1994. He received his Bachelor Degree in Physics from the 'University of Valencia' in 2016 and this M.Sc in Theoretical Physics from the same institution in 2017. Subsequently, his research interest shifted towards medical physics, developing his doctorate studies within the IRIS group of IFIC-Valencia. He received his PhD in Physics from the 'Universidad de Valencia' in 2023 (summa cum laude & international mentions). Since October 2023, he works as a research scientist at the Institute of Medical Engineering

Publications

[ 2024 ]
[ 2022 ]
[ 2021 ]
[ 2020 ]

2024[ to top ]

Kasprzak, J., Roser, J., Werner, J. and Rafecas, M.: Image Reconstruction with Regularized Origin Ensemble for Proton-Therapy Range Verification with a Compton Camera and Heterogeneous Targets, 2024, DOI: 10.1016/j.ejmp.2024.103920.
- [ BibTeX ]
- [ URL ]
@inproceedings{kasprzak2024image, author = {Kasprzak, Jona and Roser, Jorge and Werner, Julius and Rafecas, Magdalena}, booktitle = {Abstracts of the 5th European Congress of Medical Physics}, keywords = {imt}, month = {09}, title = {Image Reconstruction with Regularized Origin Ensemble for Proton-Therapy Range Verification with a Compton Camera and Heterogeneous Targets}, volume = 125, year = 2024 }
Werner, J., Schmidt, M., Pennazio, F., Roser, J., Kasprzak, J., Ferrero, V. and Rafecas, M.: An Analytical System Response Model for Spatiotemporal Emission Reconstruction from Multi-Detector Prompt Gamma Timing, 1–1, 2024, DOI: 10.1109/NSS/MIC/RTSD57108.2024.10655960.
- [ BibTeX ]
- [ URL ]
@inproceedings{10655960, abstract = {Particle therapy verification using induced prompt gamma radiation is a field of active research. We employ an iterative reconstruction algorithm to reconstruct the spatiotemporal emission distribution. Due to the fast emission of the prompt gamma radiation after the interaction, their spatiotemporal distribution can be used as a surrogate for the primary particle motion. Using a motion model, we extract the particle range and the stopping power, which should allow direct validation of expected values from treatment planning without additional imaging time. The reconstruction is based on Prompt Gamma Timing spectra from multiple detectors, i.e. the combination of primary particle time of flight before nuclear interaction and secondary photon time of flight until detection outside the patient. Reconstruction requires an accurate model of photon transport and detection, which we previously calculated using extensive Monte-Carlo simulations. Here, we present an analytical model that accelerates calculations by almost 200 times, while matching the Monte-Carlo implementation within 6% of the global maximum value for 99% of all non-zero entries. Furthermore, detection delay caused by secondary particles created by the photons in the detector is studied and its integration into the analytical model demonstrated. First reconstructions of spatiotemporal emission distributions from simulated data using both models show almost perfect agreement. The impact on range and stopping power estimates is currently under investigation.}, author = {Werner, Julius and Schmidt, Malte and Pennazio, Francesco and Roser, Jorge and Kasprzak, Jona and Ferrero, Veronica and Rafecas, Magdalena}, booktitle = {2024 IEEE Nuclear Science Symposium (NSS), Medical Imaging Conference (MIC) and Room Temperature Semiconductor Detector Conference (RTSD)}, keywords = {imt}, month = 10, pages = {1-1}, title = {An Analytical System Response Model for Spatiotemporal Emission Reconstruction from Multi-Detector Prompt Gamma Timing}, year = 2024 }
Roser, J., Hetzel, R., Clement, P., Fenger, A., Kasper, J., Kercz, M., Kołodziej, M., Mielke, L., Rusiecka, K., Stahl, A., Wrońska, A. and Rafecas, M.: Range Monitoring Capabilities with the SiFi-CC Detector: Spectral-spatial Imaging with Monte Carlo-simulated Data, 1, 2024, DOI: 10.5506/aphyspolbsupp.17.7-a9.
- [ BibTeX ]
- [ URL ]
@inproceedings{Roser_2024, abstract = {The SiFi-CC group is developing a scintillating-fiber-based Compton camera for high-efficiency gamma-ray imaging, specifically tailored for online range verification in particle therapy. After thorough optimization studies, including the development of neural-network approaches for event selection, the capability of the prototype for detecting range deviations is being studied by using realistic Monte Carlo simulations. We have implemented a spectral-spatial reconstruction based on the LM-MLEM algorithm and spectral analytical models for the system matrix and the sensitivity. In this work, we show the reconstructed images obtained from the irradiation of PMMA phantoms with 4 × 109 protons at therapeutic energies. The results show the capability of the SiFi-CC detector prototype to recover the 4.44 MeV prompt-gamma line and to detect 5 mm Bragg peak shifts.}, author = {Roser, Jorge and Hetzel, Ronja and Clement, Philippe and Fenger, Alexander and Kasper, Jonas and Kercz, Monika and Kołodziej, Magdalena and Mielke, Linn and Rusiecka, Katarzyna and Stahl, Achim and Wrońska, Aleksandra and Rafecas, Magdalena}, booktitle = {5th Jagiellonian Symposium on Advances in Particle Physics and Medicine}, journal = {Acta Physica Polonica B Proceedings Supplement}, keywords = {imt}, number = 7, pages = 1, publisher = {Jagiellonian University}, title = {Range Monitoring Capabilities with the SiFi-CC Detector: Spectral-spatial Imaging with Monte Carlo-simulated Data}, volume = 17, year = 2024 }
Roser, J., Kasprzak, J., Llosá, G., Werner, J. and Rafecas, M.: Background Reduction in Compton-Camera Based 3D Imaging by Using a Non-Uniform Discretization of the Field-of-View, 2024, DOI: 10.1016/j.ejmp.2024.104168.
- [ BibTeX ]
- [ URL ]
@inproceedings{roser2024background, author = {Roser, Jorge and Kasprzak, Jona and Llosá, Gabriela and Werner, Julius and Rafecas, Magdalena}, booktitle = {Abstracts of the 5th European Congress of Medical Physics}, keywords = {imt}, month = {09}, title = {Background Reduction in Compton-Camera Based 3D Imaging by Using a Non-Uniform Discretization of the Field-of-View}, volume = 125, year = 2024 }
Werner, J., Ferrero, V., Aglietta, M., Cerello, P., Fiorina, E., Kasprzak, J., Mas Milian, F., Mostardi, F., Pullia, M., Roser, J., Schmid, N., Pennazio, F. and Rafecas, M.: In-beam measurement of stopping power using multi-detector Prompt Gamma Timing in proton therapy, 2024, DOI: 10.1016/j.ejmp.2024.103890.
- [ BibTeX ]
- [ URL ]
@inproceedings{werner2024inbeam, author = {Werner, Julius and Ferrero, Veronica and Aglietta, Marco and Cerello, Piergiorgio and Fiorina, Elisa and Kasprzak, Jona and Mas Milian, Felix and Mostardi, Franco and Pullia, Marco and Roser, Jorge and Schmid, Niklas and Pennazio, Francesco and Rafecas, Magdalena}, booktitle = {Abstracts of the 5th European Congress of Medical Physics}, keywords = {imt}, month = {09}, title = {In-beam measurement of stopping power using multi-detector Prompt Gamma Timing in proton therapy}, volume = 125, year = 2024 }
Roser, J., Kasprzak, J., Llosá, G., Werner, J. and Rafecas, M.: Background reduction of Compton-camera based 3D imaging for range verification in proton therapy, 1–1, 2024, DOI: 10.1109/NSS/MIC/RTSD57108.2024.10655232.
- [ BibTeX ]
- [ URL ]
@inproceedings{10655232, abstract = {Low signal-to-background ratio and subsequent image degradation limits the performance of Compton cameras and hinder their application for range verification in hadron therapy. While several approaches have been explored to improve the signal-to-background ratio via event selection (e.g. with neural networks, energy cuts or using dedicated hardware), background reduction within the 3D image reconstruction process has been hitherto overlooked. In this work we present three such background reduction techniques, and show their potential for image-quality improvement by using simulated data. The explored techniques are shown to reduce image noise-edge artifacts, as well as improve the image contrast and/or be quantitatively closer to the ground truth spatial emission distribution. Such promising results encourage further study on their implementation and impact on range verification.}, author = {Roser, Jorge and Kasprzak, Jona and Llosá, Gabriela and Werner, Julius and Rafecas, Magdalena}, booktitle = {2024 IEEE Nuclear Science Symposium (NSS), Medical Imaging Conference (MIC) and Room Temperature Semiconductor Detector Conference (RTSD)}, keywords = {imt}, month = 10, pages = {1-1}, title = {Background reduction of Compton-camera based 3D imaging for range verification in proton therapy}, year = 2024 }

2022[ to top ]

Roser, J., Barrientos, L., Bernabéu, J., Borja-Lloret, M., Mu~n}}oz, E., Ros, A., Viegas, R. and Llosá, G.: Joint image reconstruction algorithm in Compton cameras, Physics in Medicine and Biology, 67(15), 155009, 2022, DOI: 10.1088/1361-6560/ac7b08.
- [ BibTeX ]
- [ URL ]
@article{Roser_2022, author = {Roser, J and Barrientos, L and Bernab{\'{e}}u, J and Borja-Lloret, M and Mu{\ {n}}oz, E and Ros, A and Viegas, R and Llos{\'{a}}, G}, journal = {Physics in Medicine and Biology}, keywords = {RoserJorge}, month = {07}, number = 15, pages = 155009, publisher = {{IOP} Publishing}, title = {Joint image reconstruction algorithm in Compton cameras}, volume = 67, year = 2022 }

2021[ to top ]

Roser, J., Hueso-González, F., Ros, A. and Llosá, G.: Compton Cameras and Their Applications, In: Radiation Detection Systems, CRC Press, , 161–198, 2021, DOI: 10.1201/9781003218364-7.
- [ BibTeX ]
- [ URL ]
@inbook{Roser_2021, author = {Roser, J. and Hueso-Gonz{\'{a}}lez, F. and Ros, A. and Llos{\'{a}}, G.}, booktitle = {Radiation Detection Systems}, editor = {Iwanczyk, Jan and Iniewski, Krzysztof}, keywords = {RoserJorge}, month = {09}, pages = {161–198}, publisher = {{CRC} Press}, title = {Compton Cameras and Their Applications}, year = 2021 }

2020[ to top ]

Roser, J., Mu~n}}oz, E., Barrientos, L., Barrio, J., Bernabéu, J., Borja-Lloret, M., Etxebeste, A., Llosá, G., Ros, A., Viegas, R. and Oliver, J. F.: Image reconstruction for a multi-layer Compton telescope: an analytical model for three interaction events, Physics in Medicine and Biology, 65(14), 145005, 2020, DOI: 10.1088/1361-6560/ab8cd4.
- [ BibTeX ]
- [ URL ]
@article{Roser_2020, author = {Roser, J and Mu{\ {n}}oz, E and Barrientos, L and Barrio, J and Bernab{\'{e}}u, J and Borja-Lloret, M and Etxebeste, A and Llos{\'{a}}, G and Ros, A and Viegas, R and Oliver, J F}, journal = {Physics in Medicine and Biology}, keywords = {RoserJorge}, month = {07}, number = 14, pages = 145005, publisher = {{IOP} Publishing}, title = {Image reconstruction for a multi-layer Compton telescope: an analytical model for three interaction events}, volume = 65, year = 2020 }