Speaker
Parisa Khateri
(Institute for Particle Physics and Astrophysics, ETH Zürich, Switzerland)
Description
The SAFIR collaboration is developing a PET insert for a pre-clinical MRI system, aiming at excellent temporal resolution, of ~5s time frames. Image reconstruction is performed using the Software for Tomographic Image Reconstruction (STIR). An accurate system matrix is necessary for the precise reconstruction of quantitative PET data and the exact representation of the scanners geometry is a key component of a precise system matrix. STIR models the scanner as a cylinder, i.e. it assumes the scanner is made of individual detector elements arranged uniformly on a cylinder, whereas the crystals in the SAFIR detector are assembled in blocks which are in turn arranged on the sides of a polygon. In this study, we implemented and evaluated the true block type model into the STIR library. We evaluated this new implementation with three sets of Monte Carlo simulations: a rotating plane source for normalization, a uniform cylinder, and a Derenzo phantom. We reconstructed the data using both the existing cylinder and the new block model. Attenuation and normalization corrections were included in the reconstruction algorithm. The random rate was estimated using Monte Carlo simulation and data were corrected prior to their reconstruction. Our results demonstrate a significant improvement for the new block model in terms of resolution and uniformity. The peak to valley ratio for the 2 mm Ø spheres of the Derenzo phantom increased from 1.64 to 2.53. The reconstructed images of the uniform cylinder show better uniformity already prior to normalization. The standard-deviation-to-mean ratio for the uniform cylinder is ~2.5 times smaller for the new block model.
Primary author
Parisa Khateri
(Institute for Particle Physics and Astrophysics, ETH Zürich, Switzerland)
Co-authors
Afroditi Eleftheriou
(Institute of Pharmacology and Toxicology, University of Zürich, Switzerland)
Agnieszka Zagozdzinska-Bochenek
(Institute for Particle Physics and Astrophysics, ETH Zürich, Switzerland)
Alfred Buck
(Clinic of Nuclear Medicine, University of Zürich, Switzerland)
Bruno Weber
(Institute of Pharmacology and Toxicology, University of Zürich, Switzerland)
Charalampos Tsoumpas
(Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, UK)
Christian Ritzer
(Institute for Particle Physics and Astrophysics, ETH Zürich, Switzerland)
Diogo Di Calafiori
(Institute for Particle Physics and Astrophysics, ETH Zürich, Switzerland)
Geoffrey Warnock
(Institute of Pharmacology and Toxicology, University of Zürich, Switzerland)
Günther Dissertori
(Institute for Particle Physics and Astrophysics, ETH Zürich, Switzerland)
Ilaria Sacco
(Institute of Computer Engineering, University Heidelberg, Germany)
Jannis Fischer
(ETH Zürich Institute für Teilchenphysik)
Jisoo Kim
(Department of Nuclear and Quantum Engineering, KAIST, South Korea)
Josep F. Oliver
(Instituto de Física Corpuscular, Universitat de València, Spain)
Lubomir Djambazov
(Institute for Particle Physics and Astrophysics, ETH Zürich, Switzerland)
Markus Rudin
(Institute for Biomedical Engineering, ETH Zürich, Switzerland)
Matthias Wyss
(Institute of Pharmacology and Toxicology, University of Zürich, Switzerland)
Michael Ritzert
(Institute of Computer Engineering, University Heidelberg, Germany)
Mikiko Ito
(Institute of Particle Physics and Astrophysics, ETH Zurich, Zurich, Switzerland)
Paola Solevi
(Institute of Medical Technology, Otto-von-Guericke University Magdeburg, Germany)
Peter Fischer
(Institute of Computer Engineering, University Heidelberg, Germany)
Robert Becker
(Institute for Particle Physics and Astrophysics, ETH Zürich, Switzerland)
Ulf Röser
(Institute for Particle Physics and Astrophysics, ETH Zürich, Switzerland)
Volker Commichau
(Institute for Particle Physics and Astrophysics, ETH Zürich, Switzerland)
Werner Lustermann
(Institute for Particle Physics and Astrophysics, ETH Zürich, Switzerland)
