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Your search keyword '"K. Kacprzak"' showing total 2 results
Start Over Author "K. Kacprzak" Journal physics in medicine & biology
2 results on '"K. Kacprzak"'

1. Simulating NEMA characteristics of the modular total-body J-PET scanner—an economic total-body PET from plastic scintillators

Author

Ewelina Kubicz, Sz. Niedźwiecki, Aleksander Gajos, K. Kacprzak, F. Tayefi, Ewa Stępień, N. Chug, Kamil Dulski, Beatrix C. Hiesmayr, Catalina Curceanu, Jakub Baran, S. Shivani, M. Dadgar, Sz Parzych, R. Y. Shopa, P. Kopka, D. Kisielewska, Eryk Czerwiński, Wojciech Wiślicki, Lech Raczyński, Grzegorz Korcyl, Sushil K. Sharma, Wojciech Krzemien, Łukasz Kapłon, N. Krawczyk, Paweł Moskal, Konrad Klimaszewski, Paweł Kowalski, and J. Raj

Subjects
Physics - Instrumentation and Detectors, Materials science, Image quality, FOS: Physical sciences, STRIPS, Scintillator, Lyso, Imaging phantom, 030218 nuclear medicine & medical imaging, law.invention, 03 medical and health sciences, 0302 clinical medicine, Optics, law, Radiology, Nuclear Medicine and imaging, Radiological and Ultrasound Technology, Phantoms, Imaging, business.industry, Detector, Instrumentation and Detectors (physics.ins-det), Physics - Medical Physics, 3. Good health, Full width at half maximum, Positron-Emission Tomography, 030220 oncology & carcinogenesis, Medical Physics (physics.med-ph), Tomography, X-Ray Computed, business, Plastics, Sensitivity (electronics)
Abstract

The purpose of the presented research is estimation of the performance characteristics of the economic Total-Body Jagiellonian-PET system (TB-J-PET) constructed from plastic scintillators. The characteristics are estimated according to the NEMA NU-2-2018 standards utilizing the GATE package. The simulated detector consists of 24 modules, each built out of 32 plastic scintillator strips (each with cross section of 6 mm times 30 mm and length of 140 cm or 200 cm) arranged in two layers in regular 24-sided polygon circumscribing a circle with the diameter of 78.6 cm. For the TB-J-PET with an axial field-of-view (AFOV) of 200 cm, a spatial resolutions of 3.7 mm (transversal) and 4.9 mm (axial) are achieved. The NECR peak of 630 kcps is expected at 30 kBq/cc activity concentration and the sensitivity at the center amounts to 38 cps/kBq. The SF is estimated to 36.2 %. The values of SF and spatial resolution are comparable to those obtained for the state-of-the-art clinical PET scanners and the first total-body tomographs: uExplorer and PennPET. With respect to the standard PET systems with AFOV in the range from 16 cm to 26 cm, the TB-J-PET is characterized by an increase in NECR approximately by factor of 4 and by the increase of the whole-body sensitivity by factor of 12.6 to 38. The TOF resolution for the TB-J-PET is expected to be at the level of CRT=240 ps (FWHM). For the TB-J-PET with an axial field-of-view (AFOV) of 140 cm, an image quality of the reconstructed images of a NEMA IEC phantom was presented with a contrast recovery coefficient (CRC) and a background variability parameters. The increase of the whole-body sensitivity and NECR estimated for the TB-J-PET with respect to current commercial PET systems makes the TB-J-PET a promising cost-effective solution for the broad clinical applications of total-body PET scanners., Comment: 31 pages, 11 figures, 6 tables, submitted to Physics in Medicine and Biology 2021

Published
2021
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2. Feasibility study of the positronium imaging with the J-PET tomograph.

Author

P Moskal, D Kisielewska, C Curceanu, E Czerwiński, K Dulski, A Gajos, M Gorgol, B Hiesmayr, B Jasińska, K Kacprzak, Ł Kapłon, G Korcyl, P Kowalski, W Krzemień, T Kozik, E Kubicz, M Mohammed, Sz Niedźwiecki, M Pałka, and M Pawlik-Niedźwiecka

Subjects
POSITRONIUM, POSITRON annihilation, QUANTUM theory, HUMAN body, FEASIBILITY studies, QUANTUM electrodynamics, SPECTRUM analysis
Abstract

A detection system of the conventional PET tomograph is set-up to record data from annihilation into two photons with energy of 511 keV, and it gives information on the density distribution of a radiopharmaceutical in the body of the object. In this paper we explore the possibility of performing the three gamma photons imaging based on ortho-positronium annihilation, as well as the possibility of positronium mean lifetime imaging with the J-PET tomograph constructed from plastic scintillators. For this purposes simulations of the ortho-positronium formation and its annihilation into three photons were performed taking into account distributions of photons’ momenta as predicted by the theory of quantum electrodynamics and the response of the J-PET tomograph. In order to test the proposed ortho-positronium lifetime image reconstruction method, we concentrate on the decay of the ortho-positronium into three photons and applications of radiopharmaceuticals labeled with isotopes emitting a prompt gamma. The proposed method of imaging is based on the determination of hit-times and hit-positions of registered photons which enables the reconstruction of the time and position of the annihilation point as well as the lifetime of the ortho-positronium on an event-by-event basis. We have simulated the production of the positronium in point-like sources and in a cylindrical phantom composed of a set of different materials in which the ortho-positronium lifetime varied from 2.0 ns to 3.0 ns, as expected for ortho-positronium created in the human body. The presented reconstruction method for total-body J-PET like detector allows to achieve a mean lifetime resolution of  ∼40 ps. Recent positron annihilation lifetime spectroscopy measurements of cancerous and healthy uterine tissues show that this sensitivity may allow to study the morphological changes in cell structures. [ABSTRACT FROM AUTHOR]

Published
2019
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