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  1. 12 Bio-Algorithms and Med-Systems
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  3. 4 Inżynier Medyczny : fizyka, inżynieria, elektroradiologia, radiologia
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  1. 5 Moskal P.
  2. 4 Bednarski T.
  3. 4 Białas P.
  4. 4 Czerwiński E.
  5. 4 Gupta-Sharma N.
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1
Content available remote Evaluation of Modular J-PET sensitivity
Tayefi Ardebili Faranak, Niedźwiecki Szymon, Moskal Paweł
Bio-Algorithms and Med-Systems
|
2023
|
Vol. 19, no. 1
132--138
EN
The Modular J-PET represents the latest advancement in the Jagiellonian-PET series, utilizing extended plastic scintillator strips. This prototype's modular design enables cost-effective imaging of multi-photon annihilation and positronium, allowing for easy assembly, portability, and versatility. Additionally, its lightweight construction facilitates static bed examinations with a mobile detection system that can be positioned conveniently alongside the patient, negating the requirement for spacious clinical settings. Comprising 24 modules arranged in regular 24-sided polygons circumscribing a 73.9 cm diameter circle, each module integrates 13 scintillator strips, measuring 50 cm in length and 6 mm × 24 mm in cross-section. Scintillation light is captured at both ends through analog Silicon Photomultipliers (SiPMs). This research presents Sensitivity of the Modular J-PET tomograph, adhering to the NEMA_NU 2-2018 standards. Sensitivity measurement was performed with 68Ge line source inside the 5 sleeves aluminium phantom placed at center of the detector`s field-of-view (FOV) and 10 cm offset from the center of detector. Analyzing the gathered data involved employing the specialized J-PET Framework software, developed within the C++ architecture. To validate the experimental findings, comparisons were made with GATE simulations, wherein the source and phantom were emulated in the same configuration as employed in the actual experiment. The system sensitivity of the Modular J-PET was assessed to be 1.03 ± 0.02 cps/kBq in the center of the detector`s FOV with the peak sensitivity of 2.1 cps/kBq. However, the simulations indicate that at the center of the detector's FOV, the Modular J-PET achieves a system sensitivity of 1.32 ± 0.03 cps/kBq, with a peak sensitivity of 2.9 cps/kBq.
2
Content available remote Estimating influence of positron range in proton-therapy-beam monitoring with PET
Mryka Wiktor, Das Manish, Beyene Ermias Y., Moskal Paweł, Stępień Ewa
Bio-Algorithms and Med-Systems
|
2023
|
Vol. 19, no. 1
96--100
EN
The application of PET scanners to proton-beam-therapy monitoring is a promising solution to obtain the range of the beam and hence the positions of a Bragg peak - maximum dose deposition point. A proton beam induces nuclear reactions in the tissue, leading to the production of isotopes that emit β+ radiation. This enables the imaging of the density distribution of β+ isotopes produced in the body, allowing the reconstruction of the proton beam range. Moreover, PET detectors may open the possibility for in-beam monitoring, which would offer an opportunity to verify the range during irradiation. PET detectors may also allow positronium imaging, which would be the indicator of the tissue conditions. However, the image of annihilation points does not represent the range of the proton beam. There are several factors influencing the translation from annihilation points to obtain the Bragg peak position. One of them is the kinetic energy of the positron. This energy corresponds to some range of the positron within the tissue. In this manuscript we estimate positron energy and its range and discuss its influence on proton therapy monitoring.
3
Content available remote Design of the neutron generator for the development of boron neutron capture therapy
Bezshyyko Oleg, Golinka-Bezshyyko Larysa
Bio-Algorithms and Med-Systems
|
2023
|
Vol. 19, no. 1
124--131
EN
In this article, we present the modern state of development of boron neutron capture therapy (BNCT) for cancer treatment using compact neutron generators. In the introduction we consider the main advantages and problems of the BNCT method, the main approaches and directions for building neutron sources, the development of chemical materials - boron-containing delivery agents and the control of irradiation of malignant tumours and healthy tissues. In the main part of the article we consider the main structures of neutron generators that can be effective for applying in BNCT. The development and building of a prototype of a compact neutron generator is also described.
4
Content available remote Convolutional neural networks in the classification of multiphoton coincidences in a J-PET scanner
Konieczka Paweł, Raczyński Lech, Wiślicki Wojciech
Bio-Algorithms and Med-Systems
|
2023
|
Vol. 19, no. 1
43--47
EN
This work describes an investigation into the utilization of convolutional neural networks for the classification of three-photon coincidences, focusing specifically on the para- -positronium decay associated with a photon from nuclear deexcitation. The data were simulated using the Monte Carlo method, with scandium-44 as the source of β+ decays. A preprocessing method that allowed for initial cleaning of the training data was described. Subsequently, the parameters of the method for transforming tabular data into images were optimized. Finally, the created images were used to train a binary classifier using a convolutional network model. The developed data preprocessing step and transformation method into image format enabled the achievement of a precision rate of 52% at a sensitivity level of 95%, which was a 10 percentage point improvement compared to the logistic regression model.
5
Content available remote A new brain dedicated PET scanner with 4D detector information
Gonzalez-Montoro Andrea, Barbera Julio, Sanchez David, Mondejar Alvaro, Freire Marta, Diaz Karel, Lucero Alejandro, Jimenez-Serrano Santiago, Alamo Jorge, Morera-Ballester Constantino, Barrio John, Cucarella Neus, Ilisie Victor, Moliner Laura, Valladares Celia, Gonzalez Antonio J., Prior John, Benlloch Jose M.
Bio-Algorithms and Med-Systems
|
2022
|
Vol. 18, no. 1
107--119
EN
In this article, we present the geometrical design and preliminary results of a high sensitivity organspecific Positron Emission Tomography (PET) system dedicated to the study of the human brain. The system, called 4D-PET, will allow accurate imaging of brain studies due to its expected high sensitivity, high 3D spatial resolution and, by including precise photon time of flight (TOF) information, a boosted signal-to-noise ratio (SNR). The 4D-PET system incorporates an innovative detector design based on crystal slabs (semi-monolithic) that enables accurate 3D photon impact positioning (including photon Depth of Interaction (DOI) measurement), while providing a precise determination of the photon arrival time to the detector. The detector includes a novel readout system that reduces the number of detector signals in a ratio of 4:1 thus, alleviating complexity and cost. The analog output signals are fed to the TOFPET2 ASIC (PETsys) for scalability purposes. The present manuscript reports the evaluation of the 4D-PET detector, achieving best values 3D resolution values of < 1,6 mm (pixelated axis), 2.7±0.5 mm (monolithic axis) and 3.4±1.1 (DOI axis) mm; 359 ± 7 ps coincidence time resolution (CTR); 10.2±1.5 % energy resolution; and sensitivity of 16.2% at the center of the scanner (simulated). Moreover, a comprehensive description of the 4D-PET architecture (that includes 320 detectors), some pictures of its mechanical assembly, and simulations on the expected image quality are provided.
6
Content available remote Radioactive nuclei for β+γ PET and theranostics: selected candidates
Matulewicz Tomasz
Bio-Algorithms and Med-Systems
|
2021
|
Vol. 17, no. 4
235--239
EN
Positron emission tomography (PET) is an established medical diagnostic imaging method. Continuous improvements are aimed at refining image reconstruction, reducing the amount of radioactive tracer and combining with targeted therapy. Time-of-flight (TOF)-PET provides the localization of the tracer through improved time resolution, nuclear physics may contribute to this goal via selection of radioactive nuclei emitting additional γ-rays. This additional radiation, when properly detected, localizes the decay of the tracer at the line of response (LoR) determined by two detected 511 keV quanta. Selected candidates are presented. Some are particularly interesting, as they are strong candidates for theranostic applications.
7
Content available remote History of positron emission tomography (PET) in Poland
Cegła Paulina, Piotrowski Tomasz
Bio-Algorithms and Med-Systems
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2021
|
Vol. 17, no. 4
259--264
EN
In this short chronological review, we showed the development of positron emission tomography (PET) starting from research on first isotopes through the concepts and prototype of PET machine to the current clinical practice and technological and clinical research. Particular emphasis was placed on a clear description of the milestones of PET development in Poland.
8
Content available remote A L 1 Minimization Strategy for Robust Joint Activity and Attenuation Estimation in Positron Emission Tomography
Presotto Luca
Fundamenta Informaticae
|
2020
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Vol. 172, nr 2
187--202
EN
Positron Emission Tomography image reconstruction needs a map of photon attenuation probability to provide the correct solution. This map is generally provided by an independent imaging modality. However, it might suffer for artifacts due to patient motion in sequential systems or from intrinsic limitation of the second modality (e.g.: bones that cannot be identified in MR images). It has been shown that such map can be estimated from the PET data themselves, but the solution to this problem has much worse conditioning than the tomographic problem. In this work we propose a new algorithm based on the use of multiple L1 regularization terms in the attenuation sub-problem, to incorporate prior knowledge. We also chose optimal maximizers for both sub-problems: preconditioned gradient descent for the emission one and split-Bregman for the attenuation one. The algorithm was then tested using digital phantom simulations. The proposed algorithm proved to provide accurate quantification over a large range of strength of the regularization terms. The algorithm is also able to reconstruct objects outside of the region where the problem is uniquely determined and it is able to fix the undetermined global scaling factor of joint attenuation and emission estimation. Thanks to the maximizers chosen, the algorithm is computationally less expensive than the current standard.
9
Content available Zastosowanie PET/CT w neurologii
Cegła Paulina, Chrapko Beata, Pietrasz Katarzyna, Cholewiński Witold
Inżynier i Fizyk Medyczny
|
2019
|
Vol. 8, nr 2
79--83
PL
Pozytonowa tomografia emisyjna w połączeniu z tomografią komputerową (positron emission tomography/computed tomography, PET/CT) jest techniką dostarczającą informacji na temat różnych procesów zachodzących w ośrodkowym układzie nerwowym (OUN). Pozwala na ocenę metabolizmu glukozy (18F-fluorodeoksyglukoza, 18F-FDG), układu dopaminergicznego (18F-DOPA) czy wychwytu aminokwasów (18F-fluoroetylotyrozyna, 18F-FET). Celem niniejszej pracy jest omówienie zastosowania techniki PET/CT w zaburzeniach neurologicznych w oparciu o analizę piśmiennictwa.
EN
Positron emission tomography/computed tomography (PET/ CT) is an imaging technique used for assessment of different metabolic processes of central nervous system (CNS). Allows to evaluate glucose metabolism (18F-Fluorodeoxyglucose, 18F-FDG), dopaminergic pathway integrity (18F-dihydroxyphenylalanine, 18F-DOPA) and amino acid uptake (18F-fluoroethylo-thyrosine, 18F-FET). The aim of this review is to discuss the usefulness of the PET/CT method in the neurological disorders based on literature review.
10
Content available remote Metody oceny parametrów biologicznych guza w oparciu o obrazy 18F-FDG-PET/CT w diagnostyce onkologicznej
Cegła P.
Inżynier i Fizyk Medyczny
|
2017
|
Vol. 6, nr 3
183--188
PL
Wczesne postawienie prawidłowej diagnozy, zwłaszcza w onkologii, pozwala na dobranie najbardziej odpowiedniego leczenia dla pacjenta. Badania radioizotopowe odgrywają kluczową rolę w ocenie czynności narządów i tkanek oraz procesów metabolicznych zachodzących w organizmie człowieka, natomiast mniejszą w ocenie budowy morfologicznej. Pozytonowa tomografia emisyjna (PET) jest nieinwazyjną metodą, która wykorzystuje techniki radioizotopowe w celu oceny procesów metabolicznych zachodzących w organizmie, zarówno w tkankach zdrowych, jak i patologicznych.
EN
Early diagnosis, especially in oncology, allows for the most appropriate treatment for the patient. Radioisotope studies play a key role in the evaluation of organ and tissue activities and metabolic processes occurring in the human body, but are of less importance in evaluating morphological structures. Positron Emission Tomography (PET) is a non-invasive method that uses positron radioisotopes to evaluate metabolic processes in the body.
11
Content available Application of the compress sensing theory for improvement of the TOF resolution in a novel J-PET instrument
Raczyński L., Moskal P., Kowalski P., Wiślicki W., Bednarski T., Białas P., Czerwiński E., Gajos A., Kapłon Ł., Kochanowski A., Korcyl G., Kowal J., Kozik T., Krzemień W., Kubicz E., Niedźwiecki S., Pałka M., Rudy Z., Salabura P., Gupta-Sharma N., Silarski M., Słomski A., Smyrski J., Strzelecki A., Wieczorek A., Zieliński M., Zoń N.
Nukleonika
|
2016
|
Vol. 61, No. 1
35--39
EN
Nowadays, in positron emission tomography (PET) systems, a time of fl ight (TOF) information is used to improve the image reconstruction process. In TOF-PET, fast detectors are able to measure the difference in the arrival time of the two gamma rays, with the precision enabling to shorten signifi cantly a range along the line-of-response (LOR) where the annihilation occurred. In the new concept, called J-PET scanner, gamma rays are detected in plastic scintillators. In a single strip of J-PET system, time values are obtained by probing signals in the amplitude domain. Owing to compressive sensing (CS) theory, information about the shape and amplitude of the signals is recovered. In this paper, we demonstrate that based on the acquired signals parameters, a better signal normalization may be provided in order to improve the TOF resolution. The procedure was tested using large sample of data registered by a dedicated detection setup enabling sampling of signals with 50-ps intervals. Experimental setup provided irradiation of a chosen position in the plastic scintillator strip with annihilation gamma quanta.
12
Content available remote Przegląd zaleceń dotyczących kontroli jakości systemów PET – kierunek zmian
Tomaszuk M., Kabat D.
Inżynier i Fizyk Medyczny
|
2015
|
Vol. 4, nr 3
123--132
PL
Pozytonowa tomografia emisyjna PET w krótkim czasie stała się metodą z wyboru w wielu wskazaniach onkologicznych – w przypadku określenia stopnia zaawansowania wybranych nowotworów oraz obserwacji odległych. Metoda ta znalazła zastosowanie również w ocenie właściwości farmakokinetycznych i skuteczności nowych leków. Prowadzanie kontroli jakości w przypadku urządzeń PET zapewnia właściwe odwzorowanie dystrybucji podanego radiofarmaceutyku w ciele pacjenta. Obecnie polskie przepisy prawne nie precyzują zagadnienia kontroli samodzielnych urządzeń PET lub hybryd PET/CT czy PET/MR. Wytyczne w zakresie procedur kontroli jakości tych systemów można znaleźć w zaleceniach Międzynarodowej Agencji Energii Atomowej (IAEA). Dostępne są również zalecenia Europejskiego Towarzystwa Medycyny Nuklearnej (EANM). Oba opracowania wskazują na potrzebę kierowania się procedurami określonymi przez Narodowe Stowarzyszenie Producentów Aparatury Elektrycznej (NEMA) oraz Międzynarodowej Komisji Elektrotechnicznej (IEC). W artykule zaprezentowano historię rozwoju procedur kontroli jakości urządzeń PET na świecie, a także omówiono założenia, niezbędne wyposażenie pomocnicze do przeprowadzenia oraz metodykę wybranych testów.
EN
Positron emission tomography (PET) has become in a short time the method of choice in many oncology indications – in cases of staging and follow-up of selected tumours. It is also useful in the evaluation of the pharmacokinetics and efficacy of new drugs. Conducting quality control (QC) in the case of PET provides an appropriate qualitative and quantitative projection of the distribution of injected radiopharmaceuticals. Polish legislation has not specified rules for QC of PET or hybrid devices, like PET/CT or PET/MR. Guidelines for QC procedures of such systems can be found in international recommendations of International Atomic Energy Agency (IAEA). Also the European Association of Nuclear Medicine (EANM) introduced its guidelines for this purposes. Both indicate the need to follow the National Electric Manufacturers Association (NEMA) and the International Electrotechnical Commission (IEC) procedures. The paper focuses on the history of development of QC procedures of PET devices, also their assumptions, necessary equipment and methodology are discussed.
13
Content available remote J-PET: nowy Pozytonowy Emisyjny Tomograf zbudowany z plastikowych detektorów
Moskal P., Kubica-Misztal A.
Inżynier i Fizyk Medyczny
|
2015
|
Vol. 4, nr 4
195--198
PL
Jagielloński Pozytonowy Tomograf Emisyjny powstał w oparciu o plastikowe detektory promieniowania na Uniwersytecie Jagiellońskim. Nowatorskie rozwiązanie pozwala na zwiększenie komory diagnostycznej przy jednoczesnym znaczącym obniżeniu kosztów tomografu w stosunku do obecnie produkowanych tomografów PET opartych na nieorganicznych detektorach kryształowych.
14
Radiofarmaceutyki w nowoczesnych technikach diagnostyki obrazowej, cz. II - synteza i kontrola jakości radiofarmaceutyków do tomografii pozytonowej
Pęgier M., Pęgier M., Kilian K., Pyrzyńska K.
Analityka : nauka i praktyka
|
2015
|
nr 2
16--23
PL
Pozytonowa tomografia emisyjna (PET) jest dynamicznie rozwijającą się techniką obrazowania medycznego. Wykorzystuje się w niej radiofarmaceutyki, stanowiące połączenie radioizotopu oraz liganda odpowiedzialnego za transport nuklidu i włączenie go w odpowiedni proces w organizmie.
15
Content available remote Positron emission tomography (PET) in oncology: current applications and future perspectives
Trofimiuk-Müldner M., Hubalewska-Dydejczyk A.
Bio-Algorithms and Med-Systems
|
2014
|
Vol. 10, no. 1
47--52
EN
Positron emission tomography (PET), particularly dual-modality imaging systems (PET/CT or PET/MRI), has evolved from being a research tool into a valuable clinical modality, particularly in the field of oncology. Currently, most of the PET/CT examinations are done with FDG when assessing glucose metabolism in tumors. FDG PET or PET/CT has been proven to be a valuable method in staging, restaging, therapy response assessment, early recurrence detection, and in unknown primary focus localization. However, PET/CT has its limitations, leading to both false-positive and false-negative results. Proper design and/or choice of an alternative tracer may overcome those problems as well as give better insight into tumor biology and result in more thorough assessment and effective therapeutic approach in patients with cancer.
16
Content available remote Plastic scintillators for positron emission tomography obtained by the bulk polymerization method
Kapłon Ł., Kochanowski A., Molenda M., Moskal P., Wieczorek A., Bednarski T., Białas P., Czerwiński E., Korcyl G., Kowal J., Kowalski P., Kozik T., Krzemień W., Niedźwiecki S., Pałka M., Pawlik M., Raczyński L., Rudy Z., Salabura P., Gupta-Sharma N., Silarski M., Słomski A., Smyrski J., Strzelecki A., Wiślicki W., Zieliński M., Zoń N.
Bio-Algorithms and Med-Systems
|
2014
|
Vol. 10, no. 1
27--31
EN
This paper describes three methods regarding the production of plastic scintillators. One method appears to be suitable for the manufacturing of plastic scintillators, revealing properties which fulfill the requirements of novel positron emission tomography scanners based on plastic scintillators. The key parameters of the manufacturing process are determined and discussed.
17
Content available remote Depth of interaction determination with temperature gradient function in continuous bismuth germanate oxide (BGO) crystal
Wolszczak W.
Bio-Algorithms and Med-Systems
|
2014
|
Vol. 10, no. 2
65--70
EN
A method for depth of interaction (DOI) estimation with temperature gradient was considered. Preliminary results covered measurements of bismuth germanate oxide (BGO) monolithic crystal light pulse dependence on temperature. The proof of concept for using temperature gradient as a way to encode DOI incident γ in monolithic BGO crystal was presented.
18
Content available remote Computing support for advanced medical data analysis and imaging
Wiślicki W., Bednarski T., Białas P., Czerwiński E., Kapłon Ł., Kochanowski A., Korcyl G., Kowal J., Kowalski P., Kozik T., Krzemień W., Molenda M., Moskal P., Niedźwiecki S., Pałka M., Pawlik-Niedźwiecka M., Raczyński L., Rudy Z., Salabura P., Gupta-Sharma N., Silarski M., Słomski A., Smyrski J., Strzelecki A., Wieczorek A., Zieliński M., Zoń N.
Bio-Algorithms and Med-Systems
|
2014
|
Vol. 10, no. 2
53--58
EN
We discuss computing issues for data analysis and image reconstruction of positron emission tomography based on time-of-flight medical scanner or other medical scanning devices producing large volumes of data. Service architecture based on grid and cloud concepts for distributed processing is proposed and critically discussed.
19
Content available remote 3D PET image reconstruction based on the maximum likelihood estimation method (MLEM) algorithm
Słomski A., Rudy Z., Bednarski T., Białas P., Czerwiński E., Kapłon Ł., Kochanowski A., Korcyl G., Kowal J., Kowalski P., Kozik T., Krzemień W., Molenda M., Moskal P., Niedźwiecki S., Pałka M., Pawlik M., Raczyński L., Salabura P., Gupta-Sharma N., Silarski M., Smyrski J., Strzelecki A., Wiślicki W., Zieliński M, Zoń N.
Bio-Algorithms and Med-Systems
|
2014
|
Vol. 10, no. 1
1--7
EN
A positron emission tomography (PET) scan does not measure an image directly. Instead, a PET scan measures a sinogram at the boundary of the field-of-view that consists of measurements of the sums of all the counts along the lines connecting the two detectors. Because there is a multitude of detectors built in a typical PET structure, there are many possible detector pairs that pertain to the measurement. The problem is how to turn this measurement into an image (this is called imaging). Significant improvement in PET image quality was achieved with the introduction of iterative reconstruction techniques. This was realized approximately 20 years ago (with the advent of new powerful computing processors). However, three-dimensional imaging still remains a challenge. The purpose of the image reconstruction algorithm is to process this imperfect count data for a large number (many millions) of lines of response and millions of detected photons to produce an image showing the distribution of the labeled molecules in space.
20
Content available remote Zastosowanie pozytonowej tomografii emisyjnej i numerycznej mechaniki płynów do badania warunków wytwarzania zawiesin w mieszalniku mechanicznym
Pianko-Oprych P.
Przemysł Chemiczny
|
2011
|
T. 90, nr 8
1561-1566
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