Realistic Total-Body J-PET Geometry Optimization--Monte Carlo Study
J. Baran, W. Krzemień, L. Raczyński, M. Bała, A. Coussat, S. Parzych, N. Chug, E. Czerwiński, C. Oana Curceanu, M. Dadgar, K. Dulski, K. Eliyan, J. Gajewski, A. Gajos, B. Hiesmayr, K. Kacprzak, Ł. Kapłon, K. Klimaszewski, G. Korcyl, T. Kozik, D. Kumar, S. Niedźwiecki, D. Panek, E. Perez del Rio, A. Ruciński, S. Sharma, Shivani, R.Y. Shopa, M. Skurzok, E. Stępień, F. Tayefiardebili, K. Tayefiardebili, W. Wiślicki, P. Moskal
abstract
Total-Body PET imaging is one of the most promising newly introduced modalities in the medical diagnostics. State-of-the-art PET scanners use inorganic scintillators such as L(Y)SO or BGO, however, those technologies are very expensive, prohibitng the broad total-body PET applications. We present the comparative studies of performance characteristics of the cost-effective Total-Body PET scanners using Jagiellonian PET (J-PET) technology that is based on plastic scintillators. Here, we investigated in silico five realistic Total-Body scanner geometries, varying the number of rings, scanner radius, and distance between the neighbouring rings. Monte Carlo simulations of two NEMA phantoms (2-meter sensitivity line source and image quality) and the anthropomorphic XCAT phantom, were used to assess the performance of the tested geometries. We compared the sensitivity profiles and we performed the quantitative analysis of the reconstructed images by using the quality metrics such as contrast recovery coefficient, background variability and root mean squared error. The optimal scanner design was selected for the first Total-Body J-PET scanner configuration.
Positronium image of the human brain in vivo
P. Moskal, J. Baran, S. Bass, J. Choiński, N. Chug, C. Curceanu, E. Czerwiński, M. Dadgar, M. Das, K. Dulski, K.V. Eliyan, K. Fronczewska, A. Gajos, K. Kacprzak, M. Kajetanowicz, T. Kaplanoglu, Ł. Kapłon, K. Klimaszewski, M. Kobylecka, G. Korcyl, T. Kozik, W. Krzemień, K. Kubat, D. Kumar, J. Kunikowska, J. Mączewska, W. Migdał, G. Moskal, W. Mryka, S. Niedźwiecki, S. Parzych, E. Perez del Rio, L. Raczyński, S. Sharma, Shivani, R.Y. Shopa, M. Silarski, M. Skurzok, F. Tayefi, K. Tayefi, P. Tanty, W. Wiślicki, L. Królicki, E. Ł. Stępień
abstract
Positronium is abundantly produced within the molecular voids of a patient?s body during positron emission tomography (PET). Its properties dynamically respond to the submolecular architecture of the tissue and the partial pressure of oxygen. Current PET systems record only two annihilation photons and cannot provide information about the positronium lifetime. This study presents the in vivo images of positronium lifetime in a human, for a patient with a glioblastoma brain tumor, by using the dedicated Jagiellonian PET system enabling simultaneous detection of annihilation photons and prompt gamma emitted by a radionuclide. The prompt gamma provides information on the time of positronium formation. The photons from positronium annihilation are used to reconstruct the place and time of its decay. In the presented case study, the determined positron and positronium lifetimes in glioblastoma cells are shorter than those in salivary glands and those in healthy brain tissues, indicating that positronium imaging could be used to diagnose disease in vivo.
Feasibility of the J-PET to monitor range oftherapeutic proton beams
J. Baran, D. Borys, K. Brzeziński, J. Gajewski, M. Silarski, N. Chug, A. Coussat, E. Czerwiński, M. Dadgar, K. Dulski, K.V. Eliyan, A. Gajos, K. Kacprzak, Ł. Kapłon, K. Klimaszewski, P. Konieczka, R. Kopeć, G. Korcyl, T. Kozik, W. Krzemień, D. Kumar, A.J. Lomax, K. McNamara, S. Niedźwiecki, P. Olko, D. Panek, S. Parzych, E. Perez del Rio, L. Raczyński, M. Simbarashe, S. Sharma, Shivani, R.Y. Shopa, T. Skóra, M. Skurzok, P. Stasica, E.Ł. Stępień, K. Tayefi, F. Tayefi, D.C. Weber, C. Winterhalter, W. Wiślicki, P. Moskal, A. Ruciński
abstract
Objective: The aim of this work is to investigate the feasibility of the JagiellonianPositron Emission Tomography (J-PET) scanner for intra-treatment proton beamrange monitoring. Approach: The Monte Carlo simulation studies with GATE and PET imagereconstruction with CASToR were performed in order to compare six J-PET scannergeometries (three dual-heads and three cylindrical). We simulated proton irradiationof a PMMA phantom with a Single Pencil Beam (SPB) and Spread-Out BraggPeak (SOBP) of various ranges. The sensitivity and precision of each scanner werecalculated, and considering the setup?s cost-effectiveness, we indicated potentiallyoptimal geometries for the J-PET scanner prototype dedicated to the proton beamrange assessment. Main results: The investigations indicate that the double-layer cylindrical andtriple-layer double-head configurations are the most promising for clinical application.We found that the scanner sensitivity is of the order of 10?5coincidences per primaryproton, while the precision of the range assessment for both SPB and SOBP irradiationplans was found below 1 mm. Among the scanners with the same number of detectormodules, the best results are found for the triple-layer dual-head geometry. Significance: We performed simulation studies demonstrating that the feasibilityof the J-PET detector for PET-based proton beam therapy range monitoring ispossible with reasonable sensitivity and precision enabling its pre-clinical tests in theclinical proton therapy environment. Considering the sensitivity, precision and cost-effectiveness, the double-layer cylindrical and triple-layer dual-head J-PET geometryconfigurations seem promising for the future clinical application. Experimental testsare needed to confirm these findings.
Feasibility studies for imaging e+e- annihilation with modular multi-strip detectors
S. Sharma, L. Povolo, S. Mariazzi, G. Korcyl, K. Kacprzak, D. Kumar, S. Niedzwiecki, J. Baran, E. Beyene, R. S. Brusa, R. Caravita, N. Chug, A. Coussat, C. Curceanu, E. Czerwinski, M. Dadgar, M. Das, K. Dulski, K. Eliyan, A. Gajos, N. Gupta, B. C. Hiesmayr, L. Kaplon, T. Kaplanoglu, K. Klimaszewski, P. Konieczka, T. Kozik, M. K. Kozani, W. Krzemien, S. Moyo, W. Mryka, L. Penasa, S. Parzych, E. Perez Del Rio, L. Raczynski, R. Y. Shopa, M. Skurzok, E. L. Stepien, P. Tanty, F. Tayefi, K. Tayefi, W. Wislicki, P. Moskal
abstract
Studies based on imaging the annihilation of the electron (e-) and its antiparticle positron (e+) open up several interesting applications in nuclear medicine and fundamental research. The annihilation process involves both the direct conversion of ee into photons and the formation of their atomically bound state, the positronium atom (Ps), which can be used as a probe for fundamental studies. With the ability to produce large quantities of Ps, manipulate them in long-lived Ps states, and image their annihilations after a free fall or after passing through atomic interferometers, this purely leptonic antimatter system can be used to perform inertial sensing studies in view of a direct test of Einstein equivalence principle. It is envisioned that modular multistrip detectors can be exploited as potential detection units for this kind of studies. In this work, we report the results of the first feasibility study performed on a e beamline using two detection modules to evaluate their reconstruction performance and spatial resolution for imaging ee annihilations and thus their applicability for gravitational studies of Ps.
First positronium image of the human brain in vivo
P. Moskal, J. Baran, S. Bass, J. Choiński, N. Chug, C. Curceanu, E. Czerwiński, M. Dadgar, M. Das, K. Dulski, K.V. Eliyan, K. Fronczewska, A. Gajos, K. Kacprzak, M. Kajetanowicz, T. Kaplanoglu, Ł. Kapłon, K. Klimaszewski, M. Kobylecka, G. Korcyl, T. Kozik, W. Krzemień, K. Kubat, D. Kumar, J. Kunikowska, J. Mączewska, W. Migdał, G. Moskal, W. Mryka, S. Niedźwiecki, S. Parzych, E. Perez del Rio, L. Raczyński, S. Sharma, Shivani, R.Y. Shopa, M. Silarski, M. Skurzok, F. Tayefi, K. Tayefi, P. Tanty, W. Wiślicki, L. Królicki, E. Ł. Stępień
abstract
Positronium, an unstable atom consisting of an electron and a positron, is abundantly produced within the molecular voids of a patient?s body during positron emission tomography (PET) diagnosis. Its properties, such as its average lifetime between formation and annihilation into photons, dynamically respond to the submolecular architecture of the tissue and the partial pressure of oxygen molecules. However, the diagnostic information that positronium may deliver about early molecular alterations remains unavailable in clinics with state-of-the-art PET scanners.
This study presents the first in vivo images of positronium lifetime in humans. We developed a dedicated J-PET system with multiphoton detection capability for imaging. The measurements of positronium lifetime were performed on a patient with a glioblastoma tumor in the brain. The patient was injected intratumorally with the 68Ga radionuclide attached to Substance-P, which accumulates in glioma cells, and intravenously with 68Ga attached to the PSMA-11 ligand, which is selective to glioma cells and salivary glands. The 68Ga radionuclide is routinely used in PET for detecting radiopharmaceutical accumulation and was applied for positronium imaging because it can emit an additional prompt gamma. The prompt gamma enables the determination of the time of positronium formation, while the photons from positronium annihilation were used to reconstruct the place and time of its decay. The determined positronium mean lifetime in glioblastoma cells is shorter than in salivary glands, which in turn is shorter than in healthy brain tissues, demonstrating for the first time that positronium imaging can be used to diagnose disease in vivo. This study also demonstrates that if current total-body PET systems were equipped with multiphoton detection capability and the 44Sc radionuclide was applied, it would be possible to perform positronium imaging at 6500 times greater sensitivity than achieved in this research. Therefore, it is anticipated that positronium imaging has the potential to bring a new quality of cancer diagnosis in clinics.
Discrete symmetries tested at 10^-4 precision using linear polarization of photons from positronium annihilations
P. Moskal, E. Czerwiński, J. Raj, S. D. Bass, E. Beyene, N. Chug, A. Coussat, C. Curceanu, M. Dadgar, M. Das, K. Dulski, A. Gajos, M. Gorgol, B. C. Hiesmayr, B. Jasińska, K. Kacprzak, T. Kaplanoglu, Ł. Kapłon, K. Klimaszewski, P. Konieczka, G. Korcyl, T. Kozik, W. Krzemień, D. Kumar, S. Moyo, W. Mryka, S. Niedźwiecki, S. Parzych, E. Pérez del Río, L. Raczyński, S. Sharma, S. Choudhary, R. Y. Shopa, M. Silarski, M. Skurzok, E. Ł. Stępień, P. Tanty, F. T. Ardebili, K. T. Ardebili, K. V. Eliyan, W. Wiślicki
abstract
Discrete symmetries play an important role in particle physics with violation of CP connected to the matter-antimatter imbalance in the Universe. We report the most precise test of P, T and CP invariance in decays of ortho-positronium, performed with methodology involving polarization of photons from these decays. Positronium, the simplest bound state of an electron and positron, is of recent interest with discrepancies reported between measured hyperfine energy structure and theory at the level of 10^-4 signaling a need for better understanding of the positronium system at this level. We test discrete symmetries using photon polarizations determined via Compton scattering in the dedicated J-PET tomograph on an event-by-event basis and without the need to control the spin of the positronium with an external magnetic field, in contrast to previous experiments. Our result is consistent with QED expectations at the level of 0.0007 and one standard deviation.
First Simultaneous K-p -> Sigma0 pi0, Lambda0 pi0 Cross Sections Measurements at 98 MeV/c
K. Piscicchia, M. Skurzok, M. Cargnelli, R. Del Grande, L. Fabbietti, J. Marton, P. Moskal, A. Scordo, A. Ramos, D. L. Sirghi, O. Vazquez Doce, J. Zmeskal, S. Wycech, P. Branchini, F. Ceradini, E. Czerwinski, E. De Lucia, S. Fiore, A. Kupsc, G. Mandaglio, M. Martini, A. Passeri, V. Patera, E. Perez Del Rio, A. Selce, M. Silarski and C. Curceanu
abstract
We report the first simultaneous and independent measurements of the K-p -> Sigma0 pi0 and K-p -> Lambda0 pi0 cross sections around 100 MeV/c kaon momentum. The kaon beam delivered by the DAFNE collider was exploited to detect K- absorptions on Hydrogen atoms, populating the gas mixture of the KLOE drift chamber. The precision of the measurements sigma_{K-p -> Sigma0 pi0} =42.8 +-1.5(stat:)+2.4-2.0(syst:) mb and sigma_{K-p -> Lambda0 pi0}= 31.0 +- 0.5(stat:)+1.2-1.2(syst:) mb is the highest
yet obtained in the low kaon momentum regime.
Comparative studies of the sensitivities of sparse and full geometries of Total-Body PET scanners built from crystals and plastic scintillators
M. Dadgar, S. Parzych, J. Baran, N. Chug, C. Curceanu, E. Czerwiński, K. Dulski, K. Elyan, A. Gajos, B.C. Hiesmayr, Ł. Kapłon, K. Klimaszewski, P. Konieczka, G. Korcyl, T. Kozik, W. Krzemień, D. Kumar, S. Niedźwiecki, D. Panek, E. Perez del Rio, L. Raczyński, S. Sharma, Shivani, R.Y. Shopa, M. Skurzok, E. L. Stępień, F. Tayefi Ardebili, K. Tayefi Ardebili, S. Vandenberghe, W. Wiślicki and P. Moskal
abstract
Background: Alongside the benefits of Total-Body imaging modalities, such as higher sensitivity, single-bed position, low dose imaging, etc., their final construction cost prevents worldwide utilization. The main aim of this study is to present a simulation-based comparison of the sensitivities of existing and currently developed tomographs to introduce a cost-efficient solution for
constructing a Total-Body PET scanner based on plastic scintillators.
Methods: For the case of this study, eight tomographs based on the uEXPLORER configuration with different scintillator materials (BGO, LYSO), axial field-of-view (97.4 cm and 194.8 cm), and detector configuration (full and sparse) were simulated. In addition, 8 J-PET scanners with different configurations, such as various axial field-of-view (200 cm and 250 cm), the different cross-sections of plastic scintillator, and the multiple numbers of the
plastic scintillator layers (2, 3, and 4), based on J-PET technology have been simulated by GATE software. Furthermore, Biograph Vision has been simulated to compare the results with standard PET scans. Two types of simulations have been performed. The first one with a centrally located source with a diameter of 1mm and a length of 250 cm, and the second one with the same source inside a water-filled cylindrical phantom with a diameter of 20 cm and a length of 183 cm.
Results: With regards to sensitivity, among all the proposed scanners, the ones constructed with BGO crystals give the best performance (? 350 cps/kBq at the center). The utilization of sparse geometry or LYSO crystals significantly lowers the achievable sensitivity of such systems. The J-PET design gives a similar sensitivity to the sparse LYSO crystal-based detectors while having full detector coverage over the body. Moreover, it provides uniform sensitivity over the body
with additional gain on its sides and provides the possibility for high-quality brain
imaging.
Conclusion: Taking into account not only the sensitivity but also the price of the Total-Body PET tomographs, which till now was one of the main obstacles in their widespread clinical availability, the J-PET tomography system based on plastic scintillators could be a cost-efficient alternative for Total-Body PET scanners.
Direct tests of T, CP, CPT symmetries in transitions of neutral K mesons with the KLOE experiment
D. Babusci, M. Berłowski, C. Bloise, F. Bossi, P. Branchini, B. Cao, F. Ceradini, P. Ciambrone, F. Curciarello, E. Czerwiński, G. D'Agostini, R. D'Amico, E. Dane, V. De Leo, E. De Lucia, A. De Santis, P. De Simone, A. Di Domenico, E. Diociaiuti, D. Domenici, A. D'Uffizi, G. Fantini, A. Gajos, S. Gamrat, P. Gauzzi, S. Giovannella, E. Graziani, X. Kang, A. Kupść, G. Mandaglio, M. Martini, S. Miscetti, P. Moskal, A. Passeri, E. Pérez del Río, M. Schioppa, A. Selce, M. Silarski, F. Sirghi, E.P. Solodov, W. Wiślicki, M. Wolke, J. Bernabéu
abstract
Tests of the T, CPand CPTsymmetries in the neutral kaon system are performed by the direct comparison of the probabilities of a kaon transition process to its symmetry-conjugate. The exchange of inand outstates required for a genuine test involving an antiunitary transformation implied by time-reversal is implemented exploiting the entanglement of K0K0 pairs produced at a ?-factory.
A data sample collected by the KLOE experiment at DAFNE corresponding to an integrated luminosity of about 1.7 fb?1 is analysed to study the Dt distributions of the ??KSKL??+????e??and ??KSKL???e??3?0 processes, with Dt the difference of the kaon decay times. A comparison of the measured Dt distributions in the asymptotic region Dt>>t? Sallows to test for the first time T and CPT symmetries in kaon transitions with a precision of few percent, and to observe CP violation with this novel method.
Transformation of PET raw data into images for event classification using convolutional neural networks
P. Konieczka, L. Raczyński, W. Wiślicki, O. Fedoruk, K. Klimaszewski, P. Kopka, W. Krzemień, R.Y. Shopa, J. Baran, A. Coussat, N. Chug, C. Curceanu, E. Czerwiński, M. Dadgar, K. Dulski, A. Gajos, B.C. Hiesmayr, K. Kacprzak, Ł. Kapłon, G. Korcyl, T. Kozik, D. Kumar, S. Niedźwiecki, S. Parzych, E. Pérez del Río, S. Sharma, S. Shivani, M. Skurzok, E.Ł. Stępień, F. Tayefi, P. Moskal
abstract
In positron emission tomography (PET) studies, convolutional neural networks (CNNs) may be applied directly to the reconstructed distribution of radioactive tracers injected into the patient's body, as a pattern recognition tool. Nonetheless, unprocessed PET coincidence data exist in tabular format. This paper develops the transformation of tabular data into -dimensional matrices, as a preparation stage for classification based on CNNs. This method explicitly introduces a nonlinear transformation at the feature engineering stage and then uses principal component analysis to create the images. We apply the proposed methodology to the classification of simulated PET coincidence events originating from NEMA IEC and anthropomorphic XCAT phantom. Comparative studies of neural network architectures, including multilayer perceptron and convolutional networks, were conducted. The developed method increased the initial number of features from 6 to 209 and gave the best precision results (79.8) for all tested neural network architectures; it also showed the smallest decrease when changing the test data to another phantom.
Detection of range shifts in proton beam therapy using the J-PET scanner: a patient simulation study
K. Brzeziński, J. Baran, D. Borys, J. Gajewski, N. Chug, A. Coussat, E. Czerwiński, M. Dadgar, K. Dulski, K.V. Eliyan, A. Gajos, K. Kacprzak, Ł. Kapłon, K. Klimaszewski, P. Konieczka, R. Kopeć, G. Korcyl, T. Kozik, W. Krzemień, D. Kumar, A.J. Lomax, K. McNamara, S. Niedźwiecki, P. Olko, D. Panek, S. Parzych, E. Perez del Rio, L. Raczyński, S. Sharma, Shivani, R.Y. Shopa, T. Skóra, M. Skurzok, P. Stasica, E.Ł. Stępień, K. Tayefi, F. Tayefi, D.C. Weber, C. Winterhalter, W. Wiślicki, P. Moskal, A. Ruciński
abstract
Objective. The Jagiellonian positron emission tomography (J-PET) technology, based on plastic scintillators, has been proposed as a cost effective tool for detecting range deviations during proton therapy. This study investigates the feasibility of using J-PET for range monitoring by means of a detailed Monte Carlo simulation study of 95 patients who underwent proton therapy at the Cyclotron Centre Bronowice (CCB) in Krakow, Poland. Approach. Discrepancies between prescribed and delivered treatments were artificially introduced in the simulations by means of shifts in patient positioning and in the Hounsfield unit to the relative proton stopping power calibration curve. A dual-layer, cylindrical J-PET geometry was simulated in an in-room monitoring scenario and a triple-layer, dual-head geometry in an in-beam protocol. The distribution of range shifts in reconstructed PET activity was visualized in the beam's eye view. Linear prediction models were constructed from all patients in the cohort, using the mean shift in reconstructed PET activity as a predictor of the mean proton range deviation. Main results. Maps of deviations in the range of reconstructed PET distributions showed agreement with those of deviations in dose range in most patients. The linear prediction model showed a good fit, with coefficient of determination r2 = 0.84 (in-room) and 0.75 (in-beam). Residual standard error was below 1 mm: 0.33 mm (in-room) and 0.23 mm (in-beam). Significance. The precision of the proposed prediction models shows the sensitivity of the proposed J-PET scanners to shifts in proton range for a wide range of clinical treatment plans. Furthermore, it motivates the use of such models as a tool for predicting proton range deviations and opens up new prospects for investigations into the use of intra-treatment PET images for predicting clinical metrics that aid in the assessment of the quality of delivered treatment.
Efficiency determination of J-PET: first plastic scintillators-based PET scanner
S. Sharma, J. Baran, N. Chug, C. Curceanu, E. Czerwiński, M. Dadgar, K. Dulski, K. Eliyan, A. Gajos, N. Gupta-Sharma, B. C. Hiesmayr, K. Kacprzak, Ł. Kapłon, K. Klimaszewski, P. Konieczka, G. Korcyl, T. Kozik, W. Krzemień, D. Kumar, Sz. Niedźwiecki, D. Panek, S. Parzych, E. Perez del Rio, L. Raczyński, Shivani, R. Y. Shopa, M. Skurzok, E. Ł. Stępień, F. Tayefi, K. Tayefi , W. Wiślicki and P. Moskal
abstract
Background:
The Jagiellonian Positron Emission Tomograph is the 3-layer prototype
of the first scanner based on plastic scintillators, consisting of 192 half-metre-long strips with readouts at both ends. Compared to crystal-based detectors, plastic scintillators
are several times cheaper and could be considered as a more economical alternative to crystal scintillators in future PETs. JPET is also a first multi-photon PET prototype. For the development of multi-photon detection, with photon characterized by the continuous energy spectrum, it is important to estimate the efficiency of J-PET as a function of energy deposition. The aim of this work is to determine the registration efficiency of the J-PET tomograph as a function of energy deposition by incident photons and the intrinsic efficiency of the J-PET scanner in detecting photons of different incident energies. In this study, 3-hit events are investigated, where 2-hits are caused by 511 keV
photons emitted in e+e- annihilations, while the third hit is caused by one of the scattered photons. The scattered photon is used to accurately measure the scattering angle and thus the energy deposition. Two hits by a primary and a scattered photon are sufficient to calculate the scattering angle of a photon, while the third hit ensures
the precise labeling of the 511 keV photons.
Results:
By comparing experimental and simulated energy distribution spectra, the registration efficiency of the J-PET scanner was determined in the energy deposition range of 70-270 keV, where it varies between 20 and 100%. In addition, the intrinsic efficiency of the J-PET was also determined as a function of the energy of the incident photons.
Conclusion:
A method for determining registration efficiency as a function of energy deposition and intrinsic efficiency as a function of incident photon energy of the J-PET scanner was demonstrated. This study is crucial for evaluating the performance of the scanner based on plastic scintillators and its applications as a standard and multi-photon PET systems. The method may be also used in the calibration of Compton-cameras developed for the ion-beam therapy monitoring and simultaneous multi-radionuclide imaging in nuclear medicine.
J-PET detection modules based on plastic scintillators for performing studies with positron and positronium beams
S. Sharma, J. Baran, R.S. Brusa, R. Caravita, N. Chug, A. Coussat, C. Curceanu, E. Czerwinski, M. Dadgar, K. Dulski, K. Eliyan, A. Gajos, B.C. Hiesmayr, K. Kacprzak, L. Kaplon, K. Klimaszewski, P. Konieczka, G. Korcyl, T. Kozik, W. Krzemien D. Kumar, S. Mariazzi, S. Niedźwiecki, L. Panasa, S. Parzych, L. Povolo, E. Perez del Rio, L. Raczynski Shivani, R.Y. Shopa, M. Skurzok, E.L. Stepien, F. Tayefi, K. Tayefi, W. Wislicki and P. Moskal
abstract
The J-PET detector, which consists of inexpensive plastic scintillators, has demonstrated its potential in the study of fundamental physics. In recent years, a prototype with 192 plastic scintillators arranged in 3 layers has been optimized for the study of positronium decays. This allows performing precision tests of discrete symmetries (C, P, T) in the decays of positronium atoms. Moreover, thanks to the possibility of measuring the polarization direction of the photon based on Compton scattering, the predicted entanglement between the linear polarization of annihilation photons in positronium decays can also be studied. Recently, a new J-PET prototype was commissioned, based on a modular design of detection units. Each module consists of 13 plastic scintillators and can be used as a stand-alone, compact and portable detection unit. In this paper, the main features of the J-PET detector, the modular prototype and their applications for possible studies with positron and positronium beams are discussed. Preliminary results of the first test experiment performed on two detection units in the continuous positron beam recently developed at the Antimatter Laboratory (AML) of Trento are also reported.
Investigation of novel preclinical Total Body PET designed with J-PET technology: A simulation study
M. Dadgar, S. Parzych, F. Tayefi Ardebili, J. Baran, N. Chug, C. Curceanu, E. Czerwiński, K. Dulski, K. Eliyan, A. Gajos, B.C. Hiesmayr, K. Kacprzak, K. Klimaszewski, P. Konieczka, G. Korcyl, T. Kozik, W. Krzemień, D. Kumar, S. Niedźwiecki, D. Panek, E. Perez del Rio, L. Raczyński, S. Sharma, R.Y. Shopa, M. Skurzok, K. Tayefi Ardebili, S. Vandenberghe, W. Wiślicki, E.Ł. Stępień, P. Moskal
abstract
The growing interest in human-grade Total Body PET systems has also application in small animal research. Due to the existing limitations in human-based studies involving drug development and novel treatment monitoring, animalbased research became a necessary step for testing and protocol preparation. In this simulation-based study two unconventional, cost effective small animal Total Body PET scanners (for mouse and rat studies) have been investigated in order to inspect their feasibility for preclinical research. They were designed with the novel technology explored by the Jagiellonian PET Collaboration (J-PET). Two main PET characteristics: sensitivity and spatial resolution were mainly inspected to evaluate their performance. Moreover, the impact of the scintillator dimension and time-offlight on the latter parameter were examined in order to design the most efficient tomographs. The presented results show that for mouse TB J-PET the achievable system sensitivity is equal to 2.35% and volumetric spatial resolution to 9.46 +- 0.54 mm3, while for rat TB J-PET they are equal to 2.6% and 14.11 ? 0.80 mm3, respectively. Furthermore, it was shown that the designed tomographs are almost parallax-free systems, hence they resolve the problem of the acceptance criterion trade-off between enhancing spatial resolution and reducing sensitivity.
ProTheRaMon - a GATE simulation framework for proton therapy range monitoring using PET imaging
D. Borys, J. Baran, K.W. Brzezinski, J. Gajewski, N. Chug, A. Coussat, E. Czerwiński, M. Dadgar, K. Dulski, K. Valsan Eliyan, A. Gajos, K. Kacprzak, Ł. Kapłon, K. Klimaszewski, P. Konieczka, R. Kopec, G. Korcyl, T. Kozik, W. Krzemień, D. Kumar, A. John Lomax, K. McNamara, S. Niedźwiecki, P. Olko, D. Panek, S. Parzych, E. Pérez del Río, L. Raczyński, S. Sharma, S. Shivani, R.Y. Shopa, T. Skóra, M. Skurzok, P. Stasica, E. Stępień, K. Tayefi Ardebili, F. Tayefi, D. Charles Weber, C. Winterhalter, W. Wiślicki, P. Moskal, A. Rucinski
abstract
Objective: This paper reports on the implementation and shows examples of the use of the ProTheRaMon framework for simulating the delivery of proton therapy treatment plans and range monitoring using positron emission tomography (PET). ProTheRaMon offers complete processing of proton therapy treatment plans, patient CT geometries, and intra-treatment PET imaging, taking into account therapy and imaging coordinate systems and activity decay during the PET imaging protocol specific to a given proton therapy facility. We present the ProTheRaMon framework and illustrate its potential use case and data processing steps for a patient treated at the Cyclotron Centre Bronowice (CCB) proton therapy center in Krakow, Poland. Approach: The ProTheRaMon framework is based on GATE Monte Carlo software, the CASToR reconstruction package and in-house developed Python and bash scripts. The framework consists of five separated simulation and data processing steps, that can be further optimized according to the user's needs and specific settings of a given proton therapy facility and PET scanner design. Main results: ProTheRaMon is presented using example data from a patient treated at CCB and the J-PET scanner to demonstrate the application of the framework for proton therapy range monitoring. The output of each simulation and data processing stage is described and visualized. Significance: We demonstrate that the ProTheRaMon simulation platform is a high-performance tool, capable of running on a computational cluster and suitable for multi-parameter studies, with databases consisting of large number of patients, as well as different PET scanner geometries and settings for range monitoring in a clinical environment. Due to its modular structure, the ProTheRaMon framework can be adjusted for different proton therapy centers and/or different PET detector geometries. It is available to the community via github.
Mirror Matter Searches with the J-PET Detector
E. Pérez del Río, W. Krzemień, B. Kłósek
abstract
The positronium system ? a bound state of an electron and a positron ? is suitable for testing the
predictions of quantum electrodynamics, since its properties can be perturbatively calculated to high
accuracy and, unlike the hydrogen system, it is not affected by the finite size or quantum chromodynamics effects at the current level of experimental precision. Experiments searching for invisible decays
of the positronium triplet state ? the ortho-positronium ? which mainly decays to three photons, are
being conducted since they are sensitive to new physics scenarios, e.g., mirror matter, milli-charged
particles, and extra space-time dimensions. The particular case of mirror matter and its search with
the novel total-body positron emission tomography scanner at the Jagiellonian University is presented.
This J-PET is a large, high precision medical imaging tool based on plastic scintillators.
Precision tests of quantum mechanics and CPT symmetry with entangled neutral kaons at KLOE
D. Babusci, M. Berlowski, C. Bloise, F. Bossi, P. Branchini, A. Budano, B. Cao, F. Ceradini, P. Ciambrone, F. Curciarello, E. Czerwiński, G. D'Agostini, E. Dane, V. De Leo, E. De Lucia, A. De Santis, P. De Simone, A. Di Cicco, A. Di Domenico, E. Diociaiuti, D. Domenici, A. D'Uffizi, A. Fantini, G. Fantini, P. Fermani, S. Fiore, A. Gajos, P. Gauzzi, S. Giovannella, E. Graziani, V. L. Ivanov, T. Johansson, X. Kang, D. Kisielewska-Kamińska, E. A. Kozyrev, W. Krzemien, A. Kupsc, P. A. Lukin, G. Mandaglio, M. Martini, R. Messi, S. Miscetti, D. Moricciani, P. Moskal, A. Passeri, V. Patera, E. Perez del Rio, P. Santangelo, M. Schioppa, A. Selce, M. Silarski, F. Sirghi, E. P. Solodov, L. Tortora, G. Venanzoni, W. Wiślicki, M. Wolke
abstract
The quantum interference between the decays of entangled neutral kaons is studied in the process phi -> KSKL -> pi(+)pi(-)pi(+)pi(-), which exhibits the characteristic Einstein-Podolsky-Rosen correlations that prevent both kaons to decay into pi(+)pi(-) at the same time. This constitutes a very powerful tool for testing at the utmost precision the quantum coherence of the entangled kaon pair state, and to search for tiny decoherence and CPT violation effects, which may be justified in a quantum gravity framework.
The analysed data sample was collected with the KLOE detector at DAFNE, the Frascati phi-factory, and corresponds to an integrated luminosity of about 1.7 fb(-1), i.e. to about 1.7 x 10(9) phi -> KSKL decays produced. From the fit of the observed Delta t distribution, being Delta t the difference of the kaon decay times, the decoherence and CPT violation parameters of various phenomenological models are measured with a largely improved accuracy with respect to previous analyses.
The results are consistent with no deviation from quantum mechanics and CPT symmetry, while for some parameters the precision reaches the interesting level at which - in the most optimistic scenarios - quantum gravity effects might show up. They provide the most stringent limits up to date on the considered models.
Upper limit on the eta->pi+pi- branching fraction with the KLOE experiment
D. Babusci, M. Berlowski, C. Bloise, F. Bossi, P. Branchini, A. Budano, B. Cao, F. Ceradini, P. Ciambrone, F. Curciarello, E. Czerwiński, G. D'Agostini, E. Dan?, V. De Leo, E. De Lucia, A. De Santis, P. De Simone, A. Di Cicco, A. Di Domenico, D. Domenici, A. D'Uffizi, A. Fantini, P. Fermani, S. Fiore, A. Gajos, P. Gauzzi, S. Giovannella, E. Graziani, V. L. Ivanov, T. Johansson, X. Kang, D. Kisielewska-Kamińska, E. A. Kozyrev, W. Krzemien, A. Kupsc, P. A. Lukin, G. Mandaglio, M. Martini, R. Messi, S. Miscetti, D. Moricciani, P. Moskal, S. Parzych, A. Passeri, V. Patera, E. Perez del Rio, P. Santangelo, M. Schioppa, A. Selce, M. Silarski, F. Sirghi, E. P. Solodov, L. Tortora, G. Venanzoni, W. Wiślicki, M. Wolke
abstract
Based on an integrated luminosity of 1.61 fb^{-1} e+e- collision data collected with the KLOE detector at DAFNE, the Frascati phi-factory, a search for the P- and CP-violating decay eta->pi+pi- has been performed. Radiative phi->eta gamma decay is exploited to access the eta mesons. No signal is observed in the pi+pi- invariant mass spectrum, and the upper limit on the branching fraction at 90% confidence level is determined to be B(eta->pi+pi-)<4.9x10^{-6}, which is approximately three times smaller than the previous KLOE result. From the combination of these two measurements we get B(eta->pi+pi-)<4.4x10^{-6} at 90% confidence level.
Measurement of the branching fraction for the decay KS -> pi mu nu with the KLOE detector
D. Babusci, M. Berlowski, C. Bloise, F. Bossi, P. Branchini, A. Budano, B. Cao, F. Ceradini, P. Ciambrone, F. Curciarello, E. Czerwisnski, G. D'Agostini, E. Dane, V. De Leo, E. De Lucia, A. De Santis, P. De Simone, A. Di Cicco, A. Di Domenico, D. Domenici, A. D'Uffizi, A. Fantini, P. Fermani, S. Fiore, A. Gajos, P. Gauzzi, S. Giovannella, E. Graziani, V. L. Ivanov, T. Johansson, X. Kang, D. Kisielewska-Kamisnska, E. A. Kozyrev, W. Krzemien, A. Kupsc, P. A. Lukin, G. Mandaglio, M. Martini, R. Messi, S. Miscetti, D. Moricciani, P. Moskal, S. Parzych, A. Passeri, V. Patera, E. Perez del Rio, P. Santangelo, M. Schioppa, A. Selce, M. Silarski, F. Sirghi, E. P. Solodov, L. Tortora, G. Venanzoni, W. Wislicki, M. Wolke
abstract
Based on a sample of 300 million KS mesons produced in phi -> KLKS decays recorded by the KLOE experiment at the DAFNE e+e- collider we have measured the branching fraction for the decay KS -> pi mu nu. The KS mesons are identified by the interaction of KL mesons in the detector. The KS -> pi mu nu decays are selected by a boosted decision tree built with kinematic variables and by a time-of-flight measurement. Signal efficiencies are evaluated with data control samples of KL -> pi mu nu decays. A fit to the reconstructed muon mass distribution finds 7223?180 signal events. Normalising to the KS -> pi+ pi- decay events the result for the branching fraction is B(KS -> pi mu nu) = (4.56+-0.11stat+-0.17syst)×10-4.
Feasibility of Ortho-positronium Lifetime Studies with the J-PET Detector in Context of Mirror Matter Models
W. Krzemien, E. Pérez del Río, K. Kacprzak
abstract
We discuss the possibility to perform the experimental searches for invisible decays in the ortho-positronium system with the J-PET detector.
First measurement of the K-n->Lambda pi- non-resonant transition amplitude below threshold
K. Piscicchia, S. Wycech, L. Fabbietti, M. Cargnelli, C. Curceanu, R. Del Grande, J. Marton, P. Moskal, A. Scordo, M. Silarski, D. Sirghi, M. Skurzok, I. Tucakovic, O. Vazquez Doce, J. Zmeskal, P. Branchini, E. Czerwinski, V. De Leo, E. De Lucia, A. Di Cicco, P. Fermani, S. Fiore, W. Krzemien, G. Mandaglio, M. Martini, E. Perez del Rio , A. Selce
abstract
We present the analysis of K- absorption processes on 4He leading to Lambda pi- final states, measured with the KLOE e+e- spectrometer at the DAFNE collider and extract, for the first time, the modulus of the non-resonant K-n->Lambda pi- direct production amplitude about 33 MeV below the KbarN threshold. This analysis also allows to disentangle the K- nuclear absorption at-rest from the in-flight capture, for K- momenta of about 120 MeV. The data are interpreted with the help of a phenomenological model, and the modulus of the non-resonant K-n->Lambda pi- amplitude for K- absorption at-rest is found to be |A_K-n->Lambda pi-| = (0.334+-0.018(stat.)+0.034 -0.058 (syst.)) fm.
K- absorption on two nucleons and ppK- bound state search in the E0p final state
O. Vazquez Doce, L. Fabbietti, M. Cargnelli, C. Curceanu, J. Marton, K. Piscicchia, A. Scordo, D. Sirghi, I. Tucakovic, S. Wycech, J. Zmeskal, A. Anastasi, F. Curciarello, E. Czerwinski, W. Krzemien, G. Mandaglio, M. Martini, P. Moskal, V. Patera, E. Perez del Rio, M. Silarski
abstract
We report the measurement of K- absorption processes in the Sigma_0p final state and the first exclusive measurement of the two nucleon absorption (2NA) with the KLOE detector. The 2NA process without further interactions is found to be 12% of the sum of all other contributing processes, including absorption on three and more nucleons or 2NA followed by final state interactions with the residual nucleons. We also determine the possible contribution of the ppK- bound state to the ?0p final state. A yield of ppK-/K_stop is found to be (0.044+/-0.009stat+0.004+/-0.005syst)?10?2 but its statistical significance based on an F-test is only 1sigma.
Feasibility studies of Dark Photon searches with the J-PET detector
Justyna Mędrala-Sowa, Elena Perez del Rio, Wojciech Krzemień
abstract
Symposium on new trends in Nuclear and Medical Physics
