First Positronium Lifetime Imaging using 52Mn and 55Co with a plastic-based PET scanner
Manish Das, Sushil Sharma, Ermias Yitayew Beyene, Aleksander Bilewicz, Jarosław Choiński, Neha Chug, Catalina Curceanu, Eryk Czerwiński, Jakub Hajduga, Sharareh Jalali, Krzysztof Kacprzak, Tevfik Kaplanoglu, Łukasz Kapłon, Kamila Kasperska, Aleksander Khreptak, Grzegorz Korcyl, Tomasz Kozik, Karol Kubat, Deepak Kumar, Sumit Kumar Kundu, Anoop Kunimmal Venadan, Edward Lisowski, Filip Lisowski, Justyna Medrala-Sowa, Simbarashe Moyo, Wiktor Mryka, Szymon Niedźwiecki, Anand Pandey, Piyush Pandey, Szymon Parzych, Alessio Porcelli, Bartłomiej Rachwał, Martin Rädler, Narendra Rathod, Noman Razzaq, Axel Rominger, Kuangyu Shi, Magdalena Skurzok, Maciej Słotwiński, Anna Stolarz, Tomasz Szumlak, Pooja Tanty, Keyvan Tayefi Ardebili, Satyam Tiwari, Kavya Valsan Eliyan, Rafał Walczak, Ewa Ł. Stępień, Paweł Moskal

abstract
This study demonstrates applicability of 52Mn and 55Co radionuclides for positronium imaging. Positronium Lifetime Imaging
(PLI) extends positron emission tomography by using the lifetime of positronium atoms as a probe of tissue molecular
architecture. However, its practical use requires ?+ emitters that also provide an additional prompt ? ray to mark the positron creation time. In this work, we report the first PLI measurements performed with 52Mn and 55Co using the modular J-PET. Four samples were studied in each experiment: two Certified Reference Materials (polycarbonate and fused silica) and two
human tissues (cardiac myxoma and adipose). The selection of PLI events was based on the registration of two 511 keV
annihilation photons and one prompt gamma in triple coincidence. From the resulting lifetime spectra we extracted the mean
ortho-positronium lifetime ?oPs and the mean positron lifetime ?Tmean for each sample. The measured values of ?oPs in
polycarbonate using both isotopes matches well with the certified reference values. Furthermore, 55Co reproduced identical
results for fused-silica measurements at their respective uncertainty levels. In contrast, measurements with 52Mn in fused silica show a minor deviation, which could be caused by the Parafilm spacer. In myxoma and adipose tissue, the reduced ?oPs values are mainly linked to the long storage history of the samples rather than to the choice of isotope. Comparing peak-to-background ratios and spectral purity, 55Co provides cleaner PLI data under the same experimental conditions. Although 52Mn offers a longer half-life and a multi gamma cascade enhancing ?+ + ? coincidences, but at the expense of higher background. In this study, we demonstrate that the applied selection criteria on the data measured with the modular J-PET can be used for PLI studies even with radionuclides with complex decay patterns.
Endorsing Titanium-Scandium Radionuclide Generator for PET and Positronium Imaging
Paweł Moskal, Aleksander Khreptak, Jarosław Choiński, Pete Jones, Ihor Kadenko, Agnieszka Majkowska-Pilip, Rudrajyoti Palit, Anna Stolarz, Rafał Walczak, Ewa Stępień

abstract
The development of PET and positronium imaging techniques is strictly related to the availability of suitable radionuclides and robust radiochemistry platforms. Among the emerging candidates, 44Sc has attracted significant interest due to its favourable physical properties, including a half-life of 4 hours, a pure emission profile, and the additional prompt -emission that enables advanced triple-photon detection schemes. These characteristics make 44Sc particularly promising for highresolution imaging and novel quantitative methodologies. However, routine clinical and preclinical implementation requires a practical, sustainable, and cost-efficient production route. In this context, we propose a titanium-scandium radionuclide generator as an optimal solution. This study focuses on optimising the synthesis of the long-lived parent isotope, 44Ti (T1/2 = 59.1 years), from which 44Sc can be selectively eluted in a chemically pure form when needed. An analysis of various production pathways was conducted, including proton and deuteron reactions on scandium, as well as alpha-particle and lithium-induced reactions on calcium, to determine the most efficient reaction parameters, target design, and expected yield. Furthermore, we identify some existing cyclotron facilities suitable for implementing this technology. Results indicate that efficient Ti production is achievable using proton beams in the 20-30 MeV range under extended irradiation conditions. The proposed generator system would enable routine and decentralised 44Sc supply. Its integration with the novel J-PET scanner may significantly reduce diagnostic costs and improve access to advanced PET imaging in regions with limited medical imaging infrastructure.
First Positronium Imaging Using 44Sc With the J-PET Scanner: a Case Study on the NEMA-Image Quality Phantom
Manish Das, Sushil Sharma, Ermias Yitayew Beyene, Aleksander Bilewicz, Jarosław Choiński, Neha Chug, Catalina Curceanu, Eryk Czerwiński, Kavya Valsan Eliyan, Jakub Hajduga, Sharareh Jalali, Krzysztof Kacprzak, Tevfik Kaplanoglu, Łukasz Kapłon, Kamila Kasperska, Aleksander Khreptak, Grzegorz Korcyl, Tomasz Kozik, Karol Kubat, Deepak Kumar, Anoop Kunimmal Venadan, Edward Lisowski, Filip Lisowski, Justyna Medrala Sowa, Simbarashe Moyo, Wiktor Mryka, Szymon Niedźwiecki, Piyush Pandey, Szymon Parzych, Alessio Porcelli, Bartłomiej Rachwał, Elena Perez del Rio, Martin Rädler, Axel Rominger, Kuangyu Shi, Magdalena Skurzok, Anna Stolarz, Tomasz Szumlak, Pooja Tanty, Keyvan Tayefi Ardebili, Satyam Tiwari, Rafał Walczak, Ewa Ł. Stępień, Paweł Moskal

abstract
Positronium Lifetime Imaging (PLI), an emerging extension of conventional positron emission tomography (PET) imaging, offers a novel window for probing the submolecular properties of biological tissues by imaging the mean lifetime of the positronium atom. Currently, the method is under rapid development in terms of reconstruction and detection systems. Recently, the first in vivo PLI of the human brain was performed using the J-PET scanner utilizing the 68Ga isotope. However, this isotope has limitations due to its comparatively low prompt gamma yields, which is crucial for positronium lifetime measurement. Among alternative radionuclides, 44Sc stands out as a promising isotope for PLI, characterized by a clinically suitable half-life (4.04 hours) emitting 1157 keV prompt gamma in 100% cases after the emission of the positron. This study reports the first experimental demonstration of PLI with 44Sc, carried out on a NEMA-Image Quality (IQ) phantom using the Modular J-PET tomograph?the first plastic scintillators-based PET scanner.
Simulation studies of a brain PET insert for the total body J-PET tomograph
Simulation studies of a brain PET insert for the total body J-PET tomograph M. Rädler, E. Y. Beyene, A. Bilewicz, J. Choiński, N. Chug, C. Curceanu, E. Czerwiński, M. Das, J. Hajduga, S. Jalali, T. Kaplanoglu, Ł. Kapłon, A. Khreptak, G. Korcyl, K. Kubat, D. Kumar, A. Kunimmal Venadan, E. Lisowski, F. Lisowski, J. Mędrala-Sowa, S. Moyo, W. Mryka, S. Niedźwiecki, P. Pandey, S. Parzych, A. Porcelli, B. Rachwał, E. P. d. Río, S. Sharma, M. Skurzok, A. Stolarz, T. Szumlak, S. Tiwari, P. Tanty, K. Tayefi Ardebili, K. Valsan Eliyan, R. Walczak, E. Ł. Stępień, P. Moskal
IEEE NSS MIC RTSD in Yokohama