Manish Das, Sushil Sharma, E. Beyene, Aleksander Bilewicz, Jarosław Choiński, Neha Chug, Catalina Curceanu, Eryk Czerwiński, Jakub Hajduga, Sharareh Jalali, K. Kacprzak, T. Kaplanoglu, Łukasz Kapłon, Kamila Kasperska, A. 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 Kr. Pandey, Piyush Pandey, S. Parzych, Alessio Porcelli, Bartłomiej Rachwał, Martin Rädler, Narendra Rathod, Noman Razzaq, Axel Rominger, Kuangyu Shi, M. Skurzok, Maciej Słotwiński, Anna Stolarz, Tomasz Szumlak, P. Tanty, Keyvan Tayefi Ardebili, Satyam Tiwari, Kavya Valsan Eliyan, Rafał Walczak, Ewa Ł. Stepień, Paweł Moskal
This study demonstrates the applicability of [Formula: see text]Mn and [Formula: see text]Co 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 [Formula: see text] emitters that also provide an additional prompt γ ray to mark the positron creation time. In this work, we report the first PLI measurements performed with [Formula: see text]Mn and [Formula: see text]Co 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 [Formula: see text] and the mean positron lifetime [Formula: see text] for each sample. The measured values of [Formula: see text] in polycarbonate using both isotopes matches well with the certified reference values. Furthermore, [Formula: see text]Co reproduced identical results for fused-silica measurements at their respective uncertainty levels. In contrast, measurements with [Formula: see text]Mn in fused silica show a minor deviation, which could be caused by the Parafilm spacer. In myxoma and adipose tissue, the reduced [Formula: see text] 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, [Formula: see text]Co provides cleaner PLI data under the same experimental conditions. Although [Formula: see text]Mn offers a longer half-life and a multi gamma cascade enhancing [Formula: see text] + γ 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.