Author Contributions: David Pérez Benito was responsible for the conception of the study, data analysis, writing, editing and reviewing. R. Chil contributed equally to this publication as responsible of the experimental section, data analysis, editing and reviewing. J.M. Udias also contributed to the data analysis. All authors were responsible for editing and reviewing. Contribution of this paper is partially included in Chapter 2. -D. Pérez-Benito, R. Chil, L.A. Hidalgo-Torres, J.J. Vaquero. "Geometrical considerations on hexagonal SiPM". IEEE Transactions on Radiation and Plasma Medical Sciences, 2022. (This paper is admitted at PSMR-TBP 2022 9th Conference on PET/MR and SPECT/MR & Total-body PET workshop and it will be published in a special issue).Author Contributions: David Pérez Benito was responsible for the conception of the study, data analysis, writing, editing and reviewing. R. Chil also contributed to the conception of the study and experimental setup. All authors were responsible for editing and reviewing. Contribution of this paper is partially included in Chapter 3.