A Monte Carlo detector response model for the IRIS PET preclinical scanner

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Manuscript Number: EJMP-D-18-00292R2

Title: A Monte Carlo detector response model for the IRIS PET preclinical scanner

Article Type: Technical note

Keywords: PET; image reconstruction; Monte Carlo simulation; system model; detector response

Corresponding Author: Mr. Alessandro Pilleri, M.D. Corresponding Author's Institution: University of Pisa First Author: Alessandro Pilleri, M.D.

Order of Authors: Alessandro Pilleri, M.D.; Niccolò Camarlinghi, PhD; Alberto Del Guerra, PhD; Giancarlo Sportelli, PhD; Nicola Belcari, PhD Abstract: PET preclinical studies require high spatial resolution due to the limited size of the animal under investigation. To achieve this target, iterative image reconstruction algorithms are commonly preferred over the analytical methods because they offer the possibility of

accurately modeling the whole imaging process. In this work, we propose an accurate factorized system matrix for the INVISCAN IRIS preclinical PET scanner to be used with an iterative algorithm. The model includes two components: the geometric component and the detector response of the system. The main innovative aspect of the work is the creation of the detector matrix using a Monte Carlo simulation, with a particular focus on the optimization of the simulation process to reduce the calculation time. The new system model is compared with the current IRIS model to evaluate the image quality, following the NEMA Standards NU 4 - 2008. The comparison showed an enhancement of the image quality, in terms of

uniformity and recovery coefficients. This work confirms that the inclusion of the detector response into the system model leads to improved reconstruction results.

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1 mm

Geometric Multiray Factorized

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