Monte Carlo simulation of the system performance of a long axial field-of-view PET based on monolithic LYSO detectors

EJNMMI Physics

Original Research

Meysam Dadgar¹  Stefaan Vandenberghe¹  Maya Abi-Akl²  Othmane Bouhali³  Yassine Toufique⁴ 

[1] Department of Electronics and Information Systems, Medical Image and Signal Processing, Ghent University, Ghent, Belgium;Department of Electronics and Information Systems, Medical Image and Signal Processing, Ghent University, Ghent, Belgium;Division of Arts and Sciences, Texas A&M University at Qatar, Doha, Qatar;Division of Arts and Sciences, Texas A&M University at Qatar, Doha, Qatar;Energy, Materials, Numerical Physics, Ecole Normal Supérieur (ENS), Abdelmalek Essaadi University, Tétouan, Morocco;

关键词: Total-body positron emission tomography;    Monolithic detector;    Spatial resolution;    NEMA performance;   

DOI  :  10.1186/s40658-023-00559-2

 received in 2023-02-02, accepted in 2023-06-05,  发布年份 2023

来源: Springer

【 摘 要 】

BackgroundIn light of the milestones achieved in PET design so far, further sensitivity improvements aim to optimise factors such as the dose, throughput, and detection of small lesions. While several longer axial field-of-view (aFOV) PET systems based on pixelated detectors have been installed, continuous monolithic scintillation detectors recently gained increased attention due to their depth of interaction capability and superior intrinsic resolution. As a result, the aim of this work is to present and evaluate the performance of two long aFOV, monolithic LYSO-based PET scanner designs.MethodsGeant4 Application for Tomographic Emission (GATE) v9.1 was used to perform the simulations. Scanner designs A and B have an aFOV of 36.2 cm (7 rings) and 72.6 cm (14 rings), respectively, with 40 detector modules per ring each and a bore diameter of 70 cm. Each module is a 50 × 50 × 16 mm3 monolithic LYSO crystal. Sensitivity, noise equivalent count rate (NECR), scatter fraction, spatial resolution, and image quality tests were performed based on NEMA NU-2018 standards.ResultsThe sensitivity of design A was calculated to be 29.2 kcps/MBq at the centre and 27 kcps/MBq at 10 cm radial offset; similarly, the sensitivity of design B was found to be 106.8 kcps/MBq and 98.3 kcps/MBq at 10 cm radial offset. NECR peaks were reached at activity concentrations beyond the range of activities used for clinical studies. In terms of spatial resolution, the values for the point sources were below 2 mm for the radial, tangential, and axial full width half maximum. The contrast recovery coefficient ranged from 53% for design B and 4:1 contrast ratio to 90% for design A and 8:1 ratio, with a reasonably low background variability.ConclusionsLonger aFOV PET designs using monolithic LYSO have superior spatial resolution compared to current pixelated total-body PET (TB-PET) scanners. These systems combine high sensitivity with improved contrast recovery.

【 授权许可】

CC BY   
© The Author(s) 2023

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