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Salvadori J, Merlet A, Presles B, Cabello J, Su KH, Cochet A, Etxebeste A, Vrigneaud JM, Sarrut D. PET digitization chain for Monte Carlo simulation in GATE. Phys Med Biol 2024; 69:165013. [PMID: 39009009 DOI: 10.1088/1361-6560/ad638c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Accepted: 07/15/2024] [Indexed: 07/17/2024]
Abstract
Objective. We introduce a versatile methodology for the accurate modelling of PET imaging systems via Monte Carlo simulations, using the Geant4 application for tomographic emission (GATE) platform. Accurate Monte Carlo modelling involves the incorporation of a complete analytical signal processing chain, called the digitizer in GATE, to emulate the different count rates encountered in actual positron emission tomography (PET) systems.Approach. The proposed approach consists of two steps: (1) modelling the digitizer to replicate the detection chain of real systems, covering all available parameters, whether publicly accessible or supplied by manufacturers; (2) estimating the remaining parameters, i.e. background noise level, detection efficiency, and pile-up, using optimisation techniques based on experimental single and prompt event rates. We show that this two-step optimisation reproduces the other experimental count rates (true, scatter, and random), without the need for additional adjustments. This method has been applied and validated with experimental data derived from the NEMA count losses test for three state-of-the-art SiPM-based time-of-flight (TOF)-PET systems: Philips Vereos, Siemens Biograph Vision 600 and GE Discovery MI 4-ring.Main results. The results show good agreement between experiments and simulations for the three PET systems, with absolute relative discrepancies below 3%, 6%, 6%, 7% and 12% for prompt, random, true, scatter and noise equivalent count rates, respectively, within the 0-10 kBq·ml-1activity concentration range typically observed in whole-body18F scans.Significance. Overall, the proposed digitizer optimisation method was shown to be effective in reproducing count rates and NECR for three of the latest generation SiPM-based TOF-PET imaging systems. The proposed methodology could be applied to other PET scanners.
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Affiliation(s)
- Julien Salvadori
- Groupement de Coopération Sanitaire, Institut de Cancérologie Strasbourg Europe (ICANS), Nuclear medicine, Strasbourg, France
| | - Antoine Merlet
- Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB), UMR CNRS 6302, University of Burgundy, Dijon, France
| | - Benoit Presles
- Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB), UMR CNRS 6302, University of Burgundy, Dijon, France
| | - Jorge Cabello
- Siemens Medical Solutions, USA, Inc., Knoxville, TN, United States of America
| | - Kuan-Hao Su
- GE Healthcare, Waukesha, WI, United States of America
| | - Alexandre Cochet
- Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB), UMR CNRS 6302, University of Burgundy, Dijon, France
- Department of Nuclear Medicine, Georges-François Leclerc Cancer Centre, Dijon, France
| | - Ane Etxebeste
- Université de Lyon, CREATIS; CNRS UMR5220, Inserm U1044, INSA-Lyon; Université Lyon 1, Centre Léon Bérard, France
| | - Jean-Marc Vrigneaud
- Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB), UMR CNRS 6302, University of Burgundy, Dijon, France
- Department of Nuclear Medicine, Georges-François Leclerc Cancer Centre, Dijon, France
| | - David Sarrut
- Université de Lyon, CREATIS; CNRS UMR5220, Inserm U1044, INSA-Lyon; Université Lyon 1, Centre Léon Bérard, France
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Merlet A, Presles B, Su KH, Salvadori J, Sayah F, Jozi H, Cochet A, Vrigneaud JM. Validation of a discovery MI 4-ring model according to the NEMA NU 2-2018 standards: from Monte Carlo simulations to clinical-like reconstructions. EJNMMI Phys 2024; 11:13. [PMID: 38294624 PMCID: PMC11266333 DOI: 10.1186/s40658-024-00616-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 01/15/2024] [Indexed: 02/01/2024] Open
Abstract
BACKGROUND We propose a comprehensive evaluation of a Discovery MI 4-ring (DMI) model, using a Monte Carlo simulator (GATE) and a clinical reconstruction software package (PET toolbox). The following performance characteristics were compared with actual measurements according to NEMA NU 2-2018 guidelines: system sensitivity, count losses and scatter fraction (SF), coincidence time resolution (CTR), spatial resolution (SR), and image quality (IQ). For SR and IQ tests, reconstruction of time-of-flight (TOF) simulated data was performed using the manufacturer's reconstruction software. RESULTS Simulated prompt, random, true, scatter and noise equivalent count rates closely matched the experimental rates with maximum relative differences of 1.6%, 5.3%, 7.8%, 6.6%, and 16.5%, respectively, in a clinical range of less than 10 kBq/mL. A 3.6% maximum relative difference was found between experimental and simulated sensitivities. The simulated spatial resolution was better than the experimental one. Simulated image quality metrics were relatively close to the experimental results. CONCLUSIONS The current model is able to reproduce the behaviour of the DMI count rates in the clinical range and generate clinical-like images with a reasonable match in terms of contrast and noise.
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Affiliation(s)
- Antoine Merlet
- Imagerie et Vision artificielle, ImViA EA 7535, University of Burgundy, Dijon, France
| | - Benoît Presles
- Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB), UMR CNRS 6302, University of Burgundy, Dijon, France
| | | | - Julien Salvadori
- ICANS, Institut de cancérologie Strasbourg Europe, Strasbourg, France
| | - Farzam Sayah
- Department of Nuclear Medicine, Georges-François Leclerc Cancer Centre, Dijon, France
| | - Hanieh Jozi
- Department of Nuclear Medicine, Georges-François Leclerc Cancer Centre, Dijon, France
| | - Alexandre Cochet
- Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB), UMR CNRS 6302, University of Burgundy, Dijon, France
- Department of Nuclear Medicine, Georges-François Leclerc Cancer Centre, Dijon, France
| | - Jean-Marc Vrigneaud
- Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB), UMR CNRS 6302, University of Burgundy, Dijon, France.
- Department of Nuclear Medicine, Georges-François Leclerc Cancer Centre, Dijon, France.
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Kalaitzidis P, Gustafsson J, Hindorf C, Ljungberg M. Monte Carlo investigation of PET [ 68Ga]Ga-DOTA-TOC activity-administration protocols for consistent image quality. Heliyon 2023; 9:e19504. [PMID: 37681181 PMCID: PMC10480678 DOI: 10.1016/j.heliyon.2023.e19504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 08/24/2023] [Accepted: 08/24/2023] [Indexed: 09/09/2023] Open
Abstract
One example of a PET exam that suffers from noise problems is [68Ga]Ga-DOTA-TOC, where patients are generally administered between 100 and 200 MBq [68Ga]Ga-DOTA-TOC, irrespective of size. However, a fixed activity can result in low signal-to-noise ratios (SNRs) in larger patients. This study aimed to evaluate the impact on image quality with respect to injected activity and patient habitus through Monte Carlo (MC) simulation. Eight anthropomorphic computer phantoms with body mass indices (BMIs) between 19 kg/m2 and 38 kg/m2 and tumours distributed in the liver were simulated using the MC software Gate v8.2 with an activity distribution defined according to [68Ga]Ga-DOTA-TOC standardised uptake values. Three activity-administration protocols were simulated: (i) with a fixed activity of 100 MBq, (ii) with the activity scaled by 2 MBq/kg, and (iii) with the activity scaled by a body size-dependent power-function based on the SNR obtained with (ii). BMI, weight, body surface area, and abdominal circumference were evaluated body size parameters. Images were reconstructed with the CASToR software and evaluated for background SNR and lesion contrast-to-noise ratio (CNR). Large SNR variabilities were obtained with protocols (i) and (ii), while (iii) generated good consistency. Several tumours failed to reach a CNR of 5 for large phantoms with protocol (i), but the CNR was generally improved by (ii) and (iii). An activity scaled by patient habitus generate better image quality consistency, which increases the likelihood that patients receive a similar standard of care.
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Affiliation(s)
| | | | - Cecilia Hindorf
- Medical Radiation Physics, Lund, Lund University, Lund, Sweden
- Department of Medical Radiation Physics and Nuclear Medicine, Karolinska University Hospital, Solna, Stockholm, Sweden
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Sarrut D, Arbor N, Baudier T, Borys D, Etxebeste A, Fuchs H, Gajewski J, Grevillot L, Jan S, Kagadis GC, Kang HG, Kirov A, Kochebina O, Krzemien W, Lomax A, Papadimitroulas P, Pommranz C, Roncali E, Rucinski A, Winterhalter C, Maigne L. The OpenGATE ecosystem for Monte Carlo simulation in medical physics. Phys Med Biol 2022; 67:10.1088/1361-6560/ac8c83. [PMID: 36001985 PMCID: PMC11149651 DOI: 10.1088/1361-6560/ac8c83] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 08/24/2022] [Indexed: 11/12/2022]
Abstract
This paper reviews the ecosystem of GATE, an open-source Monte Carlo toolkit for medical physics. Based on the shoulders of Geant4, the principal modules (geometry, physics, scorers) are described with brief descriptions of some key concepts (Volume, Actors, Digitizer). The main source code repositories are detailed together with the automated compilation and tests processes (Continuous Integration). We then described how the OpenGATE collaboration managed the collaborative development of about one hundred developers during almost 20 years. The impact of GATE on medical physics and cancer research is then summarized, and examples of a few key applications are given. Finally, future development perspectives are indicated.
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Affiliation(s)
- David Sarrut
- Université de Lyon; CREATIS; CNRS UMR5220; Inserm U1294; INSA-Lyon; Université Lyon 1, Léon Bérard cancer center, Lyon, France
| | - Nicolas Arbor
- Université de Strasbourg, IPHC, CNRS, UMR7178, F-67037 Strasbourg, France
| | - Thomas Baudier
- Université de Lyon; CREATIS; CNRS UMR5220; Inserm U1294; INSA-Lyon; Université Lyon 1, Léon Bérard cancer center, Lyon, France
| | - Damian Borys
- Department of Systems Biology and Engineering, Silesian University of Technology, Gliwice, Poland
| | - Ane Etxebeste
- Université de Lyon; CREATIS; CNRS UMR5220; Inserm U1294; INSA-Lyon; Université Lyon 1, Léon Bérard cancer center, Lyon, France
| | - Hermann Fuchs
- MedAustron Ion Therapy Center, Wiener Neustadt, Austria
- Medical University of Vienna, Department of Radiation Oncology, Vienna, Vienna, Währinger Gürtel 18-20, A-1090 Wien, Austria
| | - Jan Gajewski
- Institute of Nuclear Physics Polish Academy of Sciences, Krakow, Poland
| | | | - Sébastien Jan
- Université Paris-Saclay, Inserm, CNRS, CEA, Laboratoire d'Imagerie Biomédicale Multimodale (BioMaps), F-91401 Orsay, France
| | - George C Kagadis
- 3DMI Research Group, Department of Medical Physics, School of Medicine, University of Patras, Patras, Greece
| | - Han Gyu Kang
- National Institutes for Quantum Science and Technology (QST), 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Assen Kirov
- Memorial Sloan Kettering Cancer, New York, NY 10021, United States of America
| | - Olga Kochebina
- Université Paris-Saclay, Inserm, CNRS, CEA, Laboratoire d'Imagerie Biomédicale Multimodale (BioMaps), F-91401 Orsay, France
| | - Wojciech Krzemien
- High Energy Physics Division, National Centre for Nuclear Research, Otwock-Świerk, Poland
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, S. Lojasiewicza 11, 30-348 Krakow, Poland
- Centre for Theranostics, Jagiellonian University, Kopernika 40 St, 31 501 Krakow, Poland
| | - Antony Lomax
- Center for Proton Therapy, PSI, Switzerland
- Department of Physics, ETH Zurich, Switzerland
| | | | - Christian Pommranz
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tuebingen, Roentgenweg 13, D-72076 Tuebingen, Germany
- Institute for Astronomy and Astrophysics, Eberhard Karls University Tuebingen, Sand 1, D-72076 Tuebingen, Germany
| | - Emilie Roncali
- University of California Davis, Departments of Biomedical Engineering and Radiology, Davis, CA 95616, United States of America
| | - Antoni Rucinski
- Institute of Nuclear Physics Polish Academy of Sciences, Krakow, Poland
| | - Carla Winterhalter
- Center for Proton Therapy, PSI, Switzerland
- Department of Physics, ETH Zurich, Switzerland
| | - Lydia Maigne
- Université Clermont Auvergne, Laboratoire de Physique de Clermont, CNRS, UMR 6533, F-63178 Aubière, France
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