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Dadgar M, Maebe J, Vandenberghe S. Evaluation of lesion contrast in the walk-through long axial FOV PET scanner simulated with XCAT anthropomorphic phantoms. EJNMMI Phys 2024; 11:44. [PMID: 38722428 PMCID: PMC11082126 DOI: 10.1186/s40658-024-00645-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 05/02/2024] [Indexed: 05/12/2024] Open
Abstract
BACKGROUND This study evaluates the lesion contrast in a cost-effective long axial field of view (FOV) PET scanner, called the walk-through PET (WT-PET). The scanner consists of two flat detector panels covering the entire torso and head, scanning patients in an upright position for increased throughput. High-resolution, depth-of-interaction capable, monolithic detector technology is used to provide good spatial resolution and enable detection of smaller lesions. METHODS Monte Carlo GATE simulations are used in conjunction with XCAT anthropomorphic phantoms to evaluate lesion contrast in lung, liver and breast for various lesion diameters (10, 7 and 5 mm), activity concentration ratios (8:1, 4:1 and 2:1) and patient BMIs (18-37). Images were reconstructed iteratively with listmode maximum likelihood expectation maximization, and contrast recovery coefficients (CRCs) were obtained for the reconstructed lesions. RESULTS Results shows notable variations in contrast recovery coefficients (CRC) across different lesion sizes and organ locations within the XCAT phantoms. Specifically, our findings reveal that 10 mm lesions consistently exhibit higher CRC compared to 7 mm and 5 mm lesions, with increases of approximately 54% and 330%, respectively, across all investigated organs. Moreover, high contrast recovery is observed in most liver lesions regardless of diameter or activity ratio (average CRC = 42%), as well as in the 10 mm lesions in the lung. Notably, for the 10 mm lesions, the liver demonstrates 42% and 62% higher CRC compared to the lung and breast, respectively. This trend remains consistent across lesion sizes, with the liver consistently exhibiting higher CRC values compared to the lung and breast: 7 mm lesions show an increase of 96% and 41%, while 5 mm lesions exhibit approximately 294% and 302% higher CRC compared to the lung and breast, respectively. CONCLUSION A comparison with a conventional pixelated LSO long axial FOV PET shows similar performance, achieved at a reduced cost for the WT-PET due to a reduction in required number of detectors.
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Affiliation(s)
- Meysam Dadgar
- Department of Electronics and Information Systems, Medical Image and Signal Processing, Ghent University, C. Heymanslaan 10, Ghent, Belgium.
| | - Jens Maebe
- Department of Electronics and Information Systems, Medical Image and Signal Processing, Ghent University, C. Heymanslaan 10, Ghent, Belgium
| | - Stefaan Vandenberghe
- Department of Electronics and Information Systems, Medical Image and Signal Processing, Ghent University, C. Heymanslaan 10, Ghent, Belgium
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Muller FM, Vervenne B, Maebe J, Blankemeyer E, Sellmyer MA, Zhou R, Karp JS, Vanhove C, Vandenberghe S. Image Denoising of Low-Dose PET Mouse Scans with Deep Learning: Validation Study for Preclinical Imaging Applicability. Mol Imaging Biol 2024; 26:101-113. [PMID: 37875748 DOI: 10.1007/s11307-023-01866-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 10/09/2023] [Accepted: 10/12/2023] [Indexed: 10/26/2023]
Abstract
PURPOSE Positron emission tomography (PET) image quality can be improved by higher injected activity and/or longer acquisition time, but both may often not be practical in preclinical imaging. Common preclinical radioactive doses (10 MBq) have been shown to cause deterministic changes in biological pathways. Reducing the injected tracer activity and/or shortening the scan time inevitably results in low-count acquisitions which poses a challenge because of the inherent noise introduction. We present an image-based deep learning (DL) framework for denoising lower count micro-PET images. PROCEDURES For 36 mice, a 15-min [18F]FDG (8.15 ± 1.34 MBq) PET scan was acquired at 40 min post-injection on the Molecubes β-CUBE (in list mode). The 15-min acquisition (high-count) was parsed into smaller time fractions of 7.50, 3.75, 1.50, and 0.75 min to emulate images reconstructed at 50, 25, 10, and 5% of the full counts, respectively. A 2D U-Net was trained with mean-squared-error loss on 28 high-low count image pairs. RESULTS The DL algorithms were visually and quantitatively compared to spatial and edge-preserving denoising filters; the DL-based methods effectively removed image noise and recovered image details much better while keeping quantitative (SUV) accuracy. The largest improvement in image quality was seen in the images reconstructed with 10 and 5% of the counts (equivalent to sub-1 MBq or sub-1 min mouse imaging). The DL-based denoising framework was also successfully applied on the NEMA-NU4 phantom and different tracer studies ([18F]PSMA, [18F]FAPI, and [68 Ga]FAPI). CONCLUSION Visual and quantitative results support the superior performance and robustness in image denoising of the implemented DL models for low statistics micro-PET. This offers much more flexibility in optimizing preclinical, longitudinal imaging protocols with reduced tracer doses or shorter durations.
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Affiliation(s)
- Florence M Muller
- Medical Image and Signal Processing (MEDISIP), Department of Electronics and Information Systems, Faculty of Engineering and Architecture, Ghent University, 9000, Ghent, Belgium.
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA19104, USA.
| | - Boris Vervenne
- Medical Image and Signal Processing (MEDISIP), Department of Electronics and Information Systems, Faculty of Engineering and Architecture, Ghent University, 9000, Ghent, Belgium
| | - Jens Maebe
- Medical Image and Signal Processing (MEDISIP), Department of Electronics and Information Systems, Faculty of Engineering and Architecture, Ghent University, 9000, Ghent, Belgium
| | - Eric Blankemeyer
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA19104, USA
| | - Mark A Sellmyer
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA19104, USA
| | - Rong Zhou
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA19104, USA
| | - Joel S Karp
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA19104, USA
| | - Christian Vanhove
- Medical Image and Signal Processing (MEDISIP), Department of Electronics and Information Systems, Faculty of Engineering and Architecture, Ghent University, 9000, Ghent, Belgium
| | - Stefaan Vandenberghe
- Medical Image and Signal Processing (MEDISIP), Department of Electronics and Information Systems, Faculty of Engineering and Architecture, Ghent University, 9000, Ghent, Belgium
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Dadgar M, Maebe J, Abi Akl M, Vervenne B, Vandenberghe S. A simulation study of the system characteristics for a long axial FOV PET design based on monolithic BGO flat panels compared with a pixelated LSO cylindrical design. EJNMMI Phys 2023; 10:75. [PMID: 38036794 PMCID: PMC10689648 DOI: 10.1186/s40658-023-00593-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 11/07/2023] [Indexed: 12/02/2023] Open
Abstract
BACKGROUND Although a new generation of tomographs with a longer axial field-of-view called total-body PET have been developed, they are not widely utilized due to their high cost compared to conventional scanners. The newly designed walk-through total-body PET scanner is introduced as a high-throughput and cost-efficient alternative to total-body PET scanners, by making use of a flat panel geometry and lower cost, depth-of-interaction capable, monolithic BGO detectors. The main aim of the presented study is to evaluate through Monte Carlo simulation the system characteristics of the walk-through total-body PET scanner by comparing it with a Quadra-like total-body PET of similar attributes to the Siemens Biograph Vision Quadra. METHODS The walk-through total-body PET is comprised of two flat detector panels, spaced 50 cm apart. Each panel, 70 [Formula: see text] 106 cm[Formula: see text] in size, consists of 280 BGO-based monolithic detectors. The Quadra-like TB-PET has been simulated based on the characteristics of the Biograph Vision Quadra, one of the most common total-body PET scanners with 106 cm of axial field-of-view, which is constructed with pixelated LSO scintillation crystals. The spatial resolution, sensitivity, count rate performance, scatter fractions, and image quality of both scanners are simulated in the GATE simulation toolkit for comparison. RESULTS Due to the DOI-capable detectors used in the walk-through total-body PET, the values of the spatial resolution of this scanner were all below 2 mm along directions parallel to the panels, and reached a maximum of 3.36 mm in the direction perpendicular to the panels. This resolution is a large improvement compared to the values of the Quadra-like TB-PET. The walk-through total-body PET uses its maximum sensitivity (154 cps/kBq) for data acquisition and image reconstruction. CONCLUSION Based on the combination of very good spatial resolution and high sensitivity of the walk-through total-body PET, along with a 2.2 times lower scintillation crystal volume and 1.8 times lower SiPM surface, this scanner can be a very cost-efficient alternative for total-body PET scanners in cases where concomitant CT is not required.
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Affiliation(s)
- Meysam Dadgar
- Department of Electronics and Information Systems, Medical Image and Signal Processing, Ghent University, C. Heymanslaan 10, Ghent, Belgium.
| | - Jens Maebe
- Department of Electronics and Information Systems, Medical Image and Signal Processing, Ghent University, C. Heymanslaan 10, Ghent, Belgium
| | - Maya Abi Akl
- Department of Electronics and Information Systems, Medical Image and Signal Processing, Ghent University, C. Heymanslaan 10, Ghent, Belgium
- Division of Arts and Sciences, Texas A&M University at Qatar, Doha, Qatar
| | - Boris Vervenne
- Department of Electronics and Information Systems, Medical Image and Signal Processing, Ghent University, C. Heymanslaan 10, Ghent, Belgium
| | - Stefaan Vandenberghe
- Department of Electronics and Information Systems, Medical Image and Signal Processing, Ghent University, C. Heymanslaan 10, Ghent, Belgium
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Dadgar M, Parzych S, Baran J, Chug N, Curceanu C, Czerwiński E, Dulski K, Elyan K, Gajos A, Hiesmayr BC, Kapłon Ł, Klimaszewski K, Konieczka P, Korcyl G, Kozik T, Krzemien W, Kumar D, Niedzwiecki S, Panek D, Perez Del Rio E, Raczyński L, Sharma S, Shivani S, Shopa RY, Skurzok M, Stepień EŁ, Tayefi Ardebili F, Tayefi Ardebili K, Vandenberghe S, Wiślicki W, Moskal P. Comparative studies of the sensitivities of sparse and full geometries of Total-Body PET scanners built from crystals and plastic scintillators. EJNMMI Phys 2023; 10:62. [PMID: 37819578 PMCID: PMC10567620 DOI: 10.1186/s40658-023-00572-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 08/08/2023] [Indexed: 10/13/2023] Open
Abstract
BACKGROUND Alongside the benefits of Total-Body imaging modalities, such as higher sensitivity, single-bed position, low dose imaging, etc., their final construction cost prevents worldwide utilization. The main aim of this study is to present a simulation-based comparison of the sensitivities of existing and currently developed tomographs to introduce a cost-efficient solution for constructing a Total-Body PET scanner based on plastic scintillators. METHODS For the case of this study, eight tomographs based on the uEXPLORER configuration with different scintillator materials (BGO, LYSO), axial field-of-view (97.4 cm and 194.8 cm), and detector configurations (full and sparse) were simulated. In addition, 8 J-PET scanners with different configurations, such as various axial field-of-view (200 cm and 250 cm), different cross sections of plastic scintillator, and multiple numbers of plastic scintillator layers (2, 3, and 4), based on J-PET technology have been simulated by GATE software. Furthermore, Siemens' Biograph Vision has been simulated to compare the results with standard PET scans. Two types of simulations have been performed. The first one with a centrally located source with a diameter of 1 mm and a length of 250 cm, and the second one with the same source inside a water-filled cylindrical phantom with a diameter of 20 cm and a length of 183 cm. RESULTS With regards to sensitivity, among all the proposed scanners, the ones constructed with BGO crystals give the best performance ([Formula: see text] 350 cps/kBq at the center). The utilization of sparse geometry or LYSO crystals significantly lowers the achievable sensitivity of such systems. The J-PET design gives a similar sensitivity to the sparse LYSO crystal-based detectors while having full detector coverage over the body. Moreover, it provides uniform sensitivity over the body with additional gain on its sides and provides the possibility for high-quality brain imaging. CONCLUSION Taking into account not only the sensitivity but also the price of Total-Body PET tomographs, which till now was one of the main obstacles in their widespread clinical availability, the J-PET tomography system based on plastic scintillators could be a cost-efficient alternative for Total-Body PET scanners.
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Affiliation(s)
- M Dadgar
- Department of Experimental Particle Physics and Applications, Faculty of Physics, Astronomy, and Applied Computer Science, Jagiellonian University, Kraków, Poland.
- Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, Kraków, Poland.
| | - S Parzych
- Department of Experimental Particle Physics and Applications, Faculty of Physics, Astronomy, and Applied Computer Science, Jagiellonian University, Kraków, Poland
- Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, Kraków, Poland
| | - J Baran
- Department of Experimental Particle Physics and Applications, Faculty of Physics, Astronomy, and Applied Computer Science, Jagiellonian University, Kraków, Poland
- Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, Kraków, Poland
| | - N Chug
- Department of Experimental Particle Physics and Applications, Faculty of Physics, Astronomy, and Applied Computer Science, Jagiellonian University, Kraków, Poland
- Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, Kraków, Poland
| | - C Curceanu
- INFN, Laboratori Nazionali di Frascati, Frascati, Italy
| | - E Czerwiński
- Department of Experimental Particle Physics and Applications, Faculty of Physics, Astronomy, and Applied Computer Science, Jagiellonian University, Kraków, Poland
- Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, Kraków, Poland
| | - K Dulski
- Department of Experimental Particle Physics and Applications, Faculty of Physics, Astronomy, and Applied Computer Science, Jagiellonian University, Kraków, Poland
- Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, Kraków, Poland
| | - K Elyan
- Department of Experimental Particle Physics and Applications, Faculty of Physics, Astronomy, and Applied Computer Science, Jagiellonian University, Kraków, Poland
- Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, Kraków, Poland
| | - A Gajos
- Department of Experimental Particle Physics and Applications, Faculty of Physics, Astronomy, and Applied Computer Science, Jagiellonian University, Kraków, Poland
- Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, Kraków, Poland
| | - B C Hiesmayr
- Faculty of Physics, University of Vienna, Vienna, Austria
| | - Ł Kapłon
- Department of Experimental Particle Physics and Applications, Faculty of Physics, Astronomy, and Applied Computer Science, Jagiellonian University, Kraków, Poland
- Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, Kraków, Poland
| | - K Klimaszewski
- Department of Complex Systems, National Centre for Nuclear Research, Otwock-Świerk, Poland
| | - P Konieczka
- Department of Complex Systems, National Centre for Nuclear Research, Otwock-Świerk, Poland
| | - G Korcyl
- Department of Experimental Particle Physics and Applications, Faculty of Physics, Astronomy, and Applied Computer Science, Jagiellonian University, Kraków, Poland
- Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, Kraków, Poland
| | - T Kozik
- Department of Experimental Particle Physics and Applications, Faculty of Physics, Astronomy, and Applied Computer Science, Jagiellonian University, Kraków, Poland
| | - W Krzemien
- High Energy Physics Division, National Centre for Nuclear Research, Otwock-Świerk, Poland
| | - D Kumar
- Department of Experimental Particle Physics and Applications, Faculty of Physics, Astronomy, and Applied Computer Science, Jagiellonian University, Kraków, Poland
- Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, Kraków, Poland
| | - S Niedzwiecki
- Department of Experimental Particle Physics and Applications, Faculty of Physics, Astronomy, and Applied Computer Science, Jagiellonian University, Kraków, Poland
- Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, Kraków, Poland
| | - D Panek
- Department of Experimental Particle Physics and Applications, Faculty of Physics, Astronomy, and Applied Computer Science, Jagiellonian University, Kraków, Poland
- Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, Kraków, Poland
| | - E Perez Del Rio
- Department of Experimental Particle Physics and Applications, Faculty of Physics, Astronomy, and Applied Computer Science, Jagiellonian University, Kraków, Poland
- Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, Kraków, Poland
| | - L Raczyński
- Department of Complex Systems, National Centre for Nuclear Research, Otwock-Świerk, Poland
| | - S Sharma
- Department of Experimental Particle Physics and Applications, Faculty of Physics, Astronomy, and Applied Computer Science, Jagiellonian University, Kraków, Poland
- Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, Kraków, Poland
| | - S Shivani
- Department of Experimental Particle Physics and Applications, Faculty of Physics, Astronomy, and Applied Computer Science, Jagiellonian University, Kraków, Poland
- Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, Kraków, Poland
| | - R Y Shopa
- Department of Complex Systems, National Centre for Nuclear Research, Otwock-Świerk, Poland
| | - M Skurzok
- Department of Experimental Particle Physics and Applications, Faculty of Physics, Astronomy, and Applied Computer Science, Jagiellonian University, Kraków, Poland
- Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, Kraków, Poland
| | - E Ł Stepień
- Department of Experimental Particle Physics and Applications, Faculty of Physics, Astronomy, and Applied Computer Science, Jagiellonian University, Kraków, Poland
- Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, Kraków, Poland
- Theranostics Center, Jagiellonian University, Kraków, Poland
| | - F Tayefi Ardebili
- Department of Experimental Particle Physics and Applications, Faculty of Physics, Astronomy, and Applied Computer Science, Jagiellonian University, Kraków, Poland
- Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, Kraków, Poland
| | - K Tayefi Ardebili
- Department of Experimental Particle Physics and Applications, Faculty of Physics, Astronomy, and Applied Computer Science, Jagiellonian University, Kraków, Poland
- Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, Kraków, Poland
| | - S Vandenberghe
- Department of Electronics and Information Systems, MEDISIP, MEDISIP, Ghent University-IBiTech, Ghent, Belgium
| | - W Wiślicki
- Department of Complex Systems, National Centre for Nuclear Research, Otwock-Świerk, Poland
| | - P Moskal
- Department of Experimental Particle Physics and Applications, Faculty of Physics, Astronomy, and Applied Computer Science, Jagiellonian University, Kraków, Poland.
- Total-Body Jagiellonian-PET Laboratory, Jagiellonian University, Kraków, Poland.
- Theranostics Center, Jagiellonian University, Kraków, Poland.
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Vandenberghe S, Muller FM, Withofs N, Dadgar M, Maebe J, Vervenne B, Akl MA, Xue S, Shi K, Sportelli G, Belcari N, Hustinx R, Vanhove C, Karp JS. Walk-through flat panel total-body PET: a patient-centered design for high throughput imaging at lower cost using DOI-capable high-resolution monolithic detectors. Eur J Nucl Med Mol Imaging 2023; 50:3558-3571. [PMID: 37466650 PMCID: PMC10547652 DOI: 10.1007/s00259-023-06341-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 07/07/2023] [Indexed: 07/20/2023]
Abstract
PURPOSE Long axial field-of-view (LAFOV) systems have a much higher sensitivity than standard axial field-of-view (SAFOV) PET systems for imaging the torso or full body, which allows faster and/or lower dose imaging. Despite its very high sensitivity, current total-body PET (TB-PET) throughput is limited by patient handling (positioning on the bed) and often a shortage of available personnel. This factor, combined with high system costs, makes it hard to justify the implementation of these systems for many academic and nearly all routine nuclear medicine departments. We, therefore, propose a novel, cost-effective, dual flat panel TB-PET system for patients in upright standing positions to avoid the time-consuming positioning on a PET-CT table; the walk-through (WT) TB-PET. We describe a patient-centered, flat panel PET design that offers very efficient patient throughput and uses monolithic detectors (with BGO or LYSO) with depth-of-interaction (DOI) capabilities and high intrinsic spatial resolution. We compare system sensitivity, component costs, and patient throughput of the proposed WT-TB-PET to a SAFOV (= 26 cm) and a LAFOV (= 106 cm) LSO PET systems. METHODS Patient width, height (= top head to start of thighs) and depth (= distance from the bed to front of patient) were derived from 40 randomly selected PET-CT scans to define the design dimensions of the WT-TB-PET. We compare this new PET system to the commercially available Siemens Biograph Vision 600 (SAFOV) and Siemens Quadra (LAFOV) PET-CT in terms of component costs, system sensitivity, and patient throughput. System cost comparison was based on estimating the cost of the two main components in the PET system (Silicon Photomultipliers (SiPMs) and scintillators). Sensitivity values were determined using Gate Monte Carlo simulations. Patient throughput times (including CT and scout scan, patient positioning on bed and transfer) were recorded for 1 day on a Siemens Vision 600 PET. These timing values were then used to estimate the expected patient throughput (assuming an equal patient radiotracer injected activity to patients and considering differences in system sensitivity and time-of-flight information) for WT-TB-PET, SAFOV and LAFOV PET. RESULTS The WT-TB-PET is composed of two flat panels; each is 70 cm wide and 106 cm high, with a 50-cm gap between both panels. These design dimensions were justified by the patient sizes measured from the 40 random PET-CT scans. Each panel consists of 14 × 20 monolithic BGO detector blocks that are 50 × 50 × 16 mm in size and are coupled to a readout with 6 × 6 mm SiPMs arrays. For the WT-TB-PET, the detector surface is reduced by a factor of 1.9 and the scintillator volume by a factor of 2.2 compared to LAFOV PET systems, while demonstrating comparable sensitivity and much better uniform spatial resolution (< 2 mm in all directions over the FOV). The estimated component cost for the WT-TB-PET is 3.3 × lower than that of a 106 cm LAFOV system and only 20% higher than the PET component costs of a SAFOV. The estimated maximum number of patients scanned on a standard 8-h working day increases from 28 (for SAFOV) to 53-60 (for LAFOV in limited/full acceptance) to 87 (for the WT-TB-PET). By scanning faster (more patients), the amount of ordered activity per patient can be reduced drastically: the WT-TB-PET requires 66% less ordered activity per patient than a SAFOV. CONCLUSIONS We propose a monolithic BGO or LYSO-based WT-TB-PET system with DOI measurements that departs from the classical patient positioning on a table and allows patients to stand upright between two flat panels. The WT-TB-PET system provides a solution to achieve a much lower cost TB-PET approaching the cost of a SAFOV system. High patient throughput is increased by fast patient positioning between two vertical flat panel detectors of high sensitivity. High spatial resolution (< 2 mm) uniform over the FOV is obtained by using DOI-capable monolithic scintillators.
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Affiliation(s)
- Stefaan Vandenberghe
- Medical Image and Signal Processing, Department of Electronics and Information Systems, Faculty of Engineering and Architecture, Ghent University, Corneel Heymanslaan 10, 9000, Ghent, Belgium.
| | - Florence M Muller
- Medical Image and Signal Processing, Department of Electronics and Information Systems, Faculty of Engineering and Architecture, Ghent University, Corneel Heymanslaan 10, 9000, Ghent, Belgium
| | - Nadia Withofs
- Division of Nuclear Medicine and Oncological Imaging, Department of Medical Physics, CHU of Liege, Quartier Hôpital, Avenue de Hôpital, 1, 4000, Liège 1, Belgium
| | - Meysam Dadgar
- Medical Image and Signal Processing, Department of Electronics and Information Systems, Faculty of Engineering and Architecture, Ghent University, Corneel Heymanslaan 10, 9000, Ghent, Belgium
| | - Jens Maebe
- Medical Image and Signal Processing, Department of Electronics and Information Systems, Faculty of Engineering and Architecture, Ghent University, Corneel Heymanslaan 10, 9000, Ghent, Belgium
| | - Boris Vervenne
- Medical Image and Signal Processing, Department of Electronics and Information Systems, Faculty of Engineering and Architecture, Ghent University, Corneel Heymanslaan 10, 9000, Ghent, Belgium
| | - Maya Abi Akl
- Medical Image and Signal Processing, Department of Electronics and Information Systems, Faculty of Engineering and Architecture, Ghent University, Corneel Heymanslaan 10, 9000, Ghent, Belgium
| | - Song Xue
- Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Kuangyu Shi
- Division of Nuclear Medicine and Oncological Imaging, Department of Medical Physics, CHU of Liege, Quartier Hôpital, Avenue de Hôpital, 1, 4000, Liège 1, Belgium
| | - Giancarlo Sportelli
- Dipartimento Di Fisica "E. Fermi", Università Di Pisa, Italy and with the Instituto Nazionale Di Fisica Nucleare, Sezione Di Pisa, 56127, Pisa, Italy
| | - Nicola Belcari
- Dipartimento Di Fisica "E. Fermi", Università Di Pisa, Italy and with the Instituto Nazionale Di Fisica Nucleare, Sezione Di Pisa, 56127, Pisa, Italy
| | - Roland Hustinx
- Division of Nuclear Medicine and Oncological Imaging, Department of Medical Physics, CHU of Liege, Quartier Hôpital, Avenue de Hôpital, 1, 4000, Liège 1, Belgium
| | - Christian Vanhove
- Medical Image and Signal Processing, Department of Electronics and Information Systems, Faculty of Engineering and Architecture, Ghent University, Corneel Heymanslaan 10, 9000, Ghent, Belgium
| | - Joel S Karp
- Physics and Instrumentation, Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
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Muller FM, Maebe J, Vanhove C, Vandenberghe S. Dose reduction and image enhancement in micro-CT using deep learning. Med Phys 2023; 50:5643-5656. [PMID: 36994779 DOI: 10.1002/mp.16385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 02/14/2023] [Accepted: 03/09/2023] [Indexed: 03/31/2023] Open
Abstract
BACKGROUND In preclinical settings, micro-computed tomography (CT) provides a powerful tool to acquire high resolution anatomical images of rodents and offers the advantage to in vivo non-invasively assess disease progression and therapy efficacy. Much higher resolutions are needed to achieve scale-equivalent discriminatory capabilities in rodents as those in humans. High resolution imaging however comes at the expense of increased scan times and higher doses. Specifically, with preclinical longitudinal imaging, there are concerns that dose accumulation may affect experimental outcomes of animal models. PURPOSE Dose reduction efforts under the ALARA (as low as reasonably achievable) principles are thus a key point of attention. However, low dose CT acquisitions inherently induce higher noise levels which deteriorate image quality and negatively impact diagnostic performance. Many denoising techniques already exist, and deep learning (DL) has become increasingly popular for image denoising, but research has mostly focused on clinical CT with limited studies conducted on preclinical CT imaging. We investigate the potential of convolutional neural networks (CNN) for restoring high quality micro-CT images from low dose (noisy) images. The novelty of the CNN denoising frameworks presented in this work consists of utilizing image pairs with realistic CT noise present in the input as well as the target image used for the model training; a noisier image acquired with a low dose protocol is matched to a less noisy image acquired with a higher dose scan of the same mouse. METHODS Low and high dose ex vivo micro-CT scans of 38 mice were acquired. Two CNN models, based on a 2D and 3D four-layer U-Net, were trained with mean absolute error (30 training, 4 validation and 4 test sets). To assess denoising performance, ex vivo mice and phantom data were used. Both CNN approaches were compared to existing methods, like spatial filtering (Gaussian, Median, Wiener) and iterative total variation image reconstruction algorithm. Image quality metrics were derived from the phantom images. A first observer study (n = 23) was set-up to rank overall quality of differently denoised images. A second observer study (n = 18) estimated the dose reduction factor of the investigated 2D CNN method. RESULTS Visual and quantitative results show that both CNN algorithms exhibit superior performance in terms of noise suppression, structural preservation and contrast enhancement over comparator methods. The quality scoring by 23 medical imaging experts also indicates that the investigated 2D CNN approach is consistently evaluated as the best performing denoising method. Results from the second observer study and quantitative measurements suggest that CNN-based denoising could offer a 2-4× dose reduction, with an estimated dose reduction factor of about 3.2 for the considered 2D network. CONCLUSIONS Our results demonstrate the potential of DL in micro-CT for higher quality imaging at low dose acquisition settings. In the context of preclinical research, this offers promising future prospects for managing the cumulative severity effects of radiation in longitudinal studies.
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Affiliation(s)
- Florence M Muller
- Medical Image and Signal Processing (MEDISIP), Department of Electronics and Information Systems, Faculty of Engineering and Architecture, Ghent University, Ghent, Belgium
| | - Jens Maebe
- Medical Image and Signal Processing (MEDISIP), Department of Electronics and Information Systems, Faculty of Engineering and Architecture, Ghent University, Ghent, Belgium
| | - Christian Vanhove
- Medical Image and Signal Processing (MEDISIP), Department of Electronics and Information Systems, Faculty of Engineering and Architecture, Ghent University, Ghent, Belgium
| | - Stefaan Vandenberghe
- Medical Image and Signal Processing (MEDISIP), Department of Electronics and Information Systems, Faculty of Engineering and Architecture, Ghent University, Ghent, Belgium
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Abi-Akl M, Dadgar M, Toufique Y, Bouhali O, Vandenberghe S. Monte Carlo simulation of the system performance of a long axial field-of-view PET based on monolithic LYSO detectors. EJNMMI Phys 2023; 10:37. [PMID: 37311926 DOI: 10.1186/s40658-023-00559-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 06/05/2023] [Indexed: 06/15/2023] Open
Abstract
BACKGROUND In 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. METHODS Geant4 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. RESULTS The 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. CONCLUSIONS Longer 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.
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Affiliation(s)
- Maya Abi-Akl
- 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.
| | - Meysam Dadgar
- Department of Electronics and Information Systems, Medical Image and Signal Processing, Ghent University, Ghent, Belgium
| | - Yassine Toufique
- Energy, Materials, Numerical Physics, Ecole Normal Supérieur (ENS), Abdelmalek Essaadi University, Tétouan, Morocco
| | - Othmane Bouhali
- Division of Arts and Sciences, Texas A&M University at Qatar, Doha, Qatar
| | - Stefaan Vandenberghe
- Department of Electronics and Information Systems, Medical Image and Signal Processing, Ghent University, Ghent, Belgium
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Vandenberghe S, Karakatsanis NA, Akl MA, Maebe J, Surti S, Dierckx RA, Pryma DA, Nehmeh SA, Bouhali O, Karp JS. The potential of a medium-cost long axial FOV PET system for nuclear medicine departments. Eur J Nucl Med Mol Imaging 2023; 50:652-660. [PMID: 36178535 DOI: 10.1007/s00259-022-05981-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 09/19/2022] [Indexed: 01/24/2023]
Abstract
PURPOSE Total body positron emission tomography (TB-PET) has recently been introduced in nuclear medicine departments. There is a large interest in these systems, but for many centers, the high acquisition cost makes it very difficult to justify their current operational budget. Here, we propose medium-cost long axial FOV scanners as an alternative. METHODS Several medium-cost long axial FOV designs are described with their advantages and drawbacks. We describe their potential for higher throughput, more cost-effective scanning, a larger group of indications, and novel research opportunities. The wider spread of TB-PET can also lead to the fast introduction of new tracers (at a low dose), new methodologies, and optimized workflows. CONCLUSIONS A medium-cost TB-PET would be positioned between the current standard PET-CT and the full TB-PET systems in investment but recapitulate most advantages of full TB-PET. These systems could be more easily justified financially in a standard academic or large private nuclear medicine department and still have ample research options.
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Affiliation(s)
- Stefaan Vandenberghe
- Medical Image and Signal Processing, Ghent University, Corneel Heymans Laan 10, 9000, Ghent, Belgium.
| | | | - Maya Abi Akl
- Medical Image and Signal Processing, Ghent University, Corneel Heymans Laan 10, 9000, Ghent, Belgium
- Science Program, Texas A&M University at Qatar, Doha, Qatar
| | - Jens Maebe
- Medical Image and Signal Processing, Ghent University, Corneel Heymans Laan 10, 9000, Ghent, Belgium
| | - Suleman Surti
- Department of Radiology, University of Pennsylvania, Philadelphia, USA
| | - Rudi A Dierckx
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Daniel A Pryma
- Department of Radiology, University of Pennsylvania, Philadelphia, USA
| | - Sadek A Nehmeh
- Weill Cornell Medical College, Cornell University, NY, USA
| | | | - Joel S Karp
- Department of Radiology, University of Pennsylvania, Philadelphia, USA
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Maebe J, Vandenberghe S. Effect of detector geometry and surface finish on Cerenkov based time estimation in monolithic BGO detectors. Phys Med Biol 2023; 68. [PMID: 36595325 DOI: 10.1088/1361-6560/acabfd] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022]
Abstract
Objective.Time-of-flight positron emission tomography based on bismuth germanate (BGO) detectors is made possible due to fast emission of Cerenkov light. Only around 17 Cerenkov photons are produced per 511 keV photoelectric event, making high photon collection efficiency crucial for obtaining good time-of-flight capabilities. In this study, we investigate how different lateral and back surface finishes affect the photon collection efficiency and Cerenkov based timing performance in monolithic BGO.Approach.The study is performed using GATE for gamma and optical photon modeling, with surface reflections of photons simulated by the LUT Davis model. We compare for different detector configurations (regarding size and surface finishes) the photon collection efficiency, detection delays of the first few optical photons and coincidence time resolution estimations obtained by modeling the SiPM signals and performing leading edge discrimination. An additional comparison is made to LYSO scintillators and pixelated detectors.Main results.Although Cerenkov photon emission is directional, many high incidence angle Cerenkov photons are emitted due to electron scattering in the crystal. Substituting a polished back (photodetector side) surface for a rough surface increases the collection efficiency of these high angle of incidence photons. Results show that for a monolithic 50 × 50 × 12 mm3BGO detector with reflective side surfaces, this leads to an overall increase in photon collection efficiency of 34%. Cerenkov photon collection efficiency is also improved, resulting in a reduction of the photon detection delays (and the variation therein) of the first few optical photons. This leads to a better coincidence time resolution, primarily achieved by a shortening of the tails in the time-of-flight kernel, with an 18% reduction in full width at tenth maximum.Significance.This study shows the importance of the photon collection efficiency for timing performance in Cerenkov based monolithic detectors, and how it can be improved with different surface finishes.
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Affiliation(s)
- Jens Maebe
- Department of Electronics and Information Systems, Ghent University, Ghent, Belgium
| | - Stefaan Vandenberghe
- Department of Electronics and Information Systems, Ghent University, Ghent, Belgium
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Vandenberghe S. DETECTORS FOR NEXT GENERATION PET AND SPECT. Phys Med 2022. [DOI: 10.1016/s1120-1797(22)02114-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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Maebe J, Vandenberghe S. Simulation study on 3D convolutional neural networks for time-of-flight prediction in monolithic PET detectors using digitized waveforms. Phys Med Biol 2022; 67. [DOI: 10.1088/1361-6560/ac73d3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 05/26/2022] [Indexed: 11/12/2022]
Abstract
Abstract
Objective. We investigate the use of 3D convolutional neural networks for gamma arrival time estimation in monolithic scintillation detectors. Approach. The required data is obtained by Monte Carlo simulation in GATE v8.2, based on a 50 × 50 × 16 mm3 monolithic LYSO crystal coupled to an 8 × 8 readout array of silicon photomultipliers (SiPMs). The electronic signals are simulated as a sum of bi-exponentional functions centered around the scintillation photon detection times. We include various effects of statistical fluctuations present in non-ideal SiPMs, such as dark counts and limited photon detection efficiency. The data was simulated for two distinct overvoltages of the SensL J-Series 60 035 SiPMs, in order to test the effects of different SiPM parameters. The neural network uses the array of detector waveforms, digitized at 10 GS s−1, to predict the time at which the gamma arrived at the crystal. Main results. Best results were achieved for an overvoltage of +6 V, at which point the SiPM reaches its optimal photon detection efficiency, resulting in a coincidence time resolution (CTR) of 141 ps full width at half maximum (FWHM). It is a 26% improvement compared to a simple averaging of the first few SiPM timestamps obtained by leading edge discrimination, which in comparison produced a CTR of 177 ps FWHM. In addition, better detector uniformity was achieved, although some degradation near the corners did remain. Significance. These improvements in time resolution can lead to higher signal-to-noise ratios in time-of-flight positron emission tomography, ultimately resulting in better diagnostic capabilities.
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Muller FM, Vanhove C, Vandeghinste B, Vandenberghe S. Performance evaluation of a micro-CT system for laboratory animal imaging with iterative reconstruction capabilities. Med Phys 2022; 49:3121-3133. [PMID: 35170057 DOI: 10.1002/mp.15538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 01/22/2022] [Accepted: 02/07/2022] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND In recent years, there has been a rapid proliferation in micro-computed tomography (micro-CT) systems becoming more available for routine preclinical research, with applications in many areas including bone, lung, cancer and cardiac imaging. Micro-CT provides the means to non-invasively acquire detailed anatomical information, but high-resolution imaging comes at the cost of longer scan times and higher doses, which is not desirable given the potential risks related to x-ray radiation. To achieve dose reduction and higher throughputs without compromising image quality (noise management), fewer projections can be acquired. This is where iterative reconstruction methods can have the potential to reduce noise since these algorithms can better handle sparse projection data, compared to filtered backprojection PURPOSE: We evaluate the performance characteristics of a compact benchtop micro-CT scanner that provides iterative reconstruction capabilities with GPU-based acceleration. More specifically, we thereby investigate the potential benefit of iterative reconstruction methods for dose reduction. METHODS Based on a series of phantom experiments, the benchtop micro-CT system was characterized in terms of image uniformity, noise, low contrast detectability, linearity and spatial resolution. Whole-body images of a plasticized ex vivo mouse phantom were also acquired. Different acquisition protocols (general-purpose versus high-resolution, including low dose scans) and different reconstruction strategies (analytic versus iterative algorithms: FDK, ISRA, ISRA-TV) were compared. RESULTS Signal uniformity was maintained across the radial and axial field-of-view (no cupping effect) with an average difference in Hounsfield units (HU) between peripheral and central regions below 50. For low contrast detectability, regions with at least ∆HU of 40 to surrounding material could be discriminated (for rods of 2.5 mm diameter). A high linear correlation (R2 = 0.997) was found between measured CT values and iodine concentrations (0-40 mg/ml). Modulation transfer function (MTF) calculations on a wire phantom evaluated a resolution of 10.2 lp/mm at 10% MTF that was consistent with the 8.3% MTF measured on the 50 μm bars (10 lp/mm) of a bar-pattern phantom. Noteworthy changes in signal-to-noise and contrast-to-noise values were found for different acquisition and reconstruction protocols. Our results further showed the potential of iterative reconstruction methods to deliver images with less noise and artefacts. CONCLUSIONS In summary, the micro-CT system for laboratory animal imaging that was evaluated in the present work was shown to provide a good combination of performance characteristics between image uniformity, low contrast detectability and resolution in short scan times. With the iterative reconstruction capabilities of this micro-CT system in mind (ISRA and ISRA-TV), the adoption of such algorithms by GPU-based acceleration enables the integration of noise reduction methods which here demonstrated potential for high quality imaging at reduced doses. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Florence M Muller
- MEDISIP-INFINITY, Department of Electronics and Information Systems, Faculty of Engineering and Architecture, Ghent University, Ghent, 9000, Belgium
| | - Christian Vanhove
- MEDISIP-INFINITY, Department of Electronics and Information Systems, Faculty of Engineering and Architecture, Ghent University, Ghent, 9000, Belgium
| | | | - Stefaan Vandenberghe
- MEDISIP-INFINITY, Department of Electronics and Information Systems, Faculty of Engineering and Architecture, Ghent University, Ghent, 9000, Belgium
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Dadgar M, Parzych S, Ardebili FT, Baran J, Chug N, Curceanu C, Czerwinski E, Dulski K, Eliyan K, Gajos A, Hiesmayr B, Kacprzak K, Kaplon L, Klimaszewski K, Konieczka P, Korcyl G, Kozik T, Krzemien W, Kumar D, Niedzwiecki S, Panek D, del Rio EP, Raczynski L, Sharma S, Shivani, Shopa R, Skurzok M, Ardebili KT, Vandenberghe S, Wislicki W, Stepien E, Moskal P. Investigation of novel preclinical Total Body PET designed with J-PET technology: A simulation study. IEEE Trans Radiat Plasma Med Sci 2022. [DOI: 10.1109/trpms.2022.3211780] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- M. Dadgar
- Faculty of Physics, Astronomy, and Applied Computer Science and Center for Theranostics, Jagiellonian University, Kraków, Poland
| | - S. Parzych
- Faculty of Physics, Astronomy, and Applied Computer Science and Center for Theranostics, Jagiellonian University, Kraków, Poland
| | - F. Tayefi Ardebili
- Faculty of Physics, Astronomy, and Applied Computer Science and Center for Theranostics, Jagiellonian University, Kraków, Poland
| | - J. Baran
- Faculty of Physics, Astronomy, and Applied Computer Science and Center for Theranostics, Jagiellonian University, Kraków, Poland
| | - N. Chug
- Faculty of Physics, Astronomy, and Applied Computer Science and Center for Theranostics, Jagiellonian University, Kraków, Poland
| | - C. Curceanu
- Laboratori Nazionali di Frascati, INFN, Frascati, Italy
| | - E. Czerwinski
- Faculty of Physics, Astronomy, and Applied Computer Science and Center for Theranostics, Jagiellonian University, Kraków, Poland
| | - K. Dulski
- Faculty of Physics, Astronomy, and Applied Computer Science and Center for Theranostics, Jagiellonian University, Kraków, Poland
| | - K. Eliyan
- Faculty of Physics, Astronomy, and Applied Computer Science and Center for Theranostics, Jagiellonian University, Kraków, Poland
| | - A. Gajos
- Faculty of Physics, Astronomy, and Applied Computer Science and Center for Theranostics, Jagiellonian University, Kraków, Poland
| | - B.C. Hiesmayr
- Faculty of Physics, University of Vienna, Vienna, Austria
| | - K. Kacprzak
- Faculty of Physics, Astronomy, and Applied Computer Science and Center for Theranostics, Jagiellonian University, Kraków, Poland
| | - L. Kaplon
- Faculty of Physics, Astronomy, and Applied Computer Science and Center for Theranostics, Jagiellonian University, Kraków, Poland
| | - K. Klimaszewski
- Department of Complex Systems, National Centre for Nuclear Research, Otwock-Świerk, Poland
| | - P. Konieczka
- Department of Complex Systems, National Centre for Nuclear Research, Otwock-Świerk, Poland
| | - G. Korcyl
- Faculty of Physics, Astronomy, and Applied Computer Science and Center for Theranostics, Jagiellonian University, Kraków, Poland
| | - T. Kozik
- Faculty of Physics, Astronomy, and Applied Computer Science and Center for Theranostics, Jagiellonian University, Kraków, Poland
| | - W. Krzemien
- High Energy Physics Division, National Centre for Nuclear Research, Otwock-Świerk, Poland
| | - D. Kumar
- Faculty of Physics, Astronomy, and Applied Computer Science and Center for Theranostics, Jagiellonian University, Kraków, Poland
| | - S. Niedzwiecki
- Faculty of Physics, Astronomy, and Applied Computer Science and Center for Theranostics, Jagiellonian University, Kraków, Poland
| | - D. Panek
- Faculty of Physics, Astronomy, and Applied Computer Science and Center for Theranostics, Jagiellonian University, Kraków, Poland
| | - E. Perez del Rio
- Faculty of Physics, Astronomy, and Applied Computer Science and Center for Theranostics, Jagiellonian University, Kraków, Poland
| | - L. Raczynski
- Department of Complex Systems, National Centre for Nuclear Research, Otwock-Świerk, Poland
| | - S. Sharma
- Faculty of Physics, Astronomy, and Applied Computer Science and Center for Theranostics, Jagiellonian University, Kraków, Poland
| | - Shivani
- Faculty of Physics, Astronomy, and Applied Computer Science and Center for Theranostics, Jagiellonian University, Kraków, Poland
| | - R.Y. Shopa
- Department of Complex Systems, National Centre for Nuclear Research, Otwock-Świerk, Poland
| | - M. Skurzok
- Faculty of Physics, Astronomy, and Applied Computer Science and Center for Theranostics, Jagiellonian University, Kraków, Poland
| | - K. Tayefi Ardebili
- Faculty of Physics, Astronomy, and Applied Computer Science and Center for Theranostics, Jagiellonian University, Kraków, Poland
| | - S. Vandenberghe
- Department of Electronics and Information Systems, MEDISIP, Ghent University-IBiTech, De Pintelaan 185 block B, Ghent, Belgium
| | - W. Wislicki
- Department of Complex Systems, National Centre for Nuclear Research, Otwock-Świerk, Poland
| | - E.L. Stepien
- Faculty of Physics, Astronomy, and Applied Computer Science and Center for Theranostics, Jagiellonian University, Kraków, Poland
| | - P. Moskal
- Faculty of Physics, Astronomy, and Applied Computer Science and Center for Theranostics, Jagiellonian University, Kraków, Poland
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Thyssen C, Deprez K, Mollet P, Van Holen R, Vandenberghe S. Simulation study on the performance of time-over-threshold based positioning in monolithic PET detectors. Phys Med Biol 2021; 66. [PMID: 34875646 DOI: 10.1088/1361-6560/ac40d1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 12/07/2021] [Indexed: 11/12/2022]
Abstract
The vast majority of PET detectors in the field today are based on pixelated scintillators. Yet, the resolution of this type of detector is limited by the pixel size. To overcome this limitation, one can use monolithic detectors. However, this detector architecture demands specific and high-speed detector readout of the photodetector array. A commonly used approach is to integrate the current pulses generated by every pixel but such circuitry quickly becomes bulky, power consuming and expensive. The objective of this work is to investigate a novel readout and event positioning scheme for monolithic PET detectors, based on time-over-threshold (ToT). In this case, we measure the time that the pulse is above a certain threshold through a comparator. The pulse widths are used for event positioning using a mean nearest neighbour approach (mNNToT). For energy determination one integrating multiplexed channel is foreseen. We evaluate the positioning accuracy and uniformity of such a ToT detector by means of Monte Carlo simulations. The impact of the threshold value is investigated and the results are compared to a detector using mean nearest neighbour with pulse-integration (mNNint), which has already proven to allow sub-mm resolution. We show minimal degradation in spatial resolution and bias performance compared to mNNint. The highest threshold results in the worst resolution performance but degradation remains below 0.1 mm. Bias is largely constant over different thresholds for mNNToTand close to identical to mNNint. Furthermore we show that ToT performs well in terms of detector uniformity and that scattered photons can be positioned inside the crystal with high accuracy. We conclude from this work that ToT is a valuable alternative to pulse-integration for monolithic PET detectors. This novel approach has an impact on PET detector development since it has the advantage of lower power consumption, compactness and inherent amplitude-to-time conversion.
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Affiliation(s)
- Charlotte Thyssen
- Medical Image and Signal Processing (MEDISIP), Ghent University, Ghent, Belgium.,MOLECUBES, Ghent, Belgium
| | | | | | - Roel Van Holen
- Medical Image and Signal Processing (MEDISIP), Ghent University, Ghent, Belgium.,MOLECUBES, Ghent, Belgium
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Abstract
Abstract
Total body positron emission tomography (PET) systems are being developed by different groups worldwide. These systems have potential to change the number of applications in which molecular imaging is used. The change from a short axial field of view (FOV) to a longer one is however associated with a linear increase in the cost of these systems. This may limit their application to a small number of centers (capable of obtaining sufficient research funding). Therefore it remains interesting to see if lower cost systems can be developed and bring total body PET to the clinic for an acceptable budget. The wider availability of this low cost system can also enable more researchers to further optimize and explore the full potential of total body PET.
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Affiliation(s)
- Stefaan Vandenberghe
- Department of Electronics and Information Systems , MEDISIP, Ghent University-IBiTech , De Pintelaan 185 Block B , B-9000 Ghent , Belgium
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Decuyper M, Maebe J, Van Holen R, Vandenberghe S. Artificial intelligence with deep learning in nuclear medicine and radiology. EJNMMI Phys 2021; 8:81. [PMID: 34897550 PMCID: PMC8665861 DOI: 10.1186/s40658-021-00426-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 11/19/2021] [Indexed: 12/19/2022] Open
Abstract
The use of deep learning in medical imaging has increased rapidly over the past few years, finding applications throughout the entire radiology pipeline, from improved scanner performance to automatic disease detection and diagnosis. These advancements have resulted in a wide variety of deep learning approaches being developed, solving unique challenges for various imaging modalities. This paper provides a review on these developments from a technical point of view, categorizing the different methodologies and summarizing their implementation. We provide an introduction to the design of neural networks and their training procedure, after which we take an extended look at their uses in medical imaging. We cover the different sections of the radiology pipeline, highlighting some influential works and discussing the merits and limitations of deep learning approaches compared to other traditional methods. As such, this review is intended to provide a broad yet concise overview for the interested reader, facilitating adoption and interdisciplinary research of deep learning in the field of medical imaging.
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Affiliation(s)
- Milan Decuyper
- Department of Electronics and Information Systems, Ghent University, Ghent, Belgium
| | - Jens Maebe
- Department of Electronics and Information Systems, Ghent University, Ghent, Belgium
| | - Roel Van Holen
- Department of Electronics and Information Systems, Ghent University, Ghent, Belgium
| | - Stefaan Vandenberghe
- Department of Electronics and Information Systems, Ghent University, Ghent, Belgium
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Stockhoff M, Decuyper M, Van Holen R, Vandenberghe S. High-resolution monolithic LYSO detector with 6-layer depth-of-interaction for clinical PET. Phys Med Biol 2021; 66. [PMID: 34261049 DOI: 10.1088/1361-6560/ac1459] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 07/14/2021] [Indexed: 01/23/2023]
Abstract
The system spatial resolution of whole-body positron emission tomography (PET) is limited to around 2 mm due to positron physics and the large diameter of the bore. To stay below this 'physics'-limit a scintillation detector with an intrinsic spatial resolution of around 1.3 mm is needed. Currently used detector technology consists of arrays of 2.6-5 mm segmented scintillator pixels which are the dominant factor contributing to the system resolution. Pixelated detectors using smaller pixels exist but face major drawbacks in sensitivity, timing, energy resolution and cost. Monolithic continuous detectors, where the spatial resolution is determined by the shape of the light distribution on the photodetector array, are a promising alternative. Without having the drawbacks of pixelated detectors, monolithic ones can also provide depth-of-interaction (DOI) information. In this work we present a monolithic detector design aiming to serve high-resolution clinical PET systems while maintaining high sensitivity. A 50 × 50 × 16 mm3Lutetium-Yttrium oxyorthosilicate scintillation crystal with silicon photomultiplier (SiPM) backside readout is calibrated in singles mode by a collimated beam obtaining a reference dataset for the event positioning. A mean nearest neighbour (MNN) algorithm and an artificial neural network for positioning are compared. The targeted intrinsic detector resolution of 1.3 mm needed to reach a 2 mm resolution on system level was accomplished with both algorithms. The neural network achieved a mean spatial resolution of 1.14 mm FWHM for the whole detector and 1.02 mm in the centre (30 × 30 mm2). The MNN algorithm performed slightly worse with 1.17 mm for the whole detector and 1.13 mm in the centre. The intrinsic DOI information will also result in uniform system spatial resolution over the full field of view.
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Affiliation(s)
- Mariele Stockhoff
- Department of Electronics and Information Systems, Medical Image and Signal Processing (MEDISIP), Ghent University, Ghent, Belgium
| | - Milan Decuyper
- Department of Electronics and Information Systems, Medical Image and Signal Processing (MEDISIP), Ghent University, Ghent, Belgium
| | - Roel Van Holen
- Department of Electronics and Information Systems, Medical Image and Signal Processing (MEDISIP), Ghent University, Ghent, Belgium
| | - Stefaan Vandenberghe
- Department of Electronics and Information Systems, Medical Image and Signal Processing (MEDISIP), Ghent University, Ghent, Belgium
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Mincke J, Courtyn J, Vanhove C, Vandenberghe S, Steppe K. Guide to Plant-PET Imaging Using 11CO 2. Front Plant Sci 2021; 12:602550. [PMID: 34149742 PMCID: PMC8206809 DOI: 10.3389/fpls.2021.602550] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 05/03/2021] [Indexed: 05/12/2023]
Abstract
Due to its high sensitivity and specificity for tumor detection, positron emission tomography (PET) has become a standard and widely used molecular imaging technique. Given the popularity of PET, both clinically and preclinically, its use has been extended to study plants. However, only a limited number of research groups worldwide report PET-based studies, while we believe that this technique has much more potential and could contribute extensively to plant science. The limited application of PET may be related to the complexity of putting together methodological developments from multiple disciplines, such as radio-pharmacology, physics, mathematics and engineering, which may form an obstacle for some research groups. By means of this manuscript, we want to encourage researchers to study plants using PET. The main goal is to provide a clear description on how to design and execute PET scans, process the resulting data and fully explore its potential by quantification via compartmental modeling. The different steps that need to be taken will be discussed as well as the related challenges. Hereby, the main focus will be on, although not limited to, tracing 11CO2 to study plant carbon dynamics.
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Affiliation(s)
- Jens Mincke
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
- MEDISIP - INFINITY - IBiTech, Department of Electronics and Information Systems, Faculty of Engineering and Architecture, Ghent University, Ghent, Belgium
| | - Jan Courtyn
- Medical Molecular Imaging and Therapy, Department of Radiology and Nuclear Medicine, Ghent University Hospital, Ghent, Belgium
| | - Christian Vanhove
- MEDISIP - INFINITY - IBiTech, Department of Electronics and Information Systems, Faculty of Engineering and Architecture, Ghent University, Ghent, Belgium
| | - Stefaan Vandenberghe
- MEDISIP - INFINITY - IBiTech, Department of Electronics and Information Systems, Faculty of Engineering and Architecture, Ghent University, Ghent, Belgium
| | - Kathy Steppe
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
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Sarrut D, Bała M, Bardiès M, Bert J, Chauvin M, Chatzipapas K, Dupont M, Etxebeste A, M Fanchon L, Jan S, Kayal G, S Kirov A, Kowalski P, Krzemien W, Labour J, Lenz M, Loudos G, Mehadji B, Ménard L, Morel C, Papadimitroulas P, Rafecas M, Salvadori J, Seiter D, Stockhoff M, Testa E, Trigila C, Pietrzyk U, Vandenberghe S, Verdier MA, Visvikis D, Ziemons K, Zvolský M, Roncali E. Advanced Monte Carlo simulations of emission tomography imaging systems with GATE. Phys Med Biol 2021; 66:10.1088/1361-6560/abf276. [PMID: 33770774 PMCID: PMC10549966 DOI: 10.1088/1361-6560/abf276] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 03/26/2021] [Indexed: 12/13/2022]
Abstract
Built on top of the Geant4 toolkit, GATE is collaboratively developed for more than 15 years to design Monte Carlo simulations of nuclear-based imaging systems. It is, in particular, used by researchers and industrials to design, optimize, understand and create innovative emission tomography systems. In this paper, we reviewed the recent developments that have been proposed to simulate modern detectors and provide a comprehensive report on imaging systems that have been simulated and evaluated in GATE. Additionally, some methodological developments that are not specific for imaging but that can improve detector modeling and provide computation time gains, such as Variance Reduction Techniques and Artificial Intelligence integration, are described and discussed.
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Affiliation(s)
- David Sarrut
- Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1294, INSA-Lyon, Université Lyon 1, Lyon, France
| | | | - Manuel Bardiès
- Cancer Research Institute of Montpellier, U1194 INSERM/ICM/Montpellier University, 208 Av des Apothicaires, F-34298 Montpellier cedex 5, France
| | - Julien Bert
- LaTIM, INSERM UMR 1101, IBRBS, Faculty of Medicine, Univ Brest, 22 avenue Camille Desmoulins, F-29238, Brest, France
| | - Maxime Chauvin
- CRCT, UMR 1037, INSERM, Université Toulouse III Paul Sabatier, Toulouse, France
| | | | | | - Ane Etxebeste
- Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1294, INSA-Lyon, Université Lyon 1, Lyon, France
| | - Louise M Fanchon
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, United States of America
| | - Sébastien Jan
- Université Paris-Saclay, CEA, CNRS, Inserm, BioMaps, Service Hospitalier Frédéric Joliot, F-91401, Orsay, France
| | - Gunjan Kayal
- CRCT, UMR 1037, INSERM, Université Toulouse III Paul Sabatier, Toulouse, France
- SCK CEN, Belgian Nuclear Research Centre, Boeretang 200, Mol 2400, Belgium
| | - Assen S Kirov
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, United States of America
| | - Paweł Kowalski
- High Energy Physics Division, National Centre for Nuclear Research, Otwock-Świerk, Poland
| | - Wojciech Krzemien
- High Energy Physics Division, National Centre for Nuclear Research, Otwock-Świerk, Poland
| | - Joey Labour
- Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1294, INSA-Lyon, Université Lyon 1, Lyon, France
| | - Mirjam Lenz
- FH Aachen University of Applied Sciences, Forschungszentrum Jülich, Jülich, Germany
- Faculty of Mathematics and Natural Sciences, University of Wuppertal, Wuppertal, Germany
| | - George Loudos
- Bioemission Technology Solutions (BIOEMTECH), Alexandras Av. 116, Athens, Greece
| | | | - Laurent Ménard
- Université Paris-Saclay, CNRS/IN2P3, IJCLab, F-91405 Orsay, France
- Université de Paris, IJCLab, F-91405 Orsay France
| | | | | | - Magdalena Rafecas
- Institute of Medical Engineering, University of Lübeck, Lübeck, Germany
| | - Julien Salvadori
- Department of Nuclear Medicine and Nancyclotep molecular imaging platform, CHRU-Nancy, Université de Lorraine, F-54000, Nancy, France
| | - Daniel Seiter
- Department of Medical Physics, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, 53705, United States of America
| | - Mariele Stockhoff
- Medical Image and Signal Processing (MEDISIP), Ghent University, Ghent, Belgium
| | - Etienne Testa
- Univ. Lyon, Univ. Claude Bernard Lyon 1, CNRS/IN2P3, IP2I Lyon, F-69622, Villeurbanne, France
| | - Carlotta Trigila
- Department of Biomedical Engineering, University of California, Davis, CA 95616 United States of America
| | - Uwe Pietrzyk
- Faculty of Mathematics and Natural Sciences, University of Wuppertal, Wuppertal, Germany
| | | | - Marc-Antoine Verdier
- Université Paris-Saclay, CNRS/IN2P3, IJCLab, F-91405 Orsay, France
- Université de Paris, IJCLab, F-91405 Orsay France
| | - Dimitris Visvikis
- LaTIM, INSERM UMR 1101, IBRBS, Faculty of Medicine, Univ Brest, 22 avenue Camille Desmoulins, F-29238, Brest, France
| | - Karl Ziemons
- FH Aachen University of Applied Sciences, Forschungszentrum Jülich, Jülich, Germany
| | - Milan Zvolský
- Institute of Medical Engineering, University of Lübeck, Lübeck, Germany
| | - Emilie Roncali
- Department of Biomedical Engineering, University of California, Davis, CA 95616 United States of America
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20
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Decuyper M, Stockhoff M, Vandenberghe S, Van Holen R. Artificial neural networks for positioning of gamma interactions in monolithic PET detectors. Phys Med Biol 2021; 66. [PMID: 33662940 DOI: 10.1088/1361-6560/abebfc] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 03/04/2021] [Indexed: 11/12/2022]
Abstract
To detect gamma rays with good spatial, timing and energy resolution while maintaining high sensitivity we need accurate and efficient algorithms to estimate the first gamma interaction position from the measured light distribution. Furthermore, monolithic detectors are investigated as an alternative to pixelated detectors due to increased sensitivity, resolution and intrinsic DOI encoding. Monolithic detectors, however, are challenging because of complicated calibration setups and edge effects. In this work, we evaluate the use of neural networks to estimate the 3D first (Compton or photoelectric) interaction position. Using optical simulation data of a 50×50×16 mm3LYSO crystal, performance is evaluated as a function of network complexity (two to five hidden layers with 64 to 1024 neurons) and amount of training data (1000 to 8000 training events per calibration position). We identify and address the potential pitfall of overfitting on the training grid through evaluation on intermediate positions that are not in the training set. Additionally, the performance of neural networks is directly compared with nearest neighbour positioning. Optimal performance was achieved with a network containing three hidden layers of 256 neurons trained on 1000 events/position. For more complex networks, the performance degrades at intermediate positions and overfitting starts to occur. A median 3D positioning error of 0.77 mm and a 2D FWHM of 0.46 mm is obtained. This is a 17% improvement in terms of FWHM compared to the nearest neighbour algorithm. Evaluation only on events that are not Compton scattered results in a 3D positioning error of 0.40 mm and 2D FWHM of 0.42 mm. This reveals that Compton scatter results in a considerable increase of 93% in positioning error. This study demonstrates that very good spatial resolutions can be achieved with neural networks, superior to nearest neighbour positioning. However, potential overfitting on the training grid should be carefully evaluated.
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Affiliation(s)
- Milan Decuyper
- Department of Electronics and Information Systems, Medical Image and Signal Processing (MEDISIP), Ghent University, Gent, BELGIUM
| | - Mariele Stockhoff
- Department of Electronics and Information Systems, Medical Image and Signal Processing (MEDISIP), Ghent University, Gent, BELGIUM
| | - Stefaan Vandenberghe
- Department of Electronics and Information Systems, Medical Image and Signal Processing (MEDISIP), Ghent University, Gent, BELGIUM
| | - Roel Van Holen
- Department of Electronics and Information Systems, Medical Image and Signal Processing (MEDISIP), Ghent University, Gent, BELGIUM
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21
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Lecoq P, Morel C, Prior JO, Visvikis D, Gundacker S, Auffray E, Križan P, Turtos RM, Thers D, Charbon E, Varela J, de La Taille C, Rivetti A, Breton D, Pratte JF, Nuyts J, Surti S, Vandenberghe S, Marsden P, Parodi K, Benlloch JM, Benoit M. Roadmap toward the 10 ps time-of-flight PET challenge. Phys Med Biol 2020; 65:21RM01. [PMID: 32434156 PMCID: PMC7721485 DOI: 10.1088/1361-6560/ab9500] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Since the seventies, positron emission tomography (PET) has become an invaluable medical molecular imaging modality with an unprecedented sensitivity at the picomolar level, especially for cancer diagnosis and the monitoring of its response to therapy. More recently, its combination with x-ray computed tomography (CT) or magnetic resonance (MR) has added high precision anatomic information in fused PET/CT and PET/MR images, thus compensating for the modest intrinsic spatial resolution of PET. Nevertheless, a number of medical challenges call for further improvements in PET sensitivity. These concern in particular new treatment opportunities in the context personalized (also called precision) medicine, such as the need to dynamically track a small number of cells in cancer immunotherapy or stem cells for tissue repair procedures. A better signal-to-noise ratio (SNR) in the image would allow detecting smaller size tumours together with a better staging of the patients, thus increasing the chances of putting cancer in complete remission. Moreover, there is an increasing demand for reducing the radioactive doses injected to the patients without impairing image quality. There are three ways to improve PET scanner sensitivity: improving detector efficiency, increasing geometrical acceptance of the imaging device and pushing the timing performance of the detectors. Currently, some pre-localization of the electron-positron annihilation along a line-of-response (LOR) given by the detection of a pair of annihilation photons is provided by the detection of the time difference between the two photons, also known as the time-of-flight (TOF) difference of the photons, whose accuracy is given by the coincidence time resolution (CTR). A CTR of about 10 picoseconds FWHM will ultimately allow to obtain a direct 3D volume representation of the activity distribution of a positron emitting radiopharmaceutical, at the millimetre level, thus introducing a quantum leap in PET imaging and quantification and fostering more frequent use of 11C radiopharmaceuticals. The present roadmap article toward the advent of 10 ps TOF-PET addresses the status and current/future challenges along the development of TOF-PET with the objective to reach this mythic 10 ps frontier that will open the door to real-time volume imaging virtually without tomographic inversion. The medical impact and prospects to achieve this technological revolution from the detection and image reconstruction point-of-views, together with a few perspectives beyond the TOF-PET application are discussed.
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Affiliation(s)
- Paul Lecoq
- CERN, department EP, Geneva, Switzerland
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22
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Göker M, Marcinkowski R, Van Bockstal M, Keereman V, Van Holen R, Van Dorpe J, Vandenberghe S, Brans B, Depypere H, Van den Broecke R. 18F-FDG micro-PET/CT for intra-operative margin assessment during breast-conserving surgery. Acta Chir Belg 2020; 120:366-374. [PMID: 32452298 DOI: 10.1080/00015458.2020.1774163] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Rationale: Positive surgical margins for invasive breast cancer (BC) treated with breast-conserving surgery (BCS) are defined as ink on tumor. The rate of positive margins is approximately 20%, since a time- and cost-effective method for margin assessment is lacking. In this study, we investigated margin status by intra-operative imaging using high-resolution 18 F-fluoro-deoxyglucose (FDG) positron emission tomography (PET) and X-ray computed tomography (CT).Methods: Twenty patients were enrolled and received 4 MBq/kg of FDG prior to surgery. Intra-operative imaging of the specimens was performed by the MOLECUBES β-CUBE (PET) and X-CUBE (CT). Margin status was assessed by three surgeons and compared with an algorithm. The sensitivity and specificity were calculated by using histopathological assessment as a gold standard.Results: A region with high FDG uptake was visualized in all specimens. Automated analysis showed a sensitivity of 90%, a specificity of 60%, and an area under the curve (AUC) of 0.86 after ROC analysis. Margin assessment by the surgeons resulted in a mean sensitivity and specificity of 79% and 72%, respectively.Conclusions: This proof-of-concept study demonstrates that high-resolution FDG-PET/CT can facilitate intra-operative margin assessment during BCS. This technique achieves good sensitivity and specificity and may therefore reduce re-operation rates in the future.
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Affiliation(s)
- Menekse Göker
- Department of Gynecology, Ghent University Hospital, Ghent, Belgium
| | | | - Mieke Van Bockstal
- Department of Pathological Anatomy, Ghent University Hospital, Ghent, Belgium
- Department of Pathology, Cliniques Universitaires Saint-Luc, Brussels, Belgium
| | - Vincent Keereman
- MOLECUBES NV, MeetDistrict – Ghelamco Arena, Ghent, Belgium
- Department of Electronics and Information Systems, MEDISIP, Ghent University, Ghent, Belgium
| | - Roel Van Holen
- MOLECUBES NV, MeetDistrict – Ghelamco Arena, Ghent, Belgium
- Department of Electronics and Information Systems, MEDISIP, Ghent University, Ghent, Belgium
| | - Jo Van Dorpe
- Department of Pathological Anatomy, Ghent University Hospital, Ghent, Belgium
| | - Stefaan Vandenberghe
- Department of Electronics and Information Systems, MEDISIP, Ghent University, Ghent, Belgium
| | - Boudewijn Brans
- Department of Nuclear Medicine, Ghent University Hospital, Ghent, Belgium
| | - Herman Depypere
- Department of Gynecology, Ghent University Hospital, Ghent, Belgium
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23
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Caribé PRRV, Vandenberghe S, Diogo A, Pérez-Benito D, Efthimiou N, Thyssen C, D'Asseler Y, Koole M. Monte Carlo Simulations of the GE Signa PET/MR for Different Radioisotopes. Front Physiol 2020; 11:525575. [PMID: 33041852 PMCID: PMC7522581 DOI: 10.3389/fphys.2020.525575] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 08/13/2020] [Indexed: 12/28/2022] Open
Abstract
NEMA characterization of PET systems is generally based on 18F because it is the most relevant radioisotope for the clinical use of PET. 18F has a half-life of 109.7 min and decays into stable 18O via β+ emission with a probability of over 96% and a maximum positron energy of 0.633 MeV. Other commercially available PET radioisotopes, such as 82Rb and 68Ga have more complex decay schemes with a variety of prompt gammas, which can directly fall into the energy window and induce false coincidence detections by the PET scanner.
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Affiliation(s)
- Paulo R R V Caribé
- Medical Imaging and Signal Processing - MEDISIP, Ghent University, Ghent, Belgium
| | - Stefaan Vandenberghe
- Medical Imaging and Signal Processing - MEDISIP, Ghent University, Ghent, Belgium
| | - André Diogo
- Faculty of Sciences of the University of Lisbon (FCUL), Lisbon, Portugal
| | - David Pérez-Benito
- Bioengineering and Aerospace Department, Universidad Carlos III de Madrid, Madrid, Spain
| | - Nikos Efthimiou
- Department of Physics, University of York, York, United Kingdom
| | - Charlotte Thyssen
- Medical Imaging and Signal Processing - MEDISIP, Ghent University, Ghent, Belgium
| | - Yves D'Asseler
- Department of Diagnostic Sciences, Faculty of Medicine, Ghent University, Ghent, Belgium
| | - Michel Koole
- Nuclear Medicine and Molecular Imaging, Department of Imaging & Pathology, KU Leuven, Leuven, Belgium
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24
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Mincke J, Courtyn J, Vanhove C, Vandenberghe S, Steppe K. Studying in vivo dynamics of xylem-transported 11CO2 using positron emission tomography. Tree Physiol 2020; 40:1058-1070. [PMID: 32333788 DOI: 10.1093/treephys/tpaa048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 04/20/2020] [Indexed: 05/26/2023]
Abstract
Respired CO2 in woody tissues can build up in the xylem and dissolve in the sap solution to be transported through the plant. From the sap, a fraction of the CO2 can either be radially diffuse to the atmosphere or be assimilated in chloroplasts present in woody tissues. These processes occur simultaneously in stems and branches, making it difficult to study their specific dynamics. Therefore, an 11C-enriched aqueous solution was administered to young branches of Populus tremula L., which were subsequently imaged by positron emission tomography (PET). This approach allows in vivo visualization of the internal movement of CO2 inside branches at high spatial and temporal resolution, and enables direct measurement of the transport speed of xylem-transported CO2 (vCO2). Through compartmental modeling of the dynamic data obtained from the PET images, we (i) quantified vCO2 and (ii) proposed a new method to assess the fate of xylem-transported 11CO2 within the branches. It was found that a fraction of 0.49 min-1 of CO2 present in the xylem was transported upwards. A fraction of 0.38 min-1 diffused radially from the sap to the surrounding parenchyma and apoplastic spaces (CO2,PA) to be assimilated by woody tissue photosynthesis. Another 0.12 min-1 of the xylem-transported CO2 diffused to the atmosphere via efflux. The remaining CO2 (i.e., 0.01 min-1) was stored as CO2,PA, representing the build-up within parenchyma and apoplastic spaces to be assimilated or directed to the atmosphere. Here, we demonstrate the outstanding potential of 11CO2-based plant-PET in combination with compartmental modeling to advance our understanding of internal CO2 movement and the respiratory physiology within woody tissues.
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Affiliation(s)
- Jens Mincke
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
- MEDISIP-INFINITY, Department of Electronics and Information Systems, Faculty of Engineering and Architecture, Ghent University, Corneel Heymanslaan 10, 9000 Ghent, Belgium
| | - Jan Courtyn
- Medical Molecular Imaging and Therapy, Department of Radiology and Nuclear Medicine, Ghent University Hospital, Corneel Heymanslaan 10, 9000 Ghent, Belgium
| | - Christian Vanhove
- MEDISIP-INFINITY, Department of Electronics and Information Systems, Faculty of Engineering and Architecture, Ghent University, Corneel Heymanslaan 10, 9000 Ghent, Belgium
| | - Stefaan Vandenberghe
- MEDISIP-INFINITY, Department of Electronics and Information Systems, Faculty of Engineering and Architecture, Ghent University, Corneel Heymanslaan 10, 9000 Ghent, Belgium
| | - Kathy Steppe
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
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25
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Moskal P, Kisielewska D, Y Shopa R, Bura Z, Chhokar J, Curceanu C, Czerwiński E, Dadgar M, Dulski K, Gajewski J, Gajos A, Gorgol M, Del Grande R, C Hiesmayr B, Jasińska B, Kacprzak K, Kamińska A, Kapłon Ł, Karimi H, Korcyl G, Kowalski P, Krawczyk N, Krzemień W, Kozik T, Kubicz E, Małczak P, Mohammed M, Niedźwiecki S, Pałka M, Pawlik-Niedźwiecka M, Pędziwiatr M, Raczyński L, Raj J, Ruciński A, Sharma S, Shivani S, Silarski M, Skurzok M, Stępień EŁ, Vandenberghe S, Wiślicki W, Zgardzińska B. Performance assessment of the 2 γpositronium imaging with the total-body PET scanners. EJNMMI Phys 2020; 7:44. [PMID: 32607664 PMCID: PMC7326848 DOI: 10.1186/s40658-020-00307-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 05/17/2020] [Indexed: 02/01/2023] Open
Abstract
Purpose In living organisms, the positron-electron annihilation (occurring during the PET imaging) proceeds in about 30% via creation of a metastable ortho-positronium atom. In the tissue, due to the pick-off and conversion processes, over 98% of ortho-positronia annihilate into two 511 keV photons. In this article, we assess the feasibility for reconstruction of the mean ortho-positronium lifetime image based on annihilations into two photons. The main objectives of this work include the (i) estimation of the sensitivity of the total-body PET scanners for the ortho-positronium mean lifetime imaging using 2γ annihilations and (ii) estimation of the spatial and time resolution of the ortho-positronium image as a function of the coincidence resolving time (CRT) of the scanner. Methods Simulations are conducted assuming that radiopharmaceutical is labeled with 44Sc isotope emitting one positron and one prompt gamma. The image is reconstructed on the basis of triple coincidence events. The ortho-positronium lifetime spectrum is determined for each voxel of the image. Calculations were performed for cases of total-body detectors build of (i) LYSO scintillators as used in the EXPLORER PET and (ii) plastic scintillators as anticipated for the cost-effective total-body J-PET scanner. To assess the spatial and time resolution, the four cases were considered assuming that CRT is equal to 500 ps, 140 ps, 50 ps, and 10 ps. Results The estimated total-body PET sensitivity for the registration and selection of image forming triple coincidences (2γ+γprompt) is larger by a factor of 13.5 (for LYSO PET) and by factor of 5.2 (for plastic PET) with respect to the sensitivity for the standard 2γ imaging by LYSO PET scanners with AFOV = 20 cm. The spatial resolution of the ortho-positronium image is comparable with the resolution achievable when using TOF-FBP algorithms already for CRT = 50 ps. For the 20-min scan, the resolution better than 20 ps is expected for the mean ortho-positronium lifetime image determination. Conclusions Ortho-positronium mean lifetime imaging based on the annihilations into two photons and prompt gamma is shown to be feasible with the advent of the high sensitivity total-body PET systems and time resolution of the order of tens of picoseconds.
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Affiliation(s)
- P Moskal
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, prof. Stanisława Łojasiewicza 11, Cracow, 30-348, Poland.
| | - D Kisielewska
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, prof. Stanisława Łojasiewicza 11, Cracow, 30-348, Poland.
| | - R Y Shopa
- Department of Complex Systems, National Centre for Nuclear Research, Otwock-Świerk, 05-400, Poland
| | - Z Bura
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, prof. Stanisława Łojasiewicza 11, Cracow, 30-348, Poland
| | - J Chhokar
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, prof. Stanisława Łojasiewicza 11, Cracow, 30-348, Poland
| | - C Curceanu
- INFN, Laboratori Nazionali di Frascati, Frascati, 00044, Italy
| | - E Czerwiński
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, prof. Stanisława Łojasiewicza 11, Cracow, 30-348, Poland
| | - M Dadgar
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, prof. Stanisława Łojasiewicza 11, Cracow, 30-348, Poland
| | - K Dulski
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, prof. Stanisława Łojasiewicza 11, Cracow, 30-348, Poland
| | - J Gajewski
- Institute of Nuclear Physics PAN, Cracow, Poland
| | - A Gajos
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, prof. Stanisława Łojasiewicza 11, Cracow, 30-348, Poland
| | - M Gorgol
- Institute of Physics, Maria Curie-Skłodowska University, Lublin, 20-031, Poland
| | - R Del Grande
- INFN, Laboratori Nazionali di Frascati, Frascati, 00044, Italy
| | - B C Hiesmayr
- Faculty of Physics, University of Vienna, Vienna, 1090, Austria
| | - B Jasińska
- Institute of Physics, Maria Curie-Skłodowska University, Lublin, 20-031, Poland
| | - K Kacprzak
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, prof. Stanisława Łojasiewicza 11, Cracow, 30-348, Poland
| | - A Kamińska
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, prof. Stanisława Łojasiewicza 11, Cracow, 30-348, Poland
| | - Ł Kapłon
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, prof. Stanisława Łojasiewicza 11, Cracow, 30-348, Poland
| | - H Karimi
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, prof. Stanisława Łojasiewicza 11, Cracow, 30-348, Poland
| | - G Korcyl
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, prof. Stanisława Łojasiewicza 11, Cracow, 30-348, Poland
| | - P Kowalski
- Department of Complex Systems, National Centre for Nuclear Research, Otwock-Świerk, 05-400, Poland
| | - N Krawczyk
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, prof. Stanisława Łojasiewicza 11, Cracow, 30-348, Poland
| | - W Krzemień
- High Energy Physics Division, National Centre for Nuclear Research, Otwock-Świerk, 05-400, Poland
| | - T Kozik
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, prof. Stanisława Łojasiewicza 11, Cracow, 30-348, Poland
| | - E Kubicz
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, prof. Stanisława Łojasiewicza 11, Cracow, 30-348, Poland
| | - P Małczak
- 2nd Department of General Surgery, Jagiellonian University Medical College, Cracow, Poland
| | - M Mohammed
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, prof. Stanisława Łojasiewicza 11, Cracow, 30-348, Poland.,Department of Physics, College of Education for Pure Sciences, University of Mosul, Mosul, Iraq
| | - Sz Niedźwiecki
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, prof. Stanisława Łojasiewicza 11, Cracow, 30-348, Poland
| | - M Pałka
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, prof. Stanisława Łojasiewicza 11, Cracow, 30-348, Poland
| | - M Pawlik-Niedźwiecka
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, prof. Stanisława Łojasiewicza 11, Cracow, 30-348, Poland
| | - M Pędziwiatr
- 2nd Department of General Surgery, Jagiellonian University Medical College, Cracow, Poland
| | - L Raczyński
- Department of Complex Systems, National Centre for Nuclear Research, Otwock-Świerk, 05-400, Poland
| | - J Raj
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, prof. Stanisława Łojasiewicza 11, Cracow, 30-348, Poland
| | - A Ruciński
- Institute of Nuclear Physics PAN, Cracow, Poland
| | - S Sharma
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, prof. Stanisława Łojasiewicza 11, Cracow, 30-348, Poland
| | - S Shivani
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, prof. Stanisława Łojasiewicza 11, Cracow, 30-348, Poland
| | - M Silarski
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, prof. Stanisława Łojasiewicza 11, Cracow, 30-348, Poland
| | - M Skurzok
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, prof. Stanisława Łojasiewicza 11, Cracow, 30-348, Poland.,INFN, Laboratori Nazionali di Frascati, Frascati, 00044, Italy
| | - E Ł Stępień
- Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, prof. Stanisława Łojasiewicza 11, Cracow, 30-348, Poland
| | - S Vandenberghe
- Department of Electronics and Information Systems, MEDISIP, Ghent University-IBiTech, De Pintelaan 185 block B, Ghent, B-9000, Belgium
| | - W Wiślicki
- High Energy Physics Division, National Centre for Nuclear Research, Otwock-Świerk, 05-400, Poland
| | - B Zgardzińska
- Institute of Physics, Maria Curie-Skłodowska University, Lublin, 20-031, Poland
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26
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Abstract
The idea of a very sensitive positron emission tomography (PET) system covering a large portion of the body of a patient already dates back to the early 1990s. In the period 2000-2010, only some prototypes with long axial field of view (FOV) have been built, which never resulted in systems used for clinical research. One of the reasons was the limitations in the available detector technology, which did not yet have sufficient energy resolution, timing resolution or countrate capabilities for fully exploiting the benefits of a long axial FOV design. PET was also not yet as widespread as it is today: the growth in oncology, which has become the major application of PET, appeared only after the introduction of PET-CT (early 2000).The detector technology used in most clinical PET systems today has a combination of good energy and timing resolution with higher countrate capabilities and has now been used since more than a decade to build time-of-flight (TOF) PET systems with fully 3D acquisitions. Based on this technology, one can construct total body PET systems and the remaining challenges (data handling, fast image reconstruction, detector cooling) are mostly related to engineering. The direct benefits of long axial FOV systems are mostly related to the higher sensitivity. For single organ imaging, the gain is close to the point source sensitivity which increases linearly with the axial length until it is limited by solid angle and attenuation of the body. The gains for single organ (compared to a fully 3D PET 20-cm axial FOV) are limited to a factor 3-4. But for long objects (like body scans), it increases quadratically with scanner length and factors of 10-40 × higher sensitivity are predicted for the long axial FOV scanner. This application of PET has seen a major increase (mostly in oncology) during the last 2 decades and is now the main type of study in a PET centre. As the technology is available and the full body concept also seems to match with existing applications, the old concept of a total body PET scanner is seeing a clear revival. Several research groups are working on this concept and after showing the potential via extensive simulations; construction of these systems has started about 2 years ago. In the first phase, two PET systems with long axial FOV suitable for large animal imaging were constructed to explore the potential in more experimental settings. Recently, the first completed total body PET systems for human use, a 70-cm-long system, called PennPET Explorer, and a 2-m-long system, called uExplorer, have become reality and first clinical studies have been shown. These results illustrate the large potential of this concept with regard to low-dose imaging, faster scanning, whole-body dynamic imaging and follow-up of tracers over longer periods. This large range of possible technical improvements seems to have the potential to change the current clinical routine and to expand the number of clinical applications of molecular imaging. The J-PET prototype is a prototype system with a long axial FOV built from axially arranged plastic scintillator strips.This paper gives an overview of the recent technical developments with regard to PET scanners with a long axial FOV covering at least the majority of the body (so called total body PET systems). After explaining the benefits and challenges of total body PET systems, the different total body PET system designs proposed for large animal and clinical imaging are described in detail. The axial length is one of the major factors determining the total cost of the system, but there are also other options in detector technology, design and processing for reducing the cost these systems. The limitations and advantages of different designs for research and clinical use are discussed taking into account potential applications and the increased cost of these systems.
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Affiliation(s)
- Stefaan Vandenberghe
- Department of Electronics and Information Systems, MEDISIP, Ghent University-IBiTech, De Pintelaan 185 block B, Ghent, B-9000 Belgium
| | - Pawel Moskal
- Institute of Physics, Jagiellonian University, Krakow, Poland
| | - Joel S. Karp
- Department of Radiology, University of Pennsylvania, Philadelphia, USA
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27
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Caribé PRRV, Koole M, D’Asseler Y, Van Den Broeck B, Vandenberghe S. Noise reduction using a Bayesian penalized-likelihood reconstruction algorithm on a time-of-flight PET-CT scanner. EJNMMI Phys 2019; 6:22. [PMID: 31823084 PMCID: PMC6904688 DOI: 10.1186/s40658-019-0264-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 11/25/2019] [Indexed: 12/11/2022] Open
Abstract
PURPOSE Q.Clear is a block sequential regularized expectation maximization (BSREM) penalized-likelihood reconstruction algorithm for PET. It tries to improve image quality by controlling noise amplification during image reconstruction. In this study, the noise properties of this BSREM were compared to the ordered-subset expectation maximization (OSEM) algorithm for both phantom and patient data acquired on a state-of-the-art PET/CT. METHODS The NEMA IQ phantom and a whole-body patient study were acquired on a GE DMI 3-rings system in list mode and different datasets with varying noise levels were generated. Phantom data was evaluated using four different contrast ratios. These were reconstructed using BSREM with different β-factors of 300-3000 and with a clinical setting used for OSEM including point spread function (PSF) and time-of-flight (TOF) information. Contrast recovery (CR), background noise levels (coefficient of variation, COV), and contrast-to-noise ratio (CNR) were used to determine the performance in the phantom data. Findings based on the phantom data were compared with clinical data. For the patient study, the SUV ratio, metabolic active tumor volumes (MATVs), and the signal-to-noise ratio (SNR) were evaluated using the liver as the background region. RESULTS Based on the phantom data for the same count statistics, BSREM resulted in higher CR and CNR and lower COV than OSEM. The CR of OSEM matches to the CR of BSREM with β = 750 at high count statistics for 8:1. A similar trend was observed for the ratios 6:1 and 4:1. A dependence on sphere size, counting statistics, and contrast ratio was confirmed by the CNR of the ratio 2:1. BSREM with β = 750 for 2.5 and 1.0 min acquisition has comparable COV to the 10 and 5.0 min acquisitions using OSEM. This resulted in a noise reduction by a factor of 2-4 when using BSREM instead of OSEM. For the patient data, a similar trend was observed, and SNR was reduced by at least a factor of 2 while preserving contrast. CONCLUSION The BSREM reconstruction algorithm allowed a noise reduction without a loss of contrast by a factor of 2-4 compared to OSEM reconstructions for all data evaluated. This reduction can be used to lower the injected dose or shorten the acquisition time.
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Affiliation(s)
- Paulo R. R. V. Caribé
- Medical Image and Signal Processing – MEDISIP, Ghent University, Corneel Heymanslaan 10, 9000 Gent, Belgium
| | - M. Koole
- Division of Nuclear Medicine and Molecular Imaging, UZ/KU, Herestraat 49, B-3000 Leuven, Belgium
| | - Yves D’Asseler
- Department of Nuclear Medicine, Ghent University Hospital, Corneel Heymanslaan 10, 9000 Gent, Belgium
| | - B. Van Den Broeck
- Department of Nuclear Medicine, Ghent University Hospital, Corneel Heymanslaan 10, 9000 Gent, Belgium
| | - S. Vandenberghe
- Medical Image and Signal Processing – MEDISIP, Ghent University, Corneel Heymanslaan 10, 9000 Gent, Belgium
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28
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McDougald W, Vanhove C, Lehnert A, Lewellen B, Wright J, Mingarelli M, Corral CA, Schneider JE, Plein S, Newby DE, Welch A, Miyaoka R, Vandenberghe S, Tavares AAS. Standardization of Preclinical PET/CT Imaging to Improve Quantitative Accuracy, Precision, and Reproducibility: A Multicenter Study. J Nucl Med 2019; 61:461-468. [PMID: 31562220 PMCID: PMC7067528 DOI: 10.2967/jnumed.119.231308] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 08/19/2019] [Indexed: 12/12/2022] Open
Abstract
Preclinical PET/CT is a well-established noninvasive imaging tool for studying disease development/progression and the development of novel radiotracers and pharmaceuticals for clinical applications. Despite this pivotal role, standardization of preclinical PET/CT protocols, including CT absorbed dose guidelines, is essentially nonexistent. This study (1) quantitatively assesses the variability of current preclinical PET/CT acquisition and reconstruction protocols routinely used across multiple centers and scanners; and (2) proposes acquisition and reconstruction PET/CT protocols for standardization of multicenter data, optimized for routine scanning in the preclinical PET/CT laboratory. Methods: Five different commercial preclinical PET/CT scanners in Europe and the United States were enrolled. Seven different PET/CT phantoms were used for evaluating biases on default/general scanner protocols, followed by developing standardized protocols. PET, CT, and absorbed dose biases were assessed. Results: Site default CT protocols were the following: greatest extracted Hounsfield units (HU) were 133 HU for water and −967 HU for air; significant differences in all tissue equivalent material (TEM) groups were measured. The average CT absorbed doses for mouse and rat were 72 mGy and 40 mGy, respectively. Standardized CT protocol were the following: greatest extracted HU were −77 HU for water and −990 HU for air; TEM precision improved with a reduction in variability for each tissue group. The average CT absorbed dose for mouse and rat decreased to 37 mGy and 24 mGy, respectively. Site default PET protocols were the following: uniformity was substandard in one scanner, recovery coefficients (RCs) were either over- or underestimated (maximum of 43%), standard uptake values (SUVs) were biased by a maximum of 44%. Standardized PET protocols were the following: scanner with substandard uniformity improved by 36%, RC variability decreased by 13% points, and SUV accuracy improved to 10%. Conclusion: Data revealed important quantitative biases in preclinical PET/CT and absorbed doses with default protocols. Standardized protocols showed improvements in measured PET/CT accuracy and precision with reduced CT absorbed dose across sites. Adhering to standardized protocols generates reproducible and consistent preclinical imaging datasets, thus augmenting translation of research findings to the clinic.
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Affiliation(s)
- Wendy McDougald
- BHF-Centre for Cardiovascular Science, College of Medicine & Veterinary Medicine, Queen's Medical Research Institute, University of Edinburgh, United Kingdom .,Edinburgh Preclinical Imaging (EPI), Edinburgh Imaging, University of Edinburgh, Edinburgh, United Kingdom
| | - Christian Vanhove
- Department of Electronics and Information Systems, MEDISIP, Ghent University, Ghent, Belgium
| | - Adrienne Lehnert
- Department of Radiology, Imaging Research Laboratory, University of Washington, Seattle, Washington
| | - Barbara Lewellen
- Department of Radiology, Imaging Research Laboratory, University of Washington, Seattle, Washington
| | - John Wright
- Leeds Institute of Cardiovascular and Metabolic Medicine, Department of Biomedical Imaging Science, LIGHT Laboratories, University of Leeds, Leeds, United Kingdom; and
| | - Marco Mingarelli
- Aberdeen Biomedical Imaging Centre, School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Aberdeen, United Kingdom
| | - Carlos Alcaide Corral
- BHF-Centre for Cardiovascular Science, College of Medicine & Veterinary Medicine, Queen's Medical Research Institute, University of Edinburgh, United Kingdom.,Edinburgh Preclinical Imaging (EPI), Edinburgh Imaging, University of Edinburgh, Edinburgh, United Kingdom
| | - Jurgen E Schneider
- Leeds Institute of Cardiovascular and Metabolic Medicine, Department of Biomedical Imaging Science, LIGHT Laboratories, University of Leeds, Leeds, United Kingdom; and
| | - Sven Plein
- Leeds Institute of Cardiovascular and Metabolic Medicine, Department of Biomedical Imaging Science, LIGHT Laboratories, University of Leeds, Leeds, United Kingdom; and
| | - David E Newby
- BHF-Centre for Cardiovascular Science, College of Medicine & Veterinary Medicine, Queen's Medical Research Institute, University of Edinburgh, United Kingdom
| | - Andy Welch
- Aberdeen Biomedical Imaging Centre, School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Aberdeen, United Kingdom
| | - Robert Miyaoka
- Department of Radiology, Imaging Research Laboratory, University of Washington, Seattle, Washington
| | - Stefaan Vandenberghe
- Department of Electronics and Information Systems, MEDISIP, Ghent University, Ghent, Belgium
| | - Adriana Alexandre S Tavares
- BHF-Centre for Cardiovascular Science, College of Medicine & Veterinary Medicine, Queen's Medical Research Institute, University of Edinburgh, United Kingdom.,Edinburgh Preclinical Imaging (EPI), Edinburgh Imaging, University of Edinburgh, Edinburgh, United Kingdom
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29
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Abstract
The intrinsic spatial resolution of clinical positron emission tomography (PET) detectors is ~3-4 mm. A further improvement of the resolution using pixelated detectors will not only result in a prohibitive cost, but is also inevitably accompanied by a strong degradation of important performance parameters like timing, energy resolution and sensitivity. Therefore, it is likely that future generation high resolution PET detectors will be based on continuous monolithic scintillation detectors. Monolithic detectors have attractive properties to reach superior 3D spatial resolution while outperforming pixelated detectors in timing, energy resolution and sensitivity. In this work, optical simulations including an advanced surface reflection model, allow us to investigate the influence of three parameters on the spatial resolution: silicon photomultiplier (SiPM) pixel size, photon detection efficiency (PDE) and the number of channels used to read out the SiPM array. A lutetium-yttrium oxyorthosilicate (LYSO) crystal with dimensions 50 × 50 × 16 mm3 coupled to an SiPM array is calibrated and a nearest neighbor (NN) algorithm is used to position events. Findings show that the tested parameters affect the spatial resolution resulting in 0.40-0.66 mm full width at half maximum (FWHM). Best resolution could be obtained with smaller SiPM pixels, higher PDE, and an individual channel readout. However, it was shown that combining channels by adding their signals can significantly reduce the amount of readout channels while having small or no significant impact on the resolution. The mean depth of interaction (DOI) estimation error is 1.6 mm. This study demonstrates the ultimate spatial resolution that can be obtained with this detector without being constrained by practical limitations of experimental setups. In the future these optical simulations may be used as a more precise and fast method to obtain calibration data for real monolithic detectors.
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30
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Elsinga P, Bischof Delaloye A, Chiti A, Vandenberghe S, Giammarile F, Carrio I. Endorsement of International Consensus Radiochemistry Nomenclature Guidelines. EJNMMI Radiopharm Chem 2019; 4:8. [PMID: 31659515 PMCID: PMC6465369 DOI: 10.1186/s41181-018-0050-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 11/08/2018] [Indexed: 11/30/2022] Open
Affiliation(s)
- Philip Elsinga
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Hanzeplein 1, Groningen, 9713, EZ, The Netherlands.
| | - Angelika Bischof Delaloye
- Nuclear Medicine Service Centre Hospitalier Universitaire Vaudois, Bugnon 46, Lausanne, 1011, Switzerland
| | - Arturo Chiti
- Department of Biomedical Sciences, Humanitas University, Milan, Italy.,Department of Diagnostic Imaging, Humanitas Clinical and Research Center - IRCCS, Milan, Italy
| | - Stefaan Vandenberghe
- MEDISIP-ELIS-IBITECH, Ghent University, Corneel Heymanslaan 10, Ghent, 9000, Belgium
| | - Francesco Giammarile
- Nuclear Medicine and Diagnostic Imaging Section, Division of Human Health, International Atomic Energy Agency, Vienna, Austria
| | - Ignasi Carrio
- Department of Radiology and Medical Physics, Hospital de Sant Pau, Barcelona, Spain
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31
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Elsinga P, Delaloye AB, Chiti A, Vandenberghe S, Giammarile F, Carrio I. Endorsement of International Consensus Radiochemistry Nomenclature Guidelines. Eur J Nucl Med Mol Imaging 2019; 46:1399. [PMID: 30989249 DOI: 10.1007/s00259-018-4243-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 11/08/2018] [Indexed: 11/29/2022]
Affiliation(s)
- Philip Elsinga
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 EZ, Groningen, The Netherlands.
| | - Angelika Bischof Delaloye
- Nuclear Medicine Service, Centre Hospitalier Universitaire Vaudois, Bugnon 46, 1011, Lausanne, Switzerland
| | - Arturo Chiti
- Department of Biomedical Sciences, Humanitas University, Milan, Italy.,Department of Diagnostic Imaging, Humanitas Clinical and Research Center - IRCCS, Milan, Italy
| | - Stefaan Vandenberghe
- MEDISIP-ELIS-IBITECH, Ghent University, Corneel Heymanslaan 10, 9000, Ghent, Belgium
| | - Francesco Giammarile
- Nuclear Medicine and Diagnostic Imaging Section, Division of Human Health, International Atomic Energy Agency, Vienna, Austria
| | - Ignasi Carrio
- Department of Radiology and Medical Physics, Hospital de Sant Pau, Barcelona, Spain
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32
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Elsinga P, Delaloye AB, Chiti A, Vandenberghe S, Giammarile F, Carrio I. Endorsement of International Consensus Radiochemistry Nomenclature Guidelines. Eur J Hybrid Imaging 2019; 3:6. [PMID: 34191136 PMCID: PMC8212211 DOI: 10.1186/s41824-018-0048-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 11/08/2018] [Indexed: 11/10/2022] Open
Affiliation(s)
- Philip Elsinga
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 EZ, Groningen, The Netherlands.
| | - Angelika Bischof Delaloye
- Nuclear Medicine Service, Centre Hospitalier Universitaire Vaudois, Bugnon 46, 1011, Lausanne, Switzerland
| | - Arturo Chiti
- Department of Biomedical Sciences, Humanitas University, Milan, Italy.,Department of Diagnostic Imaging, Humanitas Clinical and Research Center - IRCCS, Milan, Italy
| | - Stefaan Vandenberghe
- MEDISIP-ELIS-IBITECH, Ghent University, Corneel Heymanslaan, 10 9000, Ghent, Belgium
| | - Francesco Giammarile
- Nuclear Medicine and Diagnostic Imaging Section, Division of Human Health, International Atomic Energy Agency, Vienna, Austria
| | - Ignasi Carrio
- Department of Radiology and Medical Physics, Hospital de Sant Pau, Barcelona, Spain
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33
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Elsinga P, Delaloye AB, Chiti A, Vandenberghe S, Giammarile F, Carrio I. Endorsement of International Consensus Radiochemistry Nomenclature Guidelines. EJNMMI Res 2019; 9:34. [PMID: 30989393 PMCID: PMC6465378 DOI: 10.1186/s13550-018-0469-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 11/08/2018] [Indexed: 11/10/2022] Open
Affiliation(s)
- Philip Elsinga
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Hanzeplein 1, Groningen, 9713 EZ, The Netherlands.
| | - Angelika Bischof Delaloye
- Nuclear Medicine Service, Centre Hospitalier Universitaire Vaudois, Bugnon 46, 1011, Lausanne, Switzerland
| | - Arturo Chiti
- Department of Biomedical Sciences, Humanitas University, Milan, Italy.,Department of Diagnostic Imaging, Humanitas Clinical and Research Center - IRCCS, Milan, Italy
| | - Stefaan Vandenberghe
- MEDISIP-ELIS-IBITECH, Ghent University, Corneel Heymanslaan 10, 9000, Gent, Belgium
| | - Francesco Giammarile
- Nuclear Medicine and Diagnostic Imaging Section, Division of Human Health, International Atomic Energy Agency, Vienna, Austria
| | - Ignasi Carrio
- Department of Radiology and Medical Physics, Hospital de Sant Pau, Barcelona, Spain
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34
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Elsinga P, Delaloye AB, Chiti A, Vandenberghe S, Giammarile F, Carrio I. Endorsement of International Consensus Radiochemistry Nomenclature Guidelines. EJNMMI Phys 2019; 6:6. [PMID: 30989452 PMCID: PMC6465374 DOI: 10.1186/s40658-018-0237-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 11/08/2018] [Indexed: 11/10/2022] Open
Affiliation(s)
- Philip Elsinga
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713, EZ, Groningen, The Netherlands.
| | - Angelika Bischof Delaloye
- Nuclear Medicine Service, Centre Hospitalier Universitaire Vaudois, Bugnon 46, 1011, Lausanne, Switzerland
| | - Arturo Chiti
- Department of Biomedical Sciences, Humanitas University, Milan, Italy.,Department of Diagnostic Imaging, Humanitas Clinical and Research Center - IRCCS, Milan, Italy
| | - Stefaan Vandenberghe
- MEDISIP-ELIS-IBITECH, Ghent University, Corneel Heymanslaan 10, ,9000, Gent, Belgium
| | - Francesco Giammarile
- Nuclear Medicine and Diagnostic Imaging Section, Division of Human Health, International Atomic Energy Agency, Vienna, Austria
| | - Ignasi Carrio
- Department of Radiology and Medical Physics, Hospital de Sant Pau, Barcelona, Spain
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35
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Vanhove C, Descamps B, Bolcaen J, Deblaere K, Acou M, De Vos F, Boterberg T, De Wagter C, Kalala J, Giorgio H, Van Den Broecke C, Leybaert L, Decrock E, Vral A, Vandenberghe S, Van Holen R, Goethals I. SP-0110 Magnetic resonance based small animal radiotherapy in neuro-oncology. Radiother Oncol 2019. [DOI: 10.1016/s0167-8140(19)30530-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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36
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Marcinkowski R, Keereman V, Van Holen R, Vandenberghe S, Van Bockstal M, Van Dorpe J, Brans B, Goker M, Depypere H, Van den Broecke R. Abstract P3-13-04: 18F-FDG micro-PET/CT for intraoperative margin assessment in breast conserving surgery using: A proof-of-concept study. Cancer Res 2019. [DOI: 10.1158/1538-7445.sabcs18-p3-13-04] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Positive surgical margins represent a high risk for adverse clinical outcome in breast conserving surgery (BCS). Therefore, the goal of BCS is to avoid positive margins and hence avoid reoperation. Unfortunately, most studies currently assess the rate of positive resection margins at 20%. This is in part due to the lack of a time- and cost-effective method for intraoperative margin assessment, which would enable the prediction of positive margins during the initial surgery. We propose to address this problem by performing intraoperative high-resolution 18F-fluoro-deoxyglucose (FDG) positron emission tomography (PET) with X-ray computed tomography (CT). This method relies on the high sensitivity of FDG-PET for detecting metabolically active tumor tissue, and the delineation of the anatomical margins of the specimen using CT. In this proof-of-concept study we assess the feasibility of this technique.
Twenty patients with breast cancer that were eligible to undergo BCS were enrolled in the study after providing informed consent. The study was approved by the Ethics Committee of Ghent University Hospital. Prior to surgery each patient was administered 4 MBq/kg of FDG. Surgery was performed 2-4 hours after tracer administration. Following surgical excision the breast specimen was oriented with sutures and micro-PET/CT images were obtained using the MOLECUBES β-CUBE (PET) and X-CUBE (CT). The scan time was 10 minutes on PET and 3 minutes on CT. The specimen was then sent for histopathological assessment. Micro-PET/CT images were analyzed using an automated algorithm. Briefly, this algorithm defined the contour of the tumor as the region with high FDG uptake and the contour of the specimen based on the CT image. The margin status of a specimen was positive if the distance between the contour of the tumor and specimen was 0 mm. Images were also analyzed postoperatively by two surgeons blinded to the histopathological and algorithm analysis results. The sensitivity and specificity of the proposed method were then calculated by comparing to the histopathological results, which is the gold standard for margin status assessment.
In all samples a region with high FDG uptake was visualized, which corresponded to the tumor on histopathological. In one specific case a small satellite lesion with high FDG uptake, 3 mm in diameter, was detected on the micro-PET images at a distance from the main tumor. Histopathological confirmed that this previously undetected lesion was a second invasive carcinoma. For margin status, a sensitivity of 75% and specificity of 75% were obtained using automated algorithm analysis. Sensitivity and specificity obtained based on surgeons' analysis was 62,5% and 75% for surgeon A and 87,5% and 91,7% for surgeon B respectively. Taking into account the intra-operative micro-PET results could theoretically have reduced the reoperation rate by 75%.
This proof-of-concept study demonstrates that high-resolution intraoperative FDG-PET/CT is a promising technique for intraoperative margin assessment in BCS that could allow to reduce re-excision rate. This technique achieves both sufficient sensitivity and specificity with minimal disruption of intraoperative workflow.
Citation Format: Marcinkowski R, Keereman V, Van Holen R, Vandenberghe S, Van Bockstal M, Van Dorpe J, Brans B, Goker M, Depypere H, Van den Broecke R. 18F-FDG micro-PET/CT for intraoperative margin assessment in breast conserving surgery using: A proof-of-concept study [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-13-04.
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Affiliation(s)
- R Marcinkowski
- MOLECUBES NV, Ghent, Belgium; MEDISIP, Ghent University, Ghent, Belgium; Ghent University Hospital, Ghent, Belgium
| | - V Keereman
- MOLECUBES NV, Ghent, Belgium; MEDISIP, Ghent University, Ghent, Belgium; Ghent University Hospital, Ghent, Belgium
| | - R Van Holen
- MOLECUBES NV, Ghent, Belgium; MEDISIP, Ghent University, Ghent, Belgium; Ghent University Hospital, Ghent, Belgium
| | - S Vandenberghe
- MOLECUBES NV, Ghent, Belgium; MEDISIP, Ghent University, Ghent, Belgium; Ghent University Hospital, Ghent, Belgium
| | - M Van Bockstal
- MOLECUBES NV, Ghent, Belgium; MEDISIP, Ghent University, Ghent, Belgium; Ghent University Hospital, Ghent, Belgium
| | - J Van Dorpe
- MOLECUBES NV, Ghent, Belgium; MEDISIP, Ghent University, Ghent, Belgium; Ghent University Hospital, Ghent, Belgium
| | - B Brans
- MOLECUBES NV, Ghent, Belgium; MEDISIP, Ghent University, Ghent, Belgium; Ghent University Hospital, Ghent, Belgium
| | - M Goker
- MOLECUBES NV, Ghent, Belgium; MEDISIP, Ghent University, Ghent, Belgium; Ghent University Hospital, Ghent, Belgium
| | - H Depypere
- MOLECUBES NV, Ghent, Belgium; MEDISIP, Ghent University, Ghent, Belgium; Ghent University Hospital, Ghent, Belgium
| | - R Van den Broecke
- MOLECUBES NV, Ghent, Belgium; MEDISIP, Ghent University, Ghent, Belgium; Ghent University Hospital, Ghent, Belgium
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Marcinkowski R, Keereman V, Van Holen R, Vandenberghe S, Van Bockstal M, Van Dorpe J, Brans B, Depypere H, Van den Broecke R. Intraoperative margin assessment for breast conserving surgery using 18F-FDG micro-PET/CT: a proof-of-concept study. Eur J Surg Oncol 2019. [DOI: 10.1016/j.ejso.2018.10.141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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Hubeau M, Mincke J, Vanhove C, Courtyn J, Vandenberghe S, Steppe K. Plant-PET to investigate phloem vulnerability to drought in Populus tremula under changing climate regimes. Tree Physiol 2019; 39:211-221. [PMID: 30597097 DOI: 10.1093/treephys/tpy131] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 10/24/2018] [Accepted: 11/06/2018] [Indexed: 05/26/2023]
Abstract
Phloem transport is of great importance in trees to distribute assimilated carbon across the entire tree. Nevertheless, knowledge of phloem is incomplete, because of the complexity of measuring its transport and characteristics. Only few studies have addressed how phloem transport might alter under climatic changes, with most data originating from theoretical studies. We measured phloem characteristics in leaves of young Populus tremula L. trees grown during 5 months under ambient (TA, 404 ppm ± 5) and elevated (TE, 659 ppm ± 3) atmospheric CO2 concentration ([CO2]) using a combination of positron emission tomography (PET) and compartmental modelling. Short-term phloem dynamics were measured in vivo and non-invasively using the short-lived isotope of carbon, 11C (half-life 20.4 min). Trees were scanned in well-watered and dry conditions to assess changes in phloem characteristics induced by drought. Reliability of the PET-derived results was verified with reported observations in the literature. Phloem speed was highest in well-watered TE trees and strongly reduced by 81% under drought, whereas phloem speed reduced by 61% in TA trees at the same level of drought. These findings led us to speculate that phloem transport in TE trees might be more vulnerable to drought. We discuss how a higher phloem vulnerability to drought in a changing climate could impact tree hydraulic functioning. Taken together our results suggest that trees grown for 5 months under elevated [CO2] seem to be less well-acclimated to face projected hotter droughts in a changing climate.
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Affiliation(s)
- Michiel Hubeau
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Jens Mincke
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
- Medical Imaging and Signal Processing - Innovative Flemish In-vivo Imaging Technology, Department of Electronics and Information Systems, Faculty of Engineering and Architecture, Ghent University, Ghent, Belgium
| | - Christian Vanhove
- Medical Imaging and Signal Processing - Innovative Flemish In-vivo Imaging Technology, Department of Electronics and Information Systems, Faculty of Engineering and Architecture, Ghent University, Ghent, Belgium
| | - Jan Courtyn
- Medical Molecular Imaging and Therapy, Department of Radiology and Nuclear Medicine, Ghent University Hospital, Ghent, Belgium
| | - Stefaan Vandenberghe
- Medical Imaging and Signal Processing - Innovative Flemish In-vivo Imaging Technology, Department of Electronics and Information Systems, Faculty of Engineering and Architecture, Ghent University, Ghent, Belgium
| | - Kathy Steppe
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
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Marin G, Vanderlinden B, Karfis I, Guiot T, Wimana Z, Reynaert N, Vandenberghe S, Flamen P. A dosimetry procedure for organs-at-risk in 177Lu peptide receptor radionuclide therapy of patients with neuroendocrine tumours. Phys Med 2018; 56:41-49. [PMID: 30527088 DOI: 10.1016/j.ejmp.2018.11.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 10/05/2018] [Accepted: 11/02/2018] [Indexed: 01/25/2023] Open
Abstract
PURPOSE Peptide receptor radionuclide therapy with 177Lu-DOTATATE has become a standard treatment modality in neuroendocrine tumours (NETs). No consensus has yet been reached however regarding the absorbed dose threshold for lesion response, the absorbed dose limit to organs-at-risk, and the optimal fractionation and activity to be administered. This is partly due to a lack of uniform and comparable dosimetry protocols. The present article details the development of an organ-at-risk dosimetry procedure, which could be implemented and used routinely in a clinical context. METHODS Forty-seven patients with NETs underwent 177Lu-DOTATATE therapy. Three SPECT/CT images were acquired at 4, 24 and 144-192 h post-injection. Three blood samples were obtained together with the SPECT/CT acquisitions and 2 additional samples were obtained around 30 min and 1 h post-injection. A bi-exponential fit was used to compute the source organ time-integrated activity coefficients. Coefficients were introduced into OLINDA/EXM software to compute organ-at-risk absorbed doses. Median values for all patients were computed for absorbed dose coefficient D/A0 and for late effective half-life T1/2eff for kidneys, spleen and red marrow. RESULTS Dosimetry resulted in a median[interquartile range] of 0.78[0.35], 1.07[0.58] and 0.028[0.010] Gy/GBq for D/A0 and of 55[9], 71[9] and 52[18] h for T1/2eff for kidneys, spleen and red marrow respectively. CONCLUSIONS A dosimetry procedure for organs-at-risk in 177Lu-DOTATATE therapy based on serial SPECT/CT images and blood samples can be implemented routinely in a clinical context with limited patient burden. The results obtained were in accordance with those of other centres.
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Affiliation(s)
- Gwennaëlle Marin
- Department of Medical Physics, Institut Jules Bordet-Université Libre de Bruxelles (ULB), 121 boulevard de Waterloo, 1000 Brussels, Belgium; Medical Imaging and Signal Processing (MEDISIP), Department of Electronics and Information Systems (ELIS), Faculty of Engineering and Architecture (FEA), Ghent University (UGent), 185 De Pintelaan, 9000 Gent, Belgium.
| | - Bruno Vanderlinden
- Department of Medical Physics, Institut Jules Bordet-Université Libre de Bruxelles (ULB), 121 boulevard de Waterloo, 1000 Brussels, Belgium.
| | - Ioannis Karfis
- Department of Nuclear Medicine, Institut Jules Bordet-Université Libre de Bruxelles (ULB), 121 boulevard de Waterloo, 1000 Brussels, Belgium.
| | - Thomas Guiot
- Department of Medical Physics, Institut Jules Bordet-Université Libre de Bruxelles (ULB), 121 boulevard de Waterloo, 1000 Brussels, Belgium.
| | - Zena Wimana
- Department of Nuclear Medicine, Institut Jules Bordet-Université Libre de Bruxelles (ULB), 121 boulevard de Waterloo, 1000 Brussels, Belgium.
| | - Nick Reynaert
- Department of Medical Physics, Institut Jules Bordet-Université Libre de Bruxelles (ULB), 121 boulevard de Waterloo, 1000 Brussels, Belgium.
| | - Stefaan Vandenberghe
- Medical Imaging and Signal Processing (MEDISIP), Department of Electronics and Information Systems (ELIS), Faculty of Engineering and Architecture (FEA), Ghent University (UGent), 185 De Pintelaan, 9000 Gent, Belgium.
| | - Patrick Flamen
- Department of Nuclear Medicine, Institut Jules Bordet-Université Libre de Bruxelles (ULB), 121 boulevard de Waterloo, 1000 Brussels, Belgium.
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Ciarrocchi E, Vanhove C, Descamps B, De Lombaerde S, Vandenberghe S, Belcari N. Performance evaluation of the LightPath imaging system for intra-operative Cerenkov luminescence imaging. Phys Med 2018; 52:122-128. [PMID: 30139600 DOI: 10.1016/j.ejmp.2018.07.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 07/13/2018] [Accepted: 07/14/2018] [Indexed: 01/17/2023] Open
Abstract
The performances of an intra-operative optical imaging system for Cerenkov luminescence imaging of resected tumor specimens were evaluated with phantom studies. The spatial resolution, the linearity of the measured signal with the activity concentration and the minimum detectable activity concentration were considered. A high linearity was observed over a broad range of activity concentration (R2⩾0.99 down to ∼40 kBq/ml of 18F-FDG). For 18F-FDG activity distributions 2 mm deep in biological tissue, the measured detection limit was 8 kBq/ml and a spatial resolution of 2.5 mm was obtained. The detection limit of the imaging system is comparable with clinical activity concentrations in tumor specimens, and the spatial resolution is compatible with clinical requirements.
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Affiliation(s)
- Esther Ciarrocchi
- University of Pisa, Department of Physics, Largo Bruno Pontecorvo 3, Pisa 56127, Italy.
| | - Christian Vanhove
- University of Ghent, IBiTech-MEDISIP, C. Heymanslaan 10, Ghent B-9000, Belgium.
| | - Benedicte Descamps
- University of Ghent, IBiTech-MEDISIP, C. Heymanslaan 10, Ghent B-9000, Belgium.
| | - Stef De Lombaerde
- University of Ghent, Faculty of Pharmaceutical Sciences Laboratory of Radiopharmacy, Ottergemsesteenweg 460, Ghent B-9000, Belgium.
| | | | - Nicola Belcari
- University of Pisa, Department of Physics, Largo Bruno Pontecorvo 3, Pisa 56127, Italy.
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Benoit DD, Jensen HI, Malmgren J, Metaxa V, Reyners AK, Darmon M, Rusinova K, Talmor D, Meert AP, Cancelliere L, Zubek L, Maia P, Michalsen A, Vanheule S, Kompanje EJO, Decruyenaere J, Vandenberghe S, Vansteelandt S, Gadeyne B, Van den Bulcke B, Azoulay E, Piers RD. Outcome in patients perceived as receiving excessive care across different ethical climates: a prospective study in 68 intensive care units in Europe and the USA. Intensive Care Med 2018; 44:1039-1049. [PMID: 29808345 PMCID: PMC6061457 DOI: 10.1007/s00134-018-5231-8] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Accepted: 05/14/2018] [Indexed: 01/01/2023]
Abstract
Purpose Whether the quality of the ethical climate in the intensive care unit (ICU) improves the identification of patients receiving excessive care and affects patient outcomes is unknown. Methods In this prospective observational study, perceptions of excessive care (PECs) by clinicians working in 68 ICUs in Europe and the USA were collected daily during a 28-day period. The quality of the ethical climate in the ICUs was assessed via a validated questionnaire. We compared the combined endpoint (death, not at home or poor quality of life at 1 year) of patients with PECs and the time from PECs until written treatment-limitation decisions (TLDs) and death across the four climates defined via cluster analysis. Results Of the 4747 eligible clinicians, 2992 (63%) evaluated the ethical climate in their ICU. Of the 321 and 623 patients not admitted for monitoring only in ICUs with a good (n = 12, 18%) and poor (n = 24, 35%) climate, 36 (11%) and 74 (12%), respectively were identified with PECs by at least two clinicians. Of the 35 and 71 identified patients with an available combined endpoint, 100% (95% CI 90.0–1.00) and 85.9% (75.4–92.0) (P = 0.02) attained that endpoint. The risk of death (HR 1.88, 95% CI 1.20–2.92) or receiving a written TLD (HR 2.32, CI 1.11–4.85) in patients with PECs by at least two clinicians was higher in ICUs with a good climate than in those with a poor one. The differences between ICUs with an average climate, with (n = 12, 18%) or without (n = 20, 29%) nursing involvement at the end of life, and ICUs with a poor climate were less obvious but still in favour of the former. Conclusion Enhancing the quality of the ethical climate in the ICU may improve both the identification of patients receiving excessive care and the decision-making process at the end of life. Electronic supplementary material The online version of this article (10.1007/s00134-018-5231-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- D D Benoit
- Department of Intensive Care Medicine, Ghent University Hospital, Corneel Heymanslaan 10, Ghent, Belgium.
| | - H I Jensen
- Department of Intensive Care Medicine, Vejle Hospital, Vejle, Denmark
- Institute of Regional Research, University of Southern Denmark, Odense C, Denmark
| | - J Malmgren
- Department of Anaesthesiology and Intensive Care, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - V Metaxa
- King's College Hospital, London, UK
| | - A K Reyners
- Department of Medical Oncology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - M Darmon
- Hôpital Saint-Louis and University, Paris-7, Paris, France
| | - K Rusinova
- Department of Anesthesiology and Intensive Care, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Prague, Czech Republic
| | - D Talmor
- Department of Anesthesia, Critical Care, and Pain Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - A P Meert
- Service des soins intensifs et urgences oncologiques, Institut Jules Bordet, ULB, Brussels, Belgium
| | - L Cancelliere
- SCDU Anestesia e Rianimazione, Azienda and Ospedaliero Universitaria, "Maggiore della Carità", Novara, Italy
| | - L Zubek
- Semmelweis University Budapest, Budapest, Hungary
| | - P Maia
- Intensive Care Department, Hospital S.António, Porto, Portugal
| | | | - S Vanheule
- Department of Psycho-analysis and Clinical Consulting, Faculty of Psychology and Educational Sciences, Ghent University, Ghent, Belgium
| | - E J O Kompanje
- Department of Intensive Care Medicine, Erasmus MC University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - J Decruyenaere
- Department of Intensive Care Medicine, Ghent University Hospital, Corneel Heymanslaan 10, Ghent, Belgium
| | - S Vandenberghe
- Department of Applied Mathematics, Computer Science and Statistics, Faculty of Sciences, Ghent University, Ghent, Belgium
| | - S Vansteelandt
- Department of Applied Mathematics, Computer Science and Statistics, Faculty of Sciences, Ghent University, Ghent, Belgium
- London School of Hygiene and Tropical Medicine, London, UK
| | - B Gadeyne
- Department of Intensive Care Medicine, Ghent University Hospital, Corneel Heymanslaan 10, Ghent, Belgium
| | - B Van den Bulcke
- Department of Intensive Care Medicine, Ghent University Hospital, Corneel Heymanslaan 10, Ghent, Belgium
| | - E Azoulay
- Hôpital Saint-Louis and University, Paris-7, Paris, France
| | - R D Piers
- Department of Geriatric Medicine, Ghent University Hospital, Ghent, Belgium
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Abstract
A new mock circulatory system (MCS) was designed to evaluate and characterise the hydraulic performance of ventricular assist devices (VADs). The MCS consists of a preload section and a multipurpose afterload section, with an adjustable compliance chamber (C) and peripheral resistor (Rp) as principal components. The MCS was connected to a pulse duplicator system for validation, simulating a wide range of afterload conditions. Both pressure and flow were measured, and the values of the different components calculated. The data perfectly fits a 4-element electrical analogon (EA). The MCS was further used to assess the hydrodynamic characteristics of the Medos VAD as an example of a displacement pump. Data was measured for various MCS settings and at different pump rates, yielding device specific pump function graphs for water and pig blood. Our data demonstrate (i) flow sensitivity to preload and afterload and (ii) the effect of test fluid on hemodynamic performance.
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Affiliation(s)
| | - P. Segers
- IBITECH, Ghent University, Gent - Belgium
| | - B. Meyns
- Department for Cardiac Surgery, University Hospital Leuven, Leuven - Belgium
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Binzel K, Adelaja A, Wright CL, Scharre D, Zhang J, Knopp MV, Teoh EJ, Bottomley D, Scarsbrook A, Payne H, Afaq A, Bomanji J, van As N, Chua S, Hoskin P, Chambers A, Cook GJ, Warbey VS, Chau A, Ward P, Miller MP, Stevens DJ, Wilson L, Gleeson FV, Scheidhauer K, Seidl C, Autenrieth M, Bruchertseifer F, Apostolidis C, Kurtz F, Horn T, Pfob C, Schwaiger M, Gschwend J, D'Alessandria C, Morgenstern A, Uprimny C, Kroiss A, Decristoforo C, von Guggenberg E, Nilica B, Horninger W, Virgolini I, Rasul S, Poetsch N, Woehrer A, Preusser M, Mitterhauser M, Wadsak W, Widhalm G, Mischkulnig M, Hacker M, Traub-Weidinger T, Wright CL, Binzel K, Wuthrick EJ, Miller ED, Maniawski P, Zhang J, Knopp MV, Rep S, Hocevar M, Vaupotic J, Zdesar U, Zaletel K, Lezaic L, Mairinger S, Filip T, Sauberer M, Flunkert S, Wanek T, Stanek J, Okamura N, Langer O, Kuntner C, Fornito MC, Balzano R, Di Martino V, Cacciaguerra S, Russo G, Seifert D, Kleinova M, Cepa A, Ralis J, Hanc P, Lebeda O, Mosa M, Vandenberghe S, Mikhaylova E, Borys D, Viswanath V, Stockhoff M, Efthimiou N, Caribe P, Van Holen R, Karp JS, Binzel K, Zhang J, Wright CL, Maniawski P, Knopp MV, Haller PM, Farhan C, Piackova E, Jäger B, Knoll P, Kiss A, Podesser BK, Wojta J, Huber K, Mirzaei S, Traxl A, Komposch K, Glitzner E, Wanek T, Mairinger S, Sibilia M, Langer O, Fornito MC, Russello M, Russo G, Balzano R, Sorko S, Gallowitsch HJ, Kohlfuerst S, Matschnig S, Rieser M, Sorschag M, Lind P, Ležaič L, Rep S, Žibert J, Frelih N, Šuštar S, Binzel K, Adelaja A, Wright CL, Scharre D, Zhang J, Knopp MV, Baum RP, Langbein T, Singh A, Shahinfar M, Schuchardt C, Volk GF, Kulkarni HR, Fornito MC, Cacciaguerra S, Balzano R, Di Martino GV, Russo G, Thomson WH, Kudlacek M, Karik M, Farhan C, Rieger H, Pokieser W, Glaser K, Mirzaei S, Petz V, Tugendsam C, Buchinger W, Schmoll-Hauer B, Schenk IP, Rudolph K, Krebs M, Zettinig G, Zoufal V, Wanek T, Krohn M, Mairinger S, Stanek J, Sauberer M, Filip T, Pahnke J, Langer O, Weitzer F, Pernthaler B, Salamon S, Aigner R, Koranda P, Henzlová L, Kamínek M, Váchalová M, Bachleda P, Summer D, Garousi J, Oroujeni M, Mitran B, Andersson KG, Vorobyeva A, Löfblom JN, Orlova A, Tolmachev V, Decristoforo C, Kaeopookum P, Summer D, Orasch T, Lechner B, Petrik M, Novy Z, Rangger C, Haas H, Decristoforo C. Abstracts of the 33rd International Austrian Winter Symposium : Zell am See, Austria. 24-27 January 2018. EJNMMI Res 2018; 8:5. [PMID: 29362999 PMCID: PMC5780335 DOI: 10.1186/s13550-017-0354-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- K Binzel
- Wright Center of Innovation in Biomedical Imaging, Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - A Adelaja
- Wright Center of Innovation in Biomedical Imaging, Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - C L Wright
- Wright Center of Innovation in Biomedical Imaging, Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - D Scharre
- Department of Neurology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - J Zhang
- Wright Center of Innovation in Biomedical Imaging, Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - M V Knopp
- Wright Center of Innovation in Biomedical Imaging, Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - E J Teoh
- Departments of Radiology and Nuclear Medicine, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - D Bottomley
- The Leeds Teaching Hospitals NHS Trust, Leeds, UK
| | - A Scarsbrook
- The Leeds Teaching Hospitals NHS Trust, Leeds, UK
| | - H Payne
- University College London, London, UK
| | - A Afaq
- University College London, London, UK
| | - J Bomanji
- University College London, London, UK
| | - N van As
- The Royal Marsden NHS Foundation Trust, London, UK
| | - S Chua
- The Royal Marsden NHS Foundation Trust, London, UK
| | - P Hoskin
- Mount Vernon Cancer Centre, London, UK
| | | | - G J Cook
- King's College London, London, UK
| | | | - A Chau
- Blue Earth Diagnostics, Oxford, UK
| | - P Ward
- Blue Earth Diagnostics, Oxford, UK
| | | | | | - L Wilson
- Blue Earth Diagnostics, Oxford, UK
| | - F V Gleeson
- Departments of Radiology and Nuclear Medicine, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - K Scheidhauer
- TU München, Klinikum rechts der Isar, Nuklearmedizin, München, Germany
| | - C Seidl
- TU München, Klinikum rechts der Isar, Nuklearmedizin, München, Germany
| | - M Autenrieth
- TU München, Klinikum rechts der Isar, Urologie, München, Germany
| | | | | | - F Kurtz
- TU München, Klinikum rechts der Isar, Urologie, München, Germany
| | - T Horn
- TU München, Klinikum rechts der Isar, Urologie, München, Germany
| | - C Pfob
- TU München, Klinikum rechts der Isar, Nuklearmedizin, München, Germany
| | - M Schwaiger
- TU München, Klinikum rechts der Isar, Nuklearmedizin, München, Germany
| | - J Gschwend
- TU München, Klinikum rechts der Isar, Urologie, München, Germany
| | - C D'Alessandria
- TU München, Klinikum rechts der Isar, Nuklearmedizin, München, Germany
| | | | - C Uprimny
- Department of Nuclear Medicine, Medical University Innsbruck, Anichstrasse 32, 6020, Innsbruck, Austria
| | - A Kroiss
- Department of Nuclear Medicine, Medical University Innsbruck, Anichstrasse 32, 6020, Innsbruck, Austria
| | - C Decristoforo
- Department of Nuclear Medicine, Medical University Innsbruck, Anichstrasse 32, 6020, Innsbruck, Austria
| | - E von Guggenberg
- Department of Nuclear Medicine, Medical University Innsbruck, Anichstrasse 32, 6020, Innsbruck, Austria
| | - B Nilica
- Department of Nuclear Medicine, Medical University Innsbruck, Anichstrasse 32, 6020, Innsbruck, Austria
| | - W Horninger
- Department of Nuclear Medicine, Medical University Innsbruck, Anichstrasse 32, 6020, Innsbruck, Austria
| | - I Virgolini
- Department of Nuclear Medicine, Medical University Innsbruck, Anichstrasse 32, 6020, Innsbruck, Austria
| | - S Rasul
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - N Poetsch
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - A Woehrer
- Clinical Institute of Neurology, Medical University of Vienna, Vienna, Austria
| | - M Preusser
- Clinical University of Internal Medicine I, Medical University of Vienna, Vienna, Austria
| | - M Mitterhauser
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - W Wadsak
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
- CBmed GmbH, Center for Biomarker Research in Medicine, Graz, Austria
| | - G Widhalm
- Clinical University of Neuro-surgery, Medical University of Vienna, Vienna, Austria
| | - M Mischkulnig
- Clinical University of Neuro-surgery, Medical University of Vienna, Vienna, Austria
| | - M Hacker
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - T Traub-Weidinger
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - C L Wright
- Wright Center of Innovation, The Ohio State University, Columbus, OH, USA
| | - K Binzel
- Wright Center of Innovation, The Ohio State University, Columbus, OH, USA
| | - E J Wuthrick
- Radiation Oncology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - E D Miller
- Radiation Oncology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - P Maniawski
- Clinical Science, Philips Healthcare, Cleveland, OH, USA
| | - J Zhang
- Wright Center of Innovation, The Ohio State University, Columbus, OH, USA
| | - M V Knopp
- Wright Center of Innovation, The Ohio State University, Columbus, OH, USA
| | - Sebastijan Rep
- Department of Nuclear Medicine, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Marko Hocevar
- Department of Oncological Surgery, Oncology Institute Ljubljana, Ljubljana, Slovenia
| | | | - Urban Zdesar
- Institute of Occupational Safety Ljubljana, Ljubljana, Slovenia
| | - Katja Zaletel
- Department of Nuclear Medicine, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Luka Lezaic
- Department of Nuclear Medicine, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - S Mairinger
- Biomedical Systems, Center for Health & Bioresources, AIT Austrian Institute of Technology GmbH, Seibersdorf, Austria
| | - Thomas Filip
- Biomedical Systems, Center for Health & Bioresources, AIT Austrian Institute of Technology GmbH, Seibersdorf, Austria
| | - M Sauberer
- Biomedical Systems, Center for Health & Bioresources, AIT Austrian Institute of Technology GmbH, Seibersdorf, Austria
| | - S Flunkert
- Neuropharmacology, QPS Austria GmbH, Grambach, Austria
| | - T Wanek
- Biomedical Systems, Center for Health & Bioresources, AIT Austrian Institute of Technology GmbH, Seibersdorf, Austria
| | - J Stanek
- Biomedical Systems, Center for Health & Bioresources, AIT Austrian Institute of Technology GmbH, Seibersdorf, Austria
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - N Okamura
- Division of Pharmacology, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - O Langer
- Biomedical Systems, Center for Health & Bioresources, AIT Austrian Institute of Technology GmbH, Seibersdorf, Austria
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - C Kuntner
- Biomedical Systems, Center for Health & Bioresources, AIT Austrian Institute of Technology GmbH, Seibersdorf, Austria
| | - M C Fornito
- Nuclear Medicine Department PET/TC center Arnas Garibaldi Catania, Catania, Italy
| | - R Balzano
- Nuclear Medicine Department PET/TC center Arnas Garibaldi Catania, Catania, Italy
| | - V Di Martino
- Nuclear Medicine Department PET/TC center Arnas Garibaldi Catania, Catania, Italy
| | - S Cacciaguerra
- Pediatric Surgery Department Arnas Garibaldi Catania, Catania, Italy
| | - G Russo
- H. Pharmacy Department Arnas Garibaldi Catania, Catania, Italy
| | - D Seifert
- Nuclear Physics Institute of the CAS, Rez, Czech Republic
| | - M Kleinova
- Nuclear Physics Institute of the CAS, Rez, Czech Republic
| | - A Cepa
- Nuclear Physics Institute of the CAS, Rez, Czech Republic
| | - J Ralis
- Nuclear Physics Institute of the CAS, Rez, Czech Republic
| | - P Hanc
- Nuclear Physics Institute of the CAS, Rez, Czech Republic
| | - O Lebeda
- Nuclear Physics Institute of the CAS, Rez, Czech Republic
| | - M Mosa
- Charles university Faculty of Science Prague, Prague, Czech Republic
| | - S Vandenberghe
- MEDISIP research group, Ghent University, Ghent, Belgium
| | | | - D Borys
- Silesian University of Technology Gliwice, Gliwice, Poland
| | - V Viswanath
- PET instrumentation group, Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - M Stockhoff
- MEDISIP research group, Ghent University, Ghent, Belgium
| | - N Efthimiou
- MEDISIP research group, Ghent University, Ghent, Belgium
| | - P Caribe
- MEDISIP research group, Ghent University, Ghent, Belgium
| | - R Van Holen
- MEDISIP research group, Ghent University, Ghent, Belgium
| | - J S Karp
- PET instrumentation group, Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - K Binzel
- Wright Center of Innovation in Biomedical Imaging, Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - J Zhang
- Wright Center of Innovation in Biomedical Imaging, Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - C L Wright
- Wright Center of Innovation in Biomedical Imaging, Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | | | - M V Knopp
- Wright Center of Innovation in Biomedical Imaging, Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - P M Haller
- 3rd Department of Medicine, Cardiology and Intensive Care Medicine, Chest Pain Unit, Wilhelminenhospital Vienna, Vienna, Austria
- Ludwig Boltzmann Cluster for Cardiovascular Research, Vienna, Austria
| | - C Farhan
- Department of Nuclear Medicine with PET-Center, Wilhelminenhospital, Vienna, Austria
| | - E Piackova
- 3rd Department of Medicine, Cardiology and Intensive Care Medicine, Chest Pain Unit, Wilhelminenhospital Vienna, Vienna, Austria
- Ludwig Boltzmann Cluster for Cardiovascular Research, Vienna, Austria
| | - B Jäger
- 3rd Department of Medicine, Cardiology and Intensive Care Medicine, Chest Pain Unit, Wilhelminenhospital Vienna, Vienna, Austria
- Ludwig Boltzmann Cluster for Cardiovascular Research, Vienna, Austria
- Department of Internal Medicine II, Division of Cardiology, Medical University of Vienna, Vienna, Austria
| | - P Knoll
- Department of Nuclear Medicine with PET-Center, Wilhelminenhospital, Vienna, Austria
| | - A Kiss
- Department of Biomedical Research, Medical University of Vienna, Vienna, Austria
| | - B K Podesser
- Ludwig Boltzmann Cluster for Cardiovascular Research, Vienna, Austria
- Department of Biomedical Research, Medical University of Vienna, Vienna, Austria
| | - J Wojta
- Ludwig Boltzmann Cluster for Cardiovascular Research, Vienna, Austria
- Department of Internal Medicine II, Division of Cardiology, Medical University of Vienna, Vienna, Austria
| | - K Huber
- 3rd Department of Medicine, Cardiology and Intensive Care Medicine, Chest Pain Unit, Wilhelminenhospital Vienna, Vienna, Austria
- Ludwig Boltzmann Cluster for Cardiovascular Research, Vienna, Austria
- Sigmund Freud University, Medical Faculty, Vienna, Austria
| | - S Mirzaei
- Department of Nuclear Medicine with PET-Center, Wilhelminenhospital, Vienna, Austria
| | - A Traxl
- Center for Health & Bioresources, Biomedical Systems, AIT Austrian Institute of Technology GmbH, Seibersdorf, Austria
| | - K Komposch
- Institute of Cancer Research, Department of Medicine I, Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
| | - Elisabeth Glitzner
- Institute of Cancer Research, Department of Medicine I, Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
| | - T Wanek
- Center for Health & Bioresources, Biomedical Systems, AIT Austrian Institute of Technology GmbH, Seibersdorf, Austria
| | - S Mairinger
- Center for Health & Bioresources, Biomedical Systems, AIT Austrian Institute of Technology GmbH, Seibersdorf, Austria
| | - M Sibilia
- Institute of Cancer Research, Department of Medicine I, Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
| | - O Langer
- Center for Health & Bioresources, Biomedical Systems, AIT Austrian Institute of Technology GmbH, Seibersdorf, Austria
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
- Department of Biomedical Imaging and Image-Guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - M C Fornito
- Nuclear Medicine Department PET/TC Center ARNAS Garibaldi, Catania, Italy
| | - M Russello
- Liver Unit ARNAS Garibaldi, Catania, Italy
| | - G Russo
- H.Pharmacy Department ARNAS Garibaldi, Catania, Italy
| | - R Balzano
- Nuclear Medicine Department PET/TC Center ARNAS Garibaldi, Catania, Italy
| | - S Sorko
- Department of Nuclear Medicine and Endocrinology, PET/CT Center, Klinikum Klagenfurt, Klagenfurt, Austria
| | - H J Gallowitsch
- Department of Nuclear Medicine and Endocrinology, PET/CT Center, Klinikum Klagenfurt, Klagenfurt, Austria
| | - S Kohlfuerst
- Department of Nuclear Medicine and Endocrinology, PET/CT Center, Klinikum Klagenfurt, Klagenfurt, Austria
| | - S Matschnig
- Department of Nuclear Medicine and Endocrinology, PET/CT Center, Klinikum Klagenfurt, Klagenfurt, Austria
| | - M Rieser
- Department of Nuclear Medicine and Endocrinology, PET/CT Center, Klinikum Klagenfurt, Klagenfurt, Austria
| | - M Sorschag
- Department of Nuclear Medicine and Endocrinology, PET/CT Center, Klinikum Klagenfurt, Klagenfurt, Austria
| | - P Lind
- Department of Nuclear Medicine and Endocrinology, PET/CT Center, Klinikum Klagenfurt, Klagenfurt, Austria
| | - L Ležaič
- Departments of Nuclear Medicine, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - S Rep
- Departments of Nuclear Medicine, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - J Žibert
- Faculty of Health Sciences, University of Ljubljana, Ljubljana, Slovenia
| | - N Frelih
- Departments of Nuclear Medicine, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - S Šuštar
- Departments of Nuclear Medicine, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - K Binzel
- Wright Center of Innovation in Biomedical Imaging, Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - A Adelaja
- Wright Center of Innovation in Biomedical Imaging, Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - C L Wright
- Wright Center of Innovation in Biomedical Imaging, Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - D Scharre
- Department of Neurology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - J Zhang
- Wright Center of Innovation in Biomedical Imaging, Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - M V Knopp
- Wright Center of Innovation in Biomedical Imaging, Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - R P Baum
- Theranostics Center for Molecular Radiotherapy and Molecular ImagZentralklinik Bad Berka, Bad Berka, Germany
| | - T Langbein
- Theranostics Center for Molecular Radiotherapy and Molecular ImagZentralklinik Bad Berka, Bad Berka, Germany
| | - A Singh
- Theranostics Center for Molecular Radiotherapy and Molecular ImagZentralklinik Bad Berka, Bad Berka, Germany
| | - M Shahinfar
- Theranostics Center for Molecular Radiotherapy and Molecular ImagZentralklinik Bad Berka, Bad Berka, Germany
| | - C Schuchardt
- Theranostics Center for Molecular Radiotherapy and Molecular ImagZentralklinik Bad Berka, Bad Berka, Germany
| | - G F Volk
- Department of Otorhinolaryngology, Jena University Hospital, Jena, Germany
| | - H R Kulkarni
- Theranostics Center for Molecular Radiotherapy and Molecular ImagZentralklinik Bad Berka, Bad Berka, Germany
| | - M C Fornito
- Nuclear Medicine Department Arnas Garibaldi, Catania, Italy
| | | | - R Balzano
- Nuclear Medicine Department Arnas Garibaldi, Catania, Italy
| | - G V Di Martino
- Department of Otorhinolaryngology, Jena University Hospital, Jena, Germany
| | - G Russo
- Pharmacy H. Department Arnas Garibaldi, Catania, Italy
| | - W H Thomson
- Physics and Nuclear Medicine, City Hospital, Birmingham, UK
| | - M Kudlacek
- Institute of Nuclear Medicine with PET-Center, Wilhelminenspital, Vienna, Austria
| | - M Karik
- Department of Viceral and General Surgery, Wilhelminenspital, Vienna, Austria
| | - C Farhan
- Institute of Nuclear Medicine with PET-Center, Wilhelminenspital, Vienna, Austria
| | - H Rieger
- Institute of Pathology and Microbiology, Wilhelminenspital, Vienna, Austria
| | - W Pokieser
- Institute of Pathology and Microbiology, Wilhelminenspital, Vienna, Austria
| | - K Glaser
- Department of Viceral and General Surgery, Wilhelminenspital, Vienna, Austria
| | - S Mirzaei
- Institute of Nuclear Medicine with PET-Center, Wilhelminenspital, Vienna, Austria
| | - V Petz
- Schilddruesenpraxis Josefstadt, Vienna, Austria
| | - C Tugendsam
- Schilddruesenpraxis Josefstadt, Vienna, Austria
| | - W Buchinger
- Schilddrueseninstitut Gleisdorf, Gleisdorf, Austria
| | - B Schmoll-Hauer
- Schilddruesenpraxis Josefstadt, Vienna, Austria
- Department of Nuclear Medicine, Krankenanstalt Rudolfstiftung, Vienna, Austria
| | - I P Schenk
- Schilddruesenpraxis Josefstadt, Vienna, Austria
- Department of Nuclear Medicine, Sozialmedizinisches Zentrum Hietzing, Vienna, Austria
| | - K Rudolph
- Schilddruesenpraxis Josefstadt, Vienna, Austria
| | - M Krebs
- Schilddruesenpraxis Josefstadt, Vienna, Austria
- Clinical Division of Endocrinology, Department of Medicine III, Medical University of Vienna, Vienna, Austria
| | - G Zettinig
- Schilddruesenpraxis Josefstadt, Vienna, Austria
| | - V Zoufal
- Center for Health & Bioresources, AIT Austrian Institute of Technology GmbH, Seibersdorf, Austria
| | - T Wanek
- Center for Health & Bioresources, AIT Austrian Institute of Technology GmbH, Seibersdorf, Austria
| | - M Krohn
- Department of Neuro-/Pathology, University of Oslo (UiO) and Oslo University Hospital (OUS), Oslo, Norway
| | - S Mairinger
- Center for Health & Bioresources, AIT Austrian Institute of Technology GmbH, Seibersdorf, Austria
| | - J Stanek
- Center for Health & Bioresources, AIT Austrian Institute of Technology GmbH, Seibersdorf, Austria
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - M Sauberer
- Center for Health & Bioresources, AIT Austrian Institute of Technology GmbH, Seibersdorf, Austria
| | - T Filip
- Center for Health & Bioresources, AIT Austrian Institute of Technology GmbH, Seibersdorf, Austria
| | - J Pahnke
- Department of Neuro-/Pathology, University of Oslo (UiO) and Oslo University Hospital (OUS), Oslo, Norway
| | - O Langer
- Center for Health & Bioresources, AIT Austrian Institute of Technology GmbH, Seibersdorf, Austria
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - F Weitzer
- Meduni Graz, Univ. Klinik für Radiologie, Abteilung für Nuklearmedizin, Graz, Austria
| | - B Pernthaler
- Meduni Graz, Univ. Klinik für Radiologie, Abteilung für Nuklearmedizin, Graz, Austria
| | - S Salamon
- Meduni Graz, Univ. Klinik für Radiologie, Abteilung für Nuklearmedizin, Graz, Austria
| | - R Aigner
- Meduni Graz, Univ. Klinik für Radiologie, Abteilung für Nuklearmedizin, Graz, Austria
| | - P Koranda
- Department of Nuclear Medicine, University Hospital Olomouc and Palacky University, Olomouc, Czech Republic
| | - L Henzlová
- Department of Nuclear Medicine, University Hospital Olomouc and Palacky University, Olomouc, Czech Republic
| | - M Kamínek
- Department of Nuclear Medicine, University Hospital Olomouc and Palacky University, Olomouc, Czech Republic
| | - Mo Váchalová
- Department of Vascular and Transplantation Surgery, University Hospital Olomouc and Palacky University, Olomouc, Czech Republic
| | - P Bachleda
- Department of Vascular and Transplantation Surgery, University Hospital Olomouc and Palacky University, Olomouc, Czech Republic
| | - D Summer
- Department of Nuclear Medicine, Medical University Innsbruck, Anichstrasse 35, A-6020, Innsbruck, Austria
| | - J Garousi
- Institute of Immunology, Genetic and Pathology, Uppsala University, SE-75185, Uppsala, Sweden
| | - M Oroujeni
- Institute of Immunology, Genetic and Pathology, Uppsala University, SE-75185, Uppsala, Sweden
| | - B Mitran
- Division of Molecular Imaging, Department of Medicinal Chemistry, Uppsala University, SE-751 83, Uppsala, Sweden
| | - K G Andersson
- Division of Protein Technology, KTH Royal Institute of Technology, SE-10691, Stockholm, Sweden
| | - A Vorobyeva
- Institute of Immunology, Genetic and Pathology, Uppsala University, SE-75185, Uppsala, Sweden
| | - J N Löfblom
- Division of Protein Technology, KTH Royal Institute of Technology, SE-10691, Stockholm, Sweden
| | - A Orlova
- Division of Molecular Imaging, Department of Medicinal Chemistry, Uppsala University, SE-751 83, Uppsala, Sweden
| | - V Tolmachev
- Institute of Immunology, Genetic and Pathology, Uppsala University, SE-75185, Uppsala, Sweden
| | - C Decristoforo
- Department of Nuclear Medicine, Medical University Innsbruck, Anichstrasse 35, A-6020, Innsbruck, Austria
| | - P Kaeopookum
- Department of Nuclear Medicine, Medical University Innsbruck, Innsbruck, Austria
- Research and Development Division, Thailand Institute of Nuclear Technology, Nakhonnayok, Thailand
| | - D Summer
- Department of Nuclear Medicine, Medical University Innsbruck, Innsbruck, Austria
| | - T Orasch
- Division of Molecular Biology, Biocenter, Medical University Innsbruck, Innsbruck, Austria
| | - B Lechner
- Division of Molecular Biology, Biocenter, Medical University Innsbruck, Innsbruck, Austria
| | - M Petrik
- Faculty of Medicine and Dentistry, Institute of Molecular and Translation Medicine, Palacky University, Olomouc, Czech Republic
| | - Z Novy
- Faculty of Medicine and Dentistry, Institute of Molecular and Translation Medicine, Palacky University, Olomouc, Czech Republic
| | - C Rangger
- Department of Nuclear Medicine, Medical University Innsbruck, Innsbruck, Austria
| | - H Haas
- Division of Molecular Biology, Biocenter, Medical University Innsbruck, Innsbruck, Austria
| | - C Decristoforo
- Department of Nuclear Medicine, Medical University Innsbruck, Innsbruck, Austria
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Dumont K, Segers R, Vandenberghe S, Van Nooten G, Verdonck P. Omnicarbon™ 21 mm Aortic Valve Prosthesis: In Vitro Hydrodynamic and Echo-Doppler Study. Int J Artif Organs 2018; 25:783-90. [PMID: 12296463 DOI: 10.1177/039139880202500806] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The aim of this study was to perform combined hydrodynamic and Doppler echocardiographic tests of the Omnicarbon 21 mm cardiac valve in aortic position in our Pulse Duplicator System for simultaneous assessment of valve performance and valve leakage data. During forward flow conditions, measured mean pressure gradients are between 4.5 and 20.2 mmHg (11.9 ± 4.4 mmHg) for cardiac outputs between 3.6 and 5.3 l/min (4.5 ± 0.4 l/min). Doppler-derived mean pressure gradients are between 2.0 and 17.0 mmHg (9.3 ± 3.9 mmHg) for the same flow conditions. Effective Orifice area is 1.31 ± 0.08 cm2 and the performance index is 0.74 ± 0.04, using the actual geometric orifice area, and 0.38 ± 0.02, using the tissue annulus diameter, for a cardiac output of 4.5 ± 0.4 l/min. Regurgitation volumes are below 3 ml. There is a trend to an effect of valve orientation on hemodynamics.
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Affiliation(s)
- K Dumont
- IBiTech, Institute of Biomedical Technology, Ghent University, Gent, Belgium.
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Abstract
The “pulsatile catheter” (PUCA) pump is a minimally invasive intra-arterial left ventricular assist device intended for acute support of critically ill heart failure patients. To assess the hydrodynamic performance of the PUCA II, driven by an Arrow AutoCat IABP driver, we used a (static) mock circulatory system in which the PUCA II was tested at different loading conditions. The PUCA II was subsequently introduced in a (dynamic) cardiovascular simulator (CVS) to mimic actual in vivo operating conditions, with different heart rates and 2 levels of left ventricular (LV) contractility. Mock circulation data shows that PUCA II pump performance is sensitive to afterload, pump rate and preload. CVS data demonstrate that PUCA II provides effective LV unloading and augments diastolic aortic pressure. The contribution of PUCA II to total flow is inversely related to LV contractility and is higher at high heart rates. We conclude that, with the current IABP driver, the PUCA II is most effective in 1:1 mode in left ventricles with low contractility.
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Affiliation(s)
- S Vandenberghe
- Hydraulics Laboratory, Institute Biomedical Technology, Ghent University, Ghent, Belgium.
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Mikhaylova E, Tabacchini V, Borghi G, Mollet P, D’Hoe E, Schaart DR, Vandenberghe S. Optimization of an ultralow-dose high-resolution pediatric PET scanner design based on monolithic scintillators with dual-sided digital SiPM readout: a simulation study. ACTA ACUST UNITED AC 2017; 62:8402-8418. [DOI: 10.1088/1361-6560/aa8eb2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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Li T, Ao ECI, Lambert B, Brans B, Vandenberghe S, Mok GSP. Quantitative Imaging for Targeted Radionuclide Therapy Dosimetry - Technical Review. Theranostics 2017; 7:4551-4565. [PMID: 29158844 PMCID: PMC5695148 DOI: 10.7150/thno.19782] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 07/25/2017] [Indexed: 01/06/2023] Open
Abstract
Targeted radionuclide therapy (TRT) is a promising technique for cancer therapy. However, in order to deliver the required dose to the tumor, minimize potential toxicity in normal organs, as well as monitor therapeutic effects, it is important to assess the individualized internal dosimetry based on patient-specific data. Advanced imaging techniques, especially radionuclide imaging, can be used to determine the spatial distribution of administered tracers for calculating the organ-absorbed dose. While planar scintigraphy is still the mainstream imaging method, SPECT, PET and bremsstrahlung imaging have promising properties to improve accuracy in quantification. This article reviews the basic principles of TRT and discusses the latest development in radionuclide imaging techniques for different theranostic agents, with emphasis on their potential to improve personalized TRT dosimetry.
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Affiliation(s)
- Tiantian Li
- Biomedical Imaging Laboratory, Department of Electrical and Computer Engineering, Faculty of Science and Technology, University of Macau, Macau SAR, China
| | - Edwin C. I. Ao
- Biomedical Imaging Laboratory, Department of Electrical and Computer Engineering, Faculty of Science and Technology, University of Macau, Macau SAR, China
| | - Bieke Lambert
- Dept of Radiology and Nuclear medicine, Ghent University, De Pintelaan 185 9000 Gent, Belgium
- AZ Maria Middelares, Buiten-Ring-Sint-Denijs 30, 9000 Gent, Belgium
| | - Boudewijn Brans
- Dept of Nuclear Medicine, UZ Ghent-Ghent University, St-Pietersnieuwstraat 41, 9000 Gent, Belgium
| | - Stefaan Vandenberghe
- MEDISIP-ELIS-IBITECH-IMEC, Ghent University, St-Pietersnieuwstraat 41, 9000 Gent, Belgium
| | - Greta S. P. Mok
- Biomedical Imaging Laboratory, Department of Electrical and Computer Engineering, Faculty of Science and Technology, University of Macau, Macau SAR, China
- Faculty of Health Sciences, University of Macau, Macau SAR, China
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49
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Staljanssens W, Strobbe G, Van Holen R, Keereman V, Gadeyne S, Carrette E, Meurs A, Pittau F, Momjian S, Seeck M, Boon P, Vandenberghe S, Vulliemoz S, Vonck K, van Mierlo P. EEG source connectivity to localize the seizure onset zone in patients with drug resistant epilepsy. Neuroimage Clin 2017; 16:689-698. [PMID: 29034162 PMCID: PMC5633847 DOI: 10.1016/j.nicl.2017.09.011] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 09/01/2017] [Accepted: 09/12/2017] [Indexed: 11/25/2022]
Abstract
Electrical source imaging (ESI) from interictal scalp EEG is increasingly validated and used as a valuable tool in the presurgical evaluation of epilepsy as a reflection of the irritative zone. ESI of ictal scalp EEG to localize the seizure onset zone (SOZ) remains challenging. We investigated the value of an approach for ictal imaging using ESI and functional connectivity analysis (FC). Ictal scalp EEG from 111 seizures in 27 patients who had Engel class I outcome at least 1 year following resective surgery was analyzed. For every seizure, an artifact-free epoch close to the seizure onset was selected and ESI using LORETA was applied. In addition, the reconstructed sources underwent FC using the spectrum-weighted Adaptive Directed Transfer Function. This resulted in the estimation of the SOZ in two ways: (i) the source with maximal power after ESI, (ii) the source with the strongest outgoing connections after combined ESI and FC. Next, we calculated the distance between the estimated SOZ and the border of the resected zone (RZ) for both approaches and called this the localization error ((i) LEpow and (ii) LEconn respectively). By comparing LEpow and LEconn, we assessed the added value of FC. The source with maximal power after ESI was inside the RZ (LEpow = 0 mm) in 31% of the seizures and estimated within 10 mm from the border of the RZ (LEpow ≤ 10 mm) in 42%. Using ESI and FC, these numbers increased to 72% for LEconn = 0 mm and 94% for LEconn ≤ 10 mm. FC provided a significant added value to ESI alone (p < 0.001). ESI combined with subsequent FC is able to localize the SOZ in a non-invasive way with high accuracy. Therefore it could be a valuable tool in the presurgical evaluation of epilepsy. ESI + functional connectivity analysis allows localizing the SOZ with high accuracy. Functional connectivity analysis offered a significant added value to ESI. The method is robust for inter- and intra-patient variability. The method could be a useful tool in the presurgical evaluation of epilepsy.
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Affiliation(s)
- Willeke Staljanssens
- Medical Image and Signal Processing Group, Department of Electronics and Information Systems, Ghent University - imec, De Pintelaan 185, 9000 Ghent, Belgium
| | | | - Roel Van Holen
- Medical Image and Signal Processing Group, Department of Electronics and Information Systems, Ghent University - imec, De Pintelaan 185, 9000 Ghent, Belgium
| | - Vincent Keereman
- Medical Image and Signal Processing Group, Department of Electronics and Information Systems, Ghent University - imec, De Pintelaan 185, 9000 Ghent, Belgium.,Laboratory for Clinical and Experimental Neurophysiology, Neurobiology and Neuropsychology, Department of Neurology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium
| | - Stefanie Gadeyne
- Laboratory for Clinical and Experimental Neurophysiology, Neurobiology and Neuropsychology, Department of Neurology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium
| | - Evelien Carrette
- Laboratory for Clinical and Experimental Neurophysiology, Neurobiology and Neuropsychology, Department of Neurology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium
| | - Alfred Meurs
- Laboratory for Clinical and Experimental Neurophysiology, Neurobiology and Neuropsychology, Department of Neurology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium
| | - Francesca Pittau
- EEG and Epilepsy Unit, Neurology Department, University Hospitals and Faculty of Medicine of Geneva, Rue Gabrielle-Perret-Gentil 4, 1205 Geneva, Switzerland
| | - Shahan Momjian
- Department of Neurosurgery, University Hospitals of Geneva and University of Geneva, rue Gabrielle-Perret-Gentil 4, 1205 Geneva, Switzerland
| | - Margitta Seeck
- Laboratory for Clinical and Experimental Neurophysiology, Neurobiology and Neuropsychology, Department of Neurology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium
| | - Paul Boon
- Laboratory for Clinical and Experimental Neurophysiology, Neurobiology and Neuropsychology, Department of Neurology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium
| | - Stefaan Vandenberghe
- Medical Image and Signal Processing Group, Department of Electronics and Information Systems, Ghent University - imec, De Pintelaan 185, 9000 Ghent, Belgium
| | - Serge Vulliemoz
- EEG and Epilepsy Unit, Neurology Department, University Hospitals and Faculty of Medicine of Geneva, Rue Gabrielle-Perret-Gentil 4, 1205 Geneva, Switzerland.,Functional Brain Mapping Lab, Department of Fundamental Neurosciences, University of Geneva, rue Gabrielle-Perret-Gentil 4, 1205 Geneva, Switzerland
| | - Kristl Vonck
- Laboratory for Clinical and Experimental Neurophysiology, Neurobiology and Neuropsychology, Department of Neurology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium
| | - Pieter van Mierlo
- Medical Image and Signal Processing Group, Department of Electronics and Information Systems, Ghent University - imec, De Pintelaan 185, 9000 Ghent, Belgium.,Functional Brain Mapping Lab, Department of Fundamental Neurosciences, University of Geneva, rue Gabrielle-Perret-Gentil 4, 1205 Geneva, Switzerland
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Marin G, Vanderlinden B, Karfis I, Guiot T, Wimana Z, Flamen P, Vandenberghe S. Accuracy and precision assessment for activity quantification in individualized dosimetry of 177Lu-DOTATATE therapy. EJNMMI Phys 2017; 4:7. [PMID: 28127694 PMCID: PMC5267757 DOI: 10.1186/s40658-017-0174-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Accepted: 01/14/2017] [Indexed: 11/16/2022] Open
Abstract
Background In order to obtain a reliable 177Lu-DOTATATE therapy dosimetry, it is crucial to acquire accurate and precise activity measurements with the radionuclide calibrator, the SPECT/CT camera, and the NaI(Tl) well counter. The aim of this study was to determine, in a clinical context, the accuracy and the precision of their activity quantification over a range of activities and time. Ninety-three 177Lu sources from the manufacturer were measured in the radionuclide calibrator over 2.5 years to evaluate its calibration accuracy and precision compared to the manufacturer’s value. A NEMA 2012/IEC 2008 phantom was filled with a 177Lu activity concentration sphere-to-background ratio of five. It was acquired with the SPECT/CT camera to determine the reconstruction parameters offering the best compromise between partial volume effect and signal-to-noise ratio. The calibration factor was computed accordingly. The calibration quality was monitored over 2.5 years with 33 phantom acquisitions with activities ranging from 7040 to 0.6 MBq. Home-made sources were used to calibrate the well counter. Its reliability was evaluated with activities ranging from 150 to 0.2 kBq measured 34 times over 2.5 years. Results For the radionuclide calibrator, median [interquartile range] for the error on activity measurement was −0.99 [1.31] %. The optimal SPECT reconstruction parameters were obtained with 16 iterations, 16 subsets and a 12-mm Gaussian post-filter. The calibration factor was 9.87 cps/MBq with an error of −1.05 [2.12] %. The well counter was calibrated with 31.5 cps/kBq, and the error was evaluated to −12.89 [16.55] %. Conclusions The accuracy and the precision of activity quantification using dedicated quality control were found to be sufficient for use in dosimetry implemented in clinical routine. The proposed methodology could be implemented in other centres to obtain reproducible 177Lu-based treatment dosimetry.
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Affiliation(s)
- Gwennaëlle Marin
- Department of Medical Physics, Institut Jules Bordet-Université Libre de Bruxelles (ULB), 121 Boulevard de Waterloo, 1000, Brussels, Belgium. .,Medical Imaging and Signal Processing (MEDISIP), Department of Electronics and Information Systems (ELIS), Faculty of Engineering and Architecture (FEA), Ghent University (UGent), 185 De Pintelaan, 9000, Gent, Belgium.
| | - Bruno Vanderlinden
- Department of Medical Physics, Institut Jules Bordet-Université Libre de Bruxelles (ULB), 121 Boulevard de Waterloo, 1000, Brussels, Belgium
| | - Ioannis Karfis
- Department of Nuclear Medicine, Institut Jules Bordet-Université Libre de Bruxelles (ULB), 121 Boulevard de Waterloo, 1000, Brussels, Belgium
| | - Thomas Guiot
- Department of Nuclear Medicine, Institut Jules Bordet-Université Libre de Bruxelles (ULB), 121 Boulevard de Waterloo, 1000, Brussels, Belgium
| | - Zena Wimana
- Department of Nuclear Medicine, Institut Jules Bordet-Université Libre de Bruxelles (ULB), 121 Boulevard de Waterloo, 1000, Brussels, Belgium
| | - Patrick Flamen
- Department of Nuclear Medicine, Institut Jules Bordet-Université Libre de Bruxelles (ULB), 121 Boulevard de Waterloo, 1000, Brussels, Belgium
| | - Stefaan Vandenberghe
- Medical Imaging and Signal Processing (MEDISIP), Department of Electronics and Information Systems (ELIS), Faculty of Engineering and Architecture (FEA), Ghent University (UGent), 185 De Pintelaan, 9000, Gent, Belgium
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