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Onwanna J, Chantadisai M, Chaiwatanarat T, Rakvongthai Y. Dual-Tracer Parathyroid Imaging Using Joint SPECT Reconstruction. Nucl Med Mol Imaging 2023; 57:126-136. [PMID: 37187950 PMCID: PMC10172461 DOI: 10.1007/s13139-022-00787-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 11/11/2022] [Accepted: 12/27/2022] [Indexed: 01/18/2023] Open
Abstract
Purpose We assessed the lesion detection performance of the dual-tracer parathyroid SPECT imaging using the joint reconstruction method. Materials and Methods Thirty-six noise realizations were created from SPECT projections collected from an in-house neck phantom to emulate 99mTc-pertechnetate/99mTc-sestamibi parathyroid SPECT datasets. Difference images representing parathyroid lesions were reconstructed using the subtraction and the joint methods whose corresponding optimal iteration was defined as the iteration which maximized the channelized Hotelling observer signal-to-noise ratio (CHO-SNR). The joint method whose initial estimate was derived from the subtraction method at optimal iteration (the joint-AltInt method) was also assessed. In a study of 36 patients, a human-observer lesion-detection study was performed using difference images from the three methods at optimal iteration and the subtraction method with four iterations. The area under the receiver operating characteristic curve (AUC) was calculated for each method. Results In the phantom study, both the joint-AltInt method and the joint method improved SNR compared to the subtraction method at their optimal iteration by 444% and 81%, respectively. In the patient study, the joint-AltInt method yielded the highest AUC of 0.73 as compared with 0.72, 0.71, and 0.64 from the joint method, the subtraction method at optimal iteration, and the subtraction method at four iterations. At a specificity of at least 0.70, the joint-AltInt method yielded significantly higher sensitivity than the other methods (0.60 vs 0.46, 042, and 0.42; p < 0.05). Conclusions The joint reconstruction method yielded higher lesion detectability than the conventional method and holds promise for dual-tracer parathyroid SPECT imaging.
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Affiliation(s)
- Jaruwan Onwanna
- Biomedical Engineering Program, Faculty of Engineering, Chulalongkorn University, Bangkok, Thailand
- Chulalongkorn University Biomedical Imaging Group, Faculty of Medicine, Department of Radiology, Chulalongkorn University, Bangkok, Thailand
| | - Maythinee Chantadisai
- Division of Nuclear Medicine, Faculty of Medicine, Department of Radiology, King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Chulalongkorn University, Bangkok, Thailand
| | - Tawatchai Chaiwatanarat
- Chulalongkorn University Biomedical Imaging Group, Faculty of Medicine, Department of Radiology, Chulalongkorn University, Bangkok, Thailand
- Division of Nuclear Medicine, Faculty of Medicine, Department of Radiology, Chulalongkorn University, Bangkok, Thailand
| | - Yothin Rakvongthai
- Chulalongkorn University Biomedical Imaging Group, Faculty of Medicine, Department of Radiology, Chulalongkorn University, Bangkok, Thailand
- Division of Nuclear Medicine, Faculty of Medicine, Department of Radiology, Chulalongkorn University, Bangkok, Thailand
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PET imaging in cardiovascular infections. Nucl Med Mol Imaging 2022. [DOI: 10.1016/b978-0-12-822960-6.00140-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Onwanna J, Chantadisai M, Tepmongkol S, Fahey F, Ouyang J, Rakvongthai Y. Impact of reconstruction parameters on lesion detection and localization in joint ictal/inter-ictal SPECT reconstruction. Ann Nucl Med 2021; 36:24-32. [PMID: 34559366 DOI: 10.1007/s12149-021-01680-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 09/14/2021] [Indexed: 10/20/2022]
Abstract
PURPOSE Previously, a joint ictal/inter-ictal SPECT reconstruction was proposed to reconstruct a differential image representing the change of brain SPECT image from an inter-ictal to an ictal study. The so-called joint method yielded better performance for epileptic foci localization than the conventional subtraction method. In this study, we evaluated the performance of different reconstruction settings of the joint reconstruction of ictal/inter-ictal SPECT data, which creates a differential image showing the difference between ictal and inter-ictal images, in lesion detection and localization in epilepsy imaging. METHODS Differential images reconstructed from phantom data using the joint and the subtraction methods were compared based on lesion detection performance (channelized Hotelling observer signal-to-noise ratio (SNRCHO) averaged across four lesion-to-background contrast levels) at the optimal iteration. The joint-initial method which was the joint method that was initialized by the subtraction method at optimal iteration was also used to reconstruct differential images. These three methods with respective optimal iteration and the subtraction method with four iterations were applied to epileptic patient datasets. A human observer lesion localization study was performed based on localization receiver operating characteristic (LROC) analysis. RESULTS From the phantom study, at their respective optimal iteration, the joint method yielded an improvement in lesion detection performance over the subtraction method of 26%, which increased to 145% when using the joint-initial method. From the patient study, the joint-initial method yielded the highest area under the LROC curve as compared with those of the joint and the subtraction methods with optimal iteration and with 4 iterations (0.44 vs 0.41, 0.39 and 0.36, respectively). CONCLUSIONS In lesion detection and localization, the joint method at optimal iteration outperformed the subtraction method at optimal iteration and at iteration typically used in clinical practice. Furthermore, initialization by the subtraction method improved the performance of the joint method.
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Affiliation(s)
- Jaruwan Onwanna
- Biomedical Engineering Program, Faculty of Engineering, Chulalongkorn University, Bangkok, Thailand.,Chulalongkorn University Biomedical Imaging Group, Department of Radiology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Maythinee Chantadisai
- Division of Nuclear Medicine, Department of Radiology, Faculty of Medicine, Chulalongkorn University, King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, Thailand
| | - Supatporn Tepmongkol
- Chulalongkorn University Biomedical Imaging Group, Department of Radiology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.,Division of Nuclear Medicine, Department of Radiology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Frederic Fahey
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Boston Children's Hospital, Boston, USA.,Department of Radiology, Harvard Medical School, Boston, USA
| | - Jinsong Ouyang
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Boston, USA.,Department of Radiology, Harvard Medical School, Boston, USA
| | - Yothin Rakvongthai
- Chulalongkorn University Biomedical Imaging Group, Department of Radiology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand. .,Division of Nuclear Medicine, Department of Radiology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
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Case JA. The Importance of Time-of-Flight Reconstruction and Point Spread Modeling in the Measurement of Myocardial Blood Flow Parameters. Curr Cardiol Rep 2021; 23:77. [PMID: 34081208 DOI: 10.1007/s11886-021-01507-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/14/2021] [Indexed: 11/29/2022]
Abstract
PURPOSE OF REVIEW Absolute quantitation of myocardial blood flow has been recognized as one of the most important advances in nuclear cardiology. The addition of absolute myocardial blood flow quantitation has had a significant impact on the determination of normalcy, artifact/defect differentiation, and the true extent of coronary artery disease in patients with known or suspected coronary disease. Time-of-flight reconstruction and point spread function modeling of the potential to greatly improve resolution and signal to background. This combined with absolute blood flow measurements could improve the reliability of regional blood flow estimates and overall image quality. RECENT FINDINGS Recent publications have demonstrated that time-of-flight reconstruction can have an impact on the amount of spillover between the blood pool ROI and the myocardial regions. This may necessitate changes to kinetic models; however, these changes if implemented correctly may result in improved accuracy and reproducibility of blood flow estimates. This may also have the benefit of assessing blood flow in the microvasculature using newer F-18 labeled blood flow tracers. Time of flight and point spread function modeling represent significant improvements in the accuracy and quality of reconstructed myocardial perfusion PET images. This may also have significant implications for the reliability of blood flow estimates. To achieve these benefits, attention must be given to blood flow models to ensure that they have been correctly optimized for the scanner-specific time-of-flight reconstruction properties.
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Affiliation(s)
- James A Case
- Cardiovascular Imaging Technologies, 4320 Wornall Rd., Suite 114, Kansas City, MO, 64111, USA.
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5
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Slart RHJA, Glaudemans AWJM, Gheysens O, Lubberink M, Kero T, Dweck MR, Habib G, Gaemperli O, Saraste A, Gimelli A, Georgoulias P, Verberne HJ, Bucerius J, Rischpler C, Hyafil F, Erba PA. Procedural recommendations of cardiac PET/CT imaging: standardization in inflammatory-, infective-, infiltrative-, and innervation (4Is)-related cardiovascular diseases: a joint collaboration of the EACVI and the EANM. Eur J Nucl Med Mol Imaging 2020; 48:1016-1039. [PMID: 33106926 PMCID: PMC8041672 DOI: 10.1007/s00259-020-05066-5] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 10/05/2020] [Indexed: 01/18/2023]
Abstract
With this document, we provide a standard for PET/(diagnostic) CT imaging procedures in cardiovascular diseases that are inflammatory, infective, infiltrative, or associated with dysfunctional innervation (4Is). This standard should be applied in clinical practice and integrated in clinical (multicenter) trials for optimal procedural standardization. A major focus is put on procedures using [18F]FDG, but 4Is PET radiopharmaceuticals beyond [18F]FDG are also described in this document. Whilst these novel tracers are currently mainly applied in early clinical trials, some multicenter trials are underway and we foresee in the near future their use in clinical care and inclusion in the clinical guidelines. Finally, PET/MR applications in 4Is cardiovascular diseases are also briefly described. Diagnosis and management of 4Is-related cardiovascular diseases are generally complex and often require a multidisciplinary approach by a team of experts. The new standards described herein should be applied when using PET/CT and PET/MR, within a multimodality imaging framework both in clinical practice and in clinical trials for 4Is cardiovascular indications.
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Affiliation(s)
- Riemer H J A Slart
- Medical Imaging Centre, Department of Nuclear Medicine & Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
- Medical Imaging Centre, Department of Nuclear medicine & Molecular Imaging (EB50), University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands.
- Faculty of Science and Technology Biomedical, Photonic Imaging, University of Twente, Enschede, The Netherlands.
| | - Andor W J M Glaudemans
- Medical Imaging Centre, Department of Nuclear Medicine & Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Olivier Gheysens
- Department of Nuclear Medicine, Cliniques Universitaires Saint-Luc, Brussels, Belgium
| | - Mark Lubberink
- Department of Surgical Sciences/Radiology, Uppsala University, Uppsala, Sweden
| | - Tanja Kero
- Department of Surgical Sciences/Radiology, Uppsala University, Uppsala, Sweden
- Medical Imaging Centre, Uppsala University Hospital, Uppsala, Sweden
| | - Marc R Dweck
- British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | - Gilbert Habib
- Cardiology Department, APHM, La Timone Hospital, Marseille, France
- Aix Marseille Université, IRD, APHM, MEPHI, IHU-Méditerranée Infection, Marseille, France
| | - Oliver Gaemperli
- HeartClinic, Hirslanden Hospital Zurich, Hirslanden, Switzerland
| | - Antti Saraste
- Turku PET Centre, Turku University Hospital, University of Turku, Turku, Finland
- Heart Center, Turku University Hospital, Turku, Finland
| | | | - Panagiotis Georgoulias
- Department of Nuclear Medicine, Faculty of Medicine, University of Thessaly, University Hospital of Larissa, Larissa, Greece
| | - Hein J Verberne
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, location AMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Jan Bucerius
- Department of Nuclear Medicine, Georg-August University Göttingen, Göttingen, Germany
| | - Christoph Rischpler
- Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Fabien Hyafil
- Department of Nuclear Medicine, DMU IMAGINA, Georges-Pompidou European Hospital, Assistance Publique - Hôpitaux de Paris, University of Paris, F75015 Paris, France
- PARCC, INSERM, University of Paris, F-75006 Paris, France
| | - Paola A Erba
- Medical Imaging Centre, Department of Nuclear Medicine & Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- Department of Nuclear Medicine, University of Pisa, Pisa, Italy
- Department of Translational Research and New Technology in Medicine, University of Pisa, Pisa, Italy
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Nappi C, Gaudieri V, Cuocolo A. Behind Traditional Semi-quantitative Scores of Myocardial Perfusion Imaging: An Eye on Niche Parameters. Eur Cardiol 2019; 14:13-17. [PMID: 31131032 PMCID: PMC6523048 DOI: 10.15420/ecr.2019.5.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The evaluation of stress-induced myocardial perfusion defects by non-invasive myocardial perfusion imaging (MPI) modalities has a leading role in the identification of coronary artery disease, and has excellent diagnostic and prognostic value. Non-invasive MPI can be performed using conventional and novel gamma cameras or by PET/CT. New software has allowed novel parameters that may have a role in the identification of early marks of cardiac impairment to be evaluated. We aim to give an overview of niche parameters obtainable by single photon emission CT (SPECT) and PET/CT MPI that may help practitioners to detect initial signs of cardiac damage and identify new therapy targets. In particular, we summarise the role of left ventricular geometry indices for remodelling, phase analysis parameters to evaluate mechanical dyssynchrony, the concept of relative flow reserve in the evaluation of flow-limiting epicardial stenosis, vascular age and epicardial adipose tissue as early markers of atherosclerotic burden, and emerging parameters for the evaluation of myocardial innervation, such as the total defect score.
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Affiliation(s)
- Carmela Nappi
- Department of Advanced Biomedical Sciences, University Federico II Naples, Italy
| | - Valeria Gaudieri
- Department of Advanced Biomedical Sciences, University Federico II Naples, Italy
| | - Alberto Cuocolo
- Department of Advanced Biomedical Sciences, University Federico II Naples, Italy
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Matheoud R, Lecchi M. Time-of-flight in cardiac PET/TC: What do we know and what we should know? J Nucl Cardiol 2018; 25:1550-1553. [PMID: 29931500 DOI: 10.1007/s12350-018-1336-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 06/02/2018] [Indexed: 11/25/2022]
Affiliation(s)
- Roberta Matheoud
- Department of Medical Physics, University Hospital Maggiore della Carità, C.so Mazzini, 18, 28100, Novara, Italy.
| | - Michela Lecchi
- Health Physics, San Paolo Hospital, University of Milan, Milan, Italy
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Matheoud R, Lecchi M, Lizio D, Scabbio C, Marcassa C, Leva L, Del Sole A, Rodella C, Indovina L, Bracco C, Brambilla M, Zoccarato O. Comparative analysis of iterative reconstruction algorithms with resolution recovery and time of flight modeling for 18F-FDG cardiac PET: A multi-center phantom study. J Nucl Cardiol 2017; 24:1036-1045. [PMID: 26758376 DOI: 10.1007/s12350-015-0385-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 08/21/2015] [Indexed: 10/22/2022]
Abstract
BACKGROUND The purpose of this study was to evaluate the image quality in cardiac 18F-FDG PET using the time of flight (TOF) and/or point spread function (PSF) modeling in the iterative reconstruction (IR). METHODS Three scanners and an anthropomorphic cardiac phantom with an insert simulating a transmural defect (TD) were used. Two sets of scans (with/without TD) were acquired, and four reconstruction schemes were considered: (1) IR; (2) IR + PSF, (3) IR + TOF, and (4) IR + TOF + PSF. LV wall thickness (FWHM), contrast between LV wall and inner chamber (C IC), and TD contrast in LV wall (C TD) were evaluated. RESULTS Tests of the reconstruction protocols showed a decrease in FWHM from IR (13 mm) to IR + PSF (11 mm); an increase in the C IC from IR (65%) to IR + PSF (71%) and from IR + TOF (72%) to IR + TOF + PSF (77%); and an increase in the C TD from IR + PSF (72%) to IR + TOF (75%) and to IR + TOF + PSF (77%). Tests of the scanner/software combinations showed a decrease in FWHM from Gemini_TF (13 mm) to Biograph_mCT (12 mm) and to Discovery_690 (11 mm); an increase in the C IC from Gemini_TF (65%) to Biograph_mCT (73%) and to Discovery_690 (75%); and an increase in the C TD from Gemini_TF/Biograph_mCT (72%) to Discovery_690 (77%). CONCLUSION The introduction of TOF and PSF increases image quality in cardiac 18F-FDG PET. The scanner/software combinations exhibit different performances, which should be taken into consideration when making cross comparisons.
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Affiliation(s)
- Roberta Matheoud
- Departments of Medical Physics and Nuclear Medicine, University Hospital, Novara, Italy
| | - Michela Lecchi
- Department of Health Sciences, University of Milan and Nuclear Medicine Unit, San Paolo Hospital, Milan, Italy
| | - Domenico Lizio
- Departments of Medical Physics and Nuclear Medicine, University Hospital, Novara, Italy
| | - Camilla Scabbio
- Department of Health Sciences, University of Milan and Nuclear Medicine Unit, San Paolo Hospital, Milan, Italy
| | - Claudio Marcassa
- Unit of Nuclear Medicine and Department of Cardiology, S. Maugeri Foundation, IRCCS, Veruno, Italy
| | - Lucia Leva
- Departments of Medical Physics and Nuclear Medicine, University Hospital, Novara, Italy
| | - Angelo Del Sole
- Department of Health Sciences, University of Milan and Nuclear Medicine Unit, San Paolo Hospital, Milan, Italy
| | - Carlo Rodella
- Health Physics Unit, Spedali Civili Hospital, Brescia, Italy
| | - Luca Indovina
- Department of Medical Physics, Polyclinic Agostino Gemelli, Rome, Italy
| | - Christian Bracco
- Medical Physics Department, Institute for Cancer Research and Treatment, Candiolo, Italy
| | - Marco Brambilla
- Departments of Medical Physics and Nuclear Medicine, University Hospital, Novara, Italy.
| | - Orazio Zoccarato
- Department of Health Sciences, University of Milan and Nuclear Medicine Unit, San Paolo Hospital, Milan, Italy
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Impact of Time-of-Flight Reconstruction on Cardiac PET Images of Obese Patients. Clin Nucl Med 2017; 42:e103-e108. [DOI: 10.1097/rlu.0000000000001441] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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10
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Munk OL, Tolbod LP, Hansen SB, Bogsrud TV. Point-spread function reconstructed PET images of sub-centimeter lesions are not quantitative. EJNMMI Phys 2017; 4:5. [PMID: 28091957 PMCID: PMC5236043 DOI: 10.1186/s40658-016-0169-9] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Accepted: 12/10/2016] [Indexed: 11/25/2022] Open
Abstract
Background PET image reconstruction methods include modeling of resolution degrading phenomena, often referred to as point-spread function (PSF) reconstruction. The aim of this study was to develop a clinically relevant phantom and characterize the reproducibility and accuracy of high-resolution PSF reconstructed images of small lesions, which is a prerequisite for using PET in the prediction and evaluation of responses to treatment. Sets of small homogeneous 18F-spheres (range 3–12 mm diameter, relevant for small lesions and lymph nodes) were suspended and covered by a 11C-silicone, which provided a scattering medium and a varying sphere-to-background ratio. Repeated measurements were made on PET/CT scanners from two vendors using a wide range of reconstruction parameters. Recovery coefficients (RCs) were measured for clinically used volume-of-interest definitions. Results For non-PSF images, RCs were reproducible and fell monotonically as the sphere diameter decreased, which is the expected behavior. PSF images converged slower and had artifacts: RCs did not fall monotonically as sphere diameters decreased but had a maximum RC for sphere sizes around 8 mm, RCs could be greater than 1, and RCs were less reproducible. To some degree, post-reconstruction filters could suppress PSF artifacts. Conclusions High-resolution PSF images of small lesions showed artifacts that could lead to serious misinterpretations when used for monitoring treatment response. Thus, it could be safer to use non-PSF reconstruction for quantitative purposes unless PSF reconstruction parameters are optimized for the specific task. Electronic supplementary material The online version of this article (doi:10.1186/s40658-016-0169-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- O L Munk
- Department of Nuclear Medicine & PET Centre, Aarhus University Hospital, Aarhus, Denmark.
| | - L P Tolbod
- Department of Nuclear Medicine & PET Centre, Aarhus University Hospital, Aarhus, Denmark
| | - S B Hansen
- Department of Nuclear Medicine & PET Centre, Aarhus University Hospital, Aarhus, Denmark
| | - T V Bogsrud
- Department of Nuclear Medicine & PET Centre, Aarhus University Hospital, Aarhus, Denmark.,Department of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway
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Tamaki N. New PET system permits reliable estimates of myocardial blood flow and flow reserve. J Nucl Cardiol 2016; 23:473-4. [PMID: 25802177 DOI: 10.1007/s12350-015-0098-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 02/09/2015] [Indexed: 11/29/2022]
Affiliation(s)
- Nagara Tamaki
- Department of Nuclear Medicine, Hokkaido University Graduate School of Medicine, N-15, W-7, Kita ku, Sapporo, 060-8638, Japan.
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12
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Akamatsu G. [Point-spread Function and Time-of-flight in PET Image Reconstruction]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2015; 71:1115-1122. [PMID: 26596203 DOI: 10.6009/jjrt.2015_jsrt_71.11.1115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
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13
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Yamashita S, Yokoyama K, Onoguchi M, Yamamoto H, Nakaichi T, Tsuji S, Nakajima K. Importance of Defect Detectability in Positron Emission Tomography Imaging of Abdominal Lesions. ASIA OCEANIA JOURNAL OF NUCLEAR MEDICINE & BIOLOGY 2015; 3:83-90. [PMID: 27408887 PMCID: PMC4937645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVES This study was designed to assess defect detectability in positron emission tomography (PET) imaging of abdominal lesions. METHODS A National Electrical Manufactures Association International Electrotechnical Commission phantom was used. The simulated abdominal lesion was scanned for 10 min using dynamic list-mode acquisition method. Images, acquired with scan duration of 1-10 min, were reconstructed using VUE point HD and a 4.7 mm full-width at half-maximum (FWHM) Gaussian filter. Iteration-subset combinations of 2-16 and 2-32 were used. Visual and physical analyses were performed using the acquired images. To sequentially evaluate defect detectability in clinical settings, we examined two middle-aged male subjects. One had a liver cyst (approximately 10 mm in diameter) and the other suffered from pancreatic cancer with an inner defect region (approximately 9 mm in diameter). RESULTS In the phantom study, at least 6 and 3 min acquisition durations were required to visualize 10 and 13 mm defect spheres, respectively. On the other hand, spheres with diameters ≥17 mm could be detected even if the acquisition duration was only 1 min. The visual scores were significantly correlated with background (BG) variability. In clinical settings, the liver cyst could be slightly visualized with an acquisition duration of 6 min, although image quality was suboptimal. For pancreatic cancer, the acquisition duration of 3 min was insufficient to clearly describe the defect region. CONCLUSION The improvement of BG variability is the most important factor for enhancing lesion detection. Our clinical scan duration (3 min/bed) may not be suitable for the detection of small lesions or accurate tumor delineation since an acquisition duration of at least 6 min is required to visualize 10 mm lesions, regardless of reconstruction parameters. Improvements in defect detectability are important for radiation treatment planning and accurate PET-based diagnosis.
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Affiliation(s)
- Shozo Yamashita
- Division of Radiology, Public Central Hospital of Matto Ishikawa, Hakusan, Japan,Department of Health Sciences, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Kunihiko Yokoyama
- PET Imaging Center, Public Central Hospital of Matto Ishikawa, Hakusan, Japan
| | - Masahisa Onoguchi
- Department of Health Sciences, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan,
*Corresponding author: Masahisa Onoguchi, Department of Health Sciences, Graduate School of Medical Sciences, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 920-0942, Japan. Tel: +81-76-265-2526;
| | - Haruki Yamamoto
- Division of Radiology, Public Central Hospital of Matto Ishikawa, Hakusan, Japan
| | - Tetsu Nakaichi
- Division of Radiology, Public Central Hospital of Matto Ishikawa, Hakusan, Japan
| | - Shiro Tsuji
- PET Imaging Center, Public Central Hospital of Matto Ishikawa, Hakusan, Japan
| | - Kenichi Nakajima
- Department of Nuclear Medicine, Kanazawa University Hospital, Kanazawa, Japan
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