51
|
Recommendations for Standardizing Thorax PET-CT in Non-Human Primates by Recent Experience from Macaque Studies. Animals (Basel) 2021; 11:ani11010204. [PMID: 33467761 PMCID: PMC7830664 DOI: 10.3390/ani11010204] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 01/11/2021] [Accepted: 01/13/2021] [Indexed: 02/07/2023] Open
Abstract
Despite the possibilities of routine clinical measures and assays on readily accessible bio-samples, it is not always essential in animals to investigate the dynamics of disease longitudinally. In this regard, minimally invasive imaging methods provide powerful tools in preclinical research. They can contribute to the ethical principle of gathering as much relevant information per animal as possible. Besides, with an obvious parallel to clinical diagnostic practice, such imaging platforms are potent and valuable instruments leading to a more refined use of animals from a welfare perspective. Non-human primates comprise highly relevant species for preclinical research to enhance our understanding of disease mechanisms and/or the development of improved prophylactic or therapeutic regimen for various human diseases. In this paper, we describe parameters that critically affect the quality of integrated positron emission tomography and computed tomography (PET-CT) in non-human primates. Lessons learned are exemplified by results from imaging experimental infectious respiratory disease in macaques; specifically tuberculosis, influenza, and SARS-CoV-2 infection. We focus on the thorax and use of 18F-fluorodeoxyglucose as a PET tracer. Recommendations are provided to guide various stages of PET-CT-supported research in non-human primates, from animal selection, scan preparation, and operation, to processing and analysis of imaging data.
Collapse
|
52
|
Kim H, Kao CM, Hua Y, Xie Q, Chen CT. Multiplexing Readout for Time-of-Flight (TOF) PET Detectors Using Striplines. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2021; 5:662-670. [PMID: 34541433 PMCID: PMC8445371 DOI: 10.1109/trpms.2021.3051364] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A recent trend in PET instrumentation is the use of silicon photomultipliers (SiPMs) for high-resolution and time-of-flight (TOF) detection. Due to its small size, a PET system can use a large number of SiPMs and hence effective and scalable multiplexing readout methods become important. Unfortunately, multiplexing readout generally degrades the fast timing properties necessary for TOF, especially at high channel reduction. Previously, we developed a stripline (SL) based readout method for PET that uses a time-based multiplexing mechanism. This method maintains fast timing by design and has been successfully used for TOF PET detectors. In this paper, we present a more systematic study in which we examine how two important design parameters of the readout - the number of inputs on an SL (n SL) and the pathlength between adjacent input positions (Δℓ) - affect its detection performance properties for PET. Our result shows that, up to n SL = 32 the readout can achieve accurate pixel discrimination and causes little degradation in the energy resolution. The TOF resolution is compromised mildly and a coincidence resolving time on the order of 300 ps FWHM can be achieved for LYSO- and SiPM-based detectors. We also discuss strategies in using the readout to further reduce the number of electronic channels that a PET system would otherwise need.
Collapse
Affiliation(s)
- Heejong Kim
- Department of Radiology, University of Chicago, Chicago, IL 60637 USA
| | - Chien-Min Kao
- Department of Radiology, University of Chicago, Chicago, IL 60637 USA
| | - Yuexuan Hua
- Raycan Technology Co., Ltd., Suzhou, Jiangsu 215163, China
| | - Qingguo Xie
- Biomedical Engineering Department, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Chin-Tu Chen
- Department of Radiology, University of Chicago, Chicago, IL 60637 USA
| |
Collapse
|
53
|
Salvadori J, Odille F, Karcher G, Marie PY, Imbert L. Fully digital PET is unaffected by any deterioration in TOF resolution and TOF image quality in the wide range of routine PET count rates. EJNMMI Phys 2021; 8:1. [PMID: 33409746 PMCID: PMC7788141 DOI: 10.1186/s40658-020-00344-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 11/30/2020] [Indexed: 12/11/2022] Open
Abstract
PURPOSE Digital PET involving silicon photomultipliers (SiPM) provides an enhanced time-of-flight (TOF) resolution as compared with photomultiplier (PMT)-based PET, but also a better prevention of the count-related rises in dead time and pile-up effects mainly due to smaller trigger domains (i.e., the detection surfaces associated with each trigger circuit). This study aimed to determine whether this latter property could help prevent against deteriorations in TOF resolution and TOF image quality in the wide range of PET count rates documented in clinical routine. METHODS Variations, according to count rates, in timing resolution and in TOF-related enhancement of the quality of phantom images were compared between the first fully digital PET (Vereos) and a PMT-based PET (Ingenuity). Single-count rate values were additionally extracted from the list-mode data of routine analog- and digital-PET exams at each 500-ms interval, in order to determine the ranges of routine PET count rates. RESULTS Routine PET count rates were lower for the Vereos than for the Ingenuity. For Ingenuity, the upper limits were estimated at approximately 21.7 and 33.2 Mcps after injection of respectively 3 and 5 MBq.kg-1 of current 18F-labeled tracers. At 5.8 Mcps, corresponding to the lower limit of the routine count rates documented with the Ingenuity, timing resolutions provided by the scatter phantom were 326 and 621 ps for Vereos and Ingenuity, respectively. At higher count rates, timing resolution was remarkably stable for Vereos but exhibited a progressive deterioration for Ingenuity, respectively reaching 732 and 847 ps at the upper limits of 21.7 and 33.2 Mcps. The averaged TOF-related gain in signal/noise ratio was stable at approximately 2 for Vereos but decreased from 1.36 at 5.8 Mcps to 1.14 and 1.00 at respectively 21.7 and 33.2 Mcps for Ingenuity. CONCLUSION Contrary to the Ingenuity PMT-based PET, the Vereos fully digital PET is unaffected by any deterioration in TOF resolution and consequently, in the quality of TOF images, in the wide range of routine PET count rates. This advantage is even more striking with higher count-rates for which the preferential use of digital PET should be further recommended (i.e., dynamic PET recording, higher injected activities).
Collapse
Affiliation(s)
- Julien Salvadori
- Department of Nuclear Medicine and Nancyclotep Molecular Imaging Platform, CHRU-Nancy, Université de Lorraine, F54000, Nancy, France. .,Université de Lorraine, INSERM, UMR 1254, F54000, Nancy, France.
| | - Freddy Odille
- Department of Nuclear Medicine and Nancyclotep Molecular Imaging Platform, CHRU-Nancy, Université de Lorraine, F54000, Nancy, France.,Université de Lorraine, INSERM, UMR 1254, F54000, Nancy, France
| | - Gilles Karcher
- Department of Nuclear Medicine and Nancyclotep Molecular Imaging Platform, CHRU-Nancy, Université de Lorraine, F54000, Nancy, France.,Université de Lorraine, INSERM, UMR 1254, F54000, Nancy, France
| | - Pierre-Yves Marie
- Department of Nuclear Medicine and Nancyclotep Molecular Imaging Platform, CHRU-Nancy, Université de Lorraine, F54000, Nancy, France.,Université de Lorraine, INSERM, UMR 1116, F54000, Nancy, France
| | - Laetitia Imbert
- Department of Nuclear Medicine and Nancyclotep Molecular Imaging Platform, CHRU-Nancy, Université de Lorraine, F54000, Nancy, France.,Université de Lorraine, INSERM, UMR 1254, F54000, Nancy, France
| |
Collapse
|
54
|
Abstract
This article describes aspects of PET scanner design for long axial field-of-view systems and how these choices have an impact on scanner performance.
Collapse
Affiliation(s)
- Margaret E Daube-Witherspoon
- Department of Radiology, University of Pennsylvania, 3620 Hamilton Walk, Room 156H, Philadelphia, PA 19104, USA.
| | - Simon R Cherry
- Department of Biomedical Engineering, University of California, 451 Health Sciences Drive, Davis, CA 95616, USA
| |
Collapse
|
55
|
Könik A, O'Donoghue JA, Wahl RL, Graham MM, Van den Abbeele AD. Theranostics: The Role of Quantitative Nuclear Medicine Imaging. Semin Radiat Oncol 2021; 31:28-36. [PMID: 33246633 DOI: 10.1016/j.semradonc.2020.07.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Theranostics is a precision medicine discipline that integrates diagnostic nuclear medicine imaging with radionuclide therapy in a manner that provides both a tumor phenotype and personalized therapy to patients with cancer using radiopharmaceuticals aimed at the same target-specific biological pathway or receptor. The aim of quantitative nuclear medicine imaging is to plan the alpha or beta-emitting therapy based on an accurate 3-dimensional representation of the in-vivo distribution of radioactivity concentration within the tumor and normal organs/tissues in a noninvasive manner. In general, imaging may be either based on positron emission tomography (PET) or single photon emission computed tomography (SPECT) invariably in combination with X-ray CT (PET/CT; SPECT/CT) or, to a much lesser extent, MRI. PET and SPECT differ in terms of the radionuclides and physical processes that give rise to the emission of high energy photons, as well as the sets of technologies involved in their detection. Using a variety of standardized quantitative parameters, system calibration, patient preparation, imaging acquisition and reconstruction protocols, and image analysis protocols, an accurate quantification of the tracer distribution can be obtained, which helps prescribe the therapeutic dose for each patient.
Collapse
Affiliation(s)
- Arda Könik
- Department of Imaging, Dana-Farber Cancer Institute, Boston, MA.
| | - Joseph A O'Donoghue
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY
| | - Richard L Wahl
- Department of Radiology, Mallinckrodt Institute of Radiology, Washington University in St Louis School of Medicine, St. Louis, MO
| | - Michael M Graham
- Past Director of Nuclear Medicine, Roy J and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA
| | - Annick D Van den Abbeele
- Department of Imaging, Dana-Farber Cancer Institute, Boston, MA; Division of Cancer Imaging, Mass General Brigham, Boston, MA; Dana-Farber Cancer Institute and Mass General Brigham, Boston, MA; Center for Biomedical Imaging in Oncology, Dana-Farber Cancer Institute, Boston, MA; Tumor Imaging Metrics Core, Dana-Farber/Harvard Cancer Center, Boston, MA
| |
Collapse
|
56
|
Surti S, Karp JS. Update on latest advances in time-of-flight PET. Phys Med 2020; 80:251-258. [PMID: 33212421 PMCID: PMC7749844 DOI: 10.1016/j.ejmp.2020.10.031] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 10/24/2020] [Accepted: 10/29/2020] [Indexed: 11/20/2022] Open
Abstract
This paper provides an update on time-of-flight (TOF) PET with a focus on latest hardware developments leading to current commercial PET/CT instruments. We describe advances in scintillator development, new photosensors and associated electronics readout, and detector designs for utilization in complete systems. Next, we introduce the latest commercial PET/CT scanners based on the aforementioned technologies, and discuss the detector design choices made that are relevant to differences in the system performance. Finally, we end with a discussion of the latest performance benchmarks for improved timing in PET detectors, challenges in scaling this performance to a complete system, and the outlook towards achieving a sub-50 ps coincidence timing resolution (CTR) in a PET detector.
Collapse
Affiliation(s)
- Suleman Surti
- Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - Joel S Karp
- Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA.
| |
Collapse
|
57
|
Wagatsuma K, Sakata M, Ishibashi K, Hirayama A, Kawakami H, Miwa K, Suzuki Y, Ishii K. Direct comparison of brain [ 18F]FDG images acquired by SiPM-based and PMT-based PET/CT: phantom and clinical studies. EJNMMI Phys 2020; 7:70. [PMID: 33226451 PMCID: PMC7683764 DOI: 10.1186/s40658-020-00337-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 11/10/2020] [Indexed: 11/24/2022] Open
Abstract
Background Silicon photomultiplier-positron emission tomography (SiPM-PET) has better sensitivity, spatial resolution, and timing resolution than photomultiplier tube (PMT)-PET. The present study aimed to clarify the advantages of SiPM-PET in 18F-fluoro-2-deoxy-D-glucose ([18F]FDG) brain imaging in a head-to-head comparison with PMT-PET in phantom and clinical studies. Methods Contrast was calculated from images acquired from a Hoffman 3D brain phantom, and image noise and uniformity were calculated from images acquired from a pool phantom using SiPM- and PMT-PET. Sequential PMT-PET and SiPM-PET [18F]FDG images were acquired over a period of 10 min from 22 controls and 10 patients. All images were separately normalized to a standard [18F]FDG PET template, then the mean standardized uptake values (SUVmean) and Z-score were calculated using MIMneuro and CortexID Suite, respectively. Results Image contrast, image noise, and uniformity in SiPM-PET changed 19.2, 3.5, and − 40.0% from PMT-PET, respectively. These physical indices of both PET scanners satisfied the criteria for acceptable image quality published by the Japanese Society of Nuclear Medicine of contrast > 55%, CV ≤ 15%, and SD ≤ 0.0249, respectively. Contrast was 70.0% for SiPM-PET without TOF and 59.5% for PMT-PET without TOF. The TOF improved contrast by 3.5% in SiPM-PET. The SUVmean using SiPM-PET was significantly higher than PMT-PET and did not correlate with a time delay. Z-scores were also significantly higher in images acquired from SiPM-PET (except for the bilateral posterior cingulate) than PMT-PET because the peak signal that was extracted by the calculation of Z-score in CortexID Suite was increased. The hypometabolic area in statistical maps was reduced and localized using SiPM-PET. The trend was independent of whether the images were derived from controls or patients. Conclusions The improved spatial resolution and sensitivity of SiPM-PET contributed to better image contrast and uniformity in brain [18F]FDG images. The SiPM-PET offers better quality and more accurate quantitation of brain PET images. The SUVmean and Z-scores were higher in SiPM-PET than PMT-PET due to improved PVE. [18F]FDG images acquired using SiPM-PET will help to improve diagnostic outcomes based on statistical image analysis because SiPM-PET would localize the distribution of glucose metabolism on Z-score maps. Supplementary Information The online version contains supplementary material available at 10.1186/s40658-020-00337-4.
Collapse
Affiliation(s)
- Kei Wagatsuma
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015, Japan.
| | - Muneyuki Sakata
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015, Japan
| | - Kenji Ishibashi
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015, Japan
| | - Akira Hirayama
- GE Healthcare Japan, 4-7-127 Asahigaoka, Hino, 191-8503, Japan
| | | | - Kenta Miwa
- Department of Radiological Sciences, School of Health Science, International University of Health and Welfare, 2600-1 Kitakanemaru, Ohtawara, 324-8501, Japan
| | - Yukihisa Suzuki
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015, Japan.,Department of Ophthalmology and Visual Science, Tokyo Medical and Dental University, Graduate School, 1-5-45, Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Kenji Ishii
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015, Japan
| |
Collapse
|
58
|
Klein R, deKemp RA. Selection of PET Camera and Implications on the Reliability and Accuracy of Absolute Myocardial Blood Flow Quantification. Curr Cardiol Rep 2020; 22:109. [DOI: 10.1007/s11886-020-01376-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
59
|
Rodríguez-Alfonso B, Simó-Perdigó M, Orcajo Rincón J. Functional imaging in soft tissue sarcomas: Update of the indications for 18F-FDG-PET/CT. Rev Esp Med Nucl Imagen Mol 2020. [DOI: 10.1016/j.remnie.2020.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
60
|
Rodríguez-Alfonso B, Simó-Perdigó M, Orcajo Rincón J. Functional image in soft tissue sarcomas: An update of the indications of 18F-FDG-PET/CT. Rev Esp Med Nucl Imagen Mol 2020; 39:233-243. [PMID: 32616457 DOI: 10.1016/j.remn.2020.06.001] [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: 06/07/2020] [Accepted: 06/08/2020] [Indexed: 11/29/2022]
Abstract
Soft tissue sarcomas (STS) are a rare and heterogeneous group of tumors. They account for 1% of solid malignant tumors in adults and 7% in children and are responsible for 2% of cancer mortality. They require a multidisciplinary approach in centers with experience. This collaboration aims to update the scientific evidence to strengthen, together with clinical experience, the bases for the use and limitations of 18F-FDG-PET/CT in STSs. The general recommendations for the use of PET/CT in STS at present are summarized as the initial evaluation of soft tissue tumours when conventional image does not establish benignity with certainty and this determines the approach; in biopsy guiding in selected cases; in the initial staging, as additional tool, for rhabdomyosarcoma and STS of extremities or superficial trunk and head and neck tumours; in the suspicion of local recurrence when the CT or MRI are inconclusive and in the presence of osteosynthesis or prosthetic material and in assessment of therapy response to local/systemic therapy in stages ii/iii. In addition, PET/CT has the added value of being a surrogate marker of the histopathological response and it provides prognostic information, both in the baseline study and after treatment.
Collapse
Affiliation(s)
- B Rodríguez-Alfonso
- Servicio de Medicina Nuclear, Hospital Universitario Puerta de Hierro de Majadahonda, Majadahonda, Madrid, España.
| | - M Simó-Perdigó
- Servicio de Medicina Nuclear, Hospital Universitari Vall d'Hebron, Barcelona, España
| | - J Orcajo Rincón
- Servicio de Medicina Nuclear, Hospital General Universitario Gregorio Marañón, Madrid, España; Miembro del Grupo Español de Investigación en Sarcomas (GEIS)
| |
Collapse
|
61
|
Surti S, Pantel AR, Karp JS. Total Body PET: Why, How, What for? IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2020; 4:283-292. [PMID: 33134653 PMCID: PMC7595297 DOI: 10.1109/trpms.2020.2985403] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PET instruments are now available with a long axial field-of-view (LAFOV) to enable imaging the total-body, or at least head and torso, simultaneously and without bed translation. This has two major benefits, a dramatic increase in system sensitivity and the ability to measure kinetics with wider axial coverage so as to include multiple organs. This manuscript presents a review of the technology leading up to the introduction of these new instruments, and explains the benefits of a LAFOV PET-CT instrument. To date there are two platforms developed for TB-PET, an outcome of the EXPLORER Consortium of the University of California at Davis (UC Davis) and the University of Pennsylvania (Penn). The uEXPLORER at UC Davis has an AFOV of 194 cm and was developed by United Imaging Healthcare. The PennPET EXPLORER was developed at Penn and is based on the digital detector from Philips Healthcare. This multi-ring system is scalable and has been tested with 3 rings but is now being expanded to 6 rings for 140 cm. Initial human studies with both EXPLORER systems have demonstrated the successful implementation and benefits of LAFOV scanners for both clinical and research applications. Examples of such studies are described in this manuscript.
Collapse
Affiliation(s)
- Suleman Surti
- Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Austin R Pantel
- Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Joel S Karp
- Departments of Radiology and Physics & Astronomy, University of Pennsylvania, Philadelphia, PA 19104, USA
| |
Collapse
|
62
|
Salvadori J, Labour J, Odille F, Marie PY, Badel JN, Imbert L, Sarrut D. Monte Carlo simulation of digital photon counting PET. EJNMMI Phys 2020; 7:23. [PMID: 32335787 PMCID: PMC7183520 DOI: 10.1186/s40658-020-00288-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 03/17/2020] [Indexed: 12/14/2022] Open
Abstract
A GATE Monte Carlo model of the Philips Vereos digital photon counting PET imaging system using silicon photo-multiplier detectors was proposed. It was evaluated against experimental data in accordance with NEMA guidelines. Comparisons were performed using listmode data in order to remain independent of image reconstruction algorithms. An original line of response-based method is proposed to estimate intrinsic spatial resolution without reconstruction. Four sets of experiments were performed: (1) count rates and scatter fraction, (2) energy and timing resolutions, (3) sensitivity, and (4) intrinsic spatial resolution. Experimental and simulated data were found to be in good agreement, with overall differences lower than 10% for activity concentrations used in most standard clinical applications. Illustrative image reconstructions were provided. In conclusion, the proposed Monte Carlo model was validated and can be used for numerous studies such as optimizing acquisition parameters or reconstruction algorithms.
Collapse
Affiliation(s)
- Julien Salvadori
- IADI, INSERM UMR 1254, Université de Lorraine, Nancy, France. .,Département de médecine nucléaire et plateforme Nancyclotep, CHRU-Nancy, Université de Lorraine, Nancy, France.
| | - Joey Labour
- CREATIS, Centre Léon Bérard, CNRS UMR 5220, INSERM U 1044, Université de Lyon; INSA-Lyon; Université Lyon 1, Lyon, France
| | - Freddy Odille
- IADI, INSERM UMR 1254, Université de Lorraine, Nancy, France
| | - Pierre-Yves Marie
- Département de médecine nucléaire et plateforme Nancyclotep, CHRU-Nancy, Université de Lorraine, Nancy, France.,DCAC, INSERM UMR 1116, Université de Lorraine, Nancy, France
| | - Jean-Noël Badel
- CREATIS, Centre Léon Bérard, CNRS UMR 5220, INSERM U 1044, Université de Lyon; INSA-Lyon; Université Lyon 1, Lyon, France
| | - Laëtitia Imbert
- IADI, INSERM UMR 1254, Université de Lorraine, Nancy, France.,Département de médecine nucléaire et plateforme Nancyclotep, CHRU-Nancy, Université de Lorraine, Nancy, France
| | - David Sarrut
- CREATIS, Centre Léon Bérard, CNRS UMR 5220, INSERM U 1044, Université de Lyon; INSA-Lyon; Université Lyon 1, Lyon, France
| |
Collapse
|
63
|
Werner RA, Thackeray JT, Diekmann J, Weiberg D, Bauersachs J, Bengel FM. The Changing Face of Nuclear Cardiology: Guiding Cardiovascular Care Toward Molecular Medicine. J Nucl Med 2020; 61:951-961. [PMID: 32303601 DOI: 10.2967/jnumed.119.240440] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 03/25/2020] [Indexed: 01/01/2023] Open
Abstract
Radionuclide imaging of myocardial perfusion, function, and viability has been established for decades and remains a robust, evidence-based and broadly available means for clinical workup and therapeutic guidance in ischemic heart disease. Yet, powerful alternative modalities have emerged for this purpose, and their growth has resulted in increasing competition. But the potential of the tracer principle goes beyond the assessment of physiology and function, toward the interrogation of biology and molecular pathways. This is a unique selling point of radionuclide imaging, which has been underrecognized in cardiovascular medicine until recently. Now, molecular imaging methods for the detection of myocardial infiltration, device infection, and cardiovascular inflammation are successfully gaining clinical acceptance. This is further strengthened by the symbiotic quest of cardiac imaging and therapy for an increasing implementation of molecule-targeted procedures, in which specific therapeutic interventions require specific diagnostic guidance toward the most suitable candidates. This review will summarize the current advent of clinical cardiovascular molecular imaging and highlight its transformative contribution to the evolution of cardiovascular therapy beyond mechanical interventions and broad blockbuster medication, toward a future of novel, individualized molecule-targeted and molecular imaging-guided therapies.
Collapse
Affiliation(s)
- Rudolf A Werner
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany; and
| | - James T Thackeray
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany; and
| | - Johanna Diekmann
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany; and
| | - Desiree Weiberg
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany; and
| | - Johann Bauersachs
- Department of Cardiology and Angiology, Hannover Medical School, Hannover, Germany
| | - Frank M Bengel
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany; and
| |
Collapse
|
64
|
Surti S, Viswanath V, Daube-Witherspoon ME, Conti M, Casey ME, Karp JS. Benefit of Improved Performance with State-of-the Art Digital PET/CT for Lesion Detection in Oncology. J Nucl Med 2020; 61:1684-1690. [PMID: 32198313 DOI: 10.2967/jnumed.120.242305] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 03/16/2020] [Indexed: 11/16/2022] Open
Abstract
The latest digital whole-body PET scanners provide a combination of higher sensitivity and improved spatial and timing resolution. We performed a lesion detectability study on two generations of Biograph PET/CT scanners, the mCT Flow and the Vision, to study the impact of improved physical performance on clinical performance. Our hypothesis was that the improved performance of the Vision would result in improved lesion detectability, allowing shorter imaging times or, equivalently, a lower injected dose. Methods: Data were acquired with the Society of Nuclear Medicine and Molecular Imaging Clinical Trials Network torso phantom combined with a 20-cm-diameter cylindrical phantom. Spherical lesions were emulated by acquiring sphere-in-air data and combining them with the phantom data to generate combined datasets with embedded lesions of known contrast. Two sphere sizes and uptakes were used: 9.89-mm-diameter spheres with 6:1 (lung) and 3:1 (cylinder) local activity concentration uptakes and 4.95-mm-diameter spheres with 9.6:1 (lung) and 4.5:1 (cylinder) local activity concentration uptakes. Standard image reconstruction was performed: an ordinary Poisson ordered-subsets expectation maximization algorithm with point-spread function and time-of-flight modeling and postreconstruction smoothing with a 5-mm gaussian filter. The Vision images were also generated without any postreconstruction smoothing. Generalized scan statistics methodology was used to estimate the area under the localized receiver-operating-characteristic curve (ALROC). Results: The higher sensitivity and improved time-of-flight performance of the Vision leads to reduced contrast in the background noise nodule distribution. Measured lesion contrast is also higher on the Vision because of its improved spatial resolution. Hence, the ALROC is noticeably higher for the Vision than for the mCT Flow. Conclusion: Improved overall performance of the Vision provides a factor of 4-6 reduction in imaging time (or injected dose) over the mCT Flow when using the ALROC metric for lesions at least 9.89 mm in diameter. Smaller lesions are barely detected in the mCT Flow, leading to even higher ALROC gains with the Vision. The improved spatial resolution of the Vision also leads to a higher measured contrast that is closer to the real uptake, implying improved quantification. Postreconstruction smoothing, however, reduces this improvement in measured contrast, thereby reducing the ALROC for small, high-uptake lesions.
Collapse
Affiliation(s)
- Suleman Surti
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania; and
| | - Varsha Viswanath
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania; and
| | | | | | | | - Joel S Karp
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania; and
| |
Collapse
|
65
|
Salvadori J, Odille F, Verger A, Olivier P, Karcher G, Marie PY, Imbert L. Head-to-head comparison between digital and analog PET of human and phantom images when optimized for maximizing the signal-to-noise ratio from small lesions. EJNMMI Phys 2020; 7:11. [PMID: 32086646 PMCID: PMC7035408 DOI: 10.1186/s40658-020-0281-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 02/13/2020] [Indexed: 02/07/2023] Open
Abstract
Background Routine PET exams are increasingly performed with reduced injected activities, leading to the use of different image reconstruction parameters than the NEMA parameters, in order to prevent from any deleterious decrease in signal-to-noise ratio (SNR) and thus, in lesion detectability. This study aimed to provide a global head-to-head comparison between digital (Vereos, Philips®) and analog (Ingenuity TF, Philips®) PET cameras of the trade-off between SNR and contrast through a wide-ranging number of reconstruction iterations, and with a further reconstruction optimization based on the SNR of small lesions. Methods Image quality parameters were compared between the two cameras on human and phantom images for a number of OSEM reconstruction iterations ranging from 1 to 10, the number of subsets being fixed at 10, and with the further identification of reconstruction parameters maximizing the SNR of spheres and adenopathies nearing 10 mm in diameter. These reconstructions were additionally obtained with and without time-of-flight (TOF) information (TOF and noTOF images, respectively) for further comparisons. Results On both human and phantom TOF images, the compromise between SNR and contrast was consistently more advantageous for digital than analog PET, with the difference being particularly pronounced for the lowest numbers of iterations and the smallest spheres. SNR was maximized with 1 and 2 OSEM iterations for the TOF images from digital and analog PET, respectively, whereas 4 OSEM iterations were required for the corresponding noTOF images from both cameras. On the TOF images obtained with this SNR optimization, digital PET exhibited a 37% to 44% higher SNR as compared with analog PET, depending on sphere size. These relative differences were however much lower for the noTOF images optimized for SNR (− 4 to + 18%), as well as for images reconstructed according to NEMA standards (− 4 to + 12%). Conclusion SNR may be dramatically higher for digital PET than for analog PET, especially when optimized for small lesions. This superiority is mostly attributable to enhanced TOF resolution and is significantly underestimated in NEMA-based analyses.
Collapse
Affiliation(s)
- Julien Salvadori
- Departement of Nuclear Medicine and Nancyclotep molecular imaging platform, CHRU-Nancy, Université de Lorraine, 54000, Nancy, France. .,IADI, INSERM, UMR 1254, Université de Lorraine, 54000, Nancy, France.
| | - Freddy Odille
- IADI, INSERM, UMR 1254, Université de Lorraine, 54000, Nancy, France
| | - Antoine Verger
- Departement of Nuclear Medicine and Nancyclotep molecular imaging platform, CHRU-Nancy, Université de Lorraine, 54000, Nancy, France.,IADI, INSERM, UMR 1254, Université de Lorraine, 54000, Nancy, France
| | - Pierre Olivier
- Departement of Nuclear Medicine and Nancyclotep molecular imaging platform, CHRU-Nancy, Université de Lorraine, 54000, Nancy, France
| | - Gilles Karcher
- Departement of Nuclear Medicine and Nancyclotep molecular imaging platform, CHRU-Nancy, Université de Lorraine, 54000, Nancy, France
| | - Pierre-Yves Marie
- Departement of Nuclear Medicine and Nancyclotep molecular imaging platform, CHRU-Nancy, Université de Lorraine, 54000, Nancy, France.,DCAC, INSERM, UMR 1116, Université de Lorraine, 54000, Nancy, France
| | - Laetitia Imbert
- Departement of Nuclear Medicine and Nancyclotep molecular imaging platform, CHRU-Nancy, Université de Lorraine, 54000, Nancy, France.,IADI, INSERM, UMR 1254, Université de Lorraine, 54000, Nancy, France
| |
Collapse
|
66
|
The impact of 18F-FDG PET on initial staging and therapy planning of pediatric soft-tissue sarcoma patients. Pediatr Radiol 2020; 50:252-260. [PMID: 31628508 DOI: 10.1007/s00247-019-04530-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 08/15/2019] [Accepted: 09/06/2019] [Indexed: 10/25/2022]
Abstract
BACKGROUND Soft-tissue sarcomas in children are a histologically heterogenous group of malignant tumors accounting for approximately 7% of childhood cancers. There is a paucity of data on the value of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) for initial staging and whether PET influenced management of these patients. OBJECTIVE The aim of this analysis is to assess the use of 18F-FDG PET exclusively, and as a supplement to cross-sectional imaging in comparison to typical imaging protocols (CT and magnetic resonance imaging [MRI]) for initial staging as well as therapy planning in pediatric soft-tissue sarcoma patients. MATERIALS AND METHODS The list of 18F-FDG PET/CT performed for soft-tissue sarcoma between March 2007 and October 2017 was obtained from the Hospital Information System database. Twenty-six patients who had received 18F-FDG PET, MRI and/or CT at initial diagnosis were included in the study. 18F-FDG PET and concurrent diagnostic CT and MRI at initial staging were independently reviewed to note the number of primary and metastatic lesions detected by each modality. A chart review was conducted to collect information on final diagnosis, staging and treatment plan. RESULTS During the study period, 26 patients (15 females) ages 1.3-17.9 years (median age: 6 years) had received 18F-FDG PET/CT at initial diagnosis of soft-tissue sarcoma. Diagnostic CT was available for comparison in all 26 patients and MRI was available in 18 patients. The mean interval between cross-sectional imaging and 18F-FDG PET was 5.9 days (range: 0-30 days). All 26 primary lesions were equally detected by 18F-FDG PET compared to CT and MRI. From 84 metastatic lesions, 16 were detected by PET as well as CT and MRI, 12 by 18F-FDG PET only (included mainly lymph node metastases) and 56 by CT and MRI only (included mainly lung metastases). 18F-FDG PET changed therapy planning in 5 patients out of 26 (19%) by showing additional lesions not detected by CT and MRI. CONCLUSION 18F-FDG PET proved to be a valuable tool for precise initial staging of pediatric soft-tissue sarcoma patients, especially in detecting lymph node metastasis, and could be included in their initial work-up. Given the relative rarity and heterogeneity of this group of tumors, additional investigations are required to definitely establish a role for 18F-FDG PET in the initial staging and therapy planning of soft-tissue sarcoma in the pediatric population.
Collapse
|
67
|
Increased 18F-FDG signal recovery from small physiological structures in digital PET/CT and application to the pituitary gland. Sci Rep 2020; 10:368. [PMID: 31942032 PMCID: PMC6962205 DOI: 10.1038/s41598-019-57313-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 12/16/2019] [Indexed: 11/14/2022] Open
Abstract
On conventional PET/CT, and under physiological conditions, the volume of the pituitary gland (PG) is small, and its metabolic activity is commonly comparable to the surrounding background level in 18F-FDG imaging. We compared the physiological 18F-FDG uptake of the PG in patients imaged with digital PET (dPET) and with conventional PET (cPET). Additionally, we performed phantom experiments to characterize signal recovery and detectability of small structures. We retrospectively included 10 dPET and 10 cPET patients and measured PG SUVmax, SUVmean and SUVratio (using cerebellum as reference). We imaged a modified NEMA/IEC phantom with both dPET and cPET (background activity 5 kBq/mL, and 3× and 5× higher concentrations in ∅2–20-mm spherical inserts). Mean recovery coefficients (RCmean) and signal-difference-to-noise-ratio (SDNR) were computed to assess lesion detectability. Patients imaged with dPET presented higher PG SUVmax and SUVratio (SUVR) compared to patients imaged with cPET (4.7 ± 2.05 vs. 2.9 ± 0.64, p = 0.004; and 0.62 ± 0.25 vs 0.39 ± 0.09, p = 0.029, respectively), while there was no difference for SUVmean (2.7 ± 1.32 vs 2.1 ± 0.44, p = 0.39). Thus, with a SUV readout scale of 0–5 g/mL, normal PG appeared abnormally hot with dPET, but not with cPET. Phantom evidenced higher RCmean in dPET compared to cPET. For both 3x and 5x measurements, lesion detectability according to size was systematically superior with dPET. In conclusion, patients imaged with dPET presented higher 18F-FDG physiological uptake of the PG as compared to patients imaged with cPET. These findings were supported by phantom experiments demonstrating superior signal recovery and small region detectability with dPET. Awareness of this new “higher” SUV of the normal 18F-FDG uptake of the PG is important to avoid potential pitfalls in image interpretation, notably in oncologic patients treated with immunotherapy, who are at increased risk to develop hypophysitis.
Collapse
|
68
|
Chicheportiche A, Marciano R, Orevi M. Comparison of NEMA characterizations for Discovery MI and Discovery MI-DR TOF PET/CT systems at different sites and with other commercial PET/CT systems. EJNMMI Phys 2020; 7:4. [PMID: 31938953 PMCID: PMC6960280 DOI: 10.1186/s40658-020-0271-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 01/05/2020] [Indexed: 12/19/2022] Open
Abstract
Background This article compares the physical performance of the 4-ring digital Discovery MI (DMI) and PMT-based Discovery MI-DR (DMI-DR) PET/CT systems. Physical performance was assessed according to the NEMA NU 2-2012 standards. Performance measures included spatial resolution, image quality, scatter fraction and count rate performance, and sensitivity. Energy and timing resolutions were also measured. Published DMI and DMI-DR performance studies from other centers are reviewed and compared. Results 4-ring DMI spatial resolution at 1-cm radial offset in the radial, tangential and axial directions was 4.62, 4.18 and 4.57 mm, respectively, compared with the DMI-DR system values of 4.58, 4.52, and 5.31 mm. Measured sensitivity was 13.3 kcps/MBq at the center of the FOV and 13.4 kcps/MBq 10 cm off-center for the SiPM-based DMI system. DMI-DR system sensitivity was 6.3 kcps/MBq at the center of the FOV and 6.8 kcps/MBq at 10 cm off-center. DMI measured noise equivalent count rate peak was 175.6 kcps at 20.1 kBq/ml; DMI-DR was 146.7 kcps at 31.7 kBq/ml. Scatter fraction was 40.5% and 36.6%, respectively. DMI image contrast recovery (CR) values ranged from 73.2% (10 mm sphere) to 91.0% (37 mm sphere); DMI-DR, values ranged from 68.4% to 91.4%. DMI background variability (BV) was 1.8%–6.5%; DMI-DR was 2.3%–9.1%. The Q.Clear algorithm improved image quality, increasing CR and decreasing BV in both systems. The photopeak energy resolution was 9.63% and 12.19% for DMI and DMI-DR, respectively. The time-of-flight (TOF) resolution was 377.26 ps and 552.71 ps, respectively. Compared with measurements in other centers, results were similar and showed an absolute mean relative deviation of 6% for DMI and 7% for DMI-DR overall performance results. Conclusions Performance measures were higher for the 4-ring DMI than the DMI-DR system. The biggest advantages of the 4-ring DMI vs DMI-DR are improved sensitivity and count rate performance. This should allow a better image signal-to-noise ratio (SNR) for the same acquisition times or, similar SNR with lower acquisition times or injected activity. In its 3-ring configuration, the DMI showed worse performance results than the PMT-based system in terms of count rate scatter fraction and image quality (for similar axial FOV).
Collapse
Affiliation(s)
- Alexandre Chicheportiche
- Department of Nuclear Medicine and Biophysics, Hadassah Hebrew University Medical Center, 91120, Jerusalem, Israel.
| | | | - Marina Orevi
- Department of Nuclear Medicine and Biophysics, Hadassah Hebrew University Medical Center, 91120, Jerusalem, Israel
| |
Collapse
|
69
|
Gnesin S, Kieffer C, Zeimpekis K, Papazyan JP, Guignard R, Prior JO, Verdun FR, Lima TVM. Phantom-based image quality assessment of clinical 18F-FDG protocols in digital PET/CT and comparison to conventional PMT-based PET/CT. EJNMMI Phys 2020; 7:1. [PMID: 31907664 PMCID: PMC6944719 DOI: 10.1186/s40658-019-0269-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Accepted: 12/16/2019] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND We assessed and compared image quality obtained with clinical 18F-FDG whole-body oncologic PET protocols used in three different, state-of-the-art digital PET/CT and two conventional PMT-based PET/CT devices. Our goal was to evaluate an improved trade-off between administered activity (patient dose exposure/signal-to-noise ratio) and acquisition time (patient comfort) while preserving diagnostic information achievable with the recently introduced digital detector technology compared to previous analogue PET technology. METHODS We performed list-mode (LM) PET acquisitions using a NEMA/IEC NU2 phantom, with activity concentrations of 5 kBq/mL and 25 kBq/mL for the background (9.5 L) and sphere inserts, respectively. For each device, reconstructions were obtained varying the image statistics (10, 30, 60, 90, 120, 180, and 300 s from LM data) and the number of iterations (range 1 to 10) in addition to the employed local clinical protocol setup. We measured for each reconstructed dataset: the quantitative cross-calibration, the image noise on the uniform background assessed by the coefficient of variation (COV), and the recovery coefficients (RCs) evaluated in the hot spheres. Additionally, we compared the characteristic time-activity-product (TAP) that is the product of scan time per bed position × mass-activity administered (in min·MBq/kg) across datasets. RESULTS Good system cross-calibration was obtained for all tested datasets with < 6% deviation from the expected value was observed. For all clinical protocol settings, image noise was compatible with clinical interpretation (COV < 15%). Digital PET showed an improved background signal-to-noise ratio as compared to conventional PMT-based PET. RCs were comparable between digital and PMT-based PET datasets. Compared to PMT-based PET, digital systems provided comparable image quality with lower TAP (from ~ 40% less and up to 70% less). CONCLUSIONS This study compared the achievable clinical image quality in three state-of-the-art digital PET/CT devices (from different vendors) as well as in two conventional PMT-based PET. Reported results show that a comparable image quality is achievable with a TAP reduction of ~ 40% in digital PET. This could lead to a significant reduction of the administered mass-activity and/or scan time with direct benefits in terms of dose exposure and patient comfort.
Collapse
Affiliation(s)
- Silvano Gnesin
- Institute of Radiation physics, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
| | - Christine Kieffer
- Institute of Radiation physics, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
| | | | - Jean-Pierre Papazyan
- Radiology and Medicine Nuclear Department, Genolier Clinique, Genolier, Switzerland
| | - Renaud Guignard
- Department of Nuclear Medicine, La Tour Medical Group, Meyrin, Switzerland
| | - John O Prior
- Department of Nuclear Medicine and Molecular Imaging, Lausanne University Hospital, University of Lausanne, Bugnon 46, Lausanne, Switzerland.
| | - Francis R Verdun
- Institute of Radiation physics, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
| | - Thiago V M Lima
- Institute of Radiation physics, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
- Radiation Protection Group, Aarau Cantonal Hospital, Aarau, Switzerland
| |
Collapse
|
70
|
Manabe O, Oyama-Manabe N, Nagai T, Furuya S, Anzai T. Detailed visualization of the right and left ventricular, left atrial, and epicardial involvement of cardiac sarcoidosis with novel semiconductor PET/CT. Eur J Nucl Med Mol Imaging 2019; 47:1773-1774. [DOI: 10.1007/s00259-019-04577-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Accepted: 10/10/2019] [Indexed: 12/13/2022]
|
71
|
Henrich TJ, Hsue PY, VanBrocklin H. Seeing Is Believing: Nuclear Imaging of HIV Persistence. Front Immunol 2019; 10:2077. [PMID: 31572355 PMCID: PMC6751256 DOI: 10.3389/fimmu.2019.02077] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 08/16/2019] [Indexed: 12/19/2022] Open
Abstract
A major obstacle to HIV eradication is the presence of infected cells that persist despite suppressive antiretroviral therapy (ART). HIV largely resides outside of the peripheral circulation, and thus, numerous anatomical and lymphoid compartments that have the capacity to harbor HIV are inaccessible to routine sampling. As a result, there is a limited understanding of the tissue burden of HIV infection or anatomical distribution of HIV transcriptional and translational activity. Novel, non-invasive, in vivo methods are urgently needed to address this fundamental gap in knowledge. In this review, we discuss past and current nuclear imaging approaches that have been applied to HIV infection with an emphasis on current strategies to implement positron emission tomography (PET)-based imaging to directly visualize and characterize whole-body HIV burden. These imaging approaches have various limitations, such as the potential for limited PET sensitivity and specificity in the setting of ART suppression or low viral burden. However, recent advances in high-sensitivity, total-body PET imaging platforms and development of new radiotracer technologies that may enhance anatomical penetration of target-specific tracer molecules are discussed. Potential strategies to image non-viral markers of HIV tissue burden or focal immune perturbation are also addressed. Overall, emerging nuclear imaging techniques and platforms may play an important role in the development of novel therapeutic and HIV reservoir eradication strategies.
Collapse
Affiliation(s)
- Timothy J Henrich
- Division of Experimental Medicine, Department of Medicine, University of San Francisco, San Francisco, CA, United States
| | - Priscilla Y Hsue
- Division of Cardiology, Department of Medicine, University of San Francisco, San Francisco, CA, United States
| | - Henry VanBrocklin
- Radiopharmaceutical Research Program, Center for Molecular and Functional Imaging, University of San Francisco, San Francisco, CA, United States
| |
Collapse
|
72
|
Economou Lundeberg J, Oddstig J, Bitzén U, Trägårdh E. Comparison between silicon photomultiplier-based and conventional PET/CT in patients with suspected lung cancer-a pilot study. EJNMMI Res 2019; 9:35. [PMID: 31511997 PMCID: PMC6738366 DOI: 10.1186/s13550-019-0504-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 04/12/2019] [Indexed: 01/22/2023] Open
Abstract
Background Lung cancer is one of the most common cancers in the world. Early detection and correct staging are fundamental for treatment and prognosis. Positron emission tomography with computed tomography (PET/CT) is recommended clinically. Silicon (Si) photomultiplier (PM)-based PET technology and new reconstruction algorithms are hoped to increase the detection of small lesions and enable earlier detection of pathologies including metastatic spread. The aim of this study was to compare the diagnostic performance of a SiPM-based PET/CT (including a new block-sequential regularization expectation maximization (BSREM) reconstruction algorithm) with a conventional PM-based PET/CT including a conventional ordered subset expectation maximization (OSEM) reconstruction algorithm. The focus was patients admitted for 18F-fluorodeoxyglucose (FDG) PET/CT for initial diagnosis and staging of suspected lung cancer. Patients were scanned on both a SiPM-based PET/CT (Discovery MI; GE Healthcare, Milwaukee, MI, USA) and a PM-based PET/CT (Discovery 690; GE Healthcare, Milwaukee, MI, USA). Standardized uptake values (SUV) and image interpretation were compared between the two systems. Image interpretations were further compared with histopathology when available. Results Seventeen patients referred for suspected lung cancer were included in our single injection, dual imaging study. No statically significant differences in SUVmax of suspected malignant primary tumours were found between the two PET/CT systems. SUVmax in suspected malignant intrathoracic lymph nodes was 10% higher on the SiPM-based system (p = 0.026). Good consistency (14/17 cases) between the PET/CT systems were found when comparing simplified TNM staging. The available histology results did not find any obvious differences between the systems. Conclusion In a clinical setting, the new SiPM-based PET/CT system with a new BSREM reconstruction algorithm provided a higher SUVmax for suspected lymph node metastases compared to the PM-based system. However, no improvement in lung cancer detection was seen.
Collapse
Affiliation(s)
- Johan Economou Lundeberg
- Department of Clinical Physiology and Nuclear Medicine, Skåne University Hospital, 221 85, Lund, Sweden.
| | - Jenny Oddstig
- Radiation Physics, Skåne University Hospital, Lund, Sweden
| | - Ulrika Bitzén
- Department of Clinical Physiology and Nuclear Medicine, Skåne University Hospital, 221 85, Lund, Sweden
| | - Elin Trägårdh
- Department of Clinical Physiology and Nuclear Medicine, Skåne University Hospital, 221 85, Lund, Sweden.,Wallenberg Center for Molecular Medicine, Lund University, Lund, Sweden
| |
Collapse
|
73
|
Salvadori J, Imbert L, Perrin M, Karcher G, Lamiral Z, Marie PY, Verger A. Head-to-head comparison of image quality between brain 18F-FDG images recorded with a fully digital versus a last-generation analog PET camera. EJNMMI Res 2019; 9:61. [PMID: 31300962 PMCID: PMC6626093 DOI: 10.1186/s13550-019-0526-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 06/05/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The quality of phantom images was previously shown to be higher on digital (Vereos Philips®) compared to analog PET (Ingenuity Philips®) cameras. This study aimed to determine the extent to which this difference still remains significant on normal brain 18F-FDG PET images. METHODS Relative noise and contrast as well as border sharpness (a spatial resolution index) of central (striata) and peripheral (occiput) gray-matter structures were compared between 10 sets of normal brain 18F-FDG PET images recorded and reconstructed on digital and analog last-generation PET cameras, together with a subjective visual analysis of image quality provided by experienced physicians. RESULTS Compared with analog PET, digital PET provided marked improvements in image quality parameters. The median relative noise was decreased (- 22%), while gray/white-matter contrast was increased (+ 27%/+ 41% for central/peripheral gray-matter structures), with these results being consistent with visual analysis. In addition, a clear enhancement in image sharpness was further documented for digital PET owing to the possible use of a 1-mm3 voxel size (+ 24%/+ 21%). CONCLUSIONS On normal brain 18F-FDG images and compared with a last-generation analog PET, the fully digital PET camera offers marked improvements in image noise and contrast, as well as significant potential for further enhancing spatial resolution.
Collapse
Affiliation(s)
- Julien Salvadori
- IADI, INSERM UMR-1254, Université de Lorraine, 54500, Vandœuvre-lès-Nancy, France. .,Plateforme Nancyclotep, CHRU-Nancy, Université de Lorraine, 54500, Vandœuvre-lès-Nancy, France.
| | - Laetitia Imbert
- IADI, INSERM UMR-1254, Université de Lorraine, 54500, Vandœuvre-lès-Nancy, France.,Plateforme Nancyclotep, CHRU-Nancy, Université de Lorraine, 54500, Vandœuvre-lès-Nancy, France.,Service de Médecine Nucléaire, CHRU-Nancy, Université de Lorraine, 54500, Vandœuvre-lès-Nancy, France.,Institut de Cancérologie de Lorraine, Université de Lorraine, 54500, Vandœuvre-lès-Nancy, France
| | - Mathieu Perrin
- Service de Médecine Nucléaire, CHRU-Nancy, Université de Lorraine, 54500, Vandœuvre-lès-Nancy, France
| | - Gilles Karcher
- Plateforme Nancyclotep, CHRU-Nancy, Université de Lorraine, 54500, Vandœuvre-lès-Nancy, France.,Service de Médecine Nucléaire, CHRU-Nancy, Université de Lorraine, 54500, Vandœuvre-lès-Nancy, France
| | - Zohra Lamiral
- Centre d'Investigations Cliniques Plurithématiques, INSERM UMR-1116, Université de Lorraine, 54500, Vandœuvre-lès-Nancy, France
| | - Pierre-Yves Marie
- Plateforme Nancyclotep, CHRU-Nancy, Université de Lorraine, 54500, Vandœuvre-lès-Nancy, France.,Service de Médecine Nucléaire, CHRU-Nancy, Université de Lorraine, 54500, Vandœuvre-lès-Nancy, France.,Centre d'Investigations Cliniques Plurithématiques, INSERM UMR-1116, Université de Lorraine, 54500, Vandœuvre-lès-Nancy, France
| | - Antoine Verger
- IADI, INSERM UMR-1254, Université de Lorraine, 54500, Vandœuvre-lès-Nancy, France.,Plateforme Nancyclotep, CHRU-Nancy, Université de Lorraine, 54500, Vandœuvre-lès-Nancy, France.,Service de Médecine Nucléaire, CHRU-Nancy, Université de Lorraine, 54500, Vandœuvre-lès-Nancy, France
| |
Collapse
|
74
|
Abstract
Purpose of Review A variety of approaches and molecular targets have emerged in recent years for radionuclide-based imaging of atherosclerosis and vulnerable plaque using single photon emission computed tomography (SPECT) and positron emission tomography (PET), with numerous methods focused on characterizing the mechanisms underlying plaque progression and rupture. This review highlights the ongoing developments in both the preclinical and clinical environment for radionuclide imaging of atherosclerosis and atherothrombosis. Recent Findings Numerous physiological processes responsible for the evolution of high-risk atherosclerotic plaque, such as inflammation, thrombosis, angiogenesis, and microcalcification, have been shown to be feasible targets for SPECT and PET imaging. For each physiological process, specific molecular markers have been identified that allow for sensitive non-invasive detection and characterization of atherosclerotic plaque. Summary The capabilities of SPECT and PET imaging continue to evolve for physiological evaluation of atherosclerosis. This review summarizes the latest developments related to radionuclide imaging of atherothrombotic diseases.
Collapse
|
75
|
Schillaci O, Urbano N. Digital PET/CT: a new intriguing chance for clinical nuclear medicine and personalized molecular imaging. Eur J Nucl Med Mol Imaging 2019; 46:1222-1225. [DOI: 10.1007/s00259-019-04300-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 02/27/2019] [Indexed: 10/27/2022]
|