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Shraim MA, Massé-Alarie H, Farrell MJ, Cavaleri R, Loggia ML, Hodges PW. Neuroinflammatory activation in sensory and motor regions of the cortex is related to sensorimotor function in individuals with low back pain maintained by nociplastic mechanisms: A preliminary proof-of-concept study. Eur J Pain 2024. [PMID: 39007713 DOI: 10.1002/ejp.2313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 06/26/2024] [Accepted: 06/30/2024] [Indexed: 07/16/2024]
Abstract
BACKGROUND Chronic pain involves communication between neural and immune systems. Recent data suggest localization of glial (brain immune cells) activation to the sensorimotor regions of the brain cortex (S1/M1) in chronic low back pain (LBP). As glia perform diverse functions that impact neural function, activation might contribute to sensorimotor changes, particularly in LBP maintained by increased nervous system sensitivity (i.e., nociplastic pain). This preliminary proof-of-concept study aimed to: (i) compare evidence of neuroinflammatory activation in S1/M1 between individuals with and without LBP (and between nociceptive and nociplastic LBP phenotypes), and (ii) evaluate relationships between neuroinflammatory activation and sensorimotor function. METHODS Simultaneous PET-fMRI measured neuroinflammatory activation in functionally defined S1/M1 in pain-free individuals (n = 8) and individuals with chronic LBP (n = 9; nociceptive: n = 4, nociplastic: n = 5). Regions of S1/M1 related to the back were identified using fMRI during motor tasks and thermal stimuli. Sensorimotor measures included single and paired-pulse transcranial magnetic stimulation (TMS) and quantitative sensory testing (QST). Sleep, depression, disability and pain questionnaires were administered. RESULTS Neuroinflammatory activation was greater in the lower back cortical representation of S1/M1 of the nociplastic LBP group than both nociceptive LBP and pain-free groups. Neuroinflammatory activation in S1/M1 was positively correlated with sensitivity to hot (r = 0.52) and cold (r = 0.55) pain stimuli, poor sleep, depression, disability and BMI, and negatively correlated with intracortical facilitation (r = -0.41). CONCLUSION This preliminary proof-of-concept study suggests that neuroinflammation in back regions of S1/M1 in individuals with nociplastic LBP could plausibly explain some characteristic features of this LBP phenotype. SIGNIFICANCE STATEMENT Neuroinflammatory activation localized to sensorimotor areas of the brain in individuals with nociplastic pain might contribute to changes in sensory and motor function and aspects of central sensitization. If cause-effect relationships are established in longitudinal studies, this may direct development of therapies that target neuroinflammatory activation.
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Affiliation(s)
- Muath A Shraim
- The University of Queensland, School of Health & Rehabilitation Sciences, St Lucia, Queensland, Australia
| | - Hugo Massé-Alarie
- The University of Queensland, School of Health & Rehabilitation Sciences, St Lucia, Queensland, Australia
- Centre Interdisciplinaire de Recherche en réadaptation et Integration Sociale (CIRRIS), Université Laval, Québec City, Québec, Canada
| | - Michael J Farrell
- Monash Biomedical Imaging, Monash University, Melbourne, Victoria, Australia
| | - Rocco Cavaleri
- Brain Stimulation and Rehabilitation Lab, Western Sydney University, School of Health Sciences, Sydney, New South Wales, Australia
| | - Marco L Loggia
- MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Paul W Hodges
- The University of Queensland, School of Health & Rehabilitation Sciences, St Lucia, Queensland, Australia
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2
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Roghani AK, Garcia RI, Roghani A, Reddy A, Khemka S, Reddy RP, Pattoor V, Jacob M, Reddy PH, Sehar U. Treating Alzheimer's disease using nanoparticle-mediated drug delivery strategies/systems. Ageing Res Rev 2024; 97:102291. [PMID: 38614367 DOI: 10.1016/j.arr.2024.102291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 03/18/2024] [Accepted: 04/01/2024] [Indexed: 04/15/2024]
Abstract
The administration of promising medications for the treatment of neurodegenerative disorders (NDDs), such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and amyotrophic lateral sclerosis (ALS) is significantly hampered by the blood-brain barrier (BBB). Nanotechnology has recently come to light as a viable strategy for overcoming this obstacle and improving drug delivery to the brain. With a focus on current developments and prospects, this review article examines the use of nanoparticles to overcome the BBB constraints to improve drug therapy for AD The potential for several nanoparticle-based approaches, such as those utilizing lipid-based, polymeric, and inorganic nanoparticles, to enhance drug transport across the BBB are highlighted. To shed insight on their involvement in aiding effective drug transport to the brain, methods of nanoparticle-mediated drug delivery, such as surface modifications, functionalization, and particular targeting ligands, are also investigated. The article also discusses the most recent findings on innovative medication formulations encapsulated within nanoparticles and the therapeutic effects they have shown in both preclinical and clinical testing. This sector has difficulties and restrictions, such as the need for increased safety, scalability, and translation to clinical applications. However, the major emphasis of this review aims to provide insight and contribute to the knowledge of how nanotechnology can potentially revolutionize the worldwide treatment of NDDs, particularly AD, to enhance clinical outcomes.
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Affiliation(s)
- Aryan Kia Roghani
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA; Frenship High School, Lubbock, TX 79382, USA.
| | - Ricardo Isaiah Garcia
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA.
| | - Ali Roghani
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA.
| | - Aananya Reddy
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA; Lubbock High School, Lubbock, TX 79401, USA.
| | - Sachi Khemka
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA.
| | - Ruhananhad P Reddy
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA; Lubbock High School, Lubbock, TX 79401, USA.
| | - Vasanthkumar Pattoor
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA; University of South Florida, Tampa, FL 33620, USA.
| | - Michael Jacob
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA; Department of Biology, The University of Texas at San Antonio, San Antonio, TX 78249, USA.
| | - P Hemachandra Reddy
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA; Nutritional Sciences Department, College of Human Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA; Public Health Department of Graduate School of Biomedical Sciences, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA; Department of Speech, Language and Hearing Services, School Health Professions, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA; Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA.
| | - Ujala Sehar
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA.
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Mirshahvalad SA, Farag A, Thiessen J, Wong R, Veit-Haibach P. Current Applications of PET/MR: Part I: Technical Basics and Preclinical/Clinical Applications. Can Assoc Radiol J 2024:8465371241255903. [PMID: 38813998 DOI: 10.1177/08465371241255903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2024] Open
Abstract
Positron emission tomography/magnetic resonance (PET/MR) imaging has gone through major hardware improvements in recent years, making it a reliable state-of-the-art hybrid modality in clinical practice. At the same time, image reconstruction, attenuation correction, and motion correction algorithms have significantly evolved to provide high-quality images. Part I of the current review discusses technical basics, pre-clinical applications, and clinical applications of PET/MR in radiation oncology and head and neck imaging. PET/MR offers a broad range of advantages in preclinical and clinical imaging. In the preclinic, small and large animal-dedicated devices were developed, making PET/MR capable of delivering new insight into animal models in diseases and facilitating the development of methods that inform clinical PET/MR. Regarding PET/MR's clinical applications in radiation medicine, PET and MR already play crucial roles in the radiotherapy process. Their combination is particularly significant as it can provide molecular and morphological characteristics that are not achievable with other modalities. In addition, the integration of PET/MR information for therapy planning with linear accelerators is expected to provide potentially unique biomarkers for treatment guidance. Furthermore, in clinical applications in the head and neck region, it has been shown that PET/MR can be an accurate modality in head and neck malignancies for staging and resectability assessment. Also, it can play a crucial role in diagnosing residual or recurrent diseases, reliably distinguishing from oedema and fibrosis. PET/MR can furthermore help with tumour characterization and patient prognostication. Lastly, in head and neck carcinoma of unknown origin, PET/MR, with its diagnostic potential, may obviate multiple imaging sessions in the near future.
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Affiliation(s)
- Seyed Ali Mirshahvalad
- University Medical Imaging Toronto, Toronto Joint Department Medical Imaging, University Health Network, Sinai Health System, Women's College Hospital, University of Toronto, Toronto, ON, Canada
- Department of Medical Imaging, University of Toronto, Toronto, ON, Canada
| | - Adam Farag
- University Medical Imaging Toronto, Toronto Joint Department Medical Imaging, University Health Network, Sinai Health System, Women's College Hospital, University of Toronto, Toronto, ON, Canada
| | - Jonathan Thiessen
- Imaging Program, Lawson Health Research Institute, London, ON, Canada
- Medical Biophysics, Medical Imaging, Western University, London, ON, Canada
| | - Rebecca Wong
- Department of Radiation Oncology, Princess Margaret Cancer Centre, University Health Network, University of Toronto, Toronto, ON, Canada
| | - Patrick Veit-Haibach
- University Medical Imaging Toronto, Toronto Joint Department Medical Imaging, University Health Network, Sinai Health System, Women's College Hospital, University of Toronto, Toronto, ON, Canada
- Department of Medical Imaging, University of Toronto, Toronto, ON, Canada
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4
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DeBay DR, Brewer KD. Combined PET/MR: Where Anatomical Imaging Meets Cellular Function. Methods Mol Biol 2024; 2729:391-408. [PMID: 38006508 DOI: 10.1007/978-1-0716-3499-8_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2023]
Abstract
Recent technological advances in medical imaging have allowed for both sequential and simultaneous acquisition of magnetic resonance imaging (MRI) and positron emission tomography (PET) data. Simultaneous PET/MRI offers distinct advantages by efficiently capturing functional and metabolic processes with co-localized, high-resolution anatomical images while minimizing time and movement. We will describe some of the technical and logistic requirements for optimizing sequential and simultaneous PET/MRI in the preclinical research setting.
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Affiliation(s)
- Drew R DeBay
- Biomedical Translational Imaging Centre (BIOTIC), Halifax, Canada
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Canada
| | - Kimberly D Brewer
- School of Biomedical Engineering, Dalhousie University, Halifax, NS, Canada.
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Canada.
- Diagnostic Radiology, Dalhousie University, Halifax, Canada.
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Lee JS, Lee MS. Advancements in Positron Emission Tomography Detectors: From Silicon Photomultiplier Technology to Artificial Intelligence Applications. PET Clin 2024; 19:1-24. [PMID: 37802675 DOI: 10.1016/j.cpet.2023.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/08/2023]
Abstract
This review article focuses on PET detector technology, which is the most crucial factor in determining PET image quality. The article highlights the desired properties of PET detectors, including high detection efficiency, spatial resolution, energy resolution, and timing resolution. Recent advancements in PET detectors to improve these properties are also discussed, including the use of silicon photomultiplier technology, advancements in depth-of-interaction and time-of-flight PET detectors, and the use of artificial intelligence for detector development. The article provides an overview of PET detector technology and its recent advancements, which can significantly enhance PET image quality.
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Affiliation(s)
- Jae Sung Lee
- Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul 03080, South Korea; Brightonix Imaging Inc., Seoul 04782, South Korea
| | - Min Sun Lee
- Environmental Radioactivity Assessment Team, Nuclear Emergency & Environmental Protection Division, Korea Atomic Energy Research Institute, Daejeon 34057, South Korea.
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Park H, Yi M, Lee JS. Silicon photomultiplier signal readout and multiplexing techniques for positron emission tomography: a review. Biomed Eng Lett 2022; 12:263-283. [PMID: 35892029 PMCID: PMC9308856 DOI: 10.1007/s13534-022-00234-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 05/21/2022] [Accepted: 05/30/2022] [Indexed: 12/03/2022] Open
Abstract
In recent years, silicon photomultiplier (SiPM) is replacing the photomultiplier tube (PMT) in positron emission tomography (PET) systems due to its superior properties, such as fast single-photon timing response, small gap between adjacent photosensitive pixels in the array, and insensitivity to magnetic fields. One of the technical challenges when developing SiPM-based PET systems or other position-sensitive radiation detectors is the large number of output channels coming from the SiPM array. Therefore, various signal multiplexing methods have been proposed to reduce the number of output channels and the load on the subsequent data acquisition (DAQ) system. However, the large PN-junction capacitance and quenching resistance of the SiPM yield undesirable resistance-capacitance delay when multiple SiPMs are combined, which subsequently causes the accumulation of dark counts and signal fluctuation of SiPMs. Therefore, without proper SiPM signal handling and processing, the SiPMs may yield worse timing characteristics than the PMTs. This article reviews the evolution of signal readout and multiplexing methods for the SiPM. In this review, we focus primarily on analog electronics for SiPM signal multiplexing, which allows for the reduction of DAQ channels required for the SiPM-based position-sensitive detectors used in PET and other radiation detector systems. Although the applications of most technologies described in the article are not limited to PET systems, the review highlights efforts to improve the physical performance (e.g. spatial, energy, and timing resolutions) of PET detectors and systems.
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Affiliation(s)
- Haewook Park
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080 South Korea
- Department of Nuclear Medicine, Seoul National University College of Medicine, 101, Daehak-ro, Jongno-gu, Seoul, 03080 South Korea
| | - Minseok Yi
- Department of Nuclear Medicine, Seoul National University College of Medicine, 101, Daehak-ro, Jongno-gu, Seoul, 03080 South Korea
- Interdisciplinary Program in Bioengineering, Seoul National University College of Engineering, Seoul, 03080 South Korea
- Integrated Major in Innovative Medical Science, Seoul National University College of Engineering, Seoul, 03080 South Korea
| | - Jae Sung Lee
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080 South Korea
- Department of Nuclear Medicine, Seoul National University College of Medicine, 101, Daehak-ro, Jongno-gu, Seoul, 03080 South Korea
- Interdisciplinary Program in Bioengineering, Seoul National University College of Engineering, Seoul, 03080 South Korea
- Integrated Major in Innovative Medical Science, Seoul National University College of Engineering, Seoul, 03080 South Korea
- Brightonix Imaging Inc, Seoul, 04782 South Korea
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7
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Modern Diagnostic Imaging Technique Applications and Risk Factors in the Medical Field: A Review. BIOMED RESEARCH INTERNATIONAL 2022; 2022:5164970. [PMID: 35707373 PMCID: PMC9192206 DOI: 10.1155/2022/5164970] [Citation(s) in RCA: 55] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 05/25/2022] [Indexed: 11/18/2022]
Abstract
Medical imaging is the process of visual representation of different tissues and organs of the human body to monitor the normal and abnormal anatomy and physiology of the body. There are many medical imaging techniques used for this purpose such as X-ray, computed tomography (CT), positron emission tomography (PET), magnetic resonance imaging (MRI), single-photon emission computed tomography (SPECT), digital mammography, and diagnostic sonography. These advanced medical imaging techniques have many applications in the diagnosis of myocardial diseases, cancer of different tissues, neurological disorders, congenital heart disease, abdominal illnesses, complex bone fractures, and other serious medical conditions. There are benefits as well as some risks to every imaging technique. There are some steps for minimizing the radiation exposure risks from imaging techniques. Advance medical imaging modalities such as PET/CT hybrid, three-dimensional ultrasound computed tomography (3D USCT), and simultaneous PET/MRI give high resolution, better reliability, and safety to diagnose, treat, and manage complex patient abnormalities. These techniques ensure the production of new accurate imaging tools with improving resolution, sensitivity, and specificity. In the future, with mounting innovations and advancements in technology systems, the medical diagnostic field will become a field of regular measurement of various complex diseases and will provide healthcare solutions.
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8
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Na S, Wang LV. Photoacoustic computed tomography for functional human brain imaging [Invited]. BIOMEDICAL OPTICS EXPRESS 2021; 12:4056-4083. [PMID: 34457399 PMCID: PMC8367226 DOI: 10.1364/boe.423707] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 06/05/2021] [Accepted: 06/08/2021] [Indexed: 05/02/2023]
Abstract
The successes of magnetic resonance imaging and modern optical imaging of human brain function have stimulated the development of complementary modalities that offer molecular specificity, fine spatiotemporal resolution, and sufficient penetration simultaneously. By virtue of its rich optical contrast, acoustic resolution, and imaging depth far beyond the optical transport mean free path (∼1 mm in biological tissues), photoacoustic computed tomography (PACT) offers a promising complementary modality. In this article, PACT for functional human brain imaging is reviewed in its hardware, reconstruction algorithms, in vivo demonstration, and potential roadmap.
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Affiliation(s)
- Shuai Na
- Caltech Optical Imaging Laboratory, Andrew
and Peggy Cherng Department of Medical Engineering,
California Institute of Technology, 1200
East California Boulevard, Pasadena, CA 91125, USA
| | - Lihong V. Wang
- Caltech Optical Imaging Laboratory, Andrew
and Peggy Cherng Department of Medical Engineering,
California Institute of Technology, 1200
East California Boulevard, Pasadena, CA 91125, USA
- Caltech Optical Imaging Laboratory,
Department of Electrical Engineering, California
Institute of Technology, 1200 East California Boulevard,
Pasadena, CA 91125, USA
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9
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Torrado-Carvajal A, Toschi N, Albrecht DS, Chang K, Akeju O, Kim M, Edwards RR, Zhang Y, Hooker JM, Duggento A, Kalpathy-Cramer J, Napadow V, Loggia ML. Thalamic neuroinflammation as a reproducible and discriminating signature for chronic low back pain. Pain 2021; 162:1241-1249. [PMID: 33065737 DOI: 10.1097/j.pain.0000000000002108] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 09/08/2020] [Indexed: 12/11/2022]
Abstract
ABSTRACT Using positron emission tomography, we recently demonstrated elevated brain levels of the 18 kDa translocator protein (TSPO), a glial activation marker, in chronic low back pain (cLBP) patients, compared to healthy controls (HCs). Here, we first sought to replicate the original findings in an independent cohort (15 cLBP, 37.8 ± 12.5 y/o; 18 HC, 48.2 ± 12.8 y/o). We then trained random forest machine learning algorithms based on TSPO imaging features combining discovery and replication cohorts (totaling 25 cLBP, 42.4 ± 13.2 y/o; 27 HC, 48.9 ± 12.6 y/o), to explore whether image features other than the mean contain meaningful information that might contribute to the discrimination of cLBP patients and HC. Feature importance was ranked using SHapley Additive exPlanations values, and the classification performance (in terms of area under the curve values) of classifiers containing only the mean, other features, or all features was compared using the DeLong test. Both region-of-interest and voxelwise analyses replicated the original observation of thalamic TSPO signal elevations in cLBP patients compared to HC (P < 0.05). The random forest-based analyses revealed that although the mean is a discriminating feature, other features demonstrate similar level of importance, including the maximum, kurtosis, and entropy. Our observations suggest that thalamic neuroinflammatory signal is a reproducible and discriminating feature for cLBP, further supporting a role for glial activation in human cLBP, and the exploration of neuroinflammation as a therapeutic target for chronic pain. This work further shows that TSPO signal contains a richness of information that the simple mean might fail to capture completely.
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Affiliation(s)
- Angel Torrado-Carvajal
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States.,Medical Image Analysis and Biometry Laboratory, Universidad Rey Juan Carlos, Madrid, Spain
| | - Nicola Toschi
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States.,Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | - Daniel S Albrecht
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
| | - Ken Chang
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
| | - Oluwaseun Akeju
- Department of Anesthesia, Critical Care and Pain Medicine, MGH/HMS, Boston, MA, United States
| | - Minhae Kim
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
| | - Robert R Edwards
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, HMS, Boston, MA, United States
| | - Yi Zhang
- Department of Anesthesia, Critical Care and Pain Medicine, MGH/HMS, Boston, MA, United States
| | - Jacob M Hooker
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
| | - Andrea Duggento
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States.,Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | - Jayashree Kalpathy-Cramer
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
| | - Vitaly Napadow
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
| | - Marco L Loggia
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
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Schaart DR. Physics and technology of time-of-flight PET detectors. Phys Med Biol 2021; 66. [PMID: 33711831 DOI: 10.1088/1361-6560/abee56] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 03/12/2021] [Indexed: 01/04/2023]
Abstract
The imaging performance of clinical positron emission tomography (PET) systems has evolved impressively during the last ∼15 years. A main driver of these improvements has been the introduction of time-of-flight (TOF) detectors with high spatial resolution and detection efficiency, initially based on photomultiplier tubes, later silicon photomultipliers. This review aims to offer insight into the challenges encountered, solutions developed, and lessons learned during this period. Detectors based on fast, bright, inorganic scintillators form the scope of this work, as these are used in essentially all clinical TOF-PET systems today. The improvement of the coincidence resolving time (CRT) requires the optimization of the entire detection chain and a sound understanding of the physics involved facilitates this effort greatly. Therefore, the theory of scintillation detector timing is reviewed first. Once the fundamentals have been set forth, the principal detector components are discussed: the scintillator and the photosensor. The parameters that influence the CRT are examined and the history, state-of-the-art, and ongoing developments are reviewed. Finally, the interplay between these components and the optimization of the overall detector design are considered. Based on the knowledge gained to date, it appears feasible to improve the CRT from the values of 200-400 ps achieved by current state-of-the-art TOF-PET systems to about 100 ps or less, even though this may require the implementation of advanced methods such as time resolution recovery. At the same time, it appears unlikely that a system-level CRT in the order of ∼10 ps can be reached with conventional scintillation detectors. Such a CRT could eliminate the need for conventional tomographic image reconstruction and a search for new approaches to timestamp annihilation photons with ultra-high precision is therefore warranted. While the focus of this review is on timing performance, it attempts to approach the topic from a clinically driven perspective, i.e. bearing in mind that the ultimate goal is to optimize the value of PET in research and (personalized) medicine.
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Affiliation(s)
- Dennis R Schaart
- Delft University of Technology, Radiation Science & Technology dept., section Medical Physics & Technology, Mekelweg 15, 2629 JB Delft, The Netherlands
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Performance Evaluation of SimPET-X, a PET Insert for Simultaneous Mouse Total-Body PET/MR Imaging. Mol Imaging Biol 2021; 23:703-713. [PMID: 33768465 DOI: 10.1007/s11307-021-01595-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 01/30/2021] [Accepted: 02/25/2021] [Indexed: 11/27/2022]
Abstract
PURPOSE In this study, a small animal PET insert (SimPET-X, Brightonix Imaging Inc.) for simultaneous PET/MR imaging studies is presented. This insert covers an 11-cm-long axial field-of-view (FOV) and enables imaging of mouse total-bodies and rat heads. PROCEDURES SimPET-X comprises 16 detector modules to yield a ring diameter of 63 mm and an axial FOV of 110 mm. The detector module supports four detector blocks, each comprising two 4 × 4 SiPM arrays coupled with a 20 × 9 array of LSO crystals (1.2 × 1.2 × 10 mm3). The physical characteristics of SimPET-X were measured in accordance with the NEMA NU4-2008 standard protocol. In addition, we assessed the compatibility of SimPET-X with a small animal-dedicated MRI (M7, Aspect Imaging) and conducted phantom and animal studies. RESULTS The radial spatial resolutions at the center based on 3D OSEM without and with the warm background were 0.73 mm and 0.99 mm, respectively. The absolute peak sensitivity of the system was 10.44% with an energy window of 100-900 keV and 8.27% with an energy window of 250-750 keV. The peak NECR and scatter fraction for the mouse phantom were 348 kcps at 26.2 MBq and 22.1% with an energy window of 250-750 keV, respectively. The standard deviation of pixel value in the uniform region of an NEMA IQ phantom was 4.57%. The spillover ratios for air- and water-filled chambers were 9.0% and 11.0%, respectively. In the hot-rod phantom image reconstructed using 3D OSEM-PSF, all small rods were resolved owing to the high spatial resolution of the SimPET-X system. There was no notable interference between SimPET-X and M7 MRI. SimPET-X provided high-quality mouse images with superior spatial resolution, sensitivity, and counting rate performance. CONCLUSION SimPET-X yielded a remarkably improved sensitivity and NECR compared with SimPETTM.
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Lee JS. A Review of Deep-Learning-Based Approaches for Attenuation Correction in Positron Emission Tomography. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2021. [DOI: 10.1109/trpms.2020.3009269] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Abstract
Positron emission tomography (PET) is a non-invasive imaging technology employed to describe metabolic, physiological, and biochemical processes in vivo. These include receptor availability, metabolic changes, neurotransmitter release, and alterations of gene expression in the brain. Since the introduction of dedicated small-animal PET systems along with the development of many novel PET imaging probes, the number of PET studies using rats and mice in basic biomedical research tremendously increased over the last decade. This article reviews challenges and advances of quantitative rodent brain imaging to make the readers aware of its physical limitations, as well as to inspire them for its potential applications in preclinical research. In the first section, we briefly discuss the limitations of small-animal PET systems in terms of spatial resolution and sensitivity and point to possible improvements in detector development. In addition, different acquisition and post-processing methods used in rodent PET studies are summarized. We further discuss factors influencing the test-retest variability in small-animal PET studies, e.g., different receptor quantification methodologies which have been mainly translated from human to rodent receptor studies to determine the binding potential and changes of receptor availability and radioligand affinity. We further review different kinetic modeling approaches to obtain quantitative binding data in rodents and PET studies focusing on the quantification of endogenous neurotransmitter release using pharmacological interventions. While several studies have focused on the dopamine system due to the availability of several PET tracers which are sensitive to dopamine release, other neurotransmitter systems have become more and more into focus and are described in this review, as well. We further provide an overview of latest genome engineering technologies, including the CRISPR/Cas9 and DREADD systems that may advance our understanding of brain disorders and function and how imaging has been successfully applied to animal models of human brain disorders. Finally, we review the strengths and opportunities of simultaneous PET/magnetic resonance imaging systems to study drug-receptor interactions and challenges for the translation of PET results from bench to bedside.
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Groll AN, Levin CS. Instrumentation and Methods to Combine Small-Animal PET With Other Imaging Modalities. Mol Imaging 2021. [DOI: 10.1016/b978-0-12-816386-3.00005-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Kaneta T. PET and SPECT imaging of the brain: a review on the current status of nuclear medicine in Japan. Jpn J Radiol 2020; 38:343-357. [DOI: 10.1007/s11604-019-00901-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 10/31/2019] [Indexed: 01/07/2023]
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16
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Radiolabeled PET/MRI Nanoparticles for Tumor Imaging. J Clin Med 2019; 9:jcm9010089. [PMID: 31905769 PMCID: PMC7019574 DOI: 10.3390/jcm9010089] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 12/23/2019] [Accepted: 12/24/2019] [Indexed: 02/07/2023] Open
Abstract
The development of integrated positron emission tomography (PET)/magnetic resonance imaging (MRI) scanners opened a new scenario for cancer diagnosis, treatment, and follow-up. Multimodal imaging combines functional and morphological information from different modalities, which, singularly, cannot provide a comprehensive pathophysiological overview. Molecular imaging exploits multimodal imaging in order to obtain information at a biological and cellular level; in this way, it is possible to track biological pathways and discover many typical tumoral features. In this context, nanoparticle-based contrast agents (CAs) can improve probe biocompatibility and biodistribution, prolonging blood half-life to achieve specific target accumulation and non-toxicity. In addition, CAs can be simultaneously delivered with drugs or, in general, therapeutic agents gathering a dual diagnostic and therapeutic effect in order to perform cancer diagnosis and treatment simultaneous. The way for personalized medicine is not so far. Herein, we report principles, characteristics, applications, and concerns of nanoparticle (NP)-based PET/MRI CAs.
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Shiri I, Ghafarian P, Geramifar P, Leung KHY, Ghelichoghli M, Oveisi M, Rahmim A, Ay MR. Direct attenuation correction of brain PET images using only emission data via a deep convolutional encoder-decoder (Deep-DAC). Eur Radiol 2019; 29:6867-6879. [PMID: 31227879 DOI: 10.1007/s00330-019-06229-1] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 04/04/2019] [Accepted: 04/08/2019] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To obtain attenuation-corrected PET images directly from non-attenuation-corrected images using a convolutional encoder-decoder network. METHODS Brain PET images from 129 patients were evaluated. The network was designed to map non-attenuation-corrected (NAC) images to pixel-wise continuously valued measured attenuation-corrected (MAC) PET images via an encoder-decoder architecture. Image quality was evaluated using various evaluation metrics. Image quantification was assessed for 19 radiomic features in 83 brain regions as delineated using the Hammersmith atlas (n30r83). Reliability of measurements was determined using pixel-wise relative errors (RE; %) for radiomic feature values in reference MAC PET images. RESULTS Peak signal-to-noise ratio (PSNR) and structural similarity index metric (SSIM) values were 39.2 ± 3.65 and 0.989 ± 0.006 for the external validation set, respectively. RE (%) of SUVmean was - 0.10 ± 2.14 for all regions, and only 3 of 83 regions depicted significant differences. However, the mean RE (%) of this region was 0.02 (range, - 0.83 to 1.18). SUVmax had mean RE (%) of - 3.87 ± 2.84 for all brain regions, and 17 regions in the brain depicted significant differences with respect to MAC images with a mean RE of - 3.99 ± 2.11 (range, - 8.46 to 0.76). Homogeneity amongst Haralick-based radiomic features had the highest number (20) of regions with significant differences with a mean RE (%) of 7.22 ± 2.99. CONCLUSIONS Direct AC of PET images using deep convolutional encoder-decoder networks is a promising technique for brain PET images. The proposed deep learning method shows significant potential for emission-based AC in PET images with applications in PET/MRI and dedicated brain PET scanners. KEY POINTS • We demonstrate direct emission-based attenuation correction of PET images without using anatomical information. • We performed radiomics analysis of 83 brain regions to show robustness of direct attenuation correction of PET images. • Deep learning methods have significant promise for emission-based attenuation correction in PET images with potential applications in PET/MRI and dedicated brain PET scanners.
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Affiliation(s)
- Isaac Shiri
- Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran, Iran
| | - Pardis Ghafarian
- Chronic Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran. .,PET/CT and Cyclotron Center, Masih Daneshvari Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | - Parham Geramifar
- Research Center for Nuclear Medicine, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Kevin Ho-Yin Leung
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA.,Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, USA
| | - Mostafa Ghelichoghli
- Department of Biomedical and Health Informatics, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Science, Tehran, Iran
| | - Mehrdad Oveisi
- Department of Biomedical and Health Informatics, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Science, Tehran, Iran.,Department of Computer Science, University of British Columbia, Vancouver, BC, Canada
| | - Arman Rahmim
- Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, USA.,Departments of Radiology and Physics & Astronomy, University of British Columbia, Vancouver, BC, Canada.,Department of Integrative Oncology, BC Cancer Research Centre, Vancouver, BC, Canada
| | - Mohammad Reza Ay
- Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran, Iran. .,Department of Medical Physics and Biomedical Engineering, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
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Prato FS, Pavlosky WF, Foster SC, Thiessen JD, Beaujot RP. Screening for Dementia Caused by Modifiable Lifestyle Choices Using Hybrid PET/MRI. J Alzheimers Dis Rep 2019; 3:31-45. [PMID: 30842996 PMCID: PMC6400112 DOI: 10.3233/adr-180098] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/19/2018] [Indexed: 12/19/2022] Open
Abstract
Significant advances in positron emission tomography (PET) and magnetic resonance imaging (MRI) brain imaging in the early detection of dementia indicate that hybrid PET/MRI would be an effective tool to screen for dementia in the population living with lifestyle risk factors. Here we investigate the associated costs and benefits along with the needed imaging infrastructure. A demographic analysis determined the prevalence of dementia and its incidence. The expected value of the screening program was calculated assuming a sensitivity and specificity of 0.9, a prevalence of 0.1, a QALY factor of 0.348, a willingness to pay $114,000 CAD and the cost per PET/MRI scan of $2,000 CAD. It was assumed that each head PET/MRI could screen 3,000 individuals per year. The prevalence of dementia is increasing by almost two-fold every 20 years due to the increased population at ages where dementia is more prevalent. It has been shown that a five-year delay in the incidence of dementia would decrease the prevalence by some 45%. In Canada, a five-year delay corresponds to a health care savings of $27,000 CAD per subject per year. The expected value for screening was estimated at $23,745 CAD. The number of subjects to be screened per year in Canada, USA, and China between 60 and 79 was 11,405,000. The corresponding number of head-only hybrid PET/MRI systems needed is 3,800. A brain PET/MRI screening program is financially justifiable with respect to health care costs and justifies the continuing development of MRI compatible brain PET technology.
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Affiliation(s)
- Frank S. Prato
- Department of Medical Biophysics, Western University, London, ON, Canada
- Lawson Health Research Institute, London, ON, Canada
- Department of Medical Imaging, Western University, London, ON, Canada
| | - William F. Pavlosky
- Lawson Health Research Institute, London, ON, Canada
- Department of Medical Imaging, Western University, London, ON, Canada
| | | | - Jonathan D. Thiessen
- Department of Medical Biophysics, Western University, London, ON, Canada
- Lawson Health Research Institute, London, ON, Canada
- Department of Medical Imaging, Western University, London, ON, Canada
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VanElzakker MB, Brumfield SA, Lara Mejia PS. Neuroinflammation and Cytokines in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): A Critical Review of Research Methods. Front Neurol 2019; 9:1033. [PMID: 30687207 PMCID: PMC6335565 DOI: 10.3389/fneur.2018.01033] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Accepted: 11/16/2018] [Indexed: 01/18/2023] Open
Abstract
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is the label given to a syndrome that can include long-term flu-like symptoms, profound fatigue, trouble concentrating, and autonomic problems, all of which worsen after exertion. It is unclear how many individuals with this diagnosis are suffering from the same condition or have the same underlying pathophysiology, and the discovery of biomarkers would be clarifying. The name "myalgic encephalomyelitis" essentially means "muscle pain related to central nervous system inflammation" and many efforts to find diagnostic biomarkers have focused on one or more aspects of neuroinflammation, from periphery to brain. As the field uncovers the relationship between the symptoms of this condition and neuroinflammation, attention must be paid to the biological mechanisms of neuroinflammation and issues with its potential measurement. The current review focuses on three methods used to study putative neuroinflammation in ME/CFS: (1) positron emission tomography (PET) neuroimaging using translocator protein (TSPO) binding radioligand (2) magnetic resonance spectroscopy (MRS) neuroimaging and (3) assays of cytokines circulating in blood and cerebrospinal fluid. PET scanning using TSPO-binding radioligand is a promising option for studies of neuroinflammation. However, methodological difficulties that exist both in this particular technique and across the ME/CFS neuroimaging literature must be addressed for any results to be interpretable. We argue that the vast majority of ME/CFS neuroimaging has failed to use optimal techniques for studying brainstem, despite its probable centrality to any neuroinflammatory causes or autonomic effects. MRS is discussed as a less informative but more widely available, less invasive, and less expensive option for imaging neuroinflammation, and existing studies using MRS neuroimaging are reviewed. Studies seeking to find a peripheral circulating cytokine "profile" for ME/CFS are reviewed, with attention paid to the biological and methodological reasons for lack of replication among these studies. We argue that both the biological mechanisms of cytokines and the innumerable sources of potential variance in their measurement make it unlikely that a consistent and replicable diagnostic cytokine profile will ever be discovered.
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Affiliation(s)
- Michael B. VanElzakker
- Division of Neurotherapeutics, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
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Abstract
PET/MR imaging has the potential to markedly alter pancreatic care in both the malignant, and premalignant states with the ability to perform robust, high-resolution, quantitative molecular imaging. The ability of PET/MR imaging to monitor disease processes, potentially correct for motion in the upper abdomen, and provide novel biomarkers that may be a combination of MR imaging and PET biomarkers, offers a unique, precise interrogation of the pancreatic milieu going forward.
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Affiliation(s)
- Nadine Mallak
- Department of Diagnostic Radiology, Oregon Health & Sciences University, 3181 Southwest Sam Jackson Park Road, Portland, OR 97239, USA
| | - Thomas A Hope
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, 505 Parnassus Avenue, M391, San Francisco, CA 94158, USA
| | - Alexander R Guimaraes
- Department of Diagnostic Radiology, Oregon Health & Sciences University, 3181 Southwest Sam Jackson Park Road, Portland, OR 97239, USA.
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Lee BJ, Watkins RD, Lee KS, Chang CM, Levin CS. Performance evaluation of RF coils integrated with an RF-penetrable PET insert for simultaneous PET/MRI. Magn Reson Med 2018; 81:1434-1446. [PMID: 30260501 DOI: 10.1002/mrm.27444] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 05/01/2018] [Accepted: 06/11/2018] [Indexed: 01/19/2023]
Abstract
PURPOSE An "RF-penetrable" PET insert that allows the MR body coil to be used for RF transmission was developed to make it easier for an existing MR center to achieve simultaneous PET/MRI. This study focuses on experiments and analyses to study PET/RF coil configurations for simultaneous PET/MR studies. METHODS To investigate the appropriate RF coil design, a transmit/receive (TX/RX) birdcage coil and an RX-only phased-array coil (TX from body coil), both fitting inside the PET ring were built and characterized. For MR performance evaluation, B1 field uniformity and MR image SNR were calculated. PET photon attenuation due to each coil was studied by means of CT-based attenuation maps and reconstructed PET images. RESULTS When using the RX-only phased-array coil (TX from body coil), compared with the TX/RX birdcage coil, the B1 field uniformity and the MR image (gradient echo and fast spin echo) SNR increased by 2.4±4.8%, 386.1±62.3%, and 205.0±56.5%, respectively. Although some components of the coil were distributed within the PET FOV, no significant PET photon attenuation was shown in the CT-based attenuation map and reconstructed PET images. CONCLUSION RF coil configurations for an RF-penetrable PET insert for simultaneous PET/MRI were studied. The RX-only phased-array coil (TX from body coil) outperformed the TX/RX birdcage coil with improved MR performance as well as negligible PET photon attenuation.
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Affiliation(s)
- Brian J Lee
- Department of Radiology, Stanford University, Stanford, California
- Department of Mechanical Engineering, Stanford University, Stanford, California
| | - Ronald D Watkins
- Department of Radiology, Stanford University, Stanford, California
| | - Keum Sil Lee
- Department of Radiology, Stanford University, Stanford, California
| | - Chen-Ming Chang
- Department of Radiology, Stanford University, Stanford, California
- Department of Applied Physics, Stanford University, Stanford, California
| | - Craig S Levin
- Department of Radiology, Stanford University, Stanford, California
- Department of Bioengineering, Stanford University, Stanford, California
- Department of Electrical Engineering, Stanford University, Stanford, California
- Department of Physics, Stanford University, Stanford, California
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Wang X, Yang B, Adams MP, Gao X, Karakatsanis NA, Tang J. Improved myocardial perfusion PET imaging with MRI assisted reconstruction incorporating multi-resolution joint entropy. ACTA ACUST UNITED AC 2018; 63:175017. [DOI: 10.1088/1361-6560/aad8f9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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23
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Zeng Y, Zhu J, Wang J, Parasuraman P, Busi S, Nauli SM, Wáng YXJ, Pala R, Liu G. Functional probes for cardiovascular molecular imaging. Quant Imaging Med Surg 2018; 8:838-852. [PMID: 30306063 PMCID: PMC6177368 DOI: 10.21037/qims.2018.09.19] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 09/17/2018] [Indexed: 12/26/2022]
Abstract
Cardiovascular diseases (CVDs) are a severely threatening disorder and frequently cause death in industrialized countries, posing critical challenges to modern research and medicine. Molecular imaging has been heralded as the solution to many problems encountered in individuals living with CVD. The use of probes in cardiovascular molecular imaging is causing a paradigmatic shift from regular imaging techniques, to future advanced imaging technologies, which will facilitate the acquisition of vital information at the cellular and molecular level. Advanced imaging for CVDs will help early detection of disease development, allow early therapeutic intervention, and facilitate better understanding of fundamental biological processes. To promote a better understanding of cardiovascular molecular imaging, this article summarizes the current developments in the use of molecular probes, highlighting some of the recent advances in probe design, preparation, and functional modification.
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Affiliation(s)
- Yun Zeng
- Department of Pharmacology, Xiamen Medical College, Xiamen 361008, China
| | - Jing Zhu
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics & Center for Molecular Imaging and Translational Medicine, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Junqing Wang
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics & Center for Molecular Imaging and Translational Medicine, School of Public Health, Xiamen University, Xiamen 361102, China
- Department of Imaging and Interventional Radiology, Prince of Wales Hospital, the Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
| | - Paramanantham Parasuraman
- Departments of Microbiology, School of Life Sciences, Pondicherry University, Puducherry 605014, India
| | - Siddhardha Busi
- Departments of Microbiology, School of Life Sciences, Pondicherry University, Puducherry 605014, India
| | - Surya M. Nauli
- Department of Biomedical and Pharmaceutical Sciences, School of Pharmacy, Chapman University, Irvine, California, USA
| | - Yì Xiáng J. Wáng
- Department of Imaging and Interventional Radiology, Prince of Wales Hospital, the Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
| | - Rajasekharreddy Pala
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics & Center for Molecular Imaging and Translational Medicine, School of Public Health, Xiamen University, Xiamen 361102, China
- Department of Biomedical and Pharmaceutical Sciences, School of Pharmacy, Chapman University, Irvine, California, USA
| | - Gang Liu
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics & Center for Molecular Imaging and Translational Medicine, School of Public Health, Xiamen University, Xiamen 361102, China
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Omidvari N, Topping G, Cabello J, Paul S, Schwaiger M, Ziegler SI. MR-compatibility assessment of MADPET4: a study of interferences between an SiPM-based PET insert and a 7 T MRI system. Phys Med Biol 2018; 63:095002. [PMID: 29582780 DOI: 10.1088/1361-6560/aab9d1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Compromises in the design of a positron emission tomography (PET) insert for a magnetic resonance imaging (MRI) system should minimize the deterioration of image quality in both modalities, particularly when simultaneous demanding acquisitions are performed. In this work, the advantages of using individually read-out crystals with high-gain silicon photomultipliers (SiPMs) were studied with a small animal PET insert for a 7 T MRI system, in which the SiPM charge was transferred to outside the MRI scanner using coaxial cables. The interferences between the two systems were studied with three radio-frequency (RF) coil configurations. The effects of PET on the static magnetic field, flip angle distribution, RF noise, and image quality of various MRI sequences (gradient echo, spin echo, and echo planar imaging (EPI) at 1H frequency, and chemical shift imaging at 13C frequency) were investigated. The effects of fast-switching gradient fields and RF pulses on PET count rate were studied, while the PET insert and the readout electronics were not shielded. Operating the insert inside a 1H volume coil, used for RF transmission and reception, limited the MRI to T1-weighted imaging, due to coil detuning and RF attenuation, and resulted in significant PET count loss. Using a surface receive coil allowed all tested MR sequences to be used with the insert, with 45-59% signal-to-noise ratio (SNR) degradation, compared to without PET. With a 1H/13C volume coil inside the insert and shielded by a copper tube, the SNR degradation was limited to 23-30% with all tested sequences. The insert did not introduce any discernible distortions into images of two tested EPI sequences. Use of truncated sinc shaped RF excitation pulses and gradient field switching had negligible effects on PET count rate. However, PET count rate was substantially affected by high-power RF block pulses and temperature variations due to high gradient duty cycles.
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Affiliation(s)
- Negar Omidvari
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675 Munich, Germany. These authors contributed equally to this work. Author to whom any correspondence should be addressed
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Ahnen M, Becker R, Buck A, Casella C, Commichau V, Calafiori DD, Dissertori G, Eleftheriou A, Fischer J, Howard AS, Ito M, Khateri P, Kim J, Lustermann W, Ritzer C, Roser U, Rudin M, Solevi P, Tsoumpas C, Warnock G, Weber B, Wyss M, Zagozdzinska-Bochenek A. Performance Measurements of the SAFIR Prototype Detector With the STiC ASIC Readout. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2018. [DOI: 10.1109/trpms.2018.2797484] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Mannheim JG, Schmid AM, Schwenck J, Katiyar P, Herfert K, Pichler BJ, Disselhorst JA. PET/MRI Hybrid Systems. Semin Nucl Med 2018; 48:332-347. [PMID: 29852943 DOI: 10.1053/j.semnuclmed.2018.02.011] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Over the last decade, the combination of PET and MRI in one system has proven to be highly successful in basic preclinical research, as well as in clinical research. Nowadays, PET/MRI systems are well established in preclinical imaging and are progressing into clinical applications to provide further insights into specific diseases, therapeutic assessments, and biological pathways. Certain challenges in terms of hardware had to be resolved concurrently with the development of new techniques to be able to reach the full potential of both combined techniques. This review provides an overview of these challenges and describes the opportunities that simultaneous PET/MRI systems can exploit in comparison with stand-alone or other combined hybrid systems. New approaches were developed for simultaneous PET/MRI systems to correct for attenuation of 511 keV photons because MRI does not provide direct information on gamma photon attenuation properties. Furthermore, new algorithms to correct for motion were developed, because MRI can accurately detect motion with high temporal resolution. The additional information gained by the MRI can be employed to correct for partial volume effects as well. The development of new detector designs in combination with fast-decaying scintillator crystal materials enabled time-of-flight detection and incorporation in the reconstruction algorithms. Furthermore, this review lists the currently commercially available systems both for preclinical and clinical imaging and provides an overview of applications in both fields. In this regard, special emphasis has been placed on data analysis and the potential for both modalities to evolve with advanced image analysis tools, such as cluster analysis and machine learning.
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Affiliation(s)
- Julia G Mannheim
- Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center, Eberhard Karls University Tuebingen, Tuebingen, Germany
| | - Andreas M Schmid
- Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center, Eberhard Karls University Tuebingen, Tuebingen, Germany
| | - Johannes Schwenck
- Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center, Eberhard Karls University Tuebingen, Tuebingen, Germany; Department of Nuclear Medicine and Clinical Molecular Imaging, Eberhard Karls University Tuebingen, Tuebingen, Germany
| | - Prateek Katiyar
- Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center, Eberhard Karls University Tuebingen, Tuebingen, Germany
| | - Kristina Herfert
- Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center, Eberhard Karls University Tuebingen, Tuebingen, Germany
| | - Bernd J Pichler
- Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center, Eberhard Karls University Tuebingen, Tuebingen, Germany.
| | - Jonathan A Disselhorst
- Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center, Eberhard Karls University Tuebingen, Tuebingen, Germany
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Mosayebi J, Kiyasatfar M, Laurent S. Synthesis, Functionalization, and Design of Magnetic Nanoparticles for Theranostic Applications. Adv Healthc Mater 2017; 6. [PMID: 28990364 DOI: 10.1002/adhm.201700306] [Citation(s) in RCA: 115] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 06/14/2017] [Indexed: 12/13/2022]
Abstract
In order to translate nanotechnology into medical practice, magnetic nanoparticles (MNPs) have been presented as a class of non-invasive nanomaterials for numerous biomedical applications. In particular, MNPs have opened a door for simultaneous diagnosis and brisk treatment of diseases in the form of theranostic agents. This review highlights the recent advances in preparation and utilization of MNPs from the synthesis and functionalization steps to the final design consideration in evading the body immune system for therapeutic and diagnostic applications with addressing the most recent examples of the literature in each section. This study provides a conceptual framework of a wide range of synthetic routes classified mainly as wet chemistry, state-of-the-art microfluidic reactors, and biogenic routes, along with the most popular coating materials to stabilize resultant MNPs. Additionally, key aspects of prolonging the half-life of MNPs via overcoming the sequential biological barriers are covered through unraveling the biophysical interactions at the bio-nano interface and giving a set of criteria to efficiently modulate MNPs' physicochemical properties. Furthermore, concepts of passive and active targeting for successful cell internalization, by respectively exploiting the unique properties of cancers and novel targeting ligands are described in detail. Finally, this study extensively covers the recent developments in magnetic drug targeting and hyperthermia as therapeutic applications of MNPs. In addition, multi-modal imaging via fusion of magnetic resonance imaging, and also innovative magnetic particle imaging with other imaging techniques for early diagnosis of diseases are extensively provided.
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Affiliation(s)
- Jalal Mosayebi
- Department of Mechanical Engineering; Urmia University; Urmia 5756151818 Iran
| | - Mehdi Kiyasatfar
- Department of Mechanical Engineering; Urmia University; Urmia 5756151818 Iran
| | - Sophie Laurent
- Laboratory of NMR and Molecular Imaging; University of Mons; Mons Belgium
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Abstract
Combined PET/MR imaging scanners capable of acquiring simultaneously the complementary information provided by the 2 imaging modalities are now available for human use. After addressing the hardware challenges for integrating the 2 imaging modalities, most of the efforts in the field have focused on developing MR-based attenuation correction methods for neurologic and whole-body applications, implementing approaches for improving one modality by using the data provided by the other and exploring research and clinical applications that could benefit from the synergistic use of the multimodal data.
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Affiliation(s)
- Ciprian Catana
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Building 149, 13th Street, Room 2.301, Charlestown, MA 02129, USA.
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Dillenseger JP, Goetz C, Sayeh A, Healy C, Duluc I, Freund JN, Constantinesco A, Aubertin-Kirch G, Choquet P. Estimation of subject coregistration errors during multimodal preclinical imaging using separate instruments: origins and avoidance of artifacts. J Med Imaging (Bellingham) 2017; 4:035503. [PMID: 28840171 DOI: 10.1117/1.jmi.4.3.035503] [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: 04/27/2017] [Accepted: 07/24/2017] [Indexed: 11/14/2022] Open
Abstract
We use high-resolution [Formula: see text] data in multiple experiments to estimate the sources of error during coregistration of images acquired on separate preclinical instruments. In combination with experiments with phantoms, we completed in vivo imaging on mice, aimed at identifying the possible sources of registration errors, caused either by transport of the animal, movement of the animal itself, or methods of coregistration. The same imaging cell was used as a holder for phantoms and animals. For all procedures, rigid coregistration was carried out using a common landmark coregistration system, placed inside the imaging cell. We used the fiducial registration error and the target registration error to analyze the coregistration accuracy. We found that moving an imaging cell between two preclinical devices during a multimodal procedure gives an error of about [Formula: see text] at most. Therefore, it could not be considered a source of coregistration errors. Errors linked to spontaneous movements of the animal increased with time, to nearly 1 mm at most, excepted for body parts that were properly restrained. This work highlights the importance of animal intrinsic movements during a multiacquisition procedure and demonstrates a simple method to identify and quantify the sources of error during coregistration.
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Affiliation(s)
- Jean-Philippe Dillenseger
- Hôpitaux Universitaires de Strasbourg, Imagerie Préclinique-UF6237, Pôle d'imagerie, Hôpital de Hautepierre, Strasbourg Cedex, France.,Université de Strasbourg, Icube, équipe MMB, CNRS, Strasbourg, France.,Université de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg, Faculté de Médecine, Strasbourg, France
| | - Christian Goetz
- Hôpitaux Universitaires de Strasbourg, Imagerie Préclinique-UF6237, Pôle d'imagerie, Hôpital de Hautepierre, Strasbourg Cedex, France.,Universitätsklinikum, Klinik für Nuklear Medizin, Freiburg, Germany
| | - Amira Sayeh
- Hôpitaux Universitaires de Strasbourg, Imagerie Préclinique-UF6237, Pôle d'imagerie, Hôpital de Hautepierre, Strasbourg Cedex, France
| | - Chris Healy
- King's College London, Department of Craniofacial Development and Stem Cell Biology, Guy's Hospital, London, United Kingdom
| | - Isabelle Duluc
- Université de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg, Faculté de Médecine, Strasbourg, France.,Université de Strasbourg, Inserm, France
| | - Jean-Noël Freund
- Université de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg, Faculté de Médecine, Strasbourg, France.,Université de Strasbourg, Inserm, France
| | - André Constantinesco
- Hôpitaux Universitaires de Strasbourg, Imagerie Préclinique-UF6237, Pôle d'imagerie, Hôpital de Hautepierre, Strasbourg Cedex, France
| | - Gaëlle Aubertin-Kirch
- Université de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg, Faculté de Médecine, Strasbourg, France.,Université de Strasbourg, Laboratoire de Neurobiologie et Pharmacologie Cardiovasculaire, Faculté de Médecine, France
| | - Philippe Choquet
- Hôpitaux Universitaires de Strasbourg, Imagerie Préclinique-UF6237, Pôle d'imagerie, Hôpital de Hautepierre, Strasbourg Cedex, France.,Université de Strasbourg, Icube, équipe MMB, CNRS, Strasbourg, France.,Université de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg, Faculté de Médecine, Strasbourg, France
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Liu JN, Bu W, Shi J. Chemical Design and Synthesis of Functionalized Probes for Imaging and Treating Tumor Hypoxia. Chem Rev 2017; 117:6160-6224. [DOI: 10.1021/acs.chemrev.6b00525] [Citation(s) in RCA: 556] [Impact Index Per Article: 79.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Jia-nan Liu
- State
Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, P.R. China
| | - Wenbo Bu
- State
Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, P.R. China
- Shanghai
Key Laboratory of Green Chemistry and Chemical Processes, School of
Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, P.R. China
| | - Jianlin Shi
- State
Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, P.R. China
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Malinge J, Géraudie B, Savel P, Nataf V, Prignon A, Provost C, Zhang Y, Ou P, Kerrou K, Talbot JN, Siaugue JM, Sollogoub M, Ménager C. Liposomes for PET and MR Imaging and for Dual Targeting (Magnetic Field/Glucose Moiety): Synthesis, Properties, and in Vivo Studies. Mol Pharm 2017; 14:406-414. [PMID: 28029258 DOI: 10.1021/acs.molpharmaceut.6b00794] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
We describe the potentiality of a new liposomal formulation enabling positron emission tomography (PET) and magnetic resonance MR() imaging. The bimodality is achieved by coupling a 68Ga-based radiotracer on the bilayer of magnetic liposomes. In order to enhance the targeting properties obtained under a permanent magnetic field, a sugar moiety was added in the lipid formulation. Two new phospholipids were synthesized, one with a specific chelator of 68Ga (DSPE-PEG-NODAGA) and one with a glucose moiety (DSPE-PEG-glucose). The liposomes were produced according to a fast and safe process, with a high radiolabeling yield. MR and PET imaging were performed on mice bearing human glioblastoma tumors (U87MG) after iv injection. The accumulation of the liposomes in solid tumor is evidenced by MR imaging and the amount is evaluated in vivo and ex vivo according to PET imaging. An efficient magnetic targeting is achieved with these new magnetic liposomes.
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Affiliation(s)
- Jérémy Malinge
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 8234, PHENIX , F-75005 Paris, France.,Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 8232, IPCM , F-75005 Paris, France
| | - Bastien Géraudie
- Laboratoire d'Imagerie Moléculaire Positonique (LIMP), UMS028 Phénotypage du petit animal, UPMC Univ Paris 06, Paris, France.,Médecine nucléaire et radiopharmacie, Hôpital Tenon, AP-HP , Paris, France
| | - Paul Savel
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 8234, PHENIX , F-75005 Paris, France.,Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 8232, IPCM , F-75005 Paris, France
| | - Valérie Nataf
- Médecine nucléaire et radiopharmacie, Hôpital Tenon, AP-HP , Paris, France
| | - Aurélie Prignon
- Laboratoire d'Imagerie Moléculaire Positonique (LIMP), UMS028 Phénotypage du petit animal, UPMC Univ Paris 06, Paris, France
| | - Claire Provost
- Laboratoire d'Imagerie Moléculaire Positonique (LIMP), UMS028 Phénotypage du petit animal, UPMC Univ Paris 06, Paris, France
| | - Yongmin Zhang
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 8232, IPCM , F-75005 Paris, France
| | - Phalla Ou
- Université Paris Diderot, Plateforme de recherche préclinique FRIM , 46 rue Henri Huchard, 75018 Paris, France
| | - Khaldoun Kerrou
- Médecine nucléaire et radiopharmacie, Hôpital Tenon, AP-HP , Paris, France
| | - Jean-Noël Talbot
- Laboratoire d'Imagerie Moléculaire Positonique (LIMP), UMS028 Phénotypage du petit animal, UPMC Univ Paris 06, Paris, France.,Médecine nucléaire et radiopharmacie, Hôpital Tenon, AP-HP , Paris, France
| | - Jean-Michel Siaugue
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 8234, PHENIX , F-75005 Paris, France
| | - Matthieu Sollogoub
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 8232, IPCM , F-75005 Paris, France
| | - Christine Ménager
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 8234, PHENIX , F-75005 Paris, France
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Yamamoto S, Watabe T, Ikeda H, Kanai Y, Ichikawa K, Nakao M, Kato K, Hatazawa J. Development of a PET/OMRI combined system for simultaneous imaging of positron and free radical probes for small animals. Med Phys 2016; 43:5676. [PMID: 27782727 DOI: 10.1118/1.4963215] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Positron emission tomography (PET) has high sensitivity for imaging radioactive tracer distributions in subjects. However, it is not possible to image free radical distribution in a subject by PET. Since free radicals are quite reactive, they are related to many diseases, including but not limited to cancer, inflammation, strokes, and heart disease. The Overhauser enhanced magnetic resonance imaging (OMRI) is so far the only method that images free radical distribution in vivo. By combining PET and OMRI, a new hybrid imaging modality might be developed that can simultaneously image the radioactive tracer and free radical distributions. For this purpose, the authors developed a PET/OMRI combined system for small animals. METHODS The developed PET/OMRI system used an optical fiber-based PET system combined with a permanent magnet-based OMRI system. The optical fiber-based PET system uses flexible optical fiber bundles. Eight optical fiber-based block detectors were arranged in a 56 mm diameter ring to form a PET system. The LGSO blocks were located inside the field-of-view (FOV) of the OMRI, and the position sensitive photomultiplier tubes were positioned behind the OMRI to minimize the interference between the PET and the OMRI. The OMRI system used a 0.0165 T permanent magnet. The system has an electron spin resonance coil to enhance the MRI signal using the Overhauser effect to image the free radical in the FOV of the PET/OMRI system. RESULTS The spatial resolution and sensitivity of the optical fiber-based PET system were 1.2 mm FWHM and 1.2% at the central FOV, respectively. The OMRI system imaged the distribution of a nitroxyl radical (NXR) solution. The interference between PET and OMRI was small. Simultaneous imaging of the positron radiotracer and the NXR solution was successfully conducted with the developed PET/OMRI system for phantom and small animal studies. CONCLUSIONS The authors developed a PET/OMRI combined system with the potential to provide interesting new results in molecular imaging research, such as in vivo molecular and free radical distributions.
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Affiliation(s)
- Seiichi Yamamoto
- Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, Nagoya, Aichi 461-8673, Japan
| | - Tadashi Watabe
- Department of Molecular Imaging in Medicine, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan
| | - Hayato Ikeda
- Department of Molecular Imaging in Medicine, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan
| | - Yasukazu Kanai
- Department of Molecular Imaging in Medicine, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan
| | - Kazuhiro Ichikawa
- Innovation Center for Medical Redox Navigation, Kyushu University, Fukuoka 812-8582, Japan
| | | | - Katsuhiko Kato
- Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, Nagoya, Aichi 461-8673, Japan
| | - Jun Hatazawa
- Department of Molecular Imaging in Medicine, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan
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Thiessen JD, Shams E, Stortz G, Schellenberg G, Bishop D, Khan MS, Kozlowski P, Retière F, Sossi V, Thompson CJ, Goertzen AL. MR-compatibility of a high-resolution small animal PET insert operating inside a 7 T MRI. Phys Med Biol 2016; 61:7934-7956. [DOI: 10.1088/0031-9155/61/22/7934] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Ko GB, Kim KY, Yoon HS, Lee MS, Son JW, Im HJ, Lee JS. Evaluation of a silicon photomultiplier PET insert for simultaneous PET and MR imaging. Med Phys 2016; 43:72. [PMID: 26745901 DOI: 10.1118/1.4937784] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
PURPOSE In this study, the authors present a silicon photomultiplier (SiPM)-based positron emission tomography (PET) insert dedicated to small animal imaging with high system performance and robustness to temperature change. METHODS The insert consists of 64 LYSO-SiPM detector blocks arranged in 4 rings of 16 detector blocks to yield a ring diameter of 64 mm and axial field of view of 55 mm. Each detector block consists of a 9 × 9 array of LYSO crystals (1.2 × 1.2 × 10 mm(3)) and a monolithic 4 × 4 SiPM array. The temperature of each monolithic SiPM is monitored, and the proper bias voltage is applied according to the temperature reading in real time to maintain uniform performance. The performance of this PET insert was characterized using National Electrical Manufacturers Association NU 4-2008 standards, and its feasibility was evaluated through in vivo mouse imaging studies. RESULTS The PET insert had a peak sensitivity of 3.4% and volumetric spatial resolutions of 1.92 (filtered back projection) and 0.53 (ordered subset expectation maximization) mm(3) at center. The peak noise equivalent count rate and scatter fraction were 42.4 kcps at 15.08 MBq and 16.5%, respectively. By applying the real-time bias voltage adjustment, an energy resolution of 14.2% ± 0.3% was maintained and the count rate varied ≤1.2%, despite severe temperature changes (10-30 °C). The mouse imaging studies demonstrate that this PET insert can produce high-quality images useful for imaging studies on the small animals. CONCLUSIONS The developed MR-compatible PET insert is designed for insertion into a narrow-bore magnetic resonance imaging scanner, and it provides excellent imaging performance for PET/MR preclinical studies.
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Affiliation(s)
- Guen Bae Ko
- Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul 110-799, South Korea and Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 110-799, South Korea
| | - Kyeong Yun Kim
- Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul 110-799, South Korea and Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 110-799, South Korea
| | - Hyun Suk Yoon
- Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul 110-799, South Korea and Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 110-799, South Korea
| | - Min Sun Lee
- Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul 110-799, South Korea and Interdisciplinary Program in Radiation Applied Life Science, Seoul National University College of Medicine, Seoul 110-799, South Korea
| | - Jeong-Whan Son
- Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul 110-799, South Korea and Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 110-799, South Korea
| | - Hyung-Jun Im
- Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul 110-799, South Korea
| | - Jae Sung Lee
- Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul 110-799, South Korea; Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 110-799, South Korea; Interdisciplinary Program in Radiation Applied Life Science, Seoul National University College of Medicine, Seoul 110-799, South Korea; and Institute of Radiation Medicine, Medical Research Center, Seoul National University College of Medicine, Seoul 110-799, South Korea
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Hutchcroft W, Wang G, Chen KT, Catana C, Qi J. Anatomically-aided PET reconstruction using the kernel method. Phys Med Biol 2016; 61:6668-6683. [PMID: 27541810 PMCID: PMC5095621 DOI: 10.1088/0031-9155/61/18/6668] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This paper extends the kernel method that was proposed previously for dynamic PET reconstruction, to incorporate anatomical side information into the PET reconstruction model. In contrast to existing methods that incorporate anatomical information using a penalized likelihood framework, the proposed method incorporates this information in the simpler maximum likelihood (ML) formulation and is amenable to ordered subsets. The new method also does not require any segmentation of the anatomical image to obtain edge information. We compare the kernel method with the Bowsher method for anatomically-aided PET image reconstruction through a simulated data set. Computer simulations demonstrate that the kernel method offers advantages over the Bowsher method in region of interest quantification. Additionally the kernel method is applied to a 3D patient data set. The kernel method results in reduced noise at a matched contrast level compared with the conventional ML expectation maximization algorithm.
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Affiliation(s)
- Will Hutchcroft
- Department of Biomedical Engineering, University of California-Davis, Davis, CA, USA
| | - Guobao Wang
- Department of Biomedical Engineering, University of California-Davis, Davis, CA, USA
| | - Kevin T. Chen
- Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Ciprian Catana
- Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Jinyi Qi
- Department of Biomedical Engineering, University of California-Davis, Davis, CA, USA
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Gebhardt P, Wehner J, Weissler B, Botnar R, Marsden PK, Schulz V. FPGA-based RF interference reduction techniques for simultaneous PET-MRI. Phys Med Biol 2016; 61:3500-26. [PMID: 27049898 PMCID: PMC5362065 DOI: 10.1088/0031-9155/61/9/3500] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Revised: 11/13/2015] [Accepted: 01/28/2016] [Indexed: 11/30/2022]
Abstract
The combination of positron emission tomography (PET) and magnetic resonance imaging (MRI) as a multi-modal imaging technique is considered very promising and powerful with regard to in vivo disease progression examination, therapy response monitoring and drug development. However, PET-MRI system design enabling simultaneous operation with unaffected intrinsic performance of both modalities is challenging. As one of the major issues, both the PET detectors and the MRI radio-frequency (RF) subsystem are exposed to electromagnetic (EM) interference, which may lead to PET and MRI signal-to-noise ratio (SNR) deteriorations. Early digitization of electronic PET signals within the MRI bore helps to preserve PET SNR, but occurs at the expense of increased amount of PET electronics inside the MRI and associated RF field emissions. This raises the likelihood of PET-related MRI interference by coupling into the MRI RF coil unwanted spurious signals considered as RF noise, as it degrades MRI SNR and results in MR image artefacts. RF shielding of PET detectors is a commonly used technique to reduce PET-related RF interferences, but can introduce eddy-current-related MRI disturbances and hinder the highest system integration. In this paper, we present RF interference reduction methods which rely on EM field coupling-decoupling principles of RF receive coils rather than suppressing emitted fields. By modifying clock frequencies and changing clock phase relations of digital circuits, the resulting RF field emission is optimised with regard to a lower field coupling into the MRI RF coil, thereby increasing the RF silence of PET detectors. Our methods are demonstrated by performing FPGA-based clock frequency and phase shifting of digital silicon photo-multipliers (dSiPMs) used in the PET modules of our MR-compatible Hyperion II (D) PET insert. We present simulations and magnetic-field map scans visualising the impact of altered clock phase pattern on the spatial RF field distribution, followed by MRI noise and SNR scans performed with an operating PET module using different clock frequencies and phase patterns. The methods were implemented via firmware design changes without any hardware modifications. This introduces new means of flexibility by enabling adaptive RF interference reduction optimisations in the field, e.g. when using a PET insert with different MRI systems or when different MRI RF coil types are to be operated with the same PET detector.
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Affiliation(s)
- P Gebhardt
- Division of Imaging Sciences and Biomedical Engineering, King’s College London, London WC2R 2LS, UK
- Department of Physics of Molecular Imaging Systems, Institute of Experimental Molecular Imaging, RWTH Aachen University, 52062 Aachen, Germany
| | - J Wehner
- Department of Physics of Molecular Imaging Systems, Institute of Experimental Molecular Imaging, RWTH Aachen University, 52062 Aachen, Germany
| | - B Weissler
- Department of Physics of Molecular Imaging Systems, Institute of Experimental Molecular Imaging, RWTH Aachen University, 52062 Aachen, Germany
| | - R Botnar
- Division of Imaging Sciences and Biomedical Engineering, King’s College London, London WC2R 2LS, UK
| | - P K Marsden
- Division of Imaging Sciences and Biomedical Engineering, King’s College London, London WC2R 2LS, UK
| | - V Schulz
- Department of Physics of Molecular Imaging Systems, Institute of Experimental Molecular Imaging, RWTH Aachen University, 52062 Aachen, Germany
- Philips Research Europe, 52066 Aachen, Germany
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Hervella P, Parra E, Needham D. Encapsulation and retention of chelated-copper inside hydrophobic nanoparticles: Liquid cored nanoparticles show better retention than a solid core formulation. Eur J Pharm Biopharm 2016; 102:64-76. [DOI: 10.1016/j.ejpb.2016.02.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 01/26/2016] [Accepted: 02/23/2016] [Indexed: 10/22/2022]
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Hansen AE, Andersen FL, Henriksen ST, Vignaud A, Ardenkjaer-Larsen JH, Højgaard L, Kjaer A, Klausen TL. Simultaneous PET/MRI with (13)C magnetic resonance spectroscopic imaging (hyperPET): phantom-based evaluation of PET quantification. EJNMMI Phys 2016; 3:7. [PMID: 27102632 PMCID: PMC4840180 DOI: 10.1186/s40658-016-0143-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 04/13/2016] [Indexed: 01/09/2023] Open
Abstract
Background Integrated PET/MRI with hyperpolarized 13C magnetic resonance spectroscopic imaging (13C-MRSI) offers simultaneous, dual-modality metabolic imaging. A prerequisite for the use of simultaneous imaging is the absence of interference between the two modalities. This has been documented for a clinical whole-body system using simultaneous 1H-MRI and PET but never for 13C-MRSI and PET. Here, the feasibility of simultaneous PET and 13C-MRSI as well as hyperpolarized 13C-MRSI in an integrated whole-body PET/MRI hybrid scanner is evaluated using phantom experiments. Methods Combined PET and 13C-MRSI phantoms including a NEMA [18F]-FDG phantom, 13C-acetate and 13C-urea sources, and hyperpolarized 13C-pyruvate were imaged repeatedly with PET and/or 13C-MRSI. Measurements evaluated for interference effects included PET activity values in the largest sphere and a background region; total number of PET trues; and 13C-MRSI signal-to-noise ratio (SNR) for urea and acetate phantoms. Differences between measurement conditions were evaluated using t tests. Results PET and 13C-MRSI data acquisition could be performed simultaneously without any discernible artifacts. The average difference in PET activity between acquisitions with and without simultaneous 13C-MRSI was 0.83 (largest sphere) and −0.76 % (background). The average difference in net trues was −0.01 %. The average difference in 13C-MRSI SNR between acquisitions with and without simultaneous PET ranged from −2.28 to 1.21 % for all phantoms and measurement conditions. No differences were significant. The system was capable of 13C-MRSI of hyperpolarized 13C-pyruvate. Conclusions Simultaneous PET and 13C-MRSI in an integrated whole-body PET/MRI hybrid scanner is feasible. Phantom experiments showed that possible interference effects introduced by acquiring data from the two modalities simultaneously are small and non-significant. Further experiments can now investigate the benefits of simultaneous PET and hyperpolarized 13C-MRI in vivo studies.
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Affiliation(s)
- Adam E Hansen
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
| | - Flemming L Andersen
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Sarah T Henriksen
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.,Department of Electrical Engineering, Technical University of Denmark, Lyngby, Denmark
| | - Alexandre Vignaud
- CEA, DRF, I2BM, NeuroSpin, UNIRS, CEA Saclay, Gif Sur Yvette, France
| | | | - Liselotte Højgaard
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Andreas Kjaer
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Thomas L Klausen
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
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Ko GB, Yoon HS, Kim KY, Lee MS, Yang BY, Jeong JM, Lee DS, Song IC, Kim SK, Kim D, Lee JS. Simultaneous Multiparametric PET/MRI with Silicon Photomultiplier PET and Ultra-High-Field MRI for Small-Animal Imaging. J Nucl Med 2016; 57:1309-15. [PMID: 27081173 DOI: 10.2967/jnumed.115.170019] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 03/11/2016] [Indexed: 12/18/2022] Open
Abstract
UNLABELLED Visualization of biologic processes at molecular and cellular levels has revolutionized the understanding and treatment of human diseases. However, no single biomedical imaging modality provides complete information, resulting in the emergence of multimodal approaches. Combining state-of-the-art PET and MRI technologies without loss of system performance and overall image quality can provide opportunities for new scientific and clinical innovations. Here, we present a multiparametric PET/MR imager based on a small-animal dedicated, high-performance, silicon photomultiplier (SiPM) PET system and a 7-T MR scanner. METHODS A SiPM-based PET insert that has the peak sensitivity of 3.4% and center volumetric resolution of 1.92/0.53 mm(3) (filtered backprojection/ordered-subset expectation maximization) was developed. The SiPM PET insert was placed between the mouse body transceiver coil and gradient coil of a 7-T small-animal MRI scanner for simultaneous PET/MRI. Mutual interference between the MRI and SiPM PET systems was evaluated using various MR pulse sequences. A cylindric corn oil phantom was scanned to assess the effects of the SiPM PET on the MR image acquisition. To assess the influence of MRI on the PET imaging functions, several PET performance indicators including scintillation pulse shape, flood image quality, energy spectrum, counting rate, and phantom image quality were evaluated with and without the application of MR pulse sequences. Simultaneous mouse PET/MRI studies were also performed to demonstrate the potential and usefulness of the multiparametric PET/MRI in preclinical applications. RESULTS Excellent performance and stability of the PET system were demonstrated, and the PET/MRI combination did not result in significant image quality degradation of either modality. Finally, simultaneous PET/MRI studies in mice demonstrated the feasibility of the developed system for evaluating the biochemical and cellular changes in a brain tumor model and facilitating the development of new multimodal imaging probes. CONCLUSION We developed a multiparametric imager with high physical performance and good system stability and demonstrated its feasibility for small-animal experiments, suggesting its usefulness for investigating in vivo molecular interactions of metabolites, and cross-validation studies of both PET and MRI.
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Affiliation(s)
- Guen Bae Ko
- Department of Nuclear Medicine, Seoul National University, Seoul, Korea Department of Biomedical Sciences, Seoul National University, Seoul, Korea
| | - Hyun Suk Yoon
- Department of Nuclear Medicine, Seoul National University, Seoul, Korea Department of Biomedical Sciences, Seoul National University, Seoul, Korea
| | - Kyeong Yun Kim
- Department of Nuclear Medicine, Seoul National University, Seoul, Korea Department of Biomedical Sciences, Seoul National University, Seoul, Korea
| | - Min Sun Lee
- Department of Nuclear Medicine, Seoul National University, Seoul, Korea Interdisciplinary Program in Radiation Applied Life Science, Seoul National University, Seoul, Korea
| | - Bo Yeun Yang
- Department of Nuclear Medicine, Seoul National University, Seoul, Korea Institute of Radiation Medicine, Medical Research Center, Seoul National University, Seoul, Korea
| | - Jae Min Jeong
- Department of Nuclear Medicine, Seoul National University, Seoul, Korea Department of Biomedical Sciences, Seoul National University, Seoul, Korea Interdisciplinary Program in Radiation Applied Life Science, Seoul National University, Seoul, Korea Institute of Radiation Medicine, Medical Research Center, Seoul National University, Seoul, Korea
| | - Dong Soo Lee
- Department of Nuclear Medicine, Seoul National University, Seoul, Korea Interdisciplinary Program in Radiation Applied Life Science, Seoul National University, Seoul, Korea Institute of Radiation Medicine, Medical Research Center, Seoul National University, Seoul, Korea Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Suwon, Korea
| | - In Chan Song
- Institute of Radiation Medicine, Medical Research Center, Seoul National University, Seoul, Korea Department of Radiology, Seoul National University, Seoul, Korea
| | - Seok-Ki Kim
- Department of Nuclear Medicine, National Cancer Center, Goyang, Korea; and Molecular Imaging and Therapy Branch, National Cancer Center, Goyang, Korea
| | - Daehong Kim
- Molecular Imaging and Therapy Branch, National Cancer Center, Goyang, Korea
| | - Jae Sung Lee
- Department of Nuclear Medicine, Seoul National University, Seoul, Korea Department of Biomedical Sciences, Seoul National University, Seoul, Korea Interdisciplinary Program in Radiation Applied Life Science, Seoul National University, Seoul, Korea Institute of Radiation Medicine, Medical Research Center, Seoul National University, Seoul, Korea
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Abstract
Effective methods of monitoring the status of patients with neurological injuries began with non-invasive observations and evolved during the past several decades to include more invasive monitoring tools and physiologic measures. The monitoring paradigm continues to evolve, this time back toward the use of less invasive tools. In parallel, the science of monitoring began with the global assessment of the patient's neurological condition, evolved to focus on regional monitoring techniques, and with the advent of enhanced computing capabilities is now moving back to focus on global monitoring. The purpose of this session of the Second Neurocritical Care Research Conference was to collaboratively develop a comprehensive understanding of the state of the science for global brain monitoring and to identify research priorities for intracranial pressure monitoring, neuroimaging, and neuro-electrophysiology monitoring.
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Ouyang Y, Judenhofer MS, Walton JH, Marik J, Williams SP, Cherry SR. Simultaneous PET/MRI Imaging During Mouse Cerebral Hypoxia-ischemia. J Vis Exp 2015. [PMID: 26437227 DOI: 10.3791/52728] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Dynamic changes in tissue water diffusion and glucose metabolism occur during and after hypoxia in cerebral hypoxia-ischemia reflecting a bioenergetics disturbance in affected cells. Diffusion weighted magnetic resonance imaging (MRI) identifies regions that are damaged, potentially irreversibly, by hypoxia-ischemia. Alterations in glucose utilization in the affected tissue may be detectable by positron emission tomography (PET) imaging of 2-deoxy-2-(18F)fluoro-ᴅ-glucose ([18F]FDG) uptake. Due to the rapid and variable nature of injury in this animal model, acquisition of both modes of data must be performed simultaneously in order to meaningfully correlate PET and MRI data. In addition, inter-animal variability in the hypoxic-ischemic injury due to vascular differences limits the ability to analyze multi-modal data and observe changes to a group-wise approach if data is not acquired simultaneously in individual subjects. The method presented here allows one to acquire both diffusion-weighted MRI and [18F]FDG uptake data in the same animal before, during, and after the hypoxic challenge in order to interrogate immediate physiological changes.
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Affiliation(s)
- Yu Ouyang
- Department of Biomedical Engineering, University of California, Davis;
| | | | - Jeffrey H Walton
- Department of Biomedical Engineering, University of California, Davis; Nuclear Magnetic Resonance Facility, University of California, Davis
| | | | | | - Simon R Cherry
- Department of Biomedical Engineering, University of California, Davis; Department of Radiology, University of California, Davis
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43
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Olcott P, Kim E, Hong K, Lee BJ, Grant AM, Chang CM, Glover G, Levin CS. Prototype positron emission tomography insert with electro-optical signal transmission for simultaneous operation with MRI. Phys Med Biol 2015; 60:3459-78. [PMID: 25856511 DOI: 10.1088/0031-9155/60/9/3459] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The simultaneous acquisition of PET and MRI data shows promise to provide powerful capabilities to study disease processes in human subjects, guide the development of novel treatments, and monitor therapy response and disease progression. A brain-size PET detector ring insert for an MRI system is being developed that, if successful, can be inserted into any existing MRI system to enable simultaneous PET and MRI images of the brain to be acquired without mutual interference. The PET insert uses electro-optical coupling to relay all the signals from the PET detectors out of the MRI system using analog modulated lasers coupled to fiber optics. Because the fibers use light instead of electrical signals, the PET detector can be electrically decoupled from the MRI making it partially transmissive to the RF field of the MRI. The SiPM devices and low power lasers were powered using non-magnetic MRI compatible batteries. Also, the number of laser-fiber channels in the system was reduced using techniques adapted from the field of compressed sensing. Using the fact that incoming PET data is sparse in time and space, electronic circuits implementing constant weight codes uniquely encode the detector signals in order to reduce the number of electro-optical readout channels by 8-fold. Two out of a total of sixteen electro-optical detector modules have been built and tested with the entire RF-shielded detector gantry for the PET ring insert. The two detectors have been tested outside and inside of a 3T MRI system to study mutual interference effects and simultaneous performance with MRI. Preliminary results show that the PET insert is feasible for high resolution simultaneous PET/MRI imaging for applications in the brain.
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Affiliation(s)
- Peter Olcott
- Stanford University School of Medicine, Department of Radiology, Molecular Imaging Instrumentation Laboratory, Alway Building, Room M001, Stanford, CA 94305-5128, USA
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44
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Niu G, Chen X. Lymphatic imaging: focus on imaging probes. Am J Cancer Res 2015; 5:686-97. [PMID: 25897334 PMCID: PMC4402493 DOI: 10.7150/thno.11862] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 03/10/2015] [Indexed: 01/10/2023] Open
Abstract
In view of the importance of sentinel lymph nodes (SLNs) in tumor staging and patient management, sensitive and accurate imaging of SLNs has been intensively explored. Along with the advance of the imaging technology, various contrast agents have been developed for lymphatic imaging. In this review, the lymph node imaging agents were summarized into three groups: tumor targeting agents, lymphatic targeting agents and lymphatic mapping agents. Tumor targeting agents are used to detect metastatic tumor tissue within LNs, lymphatic targeting agents aim to visualize lymphatic vessels and lymphangionesis, while lymphatic mapping agents are mainly for SLN detection during surgery after local administration. Coupled with various signal emitters, these imaging agents work with single or multiple imaging modalities to provide a valuable way to evaluate the location and metastatic status of SLNs.
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45
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Loggia ML, Chonde DB, Akeju O, Arabasz G, Catana C, Edwards RR, Hill E, Hsu S, Izquierdo-Garcia D, Ji RR, Riley M, Wasan AD, Zürcher NR, Albrecht DS, Vangel MG, Rosen BR, Napadow V, Hooker JM. Evidence for brain glial activation in chronic pain patients. ACTA ACUST UNITED AC 2015; 138:604-15. [PMID: 25582579 DOI: 10.1093/brain/awu377] [Citation(s) in RCA: 337] [Impact Index Per Article: 37.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Although substantial evidence has established that microglia and astrocytes play a key role in the establishment and maintenance of persistent pain in animal models, the role of glial cells in human pain disorders remains unknown. Here, using the novel technology of integrated positron emission tomography-magnetic resonance imaging and the recently developed radioligand (11)C-PBR28, we show increased brain levels of the translocator protein (TSPO), a marker of glial activation, in patients with chronic low back pain. As the Ala147Thr polymorphism in the TSPO gene affects binding affinity for (11)C-PBR28, nine patient-control pairs were identified from a larger sample of subjects screened and genotyped, and compared in a matched-pairs design, in which each patient was matched to a TSPO polymorphism-, age- and sex-matched control subject (seven Ala/Ala and two Ala/Thr, five males and four females in each group; median age difference: 1 year; age range: 29-63 for patients and 28-65 for controls). Standardized uptake values normalized to whole brain were significantly higher in patients than controls in multiple brain regions, including thalamus and the putative somatosensory representations of the lumbar spine and leg. The thalamic levels of TSPO were negatively correlated with clinical pain and circulating levels of the proinflammatory citokine interleukin-6, suggesting that TSPO expression exerts pain-protective/anti-inflammatory effects in humans, as predicted by animal studies. Given the putative role of activated glia in the establishment and or maintenance of persistent pain, the present findings offer clinical implications that may serve to guide future studies of the pathophysiology and management of a variety of persistent pain conditions.
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Affiliation(s)
- Marco L Loggia
- 1 MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA 2 Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02155, USA
| | - Daniel B Chonde
- 1 MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | - Oluwaseun Akeju
- 3 Department of Anesthesia, Critical Care and Pain Medicine, MGH/HMS, Boston, MA 02114, USA
| | - Grae Arabasz
- 1 MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | - Ciprian Catana
- 1 MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | - Robert R Edwards
- 2 Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02155, USA 4 Department of Psychiatry, Brigham and Women's Hospital, HMS, Boston, MA 02155, USA
| | - Elena Hill
- 5 Tufts University School of Medicine, Boston, MA 02111, USA
| | - Shirley Hsu
- 1 MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | - David Izquierdo-Garcia
- 1 MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | - Ru-Rong Ji
- 2 Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02155, USA 6 Departments of Anesthesiology and Neurobiology, Duke University Medical Center, Durham, NC 27705, USA
| | - Misha Riley
- 1 MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | - Ajay D Wasan
- 2 Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02155, USA 4 Department of Psychiatry, Brigham and Women's Hospital, HMS, Boston, MA 02155, USA 7 Departments of Anesthesiology and Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA 15206, USA
| | - Nicole R Zürcher
- 1 MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | - Daniel S Albrecht
- 1 MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | - Mark G Vangel
- 1 MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | - Bruce R Rosen
- 1 MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA 8 Division of Health Sciences and Technology, Harvard-Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Vitaly Napadow
- 1 MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA 2 Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02155, USA 9 Department of Biomedical Engineering, Kyung Hee University, Seoul 130-872, Republic of Korea
| | - Jacob M Hooker
- 1 MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
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46
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3D Bioprinting and 3D Imaging for Stem Cell Engineering. BIOPRINTING IN REGENERATIVE MEDICINE 2015. [DOI: 10.1007/978-3-319-21386-6_2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
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47
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Dregely I, Lanz T, Metz S, Mueller MF, Kuschan M, Nimbalkar M, Bundschuh RA, Ziegler SI, Haase A, Nekolla SG, Schwaiger M. A 16-channel MR coil for simultaneous PET/MR imaging in breast cancer. Eur Radiol 2014; 25:1154-61. [DOI: 10.1007/s00330-014-3445-x] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Revised: 08/26/2014] [Accepted: 09/16/2014] [Indexed: 02/02/2023]
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48
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Ramalho M, AlObaidy M, Catalano OA, Guimaraes AR, Salvatore M, Semelka RC. MR-PET of the body: Early experience and insights. Eur J Radiol Open 2014; 1:28-39. [PMID: 26937425 PMCID: PMC4750620 DOI: 10.1016/j.ejro.2014.09.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Accepted: 09/01/2014] [Indexed: 12/19/2022] Open
Abstract
MR-PET is a novel imaging modality that combines anatomic and metabolic data acquisition, allowing for simultaneous depiction of morphological and functional abnormalities with an excellent soft tissue contrast and good spatial resolution; as well as accurate temporal and spatial image fusion; while substantially reducing radiation dose when compared with PET-CT. In this review, we will discuss MR-PET basic principles and technical challenges and limitations, explore some practical considerations, and cover the main clinical applications, while shedding some light on some of the future trends regarding this new imaging technique.
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Affiliation(s)
- Miguel Ramalho
- Department of Radiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Mamdoh AlObaidy
- Department of Radiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Onofrio A Catalano
- Department of Radiology, SDN-IRCCS and University of Naples "Parthenope", Naples, Italy
| | | | - Marco Salvatore
- Department of Radiology, University of Naples "Federico II", Naples, Italy
| | - Richard C Semelka
- Department of Radiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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49
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Li Y, Lin TY, Luo Y, Liu Q, Xiao W, Guo W, Lac D, Zhang H, Feng C, Wachsmann-Hogiu S, Walton JH, Cherry SR, Rowland DJ, Kukis D, Pan C, Lam KS. A smart and versatile theranostic nanomedicine platform based on nanoporphyrin. Nat Commun 2014; 5:4712. [PMID: 25158161 PMCID: PMC4145614 DOI: 10.1038/ncomms5712] [Citation(s) in RCA: 293] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Accepted: 07/16/2014] [Indexed: 02/05/2023] Open
Abstract
Multifunctional nanoparticles with combined diagnostic and therapeutic functions show great promise towards personalized nanomedicine. However, attaining consistently high performance of these functions in vivo in one single nanoconstruct remains extremely challenging. Here we demonstrate the use of one single polymer to develop a smart 'all-in-one' nanoporphyrin platform that conveniently integrates a broad range of clinically relevant functions. Nanoporphyrins can be used as amplifiable multimodality nanoprobes for near-infrared fluorescence imaging (NIRFI), magnetic resonance imaging (MRI), positron emission tomography (PET) and dual modal PET-MRI. Nanoporphyrins greatly increase the imaging sensitivity for tumour detection through background suppression in blood, as well as preferential accumulation and signal amplification in tumours. Nanoporphyrins also function as multiphase nanotransducers that can efficiently convert light to heat inside tumours for photothermal therapy (PTT), and light to singlet oxygen for photodynamic therapy (PDT). Furthermore, nanoporphyrins act as programmable releasing nanocarriers for targeted delivery of drugs or therapeutic radio-metals into tumours.
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Affiliation(s)
- Yuanpei Li
- Department of Biochemistry and Molecular Medicine, UC Davis Comprehensive Cancer Center, University of California Davis, Sacramento, CA 95817, USA
| | - Tzu-yin Lin
- Department of Internal Medicine, Division of Hematology/Oncology, University of California Davis, Sacramento, CA 95817, USA
| | - Yan Luo
- Department of Biochemistry and Molecular Medicine, UC Davis Comprehensive Cancer Center, University of California Davis, Sacramento, CA 95817, USA
- Department of Oncology, PLA Cancer Research Institute of the Second Affiliated Hospital, Third Military Medical University, Chongqing, 400037, China
| | - Qiangqiang Liu
- Department of Biochemistry and Molecular Medicine, UC Davis Comprehensive Cancer Center, University of California Davis, Sacramento, CA 95817, USA
- National Chengdu Center for Safety Evaluation of Drugs, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Wenwu Xiao
- Department of Biochemistry and Molecular Medicine, UC Davis Comprehensive Cancer Center, University of California Davis, Sacramento, CA 95817, USA
| | - Wenchang Guo
- Department of Biochemistry and Molecular Medicine, UC Davis Comprehensive Cancer Center, University of California Davis, Sacramento, CA 95817, USA
| | - Diana Lac
- Department of Biochemistry and Molecular Medicine, UC Davis Comprehensive Cancer Center, University of California Davis, Sacramento, CA 95817, USA
| | - Hongyong Zhang
- Department of Internal Medicine, Division of Hematology/Oncology, University of California Davis, Sacramento, CA 95817, USA
| | - Caihong Feng
- Department of Biochemistry and Molecular Medicine, UC Davis Comprehensive Cancer Center, University of California Davis, Sacramento, CA 95817, USA
- Beijing institute of technology, Beijing, 100081, China
| | - Sebastian Wachsmann-Hogiu
- NSF Center for Biophotonics Science and Technology, University of California Davis, Sacramento, CA 95817, USA
- Department of Pathology and Laboratory Medicine, University of California Davis, Sacramento, CA 95817, USA
| | - Jeffrey H. Walton
- Department of Biochemistry and Molecular Medicine, UC Davis Comprehensive Cancer Center, University of California Davis, Sacramento, CA 95817, USA
- UC Davis NMR Facility, Davis, CA 95616, USA
| | - Simon R. Cherry
- Department of Biomedical Engineering, Center for Molecular and Genomic Imaging, University of California Davis, Davis, CA 95616, USA
| | - Douglas J. Rowland
- Department of Biomedical Engineering, Center for Molecular and Genomic Imaging, University of California Davis, Davis, CA 95616, USA
| | - David Kukis
- Department of Biomedical Engineering, Center for Molecular and Genomic Imaging, University of California Davis, Davis, CA 95616, USA
| | - Chongxian Pan
- Department of Internal Medicine, Division of Hematology/Oncology, University of California Davis, Sacramento, CA 95817, USA
- VA Northern California Health Care System, Mather, CA
| | - Kit S. Lam
- Department of Biochemistry and Molecular Medicine, UC Davis Comprehensive Cancer Center, University of California Davis, Sacramento, CA 95817, USA
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50
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In vivo monitoring of Staphylococcus aureus biofilm infections and antimicrobial therapy by [18F]fluoro-deoxyglucose-MicroPET in a mouse model. Antimicrob Agents Chemother 2014; 58:6660-7. [PMID: 25155589 DOI: 10.1128/aac.03138-14] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
A mouse model was developed for in vivo monitoring of infection and the effect of antimicrobial treatment against Staphylococcus aureus biofilms, using the [(18)F]fluoro-deoxyglucose-MicroPET ([(18)F]FDG-MicroPET) image technique. In the model, sealed Vialon catheters were briefly precolonized with S. aureus strains ATCC 15981 or V329, which differ in cytotoxic properties and biofilm matrix composition. After subcutaneous implantation of catheters in mice, the S. aureus strain differences found in bacterial counts and the inflammatory reaction triggered were detected by the regular bacteriological and histological procedures and also by [(18)F]FDG-MicroPET image signal intensity determinations in the infection area and regional lymph node. Moreover, [(18)F]FDG-MicroPET imaging allowed the monitoring of the rifampin treatment effect, identifying the periods of controlled infection and those of reactivated infection due to the appearance of bacteria naturally resistant to rifampin. Overall, the mouse model developed may be useful for noninvasive in vivo determinations in studies on S. aureus biofilm infections and assessment of new therapeutic approaches.
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