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Bouchareb Y, AlSaadi A, Zabah J, Jain A, Al-Jabri A, Phiri P, Shi JQ, Delanerolle G, Sirasanagandla SR. Technological Advances in SPECT and SPECT/CT Imaging. Diagnostics (Basel) 2024; 14:1431. [PMID: 39001321 PMCID: PMC11241697 DOI: 10.3390/diagnostics14131431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2024] [Revised: 06/11/2024] [Accepted: 06/15/2024] [Indexed: 07/16/2024] Open
Abstract
Single photon emission tomography/computed tomography (SPECT/CT) is a mature imaging technology with a dynamic role in the diagnosis and monitoring of a wide array of diseases. This paper reviews the technological advances, clinical impact, and future directions of SPECT and SPECT/CT imaging. The focus of this review is on signal amplifier devices, detector materials, camera head and collimator designs, image reconstruction techniques, and quantitative methods. Bulky photomultiplier tubes (PMTs) are being replaced by position-sensitive PMTs (PSPMTs), avalanche photodiodes (APDs), and silicon PMs to achieve higher detection efficiency and improved energy resolution and spatial resolution. Most recently, new SPECT cameras have been designed for cardiac imaging. The new design involves using specialised collimators in conjunction with conventional sodium iodide detectors (NaI(Tl)) or an L-shaped camera head, which utilises semiconductor detector materials such as CdZnTe (CZT: cadmium-zinc-telluride). The clinical benefits of the new design include shorter scanning times, improved image quality, enhanced patient comfort, reduced claustrophobic effects, and decreased overall size, particularly in specialised clinical centres. These noticeable improvements are also attributed to the implementation of resolution-recovery iterative reconstructions. Immense efforts have been made to establish SPECT and SPECT/CT imaging as quantitative tools by incorporating camera-specific modelling. Moreover, this review includes clinical examples in oncology, neurology, cardiology, musculoskeletal, and infection, demonstrating the impact of these advancements on clinical practice in radiology and molecular imaging departments.
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Affiliation(s)
- Yassine Bouchareb
- Department of Radiology & Molecular Imaging, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat 123, Oman
| | - Afrah AlSaadi
- Department of Radiology & Molecular Imaging, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat 123, Oman
| | - Jawa Zabah
- Department of Radiology & Molecular Imaging, Sultan Qaboos University Hospital, Muscat 123, Oman
| | - Anjali Jain
- Sultan Qaboos Comprehensive Cancer Care and Research Centre, Department of Radiology, Muscat 123, Oman
| | - Aziza Al-Jabri
- Department of Radiology & Molecular Imaging, Sultan Qaboos University Hospital, Muscat 123, Oman
| | - Peter Phiri
- Southern Health NHS Foundation Trust, Southampton SO40 2RZ, UK
- Psychology Department, Faculty of Environmental and Life Sciences, University of Southampton, Southampton SO17 1BJ, UK
| | - Jian Qing Shi
- Southern Health NHS Foundation Trust, Southampton SO40 2RZ, UK
- Southern University of Science and Technology, Southampton, UK
- Southern University of Science and Technology, Shenzhen 518055, China
| | - Gayathri Delanerolle
- Southern Health NHS Foundation Trust, Southampton SO40 2RZ, UK
- University of Birmingham, Birmingham, UK
| | - Srinivasa Rao Sirasanagandla
- Department of Human & Clinical Anatomy, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat 123, Oman
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Carpentier AC. Tracers and Imaging of Fatty Acid and Energy Metabolism of Human Adipose Tissues. Physiology (Bethesda) 2024; 39:0. [PMID: 38113392 PMCID: PMC11283904 DOI: 10.1152/physiol.00012.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 11/22/2023] [Accepted: 12/19/2023] [Indexed: 12/21/2023] Open
Abstract
White adipose tissue and brown adipose tissue (WAT and BAT) regulate fatty acid metabolism and control lipid fluxes to other organs. Dysfunction of these key metabolic processes contributes to organ insulin resistance and inflammation leading to chronic diseases such as type 2 diabetes, metabolic dysfunction-associated steatohepatitis, and cardiovascular diseases. Metabolic tracers combined with molecular imaging methods are powerful tools for the investigation of these pathogenic mechanisms. Herein, I review some of the positron emission tomography and magnetic resonance imaging methods combined with stable isotopic metabolic tracers to investigate fatty acid and energy metabolism, focusing on human WAT and BAT metabolism. I will discuss the complementary strengths offered by these methods for human investigations and current gaps in the field.
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Affiliation(s)
- André C Carpentier
- Department of Medicine, Division of Endocrinology, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
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3
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Sigurdsson B, Hauglund NL, Lilius TO, Mogensen FLH, Mortensen KN, Beschorner N, Klinger L, Bærentzen SL, Rosenholm MP, Shalgunov V, Herth M, Mori Y, Nedergaard M. A SPECT-based method for dynamic imaging of the glymphatic system in rats. J Cereb Blood Flow Metab 2023; 43:1153-1165. [PMID: 36809165 PMCID: PMC10291457 DOI: 10.1177/0271678x231156982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 11/17/2022] [Accepted: 12/07/2022] [Indexed: 02/23/2023]
Abstract
The glymphatic system is a brain-wide waste drainage system that promotes cerebrospinal fluid circulation through the brain to remove waste metabolites. Currently, the most common methods for assessing glymphatic function are ex vivo fluorescence microscopy of brain slices, macroscopic cortical imaging, and MRI. While all these methods have been crucial for expanding our understanding of the glymphatic system, new techniques are required to overcome their specific drawbacks. Here, we evaluate SPECT/CT imaging as a tool to assess glymphatic function in different anesthesia-induced brain states using two radiolabeled tracers, [111In]-DTPA and [99mTc]-NanoScan. Using SPECT, we confirmed the existence of brain state-dependent differences in glymphatic flow and we show brain state-dependent differences of CSF flow kinetics and CSF egress to the lymph nodes. We compare SPECT and MRI for imaging glymphatic flow and find that the two imaging modalities show the same overall pattern of CSF flow, but that SPECT was specific across a greater range of tracer concentrations than MRI. Overall, we find that SPECT imaging is a promising tool for imaging the glymphatic system, and that qualities such as high sensitivity and the variety of available tracers make SPECT imaging a good alternative for glymphatic research.
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Affiliation(s)
- Björn Sigurdsson
- Center for Translational Neuromedicine, University of Copenhagen, Denmark
| | - Natalie L Hauglund
- Center for Translational Neuromedicine, University of Copenhagen, Denmark
| | - Tuomas O Lilius
- Center for Translational Neuromedicine, University of Copenhagen, Denmark
- INDIVIDRUG Research Program, University of Helsinki, Finland
- Department of Pharmacology, University of Helsinki, Finland
- Department of Emergency Medicine and Services, Helsinki University Hospital and University of Helsinki, Finland
| | - Frida L-H Mogensen
- Center for Translational Neuromedicine, University of Copenhagen, Denmark
- Neuro-Immunology Group, Department of Cancer Research, Luxembourg Institute of Health, Luxembourg, Luxembourg
- Doctoral School of Science and Technology, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | | | - Natalie Beschorner
- Center for Translational Neuromedicine, University of Copenhagen, Denmark
| | - Laura Klinger
- Center for Translational Neuromedicine, University of Copenhagen, Denmark
| | - Simone L Bærentzen
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Nuclear Medicine and PET Center, Aarhus University Hospital, Aarhus, Denmark
| | - Marko P Rosenholm
- Center for Translational Neuromedicine, University of Copenhagen, Denmark
| | - Vladimir Shalgunov
- Department of Drug Design and Pharmacology, University of Copenhagen, Denmark
| | - Matthias Herth
- Department of Drug Design and Pharmacology, University of Copenhagen, Denmark
- Department of Clinical Physiology, Copenhagen University Hospital, Denmark
| | - Yuki Mori
- Center for Translational Neuromedicine, University of Copenhagen, Denmark
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, University of Copenhagen, Denmark
- Center for Translational Neuromedicine, University of Rochester Medical Center, USA
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Wu J, Qiao H. Medical Imaging Technology and Imaging Agents. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1199:15-38. [PMID: 37460725 DOI: 10.1007/978-981-32-9902-3_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
Medical imaging is a technology that studies the interaction between human body and irradiations of X-ray, ultrasound, magnetic field, etc. and represents anatomical structures of human organs/tissues with the implication of irradiation attenuation in the form of grayscales. With these medical images, detailed information on health status and disease diagnosis may be judged by clinical physicians to determine an appropriate therapy approach. This chapter will give a systematic introduction on the modalities, classifications, basic principles, and biomedical applications of traditional medical imaging along with the types, construction, and major features of the corresponding contrast agents or imaging probes.
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Affiliation(s)
- Jieting Wu
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Huanhuan Qiao
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China.
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5
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Assessment of mouse-specific pharmacokinetics in kidneys based on 131I activity measurements using micro-SPECT. EJNMMI Phys 2022; 9:13. [PMID: 35195790 PMCID: PMC8866625 DOI: 10.1186/s40658-022-00443-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 02/10/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In order to acquire accurate drug pharmacokinetic information, which is required for tissue dosimetry, micro-SPECT must be quantitative to allow for an accurate assessment of radioligand activity in the relevant tissue. This study investigates the feasibility of deriving accurate mouse-specific time-integrated drug pharmacokinetic data in mouse kidneys from activity measurements using micro-SPECT. METHODS An animal experiment was carried out to evaluate the accuracy of 131I activity quantification in mouse kidneys (mean tissue volume of 0.140 mL) using a micro-SPECT system against conventional ex vivo gamma counting (GC) in a NaI(Tl) detector. The imaging setting investigated was that of the mouse biodistribution of a 131I-labelled single-domain antibody fragment (sdAb), currently being investigated for targeted radionuclide therapy of HER2-expressing cancer. SPECT imaging of 131I 365-keV photons was done with a VECTor/CT system (MILabs, Netherlands) using a high-energy mouse collimator with 1.6-mm-diameter pinholes. For both activity quantification techniques, the pharmacokinetic profile of the radioligand from approximately 1-73 h p.i. was derived and the time-integrated activity coefficient per gram of tissue (ã/M) was estimated. Additionally, SPECT activity recovery coefficients were determined in a phantom setting. RESULTS SPECT activities underestimate the reference activities by an amount that is dependent on the 131I activity concentration in the kidney, and thus on the time point of the pharmacokinetic profile. This underestimation is around - 12% at 1.5 h (2.89 MBq mL-1 mean reference activity concentration), - 13% at 6.6 h (149 kBq mL-1), - 40% at 24 h (17.6 kBq mL-1) and - 46% at 73 h (5.2 kBq mL-1) p.i. The ã/M value estimated from SPECT activities is, nevertheless, within - 14% from the reference (GC) ã/M value. Furthermore, better quantitative accuracy (within 2% from GC) in the SPECT ã/M value is achieved when SPECT activities are compensated for partial recovery with a phantom-based recovery coefficient of 0.85. CONCLUSION The SPECT imaging system used, together with a robust activity quantification methodology, allows an accurate estimation of time-integrated pharmacokinetic information of the 131I-labelled sdAb in mouse kidneys. This opens the possibility to perform mouse-specific kidney-tissue dosimetry based on pharmacokinetic data acquired in vivo on the same mice used in nephrotoxicity studies.
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Dexter K, Foster J, Sosabowski J, Petrik M. Preclinical PET and SPECT Instrumentation. Nucl Med Mol Imaging 2022. [DOI: 10.1016/b978-0-12-822960-6.00055-7] [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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7
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Ma T, Wei Q, Lyu Z, Zhang D, Zhang H, Wang R, Dong J, Liu Y, Yao R, He ZX. Self-Collimating SPECT With Multi-Layer Interspaced Mosaic Detectors. IEEE TRANSACTIONS ON MEDICAL IMAGING 2021; 40:2152-2169. [PMID: 33852384 DOI: 10.1109/tmi.2021.3073288] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Conventional single photon emission computed tomography (SPECT) relies on mechanical collimation whose resolution and sensitivity are interdependent, the best performance a SPECT system can attain is only a compromise of these two equally desired properties. To simultaneously achieve high resolution and sensitivity, we propose to use sensitive detectors constructed in a multi-layer in ter spaced mosaicdetectors (MATRICES) architecture to accomplish part of the collimation needed. We name this new approach self-collimation. We evaluate three self-collimating SPECT systems and report their imaging performance: 1) A simulated human brain SPECT achieves 3.88% sensitivity, it clearly resolves 0.5-mm and 1.0-mm hot-rod patterns at noise-free and realistic count-levels, respectively; 2) a simulated mouse SPECT achieves 1.25% sensitivity, it clearly resolves 50- [Formula: see text] and 100- [Formula: see text] hot-rod patterns at noise-free and realistic count-levels, respectively; 3) a SPECT prototype achieves 0.14% sensitivity and clearly separates 0.3-mm-diameter point sources of which the center-to-center neighbor distance is also 0.3 mm. Simulated contrast phantom studies show excellent resolution and signal-to-noise performance. The unprecedented system performance demonstrated by these 3 SPECT scanners is a clear manifestation of the superiority of the self-collimating approach over conventional mechanical collimation. It represents a potential paradigm shift in SPECT technology development.
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Meng LJ, Clinthorne NH. Small-Animal SPECT, SPECT/CT, and SPECT/MRI. Mol Imaging 2021. [DOI: 10.1016/b978-0-12-816386-3.00007-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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9
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Chemistry of Molecular Imaging: An Overview. Mol Imaging 2021. [DOI: 10.1016/b978-0-12-816386-3.00029-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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10
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D'Elia A, Schiavi S, Soluri A, Massari R, Soluri A, Trezza V. Role of Nuclear Imaging to Understand the Neural Substrates of Brain Disorders in Laboratory Animals: Current Status and Future Prospects. Front Behav Neurosci 2020; 14:596509. [PMID: 33362486 PMCID: PMC7759612 DOI: 10.3389/fnbeh.2020.596509] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 11/23/2020] [Indexed: 12/18/2022] Open
Abstract
Molecular imaging, which allows the real-time visualization, characterization and measurement of biological processes, is becoming increasingly used in neuroscience research. Scintigraphy techniques such as single photon emission computed tomography (SPECT) and positron emission tomography (PET) provide qualitative and quantitative measurement of brain activity in both physiological and pathological states. Laboratory animals, and rodents in particular, are essential in neuroscience research, providing plenty of models of brain disorders. The development of innovative high-resolution small animal imaging systems together with their radiotracers pave the way to the study of brain functioning and neurotransmitter release during behavioral tasks in rodents. The assessment of local changes in the release of neurotransmitters associated with the performance of a given behavioral task is a turning point for the development of new potential drugs for psychiatric and neurological disorders. This review addresses the role of SPECT and PET small animal imaging systems for a better understanding of brain functioning in health and disease states. Brain imaging in rodent models faces a series of challenges since it acts within the boundaries of current imaging in terms of sensitivity and spatial resolution. Several topics are discussed, including technical considerations regarding the strengths and weaknesses of both technologies. Moreover, the application of some of the radioligands developed for small animal nuclear imaging studies is discussed. Then, we examine the changes in metabolic and neurotransmitter activity in various brain areas during task-induced neural activation with special regard to the imaging of opioid, dopaminergic and cannabinoid receptors. Finally, we discuss the current status providing future perspectives on the most innovative imaging techniques in small laboratory animals. The challenges and solutions discussed here might be useful to better understand brain functioning allowing the translation of preclinical results into clinical applications.
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Affiliation(s)
- Annunziata D'Elia
- Institute of Biochemistry and Cell Biology, National Research Council of Italy (CNR), Rome, Italy.,Section of Biomedical Sciences and Technologies, Department of Science, University "Roma Tre", Rome, Italy
| | - Sara Schiavi
- Section of Biomedical Sciences and Technologies, Department of Science, University "Roma Tre", Rome, Italy
| | - Andrea Soluri
- Institute of Biochemistry and Cell Biology, National Research Council of Italy (CNR), Rome, Italy
| | - Roberto Massari
- Institute of Biochemistry and Cell Biology, National Research Council of Italy (CNR), Rome, Italy
| | - Alessandro Soluri
- Institute of Biochemistry and Cell Biology, National Research Council of Italy (CNR), Rome, Italy
| | - Viviana Trezza
- Section of Biomedical Sciences and Technologies, Department of Science, University "Roma Tre", Rome, Italy
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Wilk B, Wisenberg G, Dharmakumar R, Thiessen JD, Goldhawk DE, Prato FS. Hybrid PET/MR imaging in myocardial inflammation post-myocardial infarction. J Nucl Cardiol 2020; 27:2083-2099. [PMID: 31797321 PMCID: PMC7391987 DOI: 10.1007/s12350-019-01973-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 11/13/2019] [Accepted: 11/14/2019] [Indexed: 01/24/2023]
Abstract
Hybrid PET/MR imaging is an emerging imaging modality combining positron emission tomography (PET) and magnetic resonance imaging (MRI) in the same system. Since the introduction of clinical PET/MRI in 2011, it has had some impact (e.g., imaging the components of inflammation in myocardial infarction), but its role could be much greater. Many opportunities remain unexplored and will be highlighted in this review. The inflammatory process post-myocardial infarction has many facets at a cellular level which may affect the outcome of the patient, specifically the effects on adverse left ventricular remodeling, and ultimately prognosis. The goal of inflammation imaging is to track the process non-invasively and quantitatively to determine the best therapeutic options for intervention and to monitor those therapies. While PET and MRI, acquired separately, can image aspects of inflammation, hybrid PET/MRI has the potential to advance imaging of myocardial inflammation. This review contains a description of hybrid PET/MRI, its application to inflammation imaging in myocardial infarction and the challenges, constraints, and opportunities in designing data collection protocols. Finally, this review explores opportunities in PET/MRI: improved registration, partial volume correction, machine learning, new approaches in the development of PET and MRI pulse sequences, and the use of novel injection strategies.
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Affiliation(s)
- B Wilk
- Department of Medical Imaging, Western University, London, Canada.
- Lawson Health Research Institute, London, Canada.
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Canada.
| | - G Wisenberg
- Department of Medical Imaging, Western University, London, Canada
- MyHealth Centre, Arva, Canada
| | - R Dharmakumar
- Biomedical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
- David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - J D Thiessen
- Department of Medical Imaging, Western University, London, Canada
- Lawson Health Research Institute, London, Canada
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Canada
| | - D E Goldhawk
- Department of Medical Imaging, Western University, London, Canada
- Lawson Health Research Institute, London, Canada
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Canada
| | - F S Prato
- Department of Medical Imaging, Western University, London, Canada
- Lawson Health Research Institute, London, Canada
- Collaborative Graduate Program in Molecular Imaging, Western University, London, Canada
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12
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Capabilities of multi-pinhole SPECT with two stationary detectors for in vivo rat imaging. Sci Rep 2020; 10:18616. [PMID: 33122774 PMCID: PMC7596477 DOI: 10.1038/s41598-020-75696-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 10/07/2020] [Indexed: 11/30/2022] Open
Abstract
We aimed to investigate the image quality of the U-SPECT5/CT E-Class a micro single-photon emission computed tomography (SPECT) system with two large stationary detectors for visualization of rat hearts and bones using clinically available 99mTc-labelled tracers. Sensitivity, spatial resolution, uniformity and contrast-to-noise ratio (CNR) of the small-animal SPECT scanner were investigated in phantom studies using an ultra-high-resolution rat and mouse multi-pinhole collimator (UHR-RM). Point source, hot-rod, and uniform phantoms with 99mTc-solution were scanned for high-count performance assessment and count levels equal to animal scans, respectively. Reconstruction was performed using the similarity-regulated ordered-subsets expectation maximization (SROSEM) algorithm with Gaussian smoothing. Rats were injected with ~ 100 MBq [99mTc]Tc-MIBI or ~ 150 MBq [99mTc]Tc-HMDP and received multi-frame micro-SPECT imaging after tracer distribution. Animal scans were reconstructed for three different acquisition times and post-processed with different sized Gaussian filters. Following reconstruction, CNR was calculated and image quality evaluated by three independent readers on a five-point scale from 1 = “very poor” to 5 = “very good”. Point source sensitivity was 567 cps/MBq and radioactive rods as small as 1.2 mm were resolved with the UHR-RM collimator. Collimator-dependent uniformity was 55.5%. Phantom CNR improved with increasing rod size, filter size and activity concentration. Left ventricle and bone structures were successfully visualized in rat experiments. Image quality was strongly affected by the extent of post-filtering, whereas scan time did not have substantial influence on visual assessment. Good image quality was achieved for resolution range greater than 1.8 mm in bone and 2.8 mm in heart. The recently introduced small animal SPECT system with two stationary detectors and UHR-RM collimator is capable to provide excellent image quality in heart and bone scans in a rat using standardized reconstruction parameters and appropriate post-filtering. However, there are still challenges in achieving maximum system resolution in the sub-millimeter range with in vivo settings under limited injection dose and acquisition time.
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13
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Functional characterization of human brown adipose tissue metabolism. Biochem J 2020; 477:1261-1286. [PMID: 32271883 DOI: 10.1042/bcj20190464] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 03/13/2020] [Accepted: 03/16/2020] [Indexed: 02/07/2023]
Abstract
Brown adipose tissue (BAT) has long been described according to its histological features as a multilocular, lipid-containing tissue, light brown in color, that is also responsive to the cold and found especially in hibernating mammals and human infants. Its presence in both hibernators and human infants, combined with its function as a heat-generating organ, raised many questions about its role in humans. Early characterizations of the tissue in humans focused on its progressive atrophy with age and its apparent importance for cold-exposed workers. However, the use of positron emission tomography (PET) with the glucose tracer [18F]fluorodeoxyglucose ([18F]FDG) made it possible to begin characterizing the possible function of BAT in adult humans, and whether it could play a role in the prevention or treatment of obesity and type 2 diabetes (T2D). This review focuses on the in vivo functional characterization of human BAT, the methodological approaches applied to examine these features and addresses critical gaps that remain in moving the field forward. Specifically, we describe the anatomical and biomolecular features of human BAT, the modalities and applications of non-invasive tools such as PET and magnetic resonance imaging coupled with spectroscopy (MRI/MRS) to study BAT morphology and function in vivo, and finally describe the functional characteristics of human BAT that have only been possible through the development and application of such tools.
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14
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Lukas M, Kluge A, Beindorff N, Brenner W. Multi-Isotope Capabilities of a Small-Animal Multi-Pinhole SPECT System. J Nucl Med 2020; 61:152-161. [PMID: 31896726 DOI: 10.2967/jnumed.119.226027] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 06/12/2019] [Indexed: 11/16/2022] Open
Abstract
The quantitative accuracy and image quality of multi-isotope SPECT is affected by various hardware-related perturbations. The present study evaluates the simultaneous acquisition of multiple isotopes using a multiplexed multi-pinhole SPECT system, assesses the extent of different error sources, and proposes experimental procedures for its objective characterization. Methods: Phantom measurements with single-, dual- and triple-isotope combinations of 99mTc, 111In, 123I, 177Lu, and 201Tl were performed with the NanoSPECT/CTPLUS to evaluate system energy resolution, count rate performance, sensitivity, collimator penetration, hardware versus object scatter, spectral crosstalk, spatial resolution, spatial registration accuracy, image uniformity, image noise, and image quality. Results: The intrinsic detector properties were suitable for the simultaneous acquisition of up to 3 isotopes with limitations for count rates exceeding 104 kcps and γ-energies lower than 75 keV. Spectral crosstalk between isotopes was more likely mediated by hardware than by source scatter and was strongly dependent on the isotope combination. Simultaneous multi-isotope acquisitions slightly degraded spatial resolution and image uniformity for spatially superimposed but not for spatially separated activity distributions while the background noise level was increased for all multi-isotope studies. For particular isotopes, collimator penetration and x-ray fluorescence contributed a significant portion of error. Conclusion: The NanoSPECT/CTPLUS enables the simultaneous acquisition of 3 radioisotopes with high quantitative accuracy and only little loss of image quality when the activity ratio is adapted to isotope-specific count rate sensitivities and when the system calibration is performed with phantoms of appropriate size.
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Affiliation(s)
- Mathias Lukas
- Department of Nuclear Medicine, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Anne Kluge
- Department of Radiation Oncology and Radiotherapy, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Nicola Beindorff
- Berlin Experimental Radionuclide Imaging Center, Charité-Universitätsmedizin Berlin, Berlin, Germany; and
| | - Winfried Brenner
- Department of Nuclear Medicine, Charité-Universitätsmedizin Berlin, Berlin, Germany.,German Cancer Consortium, Charité Campus Berlin, Berlin, Germany
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15
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Tarvirdipour S, Huang X, Mihali V, Schoenenberger CA, Palivan CG. Peptide-Based Nanoassemblies in Gene Therapy and Diagnosis: Paving the Way for Clinical Application. Molecules 2020; 25:E3482. [PMID: 32751865 PMCID: PMC7435460 DOI: 10.3390/molecules25153482] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 07/20/2020] [Accepted: 07/22/2020] [Indexed: 12/26/2022] Open
Abstract
Nanotechnology approaches play an important role in developing novel and efficient carriers for biomedical applications. Peptides are particularly appealing to generate such nanocarriers because they can be rationally designed to serve as building blocks for self-assembling nanoscale structures with great potential as therapeutic or diagnostic delivery vehicles. In this review, we describe peptide-based nanoassemblies and highlight features that make them particularly attractive for the delivery of nucleic acids to host cells or improve the specificity and sensitivity of probes in diagnostic imaging. We outline the current state in the design of peptides and peptide-conjugates and the paradigms of their self-assembly into well-defined nanostructures, as well as the co-assembly of nucleic acids to form less structured nanoparticles. Various recent examples of engineered peptides and peptide-conjugates promoting self-assembly and providing the structures with wanted functionalities are presented. The advantages of peptides are not only their biocompatibility and biodegradability, but the possibility of sheer limitless combinations and modifications of amino acid residues to induce the assembly of modular, multiplexed delivery systems. Moreover, functions that nature encoded in peptides, such as their ability to target molecular recognition sites, can be emulated repeatedly in nanoassemblies. Finally, we present recent examples where self-assembled peptide-based assemblies with "smart" activity are used in vivo. Gene delivery and diagnostic imaging in mouse tumor models exemplify the great potential of peptide nanoassemblies for future clinical applications.
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Affiliation(s)
- Shabnam Tarvirdipour
- Department of Chemistry, University of Basel, Mattenstrasse 24a, 4058 Basel, Switzerland; (S.T.); (X.H.); (V.M.)
- Department of Biosystem Science and Engineering, ETH Zurich, Mattenstrasse 26, 4058 Basel, Switzerland
| | - Xinan Huang
- Department of Chemistry, University of Basel, Mattenstrasse 24a, 4058 Basel, Switzerland; (S.T.); (X.H.); (V.M.)
| | - Voichita Mihali
- Department of Chemistry, University of Basel, Mattenstrasse 24a, 4058 Basel, Switzerland; (S.T.); (X.H.); (V.M.)
| | - Cora-Ann Schoenenberger
- Department of Chemistry, University of Basel, Mattenstrasse 24a, 4058 Basel, Switzerland; (S.T.); (X.H.); (V.M.)
| | - Cornelia G. Palivan
- Department of Chemistry, University of Basel, Mattenstrasse 24a, 4058 Basel, Switzerland; (S.T.); (X.H.); (V.M.)
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Tsartsalis S, Tournier BB, Millet P. In vivo absolute quantification of striatal and extrastriatal D 2/3 receptors with [ 123I]epidepride SPECT. EJNMMI Res 2020; 10:66. [PMID: 32548681 PMCID: PMC7297889 DOI: 10.1186/s13550-020-00650-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 05/27/2020] [Indexed: 01/08/2023] Open
Abstract
Background [123I]epidepride is a high-affinity radiotracer used in single-photon emission computed tomography (SPECT) imaging of the D2/3 receptors. It binds with high affinity to striatal and extrastriatal receptors. Nevertheless, its slow kinetics in the striatum impedes quantification in this region. Thus, an approach that would allow a simultaneous quantification of both striatal and extrastriatal D2/3 receptors would be of interest for preclinical and clinical SPECT neuroimaging. We describe a partial saturation protocol that allows us to produce an in vivo Scatchard plot and thus estimate Bavail and appKd separately in both striatal and extrastriatal regions, through a single dynamic SPECT session. To validate this approach, a multi-injection protocol is used for the full kinetic modeling of [123I]epidepride using a two-tissue compartment, 5-parameter model (2T-5k). Methods Eighteen male rats were used. Binding parameters were estimated using the multi-injection protocol. Various simulations were performed to estimate the optimal conditions for the partial saturation protocol, which was applied at the region and voxel level. The results of the partial saturation study were compared to those obtained with the 2T-5k model. To illustrate the interest of the partial saturation approach, we performed a preliminary study of the effect of a chronic, subcutaneous administration of haloperidol (1 mg/kg/day), a D2 receptor antagonist, on the Bavail of [123I]epidepride in the rat striatum. Results A series of simulations demonstrated that a mass of 3 ug/kg of unlabeled epidepride allows the formation of an in vivo Scatchard plot. The partial saturation study led to robust estimations of Bavail in all brain regions that highly correlated (r = 0.99) with the corresponding values from the multi-injection study. A chronic haloperidol treatment resulted in a 17.9% increase in the Bavail values in the left Caudate Putamen nucleus (CP) (p = 0.07) and a 13.8% increase in the right CP (p = 0.12). Conclusion A partial saturation method allowed the robust quantification of D2/3 receptors in striatal and extrastriatal D2/3 receptors with a single-scan approach. This approach may be applied in the mapping of the D2/3 receptor in translational biological studies and potentially, in clinical SPECT imaging.
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Affiliation(s)
- Stergios Tsartsalis
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Chemin du Petit-Bel-Air 2, CH1226, Thônex, Switzerland.,Division of Psychiatric Specialties, Department of Psychiatry, University Hospitals of Geneva, Geneva, Switzerland
| | - Benjamin B Tournier
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Chemin du Petit-Bel-Air 2, CH1226, Thônex, Switzerland
| | - Philippe Millet
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Chemin du Petit-Bel-Air 2, CH1226, Thônex, Switzerland. .,Department of Psychiatry, University of Geneva, Geneva, Switzerland.
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Naseri M, Rajabi H, Wang J, Abbasi M, Kalantari F. Simultaneous respiratory motion correction and image reconstruction in 4D-multi pinhole small animal SPECT. Med Phys 2019; 46:5047-5054. [PMID: 31495940 DOI: 10.1002/mp.13807] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 08/22/2019] [Accepted: 08/22/2019] [Indexed: 11/05/2022] Open
Abstract
PURPOSE Respiratory motion in the chest region during single photon emission computed tomography (SPECT) is a major degrading factor that reduces the accuracy of image quantification. This effect is more notable when the tumor is very small, or the spatial resolution of the imaging system is less than the respiratory motion amplitude. Small animals imaging systems with sub-millimeter spatial resolution need more attention to the respiratory motion for quantitative studies. We developed a motion-embedded four-dimensional (4D)-multi pinhole SPECT (MPS) reconstruction algorithm for respiratory motion correction. This algorithm makes full use of projection statistics for reconstruction of every individual frame. METHODS The ROBY phantom with small tumors in liver was generated in eight different phases during one respiratory cycle. The MPS projections were modeled using a fast ray tracing method simulating an MPS acquisition. Individual frames were reconstructed and used for motion estimation. The Demons non-rigid registration algorithm was used to calculate deformation vector fields (DVFs) for simultaneous motion correction and image reconstruction. A motion-embedded 4D-MPS method was used to reconstruct images using all the projections and corresponding DVFs, simultaneously. The 4D-MPS reconstructed images were compared to the low-count single frame (LCSF) reconstructed image, the three-dimensional (3D)-MPS images reconstructed using individual frames, and post reconstruction registration (PRR) that aligns all individual phases to a reference frame using Demons-derived DVFs. The tumor volume relative error (TVE), tumor contrast relative error (TCE), and dice index (DI) for 2, 3, and 4 mm liver were calculated and compared for different reconstruction methods. RESULTS For the 4D-MPS reconstruction method, TVE was reduced and DI was higher compared to PRR, 3D-MPS, and LCSF. The extent of the improvement was higher for the small tumor size (i.e. 2 mm). For the biggest tumor in contrast 3 (i.e. 4 mm) TVE for 4D-MPS, PRR, 3D-MPS and, LCSF were 1.33%, 8%, 8%, and 14.67%, respectively. CONCLUSIONS The results suggest that motion-embedded 4D-MPS method is an effective and practical way for respiratory motion correction. It reconstructs high quality gated frames while using all projection data to reconstruct each frame.
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Affiliation(s)
- Maryam Naseri
- Medical Physics Program, Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA, USA.,Department of Medical Physics, Faculty of Medicine, Tarbiat Modares University, Tehran, Iran
| | - Hossein Rajabi
- Department of Medical Physics, Faculty of Medicine, Tarbiat Modares University, Tehran, Iran
| | - Jing Wang
- Department of Radiation Oncology, UT Southwestern Medical Center Dallas, Dallas, TX, USA
| | - Mehrshad Abbasi
- Department of Nuclear Medicine, Vali-Asr Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Faraz Kalantari
- Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, AR, USA
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18
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Castro-Balado A, Mondelo-García C, González-Barcia M, Zarra-Ferro I, Otero-Espinar FJ, Ruibal-Morell Á, Aguiar-Fernández P, Fernández-Ferreiro A. Ocular Biodistribution Studies using Molecular Imaging. Pharmaceutics 2019; 11:pharmaceutics11050237. [PMID: 31100961 PMCID: PMC6572242 DOI: 10.3390/pharmaceutics11050237] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Revised: 05/05/2019] [Accepted: 05/07/2019] [Indexed: 02/07/2023] Open
Abstract
Classical methodologies used in ocular pharmacokinetics studies have difficulties to obtain information about topical and intraocular distribution and clearance of drugs and formulations. This is associated with multiple factors related to ophthalmic physiology, as well as the complexity and invasiveness intrinsic to the sampling. Molecular imaging is a new diagnostic discipline for in vivo imaging, which is emerging and spreading rapidly. Recent developments in molecular imaging techniques, such as positron emission tomography (PET), single-photon emission computed tomography (SPECT) and magnetic resonance imaging (MRI), allow obtaining reliable pharmacokinetic data, which can be translated into improving the permanence of the ophthalmic drugs in its action site, leading to dosage optimisation. They can be used to study either topical or intraocular administration. With these techniques it is possible to obtain real-time visualisation, localisation, characterisation and quantification of the compounds after their administration, all in a reliable, safe and non-invasive way. None of these novel techniques presents simultaneously high sensitivity and specificity, but it is possible to study biological procedures with the information provided when the techniques are combined. With the results obtained, it is possible to assume that molecular imaging techniques are postulated as a resource with great potential for the research and development of new drugs and ophthalmic delivery systems.
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Affiliation(s)
- Ana Castro-Balado
- Pharmacy Department, University Hospital of Santiago de Compostela (SERGAS), 15706 Santiago de Compostela, Spain.
- Pharmacology Group, Health Research Institute Santiago Compostela (IDIS), 15706 Santiago de Compostela, Spain.
| | - Cristina Mondelo-García
- Pharmacy Department, University Hospital of Santiago de Compostela (SERGAS), 15706 Santiago de Compostela, Spain.
- Pharmacology Group, Health Research Institute Santiago Compostela (IDIS), 15706 Santiago de Compostela, Spain.
| | - Miguel González-Barcia
- Pharmacy Department, University Hospital of Santiago de Compostela (SERGAS), 15706 Santiago de Compostela, Spain.
- Pharmacology Group, Health Research Institute Santiago Compostela (IDIS), 15706 Santiago de Compostela, Spain.
| | - Irene Zarra-Ferro
- Pharmacy Department, University Hospital of Santiago de Compostela (SERGAS), 15706 Santiago de Compostela, Spain.
- Pharmacology Group, Health Research Institute Santiago Compostela (IDIS), 15706 Santiago de Compostela, Spain.
| | - Francisco J Otero-Espinar
- Department of Pharmacology, Pharmacy and Pharmaceutical Technology and Industrial Pharmacy Institute, Faculty of Pharmacy, University of Santiago de Compostela (USC), 15706 Santiago de Compostela, Spain.
| | - Álvaro Ruibal-Morell
- Nuclear Medicine Department, University Hospital of Santiago de Compostela (SERGAS), University of Santiago de Compostela, 15706 Santiago de Compostela, Spain.
- Molecular Imaging Group. Health Research Institute Santiago Compostela (IDIS), 15706 Santiago de Compostela, Spain.
| | - Pablo Aguiar-Fernández
- Nuclear Medicine Department, University Hospital of Santiago de Compostela (SERGAS), University of Santiago de Compostela, 15706 Santiago de Compostela, Spain.
- Molecular Imaging Group. Health Research Institute Santiago Compostela (IDIS), 15706 Santiago de Compostela, Spain.
| | - Anxo Fernández-Ferreiro
- Pharmacy Department, University Hospital of Santiago de Compostela (SERGAS), 15706 Santiago de Compostela, Spain.
- Pharmacology Group, Health Research Institute Santiago Compostela (IDIS), 15706 Santiago de Compostela, Spain.
- Department of Pharmacology, Pharmacy and Pharmaceutical Technology and Industrial Pharmacy Institute, Faculty of Pharmacy, University of Santiago de Compostela (USC), 15706 Santiago de Compostela, Spain.
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Mannheim JG, Kara F, Doorduin J, Fuchs K, Reischl G, Liang S, Verhoye M, Gremse F, Mezzanotte L, Huisman MC. Standardization of Small Animal Imaging-Current Status and Future Prospects. Mol Imaging Biol 2019; 20:716-731. [PMID: 28971332 DOI: 10.1007/s11307-017-1126-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The benefit of small animal imaging is directly linked to the validity and reliability of the collected data. If the data (regardless of the modality used) are not reproducible and/or reliable, then the outcome of the data is rather questionable. Therefore, standardization of the use of small animal imaging equipment, as well as of animal handling in general, is of paramount importance. In a recent paper, guidance for efficient small animal imaging quality control was offered and discussed, among others, the use of phantoms in setting up a quality control program (Osborne et al. 2016). The same phantoms can be used to standardize image quality parameters for multi-center studies or multi-scanners within center studies. In animal experiments, the additional complexity due to animal handling needs to be addressed to ensure standardized imaging procedures. In this review, we will address the current status of standardization in preclinical imaging, as well as potential benefits from increased levels of standardization.
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Affiliation(s)
- Julia G Mannheim
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tuebingen, Roentgenweg 13, 72076, Tuebingen, Germany.
| | - Firat Kara
- Bio-Imaging Lab, University of Antwerp, Antwerp, Belgium
| | - Janine Doorduin
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Kerstin Fuchs
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tuebingen, Roentgenweg 13, 72076, Tuebingen, Germany
| | - Gerald Reischl
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tuebingen, Roentgenweg 13, 72076, Tuebingen, Germany
| | - Sayuan Liang
- Bio-Imaging Lab, University of Antwerp, Antwerp, Belgium
| | | | - Felix Gremse
- Institute for Experimental Molecular Imaging, RWTH Aachen University Clinic, Aachen, Germany
| | - Laura Mezzanotte
- Optical Molecular Imaging, Department of Radiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Marc C Huisman
- Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands
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Kudelin BK, Rodionov SA, Bozhko EA, Lavrent’eva LS. Radioiodination of Cellex®. RADIOCHEMISTRY 2018. [DOI: 10.1134/s1066362218060115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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21
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Occhipinti M, Carminati M, Busca P, Butt AD, Montagnani GL, Trigilio P, Piemonte C, Ferri A, Gola A, Bukki T, Czeller M, Nyitrai Z, Papp Z, Nagy K, Fiorini C. Characterization of the Detection Module of the INSERT SPECT/MRI Clinical System. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2018. [DOI: 10.1109/trpms.2018.2864792] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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22
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Rebling J, Estrada H, Gottschalk S, Sela G, Zwack M, Wissmeyer G, Ntziachristos V, Razansky D. Dual-wavelength hybrid optoacoustic-ultrasound biomicroscopy for functional imaging of large-scale cerebral vascular networks. JOURNAL OF BIOPHOTONICS 2018; 11:e201800057. [PMID: 29675962 DOI: 10.1002/jbio.201800057] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 04/18/2018] [Indexed: 05/03/2023]
Abstract
A critical link exists between pathological changes of cerebral vasculature and diseases affecting brain function. Microscopic techniques have played an indispensable role in the study of neurovascular anatomy and functions. Yet, investigations are often hindered by suboptimal trade-offs between the spatiotemporal resolution, field-of-view (FOV) and type of contrast offered by the existing optical microscopy techniques. We present a hybrid dual-wavelength optoacoustic (OA) biomicroscope capable of rapid transcranial visualization of large-scale cerebral vascular networks. The system offers 3-dimensional views of the morphology and oxygenation status of the cerebral vasculature with single capillary resolution and a FOV exceeding 6 × 8 mm2 , thus covering the entire cortical vasculature in mice. The large-scale OA imaging capacity is complemented by simultaneously acquired pulse-echo ultrasound (US) biomicroscopy scans of the mouse skull. The new approach holds great potential to provide better insights into cerebrovascular function and facilitate efficient studies into neurological and vascular abnormalities of the brain.
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Affiliation(s)
- Johannes Rebling
- Institute of Biological and Medical Imaging (IBMI), Helmholtz Center Munich, Neuherberg, Germany
- Faculty of Medicine and Faculty of Electrical Engineering, Technical University of Munich, München, Germany
| | - Héctor Estrada
- Institute of Biological and Medical Imaging (IBMI), Helmholtz Center Munich, Neuherberg, Germany
| | - Sven Gottschalk
- Institute of Biological and Medical Imaging (IBMI), Helmholtz Center Munich, Neuherberg, Germany
| | - Gali Sela
- Institute of Biological and Medical Imaging (IBMI), Helmholtz Center Munich, Neuherberg, Germany
| | - Michael Zwack
- Institute of Biological and Medical Imaging (IBMI), Helmholtz Center Munich, Neuherberg, Germany
| | - Georg Wissmeyer
- Institute of Biological and Medical Imaging (IBMI), Helmholtz Center Munich, Neuherberg, Germany
- Faculty of Medicine and Faculty of Electrical Engineering, Technical University of Munich, München, Germany
| | - Vasilis Ntziachristos
- Institute of Biological and Medical Imaging (IBMI), Helmholtz Center Munich, Neuherberg, Germany
- Faculty of Medicine and Faculty of Electrical Engineering, Technical University of Munich, München, Germany
| | - Daniel Razansky
- Institute of Biological and Medical Imaging (IBMI), Helmholtz Center Munich, Neuherberg, Germany
- Faculty of Medicine and Faculty of Electrical Engineering, Technical University of Munich, München, Germany
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23
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Tsartsalis S, Tournier BB, Habiby S, Ben Hamadi M, Barca C, Ginovart N, Millet P. Dual-radiotracer translational SPECT neuroimaging. Comparison of three methods for the simultaneous brain imaging of D2/3 and 5-HT2A receptors. Neuroimage 2018; 176:528-540. [DOI: 10.1016/j.neuroimage.2018.04.063] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 03/11/2018] [Accepted: 04/27/2018] [Indexed: 12/27/2022] Open
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Jiemy WF, Heeringa P, Kamps JA, van der Laken CJ, Slart RH, Brouwer E. Positron emission tomography (PET) and single photon emission computed tomography (SPECT) imaging of macrophages in large vessel vasculitis: Current status and future prospects. Autoimmun Rev 2018; 17:715-726. [DOI: 10.1016/j.autrev.2018.02.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 02/07/2018] [Indexed: 12/21/2022]
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25
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Carminati M, Montagnani GL, Occhipinti M, Kuehne A, Niendorf T, Nagy K, Nagy A, Czeller M, Fiorini C. SPECT/MRI INSERT Compatibility: Assessment, Solutions, and Design Guidelines. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2018. [DOI: 10.1109/trpms.2018.2823587] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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26
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Wu M, Shu J. Multimodal Molecular Imaging: Current Status and Future Directions. CONTRAST MEDIA & MOLECULAR IMAGING 2018; 2018:1382183. [PMID: 29967571 PMCID: PMC6008764 DOI: 10.1155/2018/1382183] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 04/11/2018] [Accepted: 05/10/2018] [Indexed: 12/12/2022]
Abstract
Molecular imaging has emerged at the end of the last century as an interdisciplinary method involving in vivo imaging and molecular biology aiming at identifying living biological processes at a cellular and molecular level in a noninvasive manner. It has a profound role in determining disease changes and facilitating drug research and development, thus creating new medical modalities to monitor human health. At present, a variety of different molecular imaging techniques have their advantages, disadvantages, and limitations. In order to overcome these shortcomings, researchers combine two or more detection techniques to create a new imaging mode, such as multimodal molecular imaging, to obtain a better result and more information regarding monitoring, diagnosis, and treatment. In this review, we first describe the classic molecular imaging technology and its key advantages, and then, we offer some of the latest multimodal molecular imaging modes. Finally, we summarize the great challenges, the future development, and the great potential in this field.
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Affiliation(s)
- Min Wu
- Department of Radiology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
| | - Jian Shu
- Department of Radiology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
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Zhang P, Cui Y, Anderson CF, Zhang C, Li Y, Wang R, Cui H. Peptide-based nanoprobes for molecular imaging and disease diagnostics. Chem Soc Rev 2018; 47:3490-3529. [PMID: 29497722 DOI: 10.1039/c7cs00793k] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Pathological changes in a diseased site are often accompanied by abnormal activities of various biomolecules in and around the involved cells. Identifying the location and expression levels of these biomolecules could enable early-stage diagnosis of the related disease, the design of an appropriate treatment strategy, and the accurate assessment of the treatment outcomes. Over the past two decades, a great diversity of peptide-based nanoprobes (PBNs) have been developed, aiming to improve the in vitro and in vivo performances of water-soluble molecular probes through engineering of their primary chemical structures as well as the physicochemical properties of their resultant assemblies. In this review, we introduce strategies and approaches adopted for the identification of functional peptides in the context of molecular imaging and disease diagnostics, and then focus our discussion on the design and construction of PBNs capable of navigating through physiological barriers for targeted delivery and improved specificity and sensitivity in recognizing target biomolecules. We highlight the biological and structural roles that low-molecular-weight peptides play in PBN design and provide our perspectives on the future development of PBNs for clinical translation.
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Affiliation(s)
- Pengcheng Zhang
- State Key Laboratory of Drug Research & Center for Pharmaceutics, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 501 Haike Road, Shanghai 201203, China.
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28
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Georgiou M, Fysikopoulos E, Mikropoulos K, Fragogeorgi E, Loudos G. Characterization of "γ-Eye": a Low-Cost Benchtop Mouse-Sized Gamma Camera for Dynamic and Static Imaging Studies. Mol Imaging Biol 2018; 19:398-407. [PMID: 27730469 DOI: 10.1007/s11307-016-1011-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
PURPOSE Several preclinical imaging systems are commercially available, but their purchase and maintenance costs make them unaffordable for the majority of small- and medium-sized groups. Taking into account the needs of average users, we developed "γ-eye", a mouse-sized, benchtop γ-camera suitable for in vivo scintigraphic imaging. PROCEDURES The γ-eye is based on two position-sensitive photomultiplier tubes, coupled to a CsI(Na) pixelated scintillator and a low-energy lead collimator with parallel hexagonal holes. RESULTS The spatial resolution of the system is 2 mm at 0 mm. The energy resolution is 26 % at 140 keV and the maximum recorded sensitivity 210 cps/MBq. The system was evaluated in a proof-of-concept animal study, using three different clinical Tc-99m-labeled radiopharmaceuticals. Phantom and animal studies demonstrate its ability to provide semiquantitative results even for short scans. CONCLUSIONS Systems' performance, dimensions, and cost make γ-eye a unique solution for efficient whole-body mouse nuclear imaging.
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Affiliation(s)
| | | | - Konstantinos Mikropoulos
- Department of Biomedical Engineering, Technological Educational Institute of Athens, Athens, Greece
| | - Eirini Fragogeorgi
- National Centre for Scientific Research NCSR "Demokritos", Institute of Nuclear and Radiological Sciences and Technology, Energy and Safety, Athens, Greece
| | - George Loudos
- Department of Biomedical Engineering, Technological Educational Institute of Athens, Athens, Greece.,National Centre for Scientific Research NCSR "Demokritos", Institute of Nuclear and Radiological Sciences and Technology, Energy and Safety, Athens, Greece
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Aligholikhamseh N, Ahmadpour S, Khodadust F, Abedi SM, Hosseinimehr SJ. 99mTc-HYNIC-(Ser)3-LTVPWY peptide bearing tricine as co-ligand for targeting and imaging of HER2 overexpression tumor. RADIOCHIM ACTA 2018. [DOI: 10.1515/ract-2017-2868] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Abstract
Human epidermal growth factor receptor 2 (HER2) is overexpressed in several cancers. Today’s tumor targeting is receiving more attention due to its specificity to target receptor-dependent cancers. The aim of this study was to evaluate the 99mTc-HYNIC-(tricine)-(Ser)3-LTVPWY peptide for tumor targeting and imaging with overexpression of HER2. HYNIC-(Ser)3-LTVPWY peptide was labeled with 99mTc using tricine as a co-ligand at room temperature. Specific binding of this radiolabeled peptide was assessed on four cancer cell lines with different levels of HER2 receptor expression. Also the affinity of 99mTc-HYNIC-(tricine)-(Ser)3-LTVPWY peptide to the HER2 receptor was evaluated in the SKOV-3 cell line. Biodistribution study of this radiolabeled peptide was performed in SKOV-3 tumor bearing nude mice. The HYNIC conjugated peptide was simply labeled with 99mTc radionuclide with high labeling efficiency about 98±1% showing favorable stability in normal saline and human serum. In the presence of unlabeled peptide as competitor, the HER2 binding capacity of the radiolabeled peptide reduced (approximately five-fold). The KD and Bmax values were found 2.6±0.5 nM and (2.6±0.1)×106, respectively. The tumor/muscle ratios for this radiotracer were determined 1.17±0.77, 1.15±0.32 and 2.65±0.32 at 1, 2 and 4 h after injection, respectively. Presaturation of HER2 receptors in SKOV-3 xenografted nude mice showed a reduction in the tumor/muscle ratio confirming in vivo specificity of the peptide. According to SPECT imaging, the tumor was visualized in mouse after 4 h postinjection of radiolabeled peptide. 99mTc-HYNIC-(tricine)-(Ser)3-LTVPWY peptide exhibited overexpressed HER2 tumor targeting.
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Affiliation(s)
- Nazan Aligholikhamseh
- Department of Radiopharmacy, Faculty of Pharmacy , Mazandaran University of Medical Sciences , Sari , Iran
| | - Sajjad Ahmadpour
- Department of Radiopharmacy, Faculty of Pharmacy , Mazandaran University of Medical Sciences , Sari , Iran
| | - Fatemeh Khodadust
- Department of Radiopharmacy, Faculty of Pharmacy , Mazandaran University of Medical Sciences , Sari , Iran
| | - Seyed Mohammad Abedi
- Department of Radiology, Faculty of Medicine , Mazandaran University of Medical Sciences , Sari , Iran
| | - Seyed Jalal Hosseinimehr
- Department of Radiopharmacy , Faculty of Pharmacy , Mazandaran University of Medical Sciences , Sari , Iran , Tel./Fax: +98-11- 33543083, E-mail:
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30
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Microdosing, isotopic labeling, radiotracers and metabolomics: relevance in drug discovery, development and safety. Bioanalysis 2017; 9:1913-1933. [PMID: 29171759 DOI: 10.4155/bio-2017-0137] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
This review discusses the use of stable (13C, 2D) or radioactive isotopes (14C, 11C, 18F, 131I, 64Cu, 68Ga) incorporated into the molecular structure of new drug entities for the purpose of pharmacokinetic or -dynamic studies. Metabolite in safety testing requires the administration of pharmacologically active doses. In such studies, radiotracers find application mainly in preclinical animal investigations, whereby LC-MS/MS is used to identify metabolite structure and drug-related effects. In contrast, first-in-human metabolite studies have to be carried out at nonpharmacological doses not exceeding 100 μg (microdose), which is generally too low for metabolite detection by LC-MS/MS. This short-coming can be overcome by specific radio- or isotopic labeling of the drug of interest and measurements using accelerator mass spectroscopy, single-photon emission computed tomography and positron emission tomography. Such combined radioisotope-based approaches permit Phase 0, first-in-human metabolite study.
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Shi J, Udayakumar TS, Wang Z, Dogan N, Pollack A, Yang Y. Optical molecular imaging-guided radiation therapy part 2: Integrated x-ray and fluorescence molecular tomography. Med Phys 2017. [DOI: 10.1002/mp.12414] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Affiliation(s)
- Junwei Shi
- Department of Radiation Oncology; School of Medicine; University of Miami; Miami FL 33136 USA
| | | | - Zhiqun Wang
- Department of Radiation Oncology; School of Medicine; University of Miami; Miami FL 33136 USA
| | - Nesrin Dogan
- Department of Radiation Oncology; School of Medicine; University of Miami; Miami FL 33136 USA
| | - Alan Pollack
- Department of Radiation Oncology; School of Medicine; University of Miami; Miami FL 33136 USA
| | - Yidong Yang
- Department of Radiation Oncology; School of Medicine; University of Miami; Miami FL 33136 USA
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Mahani H, Raisali G, Kamali-Asl A, Ay MR. Spinning slithole collimation for high-sensitivity small animal SPECT: Design and assessment using GATE simulation. Phys Med 2017; 40:42-50. [PMID: 28712714 DOI: 10.1016/j.ejmp.2017.07.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 06/16/2017] [Accepted: 07/06/2017] [Indexed: 10/19/2022] Open
Abstract
PURPOSE While traditional collimations are widely used in preclinical SPECT imaging, they usually suffer from possessing a low system sensitivity leading to noisy images. In this study, we are aiming at introducing a novel collimator, the slithole, offering a superior resolution-sensitivity tradeoff for small animal SPECT. METHODS The collimator was designed for a molecular SPECT scanner, the HiReSPECT. The slithole is a knife-edge narrow long aperture extended across long-axis of the camera's head. To meet the data completeness requirement, the collimator-detector assembly spins at each regular SPECT angle. The collimator was modeled within GATE Monte Carlo simulator and the data acquisition was performed for NEMA Image Quality (IQ) phantom. In addition, a dedicated 3D iterative reconstruction algorithm based upon plane-integral projections was also developed. RESULTS The mean sensitivity of the slithole is 285cps/MBq while the current parallel-hole collimator holds a sensitivity of 36cps/MBq at a 30mm distance. The slithole collimation gives rise to a tomographic resolution of 1.8mm compared to a spatial resolution of∼1.7mm for the parallel-hole one (even after resolution modeling). A 1.75 reduction factor in the noise level was observed when the current parallel-hole collimator is replaced by the slithole. Furthermore, quantitative analysis proves that 3 full-iterations of our dedicated image reconstruction lead to optimal image quality. For the largest rod in the NEMA IQ phantom, a recovery coefficient of∼0.83 was obtained. CONCLUSION The slithole collimator outperforms the current parallel-hole collimation by exhibiting a better resolution-sensitivity compromise for preclinical SPECT studies.
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Affiliation(s)
- Hojjat Mahani
- Radiation Application Research School, Nuclear Science and Technology Research Institute, Tehran, Iran; Research Center for Molecular and Cellular Imaging, Tehran University of Medical Science, Tehran, Iran
| | - Gholamreza Raisali
- Radiation Application Research School, Nuclear Science and Technology Research Institute, Tehran, Iran
| | | | - Mohammad Reza Ay
- Research Center for Molecular and Cellular Imaging, Tehran University of Medical Science, Tehran, Iran; Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Science, Tehran, Iran.
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Multi-pinhole fluorescent x-ray computed tomography for molecular imaging. Sci Rep 2017; 7:5742. [PMID: 28720758 PMCID: PMC5516015 DOI: 10.1038/s41598-017-05179-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 05/24/2017] [Indexed: 12/20/2022] Open
Abstract
We propose a multi-pinhole fluorescent x-ray computed tomography (mp-FXCT) technique for preclinical molecular imaging that can provide the complete data necessary to produce 3-D tomographic images during anaesthesia. In this method, multiple projections are simultaneously acquired through a multi-pinhole collimator with a 2-D detector and full-field volumetric beam to accelerate the data acquisition process and enhance the signal-to-noise ratios of the projections. We constructed a 15-pinhole mp-FXCT imaging system at beamline ARNE-7A at KEK and performed preliminary experiments to investigate its imaging properties using physical phantoms and a non-radioactive I imaging agent. The mp-FXCT system could detect an I concentration of 0.038 mg/ml, the minimum required for in-vivo imaging, at a spatial resolution of about 0.3 mm during a data acquisition time of 90 min, which is less than the time for which anaesthesia is effective and suggests that preclinical molecular imaging is feasible with mp-FXCT.
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Gerdekoohi SK, Vosoughi N, Tanha K, Assadi M, Ghafarian P, Rahmim A, Ay MR. Implementation of absolute quantification in small-animal SPECT imaging: Phantom and animal studies. J Appl Clin Med Phys 2017; 18:215-223. [PMID: 28508491 PMCID: PMC5874931 DOI: 10.1002/acm2.12094] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2016] [Revised: 02/22/2017] [Accepted: 03/17/2017] [Indexed: 11/06/2022] Open
Abstract
PURPOSE Presence of photon attenuation severely challenges quantitative accuracy in single-photon emission computed tomography (SPECT) imaging. Subsequently, various attenuation correction methods have been developed to compensate for this degradation. The present study aims to implement an attenuation correction method and then to evaluate quantification accuracy of attenuation correction in small-animal SPECT imaging. METHODS Images were reconstructed using an iterative reconstruction method based on the maximum-likelihood expectation maximization (MLEM) algorithm including resolution recovery. This was implemented in our designed dedicated small-animal SPECT (HiReSPECT) system. For accurate quantification, the voxel values were converted to activity concentration via a calculated calibration factor. An attenuation correction algorithm was developed based on the first-order Chang's method. Both phantom study and experimental measurements with four rats were used in order to validate the proposed method. RESULTS The phantom experiments showed that the error of -15.5% in the estimation of activity concentration in a uniform region was reduced to +5.1% when attenuation correction was applied. For in vivo studies, the average quantitative error of -22.8 ± 6.3% (ranging from -31.2% to -14.8%) in the uncorrected images was reduced to +3.5 ± 6.7% (ranging from -6.7 to +9.8%) after applying attenuation correction. CONCLUSION The results indicate that the proposed attenuation correction algorithm based on the first-order Chang's method, as implemented in our dedicated small-animal SPECT system, significantly improves accuracy of the quantitative analysis as well as the absolute quantification.
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Affiliation(s)
- Shabnam Khorasani Gerdekoohi
- Department of Energy EngineeringSharif University of TechnologyTehranIran
- Research Center for Molecular and Cellular ImagingTehran University of Medical SciencesTehranIran
| | - Naser Vosoughi
- Department of Energy EngineeringSharif University of TechnologyTehranIran
| | - Kaveh Tanha
- The Persian Gulf Nuclear Medicine Research CenterBushehr University of Medical SciencesBushehrIran
| | - Majid Assadi
- The Persian Gulf Nuclear Medicine Research CenterBushehr University of Medical SciencesBushehrIran
| | - Pardis Ghafarian
- Chronic Respiratory Diseases Research CenterNational Research Institute of Tuberculosis and Lung Diseases (NRITLD)Shahid Beheshti University of Medical SciencesTehranIran
- PET/CT and Cyclotron CenterMasih Daneshvari HospitalShahid Beheshti University of Medical SciencesTehranIran
| | - Arman Rahmim
- Department of RadiologyJohns Hopkins UniversityBaltimoreMarylandUSA
- Department of Electrical and Computer EngineeringJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Mohammad Reza Ay
- Research Center for Molecular and Cellular ImagingTehran University of Medical SciencesTehranIran
- Departmen of Medical Physics and Biomedical EngineeringTehran University of Medical SciencesTehranIran
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Angelis GI, Ryder WJ, Gillam JE, Boisson F, Kyme AZ, Fulton RR, Meikle SR, Kench PL. Rigid motion correction of dual opposed planar projections in single photon imaging. Phys Med Biol 2017; 62:3923-3943. [PMID: 28333040 DOI: 10.1088/1361-6560/aa68cd] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Awake and/or freely moving small animal single photon emission imaging allows the continuous study of molecules exhibiting slow kinetics without the need to restrain or anaesthetise the animals. Estimating motion free projections in freely moving small animal planar imaging can be considered as a limited angle tomography problem, except that we wish to estimate the 2D planar projections rather than the 3D volume, where the angular sampling in all three axes depends on the rotational motion of the animal. In this study, we hypothesise that the motion corrected planar projections estimated by reconstructing an estimate of the 3D volume using an iterative motion compensating reconstruction algorithm and integrating it along the projection path, will closely match the true, motion-less, planar distribution regardless of the object motion. We tested this hypothesis for the case of rigid motion using Monte-Carlo simulations and experimental phantom data based on a dual opposed detector system, where object motion was modelled with 6 degrees of freedom. In addition, we investigated the quantitative accuracy of the regional activity extracted from the geometric mean of opposing motion corrected planar projections. Results showed that it is feasible to estimate qualitatively accurate motion-corrected projections for a wide range of motions around all 3 axes. Errors in the geometric mean estimates of regional activity were relatively small and within 10% of expected true values. In addition, quantitative regional errors were dependent on the observed motion, as well as on the surrounding activity of overlapping organs. We conclude that both qualitatively and quantitatively accurate motion-free projections of the tracer distribution in a rigidly moving object can be estimated from dual opposed detectors using a correction approach within an iterative reconstruction framework and we expect this approach can be extended to the case of non-rigid motion.
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Affiliation(s)
- G I Angelis
- Imaging Physics Laboratory, Brain and Mind Centre, Camperdown, NSW 2050, Australia. Faculty of Health Sciences, The University of Sydney, NSW 2006, Sydney, Australia
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Schrauwen-Hinderling VB, Carpentier AC. Molecular imaging of postprandial metabolism. J Appl Physiol (1985) 2017; 124:504-511. [PMID: 28495844 DOI: 10.1152/japplphysiol.00212.2017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Disordered postprandial metabolism of energy substrates is one of the main defining features of prediabetes and contributes to the development of several chronic diseases associated with obesity, such as type 2 diabetes and cardiovascular diseases. Postprandial energy metabolism has been studied using classical isotopic tracer approaches that are limited by poor access to splanchnic metabolism and highly dynamic and complex exchanges of energy substrates involving multiple organs and systems. Advances in noninvasive molecular imaging modalities, such as PET and MRI/magnetic resonance spectroscopy (MRS), have recently allowed important advances in our understanding of postprandial energy metabolism in humans. The present review describes some of these recent advances, with particular focus on glucose and fatty acid metabolism in the postprandial state, and discusses current gaps in knowledge and new perspectives of application of PET and MRI/MRS for the investigation and treatment of human metabolic diseases.
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Affiliation(s)
- Vera B Schrauwen-Hinderling
- Department of Radiology and Human Biology and Human Movement Sciences, Maastricht University Medical Center , Maastricht , The Netherlands
| | - André C Carpentier
- Department of Medicine, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke , Sherbrooke, Québec , Canada
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Brayet P, Petit D, Baril AA, Gosselin N, Gagnon JF, Soucy JP, Gauthier S, Kergoat MJ, Carrier J, Rouleau I, Montplaisir J. Brain perfusion during rapid-eye-movement sleep successfully identifies amnestic mild cognitive impairment. Sleep Med 2017; 34:134-140. [PMID: 28522082 DOI: 10.1016/j.sleep.2017.01.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 01/20/2017] [Accepted: 01/24/2017] [Indexed: 11/24/2022]
Abstract
INTRODUCTION Prodromal markers of Alzheimer's disease (AD) have been derived from wakefulness. However, brain perfusion during rapid-eye movement (REM) sleep could be a sensitive marker of amnestic mild cognitive impairment (aMCI), as activation of REM sleep relies more on the cholinergic system. METHODS Eight subjects with aMCI, and 16 controls, underwent two single-photon emission computed tomography (SPECT) scans with tracer injected during REM sleep then wakefulness. RESULTS Perfusion in the anterior cingulate cortex was significantly decreased in aMCI cases compared to controls for both conditions. That defect was much larger and more severe in REM sleep (1795 voxels) compared to wakefulness (398 voxels), and extended to the middle cingulate cortex and the olfactory cortex. Hypoperfusion in the anterior cingulate cortex during REM sleep allowed better classification than hypoperfusion found in wakefulness (93.8 vs 81.3%). CONCLUSION REM sleep imaging is a valuable tool with which to identify individuals at risk of developing AD.
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Affiliation(s)
- Pauline Brayet
- Department of Psychology, Université du Québec à Montréal, Montréal, Canada; Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Coeur de Montréal, Montréal, Canada
| | - Dominique Petit
- Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Coeur de Montréal, Montréal, Canada
| | - Andrée-Ann Baril
- Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Coeur de Montréal, Montréal, Canada; Faculty of Medicine, Université de Montréal, Montréal, Canada
| | - Nadia Gosselin
- Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Coeur de Montréal, Montréal, Canada; Department of Psychology, Université de Montréal, Montréal, Canada
| | - Jean-François Gagnon
- Department of Psychology, Université du Québec à Montréal, Montréal, Canada; Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Coeur de Montréal, Montréal, Canada
| | - Jean-Paul Soucy
- Montreal Neurological Institute, McGill University, Montréal, Canada; PERFORM Centre, Concordia University, Montréal, Canada
| | - Serge Gauthier
- McGill University Research Centre for Studies in Aging, Douglas Hospital, Verdun, Canada
| | - Marie-Jeanne Kergoat
- Faculty of Medicine, Université de Montréal, Montréal, Canada; Research Center, Institut universitaire de gériatrie de Montréal, Montreal, Canada
| | - Julie Carrier
- Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Coeur de Montréal, Montréal, Canada; Department of Psychology, Université de Montréal, Montréal, Canada
| | - Isabelle Rouleau
- Department of Psychology, Université du Québec à Montréal, Montréal, Canada; Neurology Service, Hôpital Notre-Dame du CHUM, Montréal, Canada
| | - Jacques Montplaisir
- Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Coeur de Montréal, Montréal, Canada; Faculty of Medicine, Université de Montréal, Montréal, Canada.
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Sasaya T, Sunaguchi N, Thet-Lwin T, Hyodo K, Zeniya T, Takeda T, Yuasa T. Dual-energy fluorescent x-ray computed tomography system with a pinhole design: Use of K-edge discontinuity for scatter correction. Sci Rep 2017; 7:44143. [PMID: 28272496 PMCID: PMC5341157 DOI: 10.1038/srep44143] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 02/03/2017] [Indexed: 12/02/2022] Open
Abstract
We propose a pinhole-based fluorescent x-ray computed tomography (p-FXCT) system with a 2-D detector and volumetric beam that can suppress the quality deterioration caused by scatter components. In the corresponding p-FXCT technique, projections are acquired at individual incident energies just above and below the K-edge of the imaged trace element; then, reconstruction is performed based on the two sets of projections using a maximum likelihood expectation maximization algorithm that incorporates the scatter components. We constructed a p-FXCT imaging system and performed a preliminary experiment using a physical phantom and an I imaging agent. The proposed dual-energy p-FXCT improved the contrast-to-noise ratio by a factor of more than 2.5 compared to that attainable using mono-energetic p-FXCT for a 0.3 mg/ml I solution. We also imaged an excised rat's liver infused with a Ba contrast agent to demonstrate the feasibility of imaging a biological sample.
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Affiliation(s)
- Tenta Sasaya
- Graduate School of Science and Engineering, Yamagata University, Japan
| | - Naoki Sunaguchi
- Graduate School of Science and Technology, Gunma University, Japan
| | - Thet- Thet-Lwin
- School of Allied Health Sciences, Kitasato University, Japan
| | - Kazuyuki Hyodo
- Institute of Materials Structure Science, High Energy Accelerator Organization (KEK), Japan
| | - Tsutomu Zeniya
- Graduate School of Science and Technology, Hirosaki University, Japan
| | - Tohoru Takeda
- School of Allied Health Sciences, Kitasato University, Japan
| | - Tetsuya Yuasa
- Graduate School of Science and Engineering, Yamagata University, Japan
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Lauber DT, Fülöp A, Kovács T, Szigeti K, Máthé D, Szijártó A. State of the art in vivo imaging techniques for laboratory animals. Lab Anim 2017; 51:465-478. [PMID: 28948893 DOI: 10.1177/0023677217695852] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In recent decades, imaging devices have become indispensable tools in the basic sciences, in preclinical research and in modern drug development. The rapidly evolving high-resolution in vivo imaging technologies provide a unique opportunity for studying biological processes of living organisms in real time on a molecular level. State of the art small-animal imaging modalities provide non-invasive images rich in quantitative anatomical and functional information, which renders longitudinal studies possible allowing precise monitoring of disease progression and response to therapy in models of different diseases. The number of animals in a scientific investigation can be substantially reduced using imaging techniques, which is in full compliance with the ethical endeavours for the 3R (reduction, refinement, replacement) policies formulated by Russell and Burch; furthermore, biological variability can be alleviated, as each animal serves as its own control. The most suitable and commonly used imaging modalities for in vivo small-animal imaging are optical imaging (OI), ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI), and finally the methods of nuclear medicine: positron emission tomography (PET) and single photon emission computed tomography (SPECT).
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Affiliation(s)
- David Tibor Lauber
- 1 Hepato-Pancreatico-Biliary Surgery Research Center Hungary, 1st Department of Surgery, Semmelweis University, Budapest, Hungary
| | - András Fülöp
- 1 Hepato-Pancreatico-Biliary Surgery Research Center Hungary, 1st Department of Surgery, Semmelweis University, Budapest, Hungary
| | - Tibor Kovács
- 1 Hepato-Pancreatico-Biliary Surgery Research Center Hungary, 1st Department of Surgery, Semmelweis University, Budapest, Hungary
- 2 Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
| | - Krisztián Szigeti
- 2 Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
| | - Domokos Máthé
- 2 Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
- 3 CROmed Translational Research Centers Ltd, Budapest, Hungary
| | - Attila Szijártó
- 1 Hepato-Pancreatico-Biliary Surgery Research Center Hungary, 1st Department of Surgery, Semmelweis University, Budapest, Hungary
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Abstract
PURPOSE OF REVIEW Experimental evidences are strong for a role of long-chain saturated fatty acids in the development of insulin resistance and type 2 diabetes. Ectopic accretion of triglycerides in lean organs is a characteristic of prediabetes and type 2 diabetes and has been linked to end-organ complications. The contribution of disordered dietary fatty acid (DFA) metabolism to lean organ overexposure and lipotoxicity is still unclear, however. DFA metabolism is very complex and very difficult to study in vivo in humans. RECENT FINDINGS We have recently developed a novel imaging method using PET with oral administration of 14-R,S-F-fluoro-6-thia-heptadecanoic acid (FTHA) to quantify organ-specific DFA partitioning. Our studies thus far confirmed impaired storage of DFA per volume of fat mass in abdominal adipose tissues of individuals with prediabetes. They also highlighted the increased channeling of DFA toward the heart, associated with subclinical reduction in cardiac systolic and diastolic function in individuals with prediabetes. SUMMARY In the present review, we summarize previous work on DFA metabolism in healthy and prediabetic states and discuss these in the light of our novel findings using PET imaging of DFA metabolism. We herein provide an integrated view of abnormal organ-specific DFA partitioning in prediabetes in humans.
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Affiliation(s)
- Christophe Noll
- Division of Endocrinology, Department of Medicine, Centre de recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec, Canada
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In vivo detection of cucurbit[6]uril, a hyperpolarized xenon contrast agent for a xenon magnetic resonance imaging biosensor. Sci Rep 2017; 7:41027. [PMID: 28106110 PMCID: PMC5247686 DOI: 10.1038/srep41027] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 12/14/2016] [Indexed: 01/02/2023] Open
Abstract
The Hyperpolarized gas Chemical Exchange Saturation Transfer (HyperCEST) Magnetic Resonance (MR) technique has the potential to increase the sensitivity of a hyperpolarized xenon-129 MRI contrast agent. Signal enhancement is accomplished by selectively depolarizing the xenon within a cage molecule which, upon exchange, reduces the signal in the dissolved phase pool. Herein we demonstrate the in vivo detection of the cucurbit[6]uril (CB6) contrast agent within the vasculature of a living rat. Our work may be used as a stepping stone towards using the HyperCEST technique as a molecular imaging modality.
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Fischer IW, Hansen TM, Lelic D, Brokjaer A, Frøkjær J, Christrup LL, Olesen AE. Objective methods for the assessment of the spinal and supraspinal effects of opioids. Scand J Pain 2016; 14:15-24. [PMID: 28850426 DOI: 10.1016/j.sjpain.2016.10.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 09/30/2016] [Accepted: 10/03/2016] [Indexed: 01/08/2023]
Abstract
BACKGROUND AND PURPOSE Opioids are potent analgesics. Opioids exert effects after interaction with opioid receptors. Opioid receptors are present in the peripheral- and central nervous system (CNS), but the analgesic effects are primarily mediated via receptors in the CNS. Objective methods for assessment of opioid effects may increase knowledge on the CNS processes responsible for analgesia. The aim of this review was to provide an overview of the most common objective methods for assessment of the spinal and supraspinal effects of opioids and discuss their advantages and limitations. METHOD The literature search was conducted in Pub Med (http://www.ncbi.nlm.nih.gov/pubmed) from November 2014 to June 2016, using free-text terms: "opioid", "morphine" and "oxycodone" combined with the terms "pupillometry," "magnetic resonance spectroscopy," "fMRI," "BOLD," "PET," "pharmaco-EEG", "electroencephalogram", "EEG," "evoked potentials," and "nociceptive reflex". Only original articles published in English were included. RESULTS For assessment of opioid effects at the supraspinal level, the following methods are evaluated: pupillometry, proton magnetic resonance spectroscopy, functional resonance magnetic imaging (fMRI), positron emission tomography (PET), spontaneous electroencephalogram (EEG) and evoked potentials (EPs). Pupillometry is a non-invasive tool used in research as well as in the clinical setting. Proton magnetic resonance spectroscopy has been used for the last decades and it is a non-invasive technique for measurement of in vivo brain metabolite concentrations. fMRI has been a widely used non-invasive method to estimate brain activity, where typically from the blood oxygen level-dependent (BOLD) signal. PET is a nuclear imaging technique based on tracing radio labeled molecules injected into the blood, where receptor distribution, density and activity in the brain can be visualized. Spontaneous EEG is typically quantified in frequency bands, power spectrum and spectral edge frequency. EPs are brain responses (assessed by EEG) to a predefined number of short phasic stimuli. EPs are quantified by their peak latencies and amplitudes, power spectrum, scalp topographies and brain source localization. For assessment of opioid effects at the spinal level, the following methods are evaluated: the nociceptive withdrawal reflex (NWR) and spinal EPs. The nociceptive withdrawal reflex can be recorded from all limbs, but it is standard to record the electromyography signal at the biceps femoris muscle after stimulation of the ipsilateral sural nerve; EPs can be recorded from the spinal cord and are typically recorded after stimulation of the median nerve at the wrist. CONCLUSION AND IMPLICATIONS The presented methods can all be used as objective methods for assessing the centrally mediated effects of opioids. Advantages and limitations should be considered before implementation in drug development, future experimental studies as well as in clinical settings. In conclusion, pupillometry is a sensitive measurement of opioid receptor activation in the CNS and from a practical and economical perspective it may be used as a biomarker for opioid effects in the CNS. However, if more detailed information is needed on opioid effects at different levels of the CNS, then EEG, fMRI, PET and NWR have the potential to be used. Finally, it is conceivable that information from different methods should be considered together for complementary information.
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Affiliation(s)
- Iben W Fischer
- Mech-Sense, Department of Gastroenterology &Hepatology, Aalborg University Hospital, Mølleparkvej 4, 9000, Aalborg, Denmark.,Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Tine M Hansen
- Mech-Sense, Department of Radiology, Aalborg University Hospital, Hobrovej 18-22, 9000, Aalborg, Denmark.,Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
| | - Dina Lelic
- Mech-Sense, Department of Gastroenterology &Hepatology, Aalborg University Hospital, Mølleparkvej 4, 9000, Aalborg, Denmark
| | - Anne Brokjaer
- Mech-Sense, Department of Gastroenterology &Hepatology, Aalborg University Hospital, Mølleparkvej 4, 9000, Aalborg, Denmark
| | - Jens Frøkjær
- Mech-Sense, Department of Radiology, Aalborg University Hospital, Hobrovej 18-22, 9000, Aalborg, Denmark.,Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
| | - Lona L Christrup
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Anne E Olesen
- Mech-Sense, Department of Gastroenterology &Hepatology, Aalborg University Hospital, Mølleparkvej 4, 9000, Aalborg, Denmark.,Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
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Leahy M, Thompson K, Zafar H, Alexandrov S, Foley M, O'Flatharta C, Dockery P. Functional imaging for regenerative medicine. Stem Cell Res Ther 2016; 7:57. [PMID: 27095443 PMCID: PMC4837501 DOI: 10.1186/s13287-016-0315-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
In vivo imaging is a platform technology with the power to put function in its natural structural context. With the drive to translate stem cell therapies into pre-clinical and clinical trials, early selection of the right imaging techniques is paramount to success. There are many instances in regenerative medicine where the biological, biochemical, and biomechanical mechanisms behind the proposed function of stem cell therapies can be elucidated by appropriate imaging. Imaging techniques can be divided according to whether labels are used and as to whether the imaging can be done in vivo. In vivo human imaging places additional restrictions on the imaging tools that can be used. Microscopies and nanoscopies, especially those requiring fluorescent markers, have made an extraordinary impact on discovery at the molecular and cellular level, but due to their very limited ability to focus in the scattering tissues encountered for in vivo applications they are largely confined to superficial imaging applications in research laboratories. Nanoscopy, which has tremendous benefits in resolution, is limited to the near-field (e.g. near-field scanning optical microscope (NSNOM)) or to very high light intensity (e.g. stimulated emission depletion (STED)) or to slow stochastic events (photo-activated localization microscopy (PALM) and stochastic optical reconstruction microscopy (STORM)). In all cases, nanoscopy is limited to very superficial applications. Imaging depth may be increased using multiphoton or coherence gating tricks. Scattering dominates the limitation on imaging depth in most tissues and this can be mitigated by the application of optical clearing techniques that can impose mild (e.g. topical application of glycerol) or severe (e.g. CLARITY) changes to the tissue to be imaged. Progression of therapies through to clinical trials requires some thought as to the imaging and sensing modalities that should be used. Smoother progression is facilitated by the use of comparable imaging modalities throughout the discovery and trial phases, giving label-free techniques an advantage wherever they can be used, although this is seldom considered in the early stages. In this paper, we will explore the techniques that have found success in aiding discovery in stem cell therapies and try to predict the likely technologies best suited to translation and future directions.
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Affiliation(s)
- Martin Leahy
- Tissue Optics & Microcirculation Imaging Group, School of Physics, National University of Ireland (NUI), Galway, Ireland. .,Chair of Applied Physics, National University of Ireland (NUI), Galway, Ireland.
| | - Kerry Thompson
- Centre for Microscopy and Imaging, Anatomy, School of Medicine, National University of Ireland (NUI), Galway, Ireland
| | - Haroon Zafar
- Tissue Optics & Microcirculation Imaging Group, School of Physics, National University of Ireland (NUI), Galway, Ireland
| | - Sergey Alexandrov
- Tissue Optics & Microcirculation Imaging Group, School of Physics, National University of Ireland (NUI), Galway, Ireland
| | - Mark Foley
- Medical Physics Research Cluster, School of Physics, National University of Ireland (NUI), Galway, Ireland
| | - Cathal O'Flatharta
- Regenerative Medicine Institute (REMEDI), National University of Ireland (NUI), Galway, Ireland
| | - Peter Dockery
- Centre for Microscopy and Imaging, Anatomy, School of Medicine, National University of Ireland (NUI), Galway, Ireland
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Mizuno Y, Uehara T, Hanaoka H, Endo Y, Jen CW, Arano Y. Purification-Free Method for Preparing Technetium-99m-Labeled Multivalent Probes for Enhanced in Vivo Imaging of Saturable Systems. J Med Chem 2016; 59:3331-9. [PMID: 26999587 DOI: 10.1021/acs.jmedchem.6b00024] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Metallic radionuclides provide target-specific radiolabeled probes for molecular imaging in radiochemical yields sufficient for administration to subjects without purification. However, unlabeled ligands in the injectate can compete for targeted molecules with radiolabeled probes, which eventually necessitates postlabeling purification. Herein we describe a "1 to 3" design to circumvent the issue by taking advantage of inherent coordination properties of technetium-99m ((99m)Tc). A monovalent RGD ligand possessing an isonitrile as a coordinating moiety (CN-RGD) was reacted with [(99m)Tc(CO)3(OH2)3](+) to prepare [(99m)Tc(CO)3(CN-RGD)3](+) in over 95% radiochemical yields. This complex exhibited higher integrin αvβ3 binding affinity than its unlabeled monovalent ligand, primarily due to its multivalency. This compound visualized a murine tumor without removing unlabeled ligands, while a (99m)Tc-labeled monovalent probe derived from a monovalent ligand could not. The metal coordination-mediated synthesis of radiolabeled multivalent probes thereby can be a useful approach for preparing ready-to-use target-specific probes labeled with (99m)Tc and other metallic radionuclides of interest.
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Affiliation(s)
- Yuki Mizuno
- Department of Molecular Imaging and Radiotherapy, Graduate School of Pharmaceutical Sciences, Chiba University , 1-8-1 Inohana, Chuo-ku, Chiba 260-8675 Japan
| | - Tomoya Uehara
- Department of Molecular Imaging and Radiotherapy, Graduate School of Pharmaceutical Sciences, Chiba University , 1-8-1 Inohana, Chuo-ku, Chiba 260-8675 Japan
| | - Hirofumi Hanaoka
- Department of Molecular Imaging and Radiotherapy, Graduate School of Pharmaceutical Sciences, Chiba University , 1-8-1 Inohana, Chuo-ku, Chiba 260-8675 Japan
| | - Yota Endo
- Department of Molecular Imaging and Radiotherapy, Graduate School of Pharmaceutical Sciences, Chiba University , 1-8-1 Inohana, Chuo-ku, Chiba 260-8675 Japan
| | - Chun-Wei Jen
- Department of Molecular Imaging and Radiotherapy, Graduate School of Pharmaceutical Sciences, Chiba University , 1-8-1 Inohana, Chuo-ku, Chiba 260-8675 Japan
| | - Yasushi Arano
- Department of Molecular Imaging and Radiotherapy, Graduate School of Pharmaceutical Sciences, Chiba University , 1-8-1 Inohana, Chuo-ku, Chiba 260-8675 Japan
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van Leeuwen FWB, Valdés-Olmos R, Buckle T, Vidal-Sicart S. Hybrid surgical guidance based on the integration of radionuclear and optical technologies. Br J Radiol 2016; 89:20150797. [PMID: 26943463 DOI: 10.1259/bjr.20150797] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
With the evolution of imaging technologies and tracers, the applications for nuclear molecular imaging are growing rapidly. For example, nuclear medicine is increasingly being used to guide surgical resections in complex anatomical locations. Here, a future workflow is envisioned that uses a combination of pre-operative diagnostics, navigation and intraoperative guidance. Radioguidance can provide means for pre-operative and intraoperative identification of "hot" lesions, forming the basis of a virtual data set that can be used for navigation. Luminescence guidance has shown great potential in the intraoperative setting by providing optical feedback, in some cases even in real time. Both of these techniques have distinct drawbacks, which include inaccuracy in areas that contain a background signal (radioactivity) or a limited degree of signal penetration (luminescence). We, and others, have reasoned that hybrid/multimodal approaches that integrate the use of these complementary modalities may help overcome their individual weaknesses. Ultimately, this will lead to advancement of the field of interventional molecular imaging/image-guided surgery. In this review, an overview of clinically applied hybrid surgical guidance technologies is given, whereby the focus is placed on tracers and hardware.
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Affiliation(s)
- Fijs W B van Leeuwen
- 1 Interventional Molecular Imaging Laboratory, Department of Radiology, Leiden University Medical Center, Leiden, Netherlands
| | - Renato Valdés-Olmos
- 1 Interventional Molecular Imaging Laboratory, Department of Radiology, Leiden University Medical Center, Leiden, Netherlands.,2 Department of Nuclear Medicine, Netherlands Cancer Institute-Antoni van Leeuwenhoek, Amsterdam, Netherlands
| | - Tessa Buckle
- 1 Interventional Molecular Imaging Laboratory, Department of Radiology, Leiden University Medical Center, Leiden, Netherlands
| | - Sergi Vidal-Sicart
- 3 Nuclear Medicine Department, Hospital Clínic of Barcelona, Barcelona, Spain
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Vanhove C, Bankstahl JP, Krämer SD, Visser E, Belcari N, Vandenberghe S. Accurate molecular imaging of small animals taking into account animal models, handling, anaesthesia, quality control and imaging system performance. EJNMMI Phys 2015; 2:31. [PMID: 26560138 PMCID: PMC4642455 DOI: 10.1186/s40658-015-0135-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 11/05/2015] [Indexed: 11/22/2022] Open
Abstract
Small-animal imaging has become an important technique for the development of new radiotracers, drugs and therapies. Many laboratories have now a combination of different small-animal imaging systems, which are being used by biologists, pharmacists, medical doctors and physicists. The aim of this paper is to give an overview of the important factors in the design of a small animal, nuclear medicine and imaging experiment. Different experts summarize one specific aspect important for a good design of a small-animal experiment.
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Affiliation(s)
- Christian Vanhove
- Department of Electronics and Information Systems, MEDISIP, Ghent University-iMinds Medical IT-IBiTech, De Pintelaan 185 block B, B-9000, Ghent, Belgium.
| | - Jens P Bankstahl
- Department of Nuclear Medicine, Preclinical Molecular Imaging, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
| | - Stefanie D Krämer
- Radiopharmaceutical Sciences/Biopharmacy, ETH Zurich, Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, Vladimir-Prelog-Weg 4, CH-8093, Zurich, Switzerland
| | - Eric Visser
- Department of Radiology and Nuclear Medicine, Radboudumc, 6525 GA Nijmegen, the Netherlands
| | - Nicola Belcari
- Department of Physics, University of Pisa and INFN sezione di Pisa, 56127 Pisa, Italy
| | - Stefaan Vandenberghe
- Department of Electronics and Information Systems, MEDISIP, Ghent University-iMinds Medical IT-IBiTech, De Pintelaan 185 block B, B-9000, Ghent, Belgium
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Si C, Mok GSP, Chen L, Tsui BMW. Design and evaluation of an adaptive multipinhole collimator for high-performance clinical and preclinical imaging. Nucl Med Commun 2015; 37:313-21. [PMID: 26528787 DOI: 10.1097/mnm.0000000000000429] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Pinhole single-photon emission computed tomography provides superior trade-off between resolution and detection efficiency as compared with conventional parallel-hole collimators for imaging small objects. This study aims to design and evaluate an optimized adaptive multipinhole (MPH) collimator for improved clinical myocardial perfusion single-photon emission computed tomography imaging (MPI) and preclinical small-animal imaging (SAI) of rats based on a clinical scanner. METHODS The target resolution and field of view was set to be 1/20 cm for MPI and 0.15/5 cm for SAI, respectively. We determined the design parameters by maximizing the detection efficiency based on system constraints. Point source simulations using Geant4 Application for Emission Tomography were performed for different collimator-to-center of field of view distances to assess the detection efficiency and resolution trade-off. The XCAT phantom with Tc-99m sestamibi distribution and the four-dimensional mouse whole-body phantom with Tc-99m methylene diphosphonate distribution were used to generate noise-free and noisy projections using a three-dimensional analytical MPH projector. Projections were reconstructed using a three-dimensional MPH ordered-subset expectation maximization algorithm. Noise and bias were assessed on the reconstructed images for different collimators. RESULTS The design parameters are (i) 14 pinholes with 3.42 mm aperture size, 14.5 cm collimator-to-detector distance for MPI; (ii) six pinholes with an aperture size of 0.94 mm, 21.2 cm collimator-to-detector distance for SAI. For MPI, the projected full width at half maximum values were 10.68 and 8.19 mm for low energy high resolution (LEHR) and MPH, respectively, whereas MPH had double detection efficiency. For SAI, the projected full width at half maximum values for LEHR and MPH were 4.93 and 1.20 mm, respectively, whereas the detection efficiency of MPH showed 17.5% improvement as compared with LEHR. The noise-bias trade-off improved for MPH as compared with LEHR for both MPI and SAI. The proposed collimator will have adjustable collimator-to-detector distances - that is, 14.5 cm for MPI and 21.2 cm for SAI. CONCLUSION The new collimator yields substantial improvement in image quality as compared with current MPI using LEHR with extra capability for SAI, bridging the clinical and preclinical imaging based on the same platform.
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Affiliation(s)
- Chinhong Si
- aBiomedical Imaging Laboratory, Department of Electrical and Computer Engineering, Faculty of Science and Technology, University of Macau, Macau SAR, China bThe Russell H. Morgan Department of Radiology and Radiological Science, Division of Medical Imaging Physics, Johns Hopkins University, Baltimore, Maryland, USA
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Kojima A, Gotoh K, Shimamoto M, Hasegawa K, Okada S. Iodine-131 imaging using 284 keV photons with a small animal CZT-SPECT system dedicated to low-medium-energy photon detection. Ann Nucl Med 2015; 30:169-75. [DOI: 10.1007/s12149-015-1028-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 09/11/2015] [Indexed: 01/28/2023]
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Brill DA, MacKay JA. Image-driven pharmacokinetics: nanomedicine concentration across space and time. Nanomedicine (Lond) 2015; 10:2861-79. [PMID: 26370694 DOI: 10.2217/nnm.15.127] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Clinical pharmacokinetics (PK) primarily measures the concentration of drugs in the blood. For nanomedicines it may be more relevant to determine concentration within a target tissue. The emerging field of image-driven PK, which utilizes clinically accepted molecular imaging technology, empirically and noninvasively, measures concentration in multiple tissues. Image-driven PK represents the intersection of PK and biodistribution, combining to provide models of concentration across space and time. Image-driven PK can be used both as a research tool and in the clinic. This review explores the history of pharmacokinetics, technologies used in molecular imaging (especially positron emission tomography) and research using image-driven pharmacokinetic analysis. When standardized, image-driven PK may have significant implications in preclinical development as well as clinical optimization of targeted nanomedicines.
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Affiliation(s)
- Dab A Brill
- Department of Pharmacology & Pharmaceutical Sciences, University of Southern California, Los Angeles, CA, USA
| | - J Andrew MacKay
- Department of Pharmacology & Pharmaceutical Sciences, University of Southern California, Los Angeles, CA, USA.,Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA
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5-HT2A receptor SPECT imaging with [¹²³I]R91150 under P-gp inhibition with tariquidar: More is better? Nucl Med Biol 2015; 43:81-88. [PMID: 26454782 DOI: 10.1016/j.nucmedbio.2015.09.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 08/18/2015] [Accepted: 09/05/2015] [Indexed: 12/11/2022]
Abstract
INTRODUCTION Pharmacological P-glycoprotein (P-gp) inhibition with tariquidar (TQD) is considered a promising strategy for the augmentation of radiotracer brain uptake. However, a region-dependent effect may compromise the robustness of quantitative studies. For this reason, we studied the effect of a TQD pretreatment on 5-HT2A imaging with [(123)I]R91150 and compared results with those obtained in Mdr1a knock-out (KO) rats. METHODS Ex vivo autoradiography was performed in TQD (15 mg/kg) pretreated wild-type (WT-TQD), Mdr1a knock-out (KO) and untreated WT rats for Specific Binding Ratio (SBR) estimation. In vivo dynamic SPECT imaging with serial arterial blood sampling was performed in the former two groups of rats and kinetic analysis was performed with a one tissue-compartment (1TC) model and the Specific Uptake Ratio (SUR). Results were analyzed statistically using repeated measures ANOVA. RESULTS SBR values differed between WT-TQD, Mdr1a KO and WT rats in a region-dependent manner (p<0.0001). In vivo brain uptake of radiotracer did not differ between groups. Similarly, kinetic analysis provided distribution volume (V(T)) values that did not differ significantly between groups. SUR binding potential (BPND) values from both groups highly correlated with corresponding V(T) (r=0.970, p<0.0001 and r=0.962, p<0.0001, respectively). However, SUR measured over averaged images between 100 and 120 min, using cerebellum as reference region, demonstrated values that were, by average, 2.99±0.53 times higher in the WT-TQD group, with the difference between groups being region-dependent (p<0.001). In addition, coefficient of variation of the SUR BPND values across brain regions was significantly higher in the WT-TQD rats (41.25%±9.63% versus 11.13%±5.59%, p<0.0001). CONCLUSION P-gp inhibition with TQD leads to region-dependent effect in the rat brain, with probably sub-optimal effect in cerebellum. This warrants attention when it is used as a reference region for quantitative studies.
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