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Vrachliotis A, Gaitanis A, Protonotarios NE, Kastis GA, Costaridou L. Noninvasive Quantification of Glucose Metabolism in Mice Myocardium Using the Spline Reconstruction Technique. J Imaging 2024; 10:170. [PMID: 39057741 PMCID: PMC11278115 DOI: 10.3390/jimaging10070170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2024] [Revised: 06/25/2024] [Accepted: 07/12/2024] [Indexed: 07/28/2024] Open
Abstract
The spline reconstruction technique (SRT) is a fast algorithm based on a novel numerical implementation of an analytic representation of the inverse Radon transform. The purpose of this study was to compare the SRT, filtered back-projection (FBP), and the Tera-Tomo 3D algorithm for various iteration numbers, using small-animal dynamic PET data obtained from a Mediso nanoScan® PET/CT scanner. For this purpose, Patlak graphical kinetic analysis was employed to noninvasively quantify the myocardial metabolic rate of glucose (MRGlu) in seven male C57BL/6 mice (n=7). All analytic reconstructions were performed via software for tomographic image reconstruction. The analysis of all PET-reconstructed images was conducted with PMOD software (version 3.506, PMOD Technologies LLC, Fällanden, Switzerland) using the inferior vena cava as the image-derived input function. Statistical significance was determined by employing the one-way analysis of variance test. The results revealed that the differences between the values of MRGlu obtained via SRT versus FBP, and the variants of he Tera-Tomo 3D algorithm were not statistically significant (p > 0.05). Overall, the SRT appears to perform similarly to the other algorithms investigated, providing a valid alternative analytic method for preclinical dynamic PET studies.
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Affiliation(s)
- Alexandros Vrachliotis
- Department of Medical Physics, School of Medicine, University of Patras, 26504 Patras, Greece; (A.V.); (L.C.)
- Clinical, Experimental Surgery & Translational Research, Biomedical Research Foundation (BRFAA), Academy of Athens, 4 Soranou Ephessiou, 11527 Athens, Greece;
| | - Anastasios Gaitanis
- Clinical, Experimental Surgery & Translational Research, Biomedical Research Foundation (BRFAA), Academy of Athens, 4 Soranou Ephessiou, 11527 Athens, Greece;
| | - Nicholas E. Protonotarios
- Mathematics Research Center, Academy of Athens, 11527 Athens, Greece;
- Institute of Nuclear & Radiological Sciences & Technology, Energy & Safety, National Center for Scientific Research “Demokritos”, 15341 Athens, Greece
| | - George A. Kastis
- Mathematics Research Center, Academy of Athens, 11527 Athens, Greece;
- Institute of Nuclear & Radiological Sciences & Technology, Energy & Safety, National Center for Scientific Research “Demokritos”, 15341 Athens, Greece
| | - Lena Costaridou
- Department of Medical Physics, School of Medicine, University of Patras, 26504 Patras, Greece; (A.V.); (L.C.)
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Lee H, Hwang KH. Focal incidental colorectal fluorodeoxyglucose uptake: Should it be spotlighted? World J Clin Cases 2024; 12:2466-2474. [PMID: 38817235 PMCID: PMC11135452 DOI: 10.12998/wjcc.v12.i15.2466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 03/17/2024] [Accepted: 04/12/2024] [Indexed: 05/14/2024] Open
Abstract
Fluorine-18 fluorodeoxyglucose (F-18 FDG) positron emission tomography/computed tomography (PET/CT) has emerged as a cornerstone in cancer evaluation imaging, with a well-established history spanning several years. This imaging modality, encompassing the examination of the body from the base of the skull to the upper thighs, comprehensively covers the chest and abdominopelvic regions in a singular scan, allowing for a holistic assessment of nearly the entire body, including areas of marginal interest. The inherent advantage of this expansive scan range lies in its potential to unveil unexpected incidental abnormal hypermetabolic areas. The identification of incidental focal FDG uptake within colorectal regions during PET/CT scans is not an uncommon occurrence, albeit fraught with challenges associated with non-specific FDG uptake. The presence of benign colorectal lesions or physiological uptake poses a particular obstacle, as these may manifest with FDG uptake levels that mimic malignancy. Consequently, physicians are confronted with a diagnostic dilemma when encountering abnormal FDG uptake in unexpected colorectal areas. Existing studies have presented divergent results concerning these uptakes. Standardized uptake value and its derivatives have served as pivotal metrics in quantifying FDG uptake in PET images. In this article, we aim to succinctly explore the distinctive characteristics of FDG, delve into imaging findings, and elucidate the clinical significance of incidental focal colorectal uptake. This discussion aims to contribute valuable insights into the nuanced interpretation of such findings, fostering a comprehensive understanding.
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Affiliation(s)
- Haejun Lee
- Department of Nuclear Medicine, Gachon University College of Medicine, Gil Medical Center, Incheon 21565, South Korea
| | - Kyung-Hoon Hwang
- Department of Nuclear Medicine, Gachon University College of Medicine, Gil Medical Center, Incheon 21565, South Korea
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3
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Lee H, Hwang KH. Unexpected focal fluorodeoxyglucose uptake in main organs; pass through or pass by? World J Clin Cases 2024; 12:1885-1899. [PMID: 38660550 PMCID: PMC11036514 DOI: 10.12998/wjcc.v12.i11.1885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Revised: 01/31/2024] [Accepted: 03/21/2024] [Indexed: 04/11/2024] Open
Abstract
Since the inception of fluorine-18 fluorodeoxyglucose (F-18 FDG), positron emission tomography/computed tomography (PET/CT) utilizing F-18 FDG has become widely accepted as a valuable imaging modality in the field of oncology, with global prevalence in clinical practice. Given that a single Torso PET/CT scan encompasses the anatomical region from the skull base to the upper thigh, the detection of incidental abnormal focal hypermetabolism in areas of limited clinical interest is both feasible and not uncommon. Numerous investigations have been undertaken to delineate the distinctive features of these findings, yet the outcomes have proven inconclusive. The incongruent results of these studies present a challenge for physicians, leaving them uncertain about the appropriate course of action. This article provides a succinct overview of the characteristics of fluorodeoxyglucose, followed by a comprehensive discussion of the imaging findings and clinical significance associated with incidental focal abnormal F-18 FDG activity in several representative organs. In conclusion, while the prevalence of unrecognized malignancy varies across organs, malignancies account for a substantial proportion, ranging from approximately one-third to over half, of incidental focal uptake. In light of these rates, physicians are urged to exercise vigilance in not disregarding unexpected uptake, facilitating more assured clinical decisions, and advocating for further active evaluation.
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Affiliation(s)
- Haejun Lee
- Department of Nuclear Medicine, Gachon University College of Medicine, Gil Medical Center, Incheon 21565, South Korea
| | - Kyung-Hoon Hwang
- Department of Nuclear Medicine, Gachon University College of Medicine, Gil Medical Center, Incheon 21565, South Korea
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4
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Jiang X, Hu Z, Wang S, Zhang Y. Deep Learning for Medical Image-Based Cancer Diagnosis. Cancers (Basel) 2023; 15:3608. [PMID: 37509272 PMCID: PMC10377683 DOI: 10.3390/cancers15143608] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 07/10/2023] [Accepted: 07/10/2023] [Indexed: 07/30/2023] Open
Abstract
(1) Background: The application of deep learning technology to realize cancer diagnosis based on medical images is one of the research hotspots in the field of artificial intelligence and computer vision. Due to the rapid development of deep learning methods, cancer diagnosis requires very high accuracy and timeliness as well as the inherent particularity and complexity of medical imaging. A comprehensive review of relevant studies is necessary to help readers better understand the current research status and ideas. (2) Methods: Five radiological images, including X-ray, ultrasound (US), computed tomography (CT), magnetic resonance imaging (MRI), positron emission computed tomography (PET), and histopathological images, are reviewed in this paper. The basic architecture of deep learning and classical pretrained models are comprehensively reviewed. In particular, advanced neural networks emerging in recent years, including transfer learning, ensemble learning (EL), graph neural network, and vision transformer (ViT), are introduced. Five overfitting prevention methods are summarized: batch normalization, dropout, weight initialization, and data augmentation. The application of deep learning technology in medical image-based cancer analysis is sorted out. (3) Results: Deep learning has achieved great success in medical image-based cancer diagnosis, showing good results in image classification, image reconstruction, image detection, image segmentation, image registration, and image synthesis. However, the lack of high-quality labeled datasets limits the role of deep learning and faces challenges in rare cancer diagnosis, multi-modal image fusion, model explainability, and generalization. (4) Conclusions: There is a need for more public standard databases for cancer. The pre-training model based on deep neural networks has the potential to be improved, and special attention should be paid to the research of multimodal data fusion and supervised paradigm. Technologies such as ViT, ensemble learning, and few-shot learning will bring surprises to cancer diagnosis based on medical images.
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Grants
- RM32G0178B8 BBSRC
- MC_PC_17171 MRC, UK
- RP202G0230 Royal Society, UK
- AA/18/3/34220 BHF, UK
- RM60G0680 Hope Foundation for Cancer Research, UK
- P202PF11 GCRF, UK
- RP202G0289 Sino-UK Industrial Fund, UK
- P202ED10, P202RE969 LIAS, UK
- P202RE237 Data Science Enhancement Fund, UK
- 24NN201 Fight for Sight, UK
- OP202006 Sino-UK Education Fund, UK
- RM32G0178B8 BBSRC, UK
- 2023SJZD125 Major project of philosophy and social science research in colleges and universities in Jiangsu Province, China
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Affiliation(s)
- Xiaoyan Jiang
- School of Mathematics and Information Science, Nanjing Normal University of Special Education, Nanjing 210038, China; (X.J.); (Z.H.)
| | - Zuojin Hu
- School of Mathematics and Information Science, Nanjing Normal University of Special Education, Nanjing 210038, China; (X.J.); (Z.H.)
| | - Shuihua Wang
- School of Computing and Mathematical Sciences, University of Leicester, Leicester LE1 7RH, UK;
| | - Yudong Zhang
- School of Computing and Mathematical Sciences, University of Leicester, Leicester LE1 7RH, UK;
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Kanasuwan A, Deuther-Conrad W, Chongruchiroj S, Sarasamkan J, Chotipanich C, Vajragupta O, Arunrungvichian K. Selective α 3β 4 Nicotinic Acetylcholine Receptor Ligand as a Potential Tracer for Drug Addiction. Int J Mol Sci 2023; 24:ijms24043614. [PMID: 36835028 PMCID: PMC9959096 DOI: 10.3390/ijms24043614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 02/03/2023] [Accepted: 02/08/2023] [Indexed: 02/16/2023] Open
Abstract
α3β4 Nicotinic acetylcholine receptor (nAChR) has been recognized as an emerging biomarker for the early detection of drug addiction. Herein, α3β4 nAChR ligands were designed and synthesized to improve the binding affinity and selectivity of two lead compounds, (S)-QND8 and (S)-T2, for the development of an α3β4 nAChR tracer. The structural modification was achieved by retaining the key features and expanding the molecular structure with a benzyloxy group to increase the lipophilicity for blood-brain barrier penetration and to extend the ligand-receptor interaction. The preserved key features are a fluorine atom for radiotracer development and a p-hydroxyl motif for ligand-receptor binding affinity. Four (R)- and (S)-quinuclidine-triazole (AK1-AK4) were synthesized and the binding affinity, together with selectivity to α3β4 nAChR subtype, were determined by competitive radioligand binding assay using [3H]epibatidine as a radioligand. Among all modified compounds, AK3 showed the highest binding affinity and selectivity to α3β4 nAChR with a Ki value of 3.18 nM, comparable to (S)-QND8 and (S)-T2 and 3069-fold higher affinity to α3β4 nAChR in comparison to α7 nAChR. The α3β4 nAChR selectivity of AK3 was considerably higher than those of (S)-QND8 (11.8-fold) and (S)-T2 (294-fold). AK3 was shown to be a promising α3β4 nAChR tracer for further development as a radiotracer for drug addiction.
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Affiliation(s)
- Apinan Kanasuwan
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Mahidol University, 447 Sri-Ayutthaya Rd., Bangkok 10400, Thailand
- National Cyclotron and PET Centre, Chulabhorn Hospital, Chulabhorn Royal Academy, 906 Kamphaengphet 6 Rd., Bangkok 10210, Thailand
| | - Winnie Deuther-Conrad
- Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Permoserstraße 15, 04318 Leipzig, Germany
| | - Sumet Chongruchiroj
- Department of Microbiology, Faculty of Pharmacy, Mahidol University, 447 Sri-Ayutthaya Rd., Bangkok 10400, Thailand
| | - Jiradanai Sarasamkan
- Department of Radiology, Faculty of Medicine, Khon Kaen University, 123 Mittraphap Rd., Khon Kaen 40002, Thailand
| | - Chanisa Chotipanich
- National Cyclotron and PET Centre, Chulabhorn Hospital, Chulabhorn Royal Academy, 906 Kamphaengphet 6 Rd., Bangkok 10210, Thailand
| | - Opa Vajragupta
- Molecular Probes for Imaging Research Network, Faculty of Pharmaceutical Sciences, Chulalongkorn University, 254 Phayathai Rd., Bangkok 10330, Thailand
| | - Kuntarat Arunrungvichian
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Mahidol University, 447 Sri-Ayutthaya Rd., Bangkok 10400, Thailand
- Correspondence:
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Applegate CC, Deng H, Kleszynski BL, Cross TWL, Konopka CJ, Dobrucki LW, Nelson ER, Wallig MA, Smith AM, Swanson KS. Impact of administration route on nanocarrier biodistribution in a murine colitis model. JOURNAL OF EXPERIMENTAL NANOSCIENCE 2022; 17:599-616. [PMID: 36968097 PMCID: PMC10038121 DOI: 10.1080/17458080.2022.2134563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 09/08/2022] [Accepted: 09/08/2022] [Indexed: 06/18/2023]
Abstract
The incidence of inflammatory bowel disease (IBD) is increasing worldwide. Although current diagnostic and disease monitoring tests for IBD sensitively detect gut inflammation, they lack the molecular and cellular specificity of positron emission tomography (PET). In this proof-of-concept study, we use a radiolabeled macrophage-targeted nanocarrier probe (64Cu-NOTA-D500) administered by oral, enema, and intraperitoneal routes to evaluate the delivery route dependence of biodistribution across healthy and diseased tissues in a murine model of dextran sodium sulfate (DSS)-induced colitis. High inter-subject variability of probe uptake in intestinal tissue was reduced by normalization to uptake in liver or total intestines. Differences in normalized uptake between healthy and DSS colitis animal intestines were highest for oral and IP routes. Differences in absolute liver uptake reflected a possible secondary diagnostic metric of IBD pathology. These results should inform the preclinical development of inflammation-targeted contrast agents for IBD and related gut disorders to improve diagnostic accuracy.
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Affiliation(s)
- Catherine C. Applegate
- Division of Nutritional Sciences, University of Illinois at Urbana – Champaign, Urbana, Illinois, USA
- Department of Animal Sciences, University of Illinois at Urbana – Champaign, Urbana, Illinois, USA
| | - Hongping Deng
- Department of Bioengineering, University of Illinois at Urbana – Champaign, Urbana, Illinois, USA
| | - Brittany L. Kleszynski
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana – Champaign, Urbana, Illinois, USA
| | - Tzu-Wen L. Cross
- Department of Nutrition Science, Purdue University, West Lafayette, Indiana, USA
| | | | - L. Wawrzyniec Dobrucki
- Beckman Institute for Advanced Science and Technology, Urbana, Illinois, USA
- Cancer Center at Illinois, University of Illinois at Urbana – Champaign, Urbana, Illinois, USA
| | - Erik R. Nelson
- Division of Nutritional Sciences, University of Illinois at Urbana – Champaign, Urbana, Illinois, USA
- Beckman Institute for Advanced Science and Technology, Urbana, Illinois, USA
- Cancer Center at Illinois, University of Illinois at Urbana – Champaign, Urbana, Illinois, USA
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana – Champaign, Urbana, Illinois, USA
- University of Illinois Cancer Center, University of Illinois at Chicago, Chicago, Illinois, USA
- Carl R. Woese Institute for Genomic Biology, Anticancer Discovery from Pets to People Theme, University of Illinois at Urbana – Champaign, Urbana, Illinois, USA
| | - Matthew A. Wallig
- Division of Nutritional Sciences, University of Illinois at Urbana – Champaign, Urbana, Illinois, USA
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana – Champaign, Urbana, Illinois, USA
| | - Andrew M. Smith
- Department of Bioengineering, University of Illinois at Urbana – Champaign, Urbana, Illinois, USA
- Cancer Center at Illinois, University of Illinois at Urbana – Champaign, Urbana, Illinois, USA
- Carle Illinois College of Medicine, Urbana, Illinois, USA
- Micro and Nanotechnology Laboratory, University of Illinois at Urbana – Champaign, Urbana, Illinois, USA
- Department of Materials Science and Engineering, University of Illinois at Urbana – Champaign, Urbana, Illinois, USA
| | - Kelly S. Swanson
- Division of Nutritional Sciences, University of Illinois at Urbana – Champaign, Urbana, Illinois, USA
- Department of Animal Sciences, University of Illinois at Urbana – Champaign, Urbana, Illinois, USA
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Microliter-scale reaction arrays for economical high-throughput experimentation in radiochemistry. Sci Rep 2022; 12:10263. [PMID: 35715457 PMCID: PMC9205965 DOI: 10.1038/s41598-022-14022-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 05/31/2022] [Indexed: 01/14/2023] Open
Abstract
The increasing number of positron-emission tomography (PET) tracers being developed to aid drug development and create new diagnostics has led to an increased need for radiosynthesis development and optimization. Current radiosynthesis instruments are designed to produce large-scale clinical batches and are often limited to performing a single synthesis before they must be decontaminated by waiting for radionuclide decay, followed by thorough cleaning or disposal of synthesizer components. Though with some radiosynthesizers it is possible to perform a few sequential radiosyntheses in a day, none allow for parallel radiosyntheses. Throughput of one or a few experiments per day is not well suited for rapid optimization experiments. To combat these limitations, we leverage the advantages of droplet-radiochemistry to create a new platform for high-throughput experimentation in radiochemistry. This system contains an array of 4 heaters, each used to heat a set of 16 reactions on a small chip, enabling 64 parallel reactions for the rapid optimization of conditions in any stage of a multi-step radiosynthesis process. As examples, we study the syntheses of several 18F-labeled radiopharmaceuticals ([18F]Flumazenil, [18F]PBR06, [18F]Fallypride, and [18F]FEPPA), performing > 800 experiments to explore the influence of parameters including base type, base amount, precursor amount, solvent, reaction temperature, and reaction time. The experiments were carried out within only 15 experiment days, and the small volume (~ 10 μL compared to the ~ 1 mL scale of conventional instruments) consumed ~ 100 × less precursor per datapoint. This new method paves the way for more comprehensive optimization studies in radiochemistry and substantially shortening PET tracer development timelines.
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8
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PET Imaging of the Neuropeptide Y System: A Systematic Review. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27123726. [PMID: 35744852 PMCID: PMC9227365 DOI: 10.3390/molecules27123726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 06/03/2022] [Accepted: 06/05/2022] [Indexed: 11/16/2022]
Abstract
Neuropeptide Y (NPY) is a vastly studied biological peptide with numerous physiological functions that activate the NPY receptor family (Y1, Y2, Y4 and Y5). Moreover, these receptors are correlated with the pathophysiology of several diseases such as feeding disorders, anxiety, metabolic diseases, neurodegenerative diseases, some types of cancers and others. In order to deepen the knowledge of NPY receptors' functions and molecular mechanisms, neuroimaging techniques such as positron emission tomography (PET) have been used. The development of new radiotracers for the different NPY receptors and their subsequent PET studies have led to significant insights into molecular mechanisms involving NPY receptors. This article provides a systematic review of the imaging biomarkers that have been developed as PET tracers in order to study the NPY receptor family.
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Vrachliotis A, Kastis GA, Protonotarios NE, Fokas AS, Nekolla SG, Anagnostopoulos CD, Costaridou L, Gaitanis A. Evaluation of the spline reconstruction technique for preclinical PET imaging. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2022; 217:106668. [PMID: 35176596 DOI: 10.1016/j.cmpb.2022.106668] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 12/27/2021] [Accepted: 01/26/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND AND OBJECTIVE The Spline Reconstruction Technique (SRT) is a fast algorithm based on a novel numerical implementation of an analytic representation of the inverse Radon transform. The purpose of this study is to provide a comparison between SRT, Filtered Back-Projection (FBP), Ordered Subset Expectation Maximization 2D (2D-OSEM), and the Tera-Tomo 3D algorithm, using phantom data at various acquisition durations as well as small-animal data obtained from the Mediso nanoScan® PET/CT scanner. METHODS For this purpose, the "NEMA NU 4-2008 standards" protocol was employed at five different realizations and acquisition durations. In addition to the image quality metrics described by the NEMA protocol, Cold Region Contrast was also considered as a figure-of-merit. Furthermore, Cold Region Contrast was measured in the myocardial infarction region of six male Wistar rats. The volumetric defect quantification was assessed with dedicated computer software. Lastly, plots of Recovery Coefficient and Spill-Over Ratio as a function of the Percentage Standard Deviation were generated, after smoothing the phantom reconstructions with four different Gaussian filters. Statistical significance was determined by employing the Kruskal-Wallis test or One-way Analysis of Variance depending on the normality of the variable's distribution. RESULTS The present study revealed that, at the expense of slightly increased noise in the reconstructed images, SRT resulted in higher Recovery Coefficient values for small hot regions of interest, when compared with FBP and 2D-OSEM at all acquisition durations. Furthermore, SRT reconstructed images exhibit higher Recovery Coefficient values, for all hot regions of interest, when compared to the other 2D algorithms at short acquisition durations. In both phantom and animal studies, SRT achieved a significant improvement over 2D-OSEM for the Spill-Over Ratio and the Cold Region Contrast. These advantages were maintained even after comparing the algorithms at equal noise levels. The Tera-Tomo 3D algorithm (4 subsets, iterations≥ 13) performed significantly better compared to the other algorithms for all figures-of-merit. No statistically significant differences regarding the myocardial defect size were observed between the algorithms investigated. CONCLUSIONS Overall, SRT appears that could be useful for the quantification of small hot regions of interest, cold regions of interest, as well as in low-count imaging applications.
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Affiliation(s)
- Alexandros Vrachliotis
- Department of Medical Physics, School of Medicine, University of Patras, Patras 26504, Greece; Clinical, Experimental Surgery and Translational Research, Biomedical Research Foundation, Academy of Athens (BRFAA), Athens 11527, Greece
| | - George A Kastis
- Mathematics Research Center, Academy of Athens, Athens 11527, Greece; Institute of Nuclear & Radiological Sciences & Technology, Energy & Safety, National Center for Scientific Research "Demokritos", 15341 Athens, Greece
| | - Nicholas E Protonotarios
- Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge CB30WA, United Kingdom
| | - Athanasios S Fokas
- Mathematics Research Center, Academy of Athens, Athens 11527, Greece; Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge CB30WA, United Kingdom
| | - Stephan G Nekolla
- Klinikum rechts der Isar, Department of Nuclear Medicine and DZHK (German Centre for Cardiovascular Research), Technical University Munich, Partner Site Munich Heart Alliance, Munich 80336, Germany
| | - Constantinos D Anagnostopoulos
- Clinical, Experimental Surgery and Translational Research, Biomedical Research Foundation, Academy of Athens (BRFAA), Athens 11527, Greece
| | - Lena Costaridou
- Department of Medical Physics, School of Medicine, University of Patras, Patras 26504, Greece
| | - Anastasios Gaitanis
- Clinical, Experimental Surgery and Translational Research, Biomedical Research Foundation, Academy of Athens (BRFAA), Athens 11527, Greece.
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10
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Experimental Nuclear Medicine Meets Tumor Biology. Pharmaceuticals (Basel) 2022; 15:ph15020227. [PMID: 35215337 PMCID: PMC8878163 DOI: 10.3390/ph15020227] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 02/01/2022] [Accepted: 02/04/2022] [Indexed: 02/01/2023] Open
Abstract
Personalized treatment of cancer patients demands specific and validated biomarkers for tumor diagnosis and therapy. The development and validation of such require translational preclinical models that recapitulate human diseases as accurately as possible. Moreover, there is a need for convergence of different (pre)clinical disciplines that openly share their knowledge and methodologies. This review sheds light on the differential perception of biomarkers and gives an overview of currently used models in tracer development and approaches for biomarker discovery.
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11
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Bonnet S, Elfatairi R, Franconi F, Roger E, Legeay S. Organic nanoparticle tracking during pharmacokinetic studies. Nanomedicine (Lond) 2021; 16:2539-2536. [PMID: 34814704 DOI: 10.2217/nnm-2021-0155] [Citation(s) in RCA: 3] [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
To understand how nanoparticles (NPs) interact with biological barriers and to ensure they maintain their integrity over time, it is crucial to study their in vivo pharmacokinetic (PK) profiles. Many methods of tracking have been used to describe the in vivo fate of NPs and to evaluate their PKs and structural integrity. However, they do not deliver the same level of information and this may cause misinterpretations. Here, the authors review and discuss the different methods for in vivo tracking of organic NPs. Among them, Förster resonance energy transfer (FRET) presents great potential to track NPs' integrity. However, FRET still requires validated methods to extract and quantify NPs in biological fluids and tissues.
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Affiliation(s)
- Samuel Bonnet
- Université d'Angers, PRISM, SFR ICAT, Plate-forme de recherche en imagerie et spectroscopie multi-modales, Angers F-49000, France
| | - Rana Elfatairi
- Université d'Angers, Inserm, CNRS, MINT, SFR ICAT, Angers F-49000, France
| | - Florence Franconi
- Université d'Angers, PRISM, SFR ICAT, Plate-forme de recherche en imagerie et spectroscopie multi-modales, Angers F-49000, France.,Université d'Angers, Inserm, CNRS, MINT, SFR ICAT, Angers F-49000, France
| | - Emilie Roger
- Université d'Angers, Inserm, CNRS, MINT, SFR ICAT, Angers F-49000, France
| | - Samuel Legeay
- Université d'Angers, Inserm, CNRS, MINT, SFR ICAT, Angers F-49000, France
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12
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Abstract
Positron emission tomography (PET) is a non-invasive imaging technology employed to describe metabolic, physiological, and biochemical processes in vivo. These include receptor availability, metabolic changes, neurotransmitter release, and alterations of gene expression in the brain. Since the introduction of dedicated small-animal PET systems along with the development of many novel PET imaging probes, the number of PET studies using rats and mice in basic biomedical research tremendously increased over the last decade. This article reviews challenges and advances of quantitative rodent brain imaging to make the readers aware of its physical limitations, as well as to inspire them for its potential applications in preclinical research. In the first section, we briefly discuss the limitations of small-animal PET systems in terms of spatial resolution and sensitivity and point to possible improvements in detector development. In addition, different acquisition and post-processing methods used in rodent PET studies are summarized. We further discuss factors influencing the test-retest variability in small-animal PET studies, e.g., different receptor quantification methodologies which have been mainly translated from human to rodent receptor studies to determine the binding potential and changes of receptor availability and radioligand affinity. We further review different kinetic modeling approaches to obtain quantitative binding data in rodents and PET studies focusing on the quantification of endogenous neurotransmitter release using pharmacological interventions. While several studies have focused on the dopamine system due to the availability of several PET tracers which are sensitive to dopamine release, other neurotransmitter systems have become more and more into focus and are described in this review, as well. We further provide an overview of latest genome engineering technologies, including the CRISPR/Cas9 and DREADD systems that may advance our understanding of brain disorders and function and how imaging has been successfully applied to animal models of human brain disorders. Finally, we review the strengths and opportunities of simultaneous PET/magnetic resonance imaging systems to study drug-receptor interactions and challenges for the translation of PET results from bench to bedside.
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Almeida S, Santos L, Falcão A, Gomes C, Abrunhosa A. In Vivo Tracking of Extracellular Vesicles by Nuclear Imaging: Advances in Radiolabeling Strategies. Int J Mol Sci 2020; 21:ijms21249443. [PMID: 33322484 PMCID: PMC7764519 DOI: 10.3390/ijms21249443] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 12/08/2020] [Accepted: 12/09/2020] [Indexed: 02/07/2023] Open
Abstract
Extracellular vesicles (EVs) are naturally secreted vesicles that have attracted a large amount of interest in nanomedicine in recent years due to their innate biocompatibility, high stability, low immunogenicity, and important role in cell-to-cell communication during pathological processes. Their versatile nature holds great potential to improve the treatment of several diseases through their use as imaging biomarkers, therapeutic agents, and drug-delivery vehicles. However, the clinical translation of EV-based approaches requires a better understanding of their in vivo behavior. Several imaging technologies have been used for the non-invasive in vivo tracking of EVs, with a particular emphasis on nuclear imaging due to its high sensitivity, unlimited penetration depth and accurate quantification. In this article, we will review the biological function and inherent characteristics of EVs and provide an overview of molecular imaging modalities used for their in vivo monitoring, with a special focus on nuclear imaging. The advantages of radionuclide-based imaging modalities make them a promising tool to validate the use of EVs in the clinical setting, as they have the potential to characterize in vivo the pharmacokinetics and biological behavior of the vesicles. Furthermore, we will discuss the current methods available for radiolabeling EVs, such as covalent binding, encapsulation or intraluminal labeling and membrane radiolabeling, reporting the advantages and drawbacks of each radiolabeling approach.
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Affiliation(s)
- Sara Almeida
- CIBIT/ICNAS—Institute for Nuclear Sciences Applied to Health, University of Coimbra, 3000-548 Coimbra, Portugal; (S.A.); (L.S.); (A.F.)
| | - Liliana Santos
- CIBIT/ICNAS—Institute for Nuclear Sciences Applied to Health, University of Coimbra, 3000-548 Coimbra, Portugal; (S.A.); (L.S.); (A.F.)
| | - Amílcar Falcão
- CIBIT/ICNAS—Institute for Nuclear Sciences Applied to Health, University of Coimbra, 3000-548 Coimbra, Portugal; (S.A.); (L.S.); (A.F.)
| | - Célia Gomes
- iCBR—Coimbra Institute for Clinical and Biomedical Research, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
- CIBB—Center for Innovative Biomedicine and Biotechnology, University of Coimbra, 3000-548 Coimbra, Portugal
- CACC—Clinical Academic Center of Coimbra, 3000-075 Coimbra, Portugal
- Correspondence: (C.G.); (A.A.)
| | - Antero Abrunhosa
- CIBIT/ICNAS—Institute for Nuclear Sciences Applied to Health, University of Coimbra, 3000-548 Coimbra, Portugal; (S.A.); (L.S.); (A.F.)
- Correspondence: (C.G.); (A.A.)
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14
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Tai YC. Small-Animal PET: A Technology That Changed Our Field. J Nucl Med 2020; 61:153S-154S. [PMID: 33293436 DOI: 10.2967/jnumed.120.251280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 07/25/2020] [Indexed: 11/16/2022] Open
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15
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Pharmaco-fUS: Quantification of pharmacologically-induced dynamic changes in brain perfusion and connectivity by functional ultrasound imaging in awake mice. Neuroimage 2020; 222:117231. [DOI: 10.1016/j.neuroimage.2020.117231] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 07/24/2020] [Accepted: 07/31/2020] [Indexed: 11/20/2022] Open
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16
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LaBella A, Zhao W, Lubinsky R, Goldan AH. Prismatoid light guide array for enhanced gamma ray localization in PET: a Monte Carlo simulation study of scintillation photon transport. Phys Med Biol 2020; 65:18LT01. [PMID: 32413872 PMCID: PMC11025681 DOI: 10.1088/1361-6560/ab9373] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
High spatial resolution PET relies on having excellent depth-of-interaction (DOI) resolution and small detector elements. Depth-encoding in PET modules has traditionally been performed using dual-ended readout. In recent years, researchers have explored the feasibility of replacing the second readout array with a light guide at the entrance layer that introduces intercrystal light sharing in order to reduce cost and and make depth-encoding modules more compact. However, single-ended readout depth-encoding modules have suboptimal and non-uniform crystal separation and DOI performance due to the random light sharing patterns of the uniform light guide, resulting in degraded peformance along the edges and corners of the detector arrays. In this paper, we introduce and characterize a segmented light guide composed of an array of prism mirrors which introduce deterministic intercrystal light sharing in single-ended readout PET detectors. We determined the expected spatial performance of our modules with our light guide using optical ray tracing Monte Carlo simulations. We demonstrate that having controlled, deterministic light sharing improves both DOI and crystal identification performance, enabling uniform spatial performance throughout the detector array. Designed specifically for high resolution PET, our prismatoid light guide array can be used to build cost-effective total-body and organ-dedicated PET systems with single-ended readout depth-encoding modules.
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Affiliation(s)
- Andy LaBella
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, United States of America
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17
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Davis KD, Aghaeepour N, Ahn AH, Angst MS, Borsook D, Brenton A, Burczynski ME, Crean C, Edwards R, Gaudilliere B, Hergenroeder GW, Iadarola MJ, Iyengar S, Jiang Y, Kong JT, Mackey S, Saab CY, Sang CN, Scholz J, Segerdahl M, Tracey I, Veasley C, Wang J, Wager TD, Wasan AD, Pelleymounter MA. Discovery and validation of biomarkers to aid the development of safe and effective pain therapeutics: challenges and opportunities. Nat Rev Neurol 2020; 16:381-400. [PMID: 32541893 PMCID: PMC7326705 DOI: 10.1038/s41582-020-0362-2] [Citation(s) in RCA: 190] [Impact Index Per Article: 47.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/21/2020] [Indexed: 02/06/2023]
Abstract
Pain medication plays an important role in the treatment of acute and chronic pain conditions, but some drugs, opioids in particular, have been overprescribed or prescribed without adequate safeguards, leading to an alarming rise in medication-related overdose deaths. The NIH Helping to End Addiction Long-term (HEAL) Initiative is a trans-agency effort to provide scientific solutions to stem the opioid crisis. One component of the initiative is to support biomarker discovery and rigorous validation in collaboration with industry leaders to accelerate high-quality clinical research into neurotherapeutics and pain. The use of objective biomarkers and clinical trial end points throughout the drug discovery and development process is crucial to help define pathophysiological subsets of pain, evaluate target engagement of new drugs and predict the analgesic efficacy of new drugs. In 2018, the NIH-led Discovery and Validation of Biomarkers to Develop Non-Addictive Therapeutics for Pain workshop convened scientific leaders from academia, industry, government and patient advocacy groups to discuss progress, challenges, gaps and ideas to facilitate the development of biomarkers and end points for pain. The outcomes of this workshop are outlined in this Consensus Statement.
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Affiliation(s)
- Karen D Davis
- Department of Surgery and Institute of Medical Science, University of Toronto, Toronto, ON, Canada.
- Division of Brain, Imaging and Behaviour, Krembil Brain Institute, Toronto Western Hospital, University Health Network, Toronto, ON, Canada.
| | - Nima Aghaeepour
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | | | - Martin S Angst
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - David Borsook
- Center for Pain and the Brain, Harvard Medical School, Boston, MA, USA
| | | | | | | | - Robert Edwards
- Pain Management Center, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Brice Gaudilliere
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Georgene W Hergenroeder
- The Vivian L. Smith Department of Neurosurgery, The University of Texas Health Science Center at Houston, McGovern Medical School, Houston, TX, USA
| | - Michael J Iadarola
- Department of Perioperative Medicine, Clinical Center, NIH, Rockville, MD, USA
| | - Smriti Iyengar
- Division of Translational Research, National Institute of Neurological Disorders and Stroke, NIH, Rockville, MD, USA
| | - Yunyun Jiang
- The Biostatistics Center, Milken Institute School of Public Health, The George Washington University, Washington, DC, USA
| | - Jiang-Ti Kong
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Sean Mackey
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Carl Y Saab
- Department of Neuroscience and Department of Neurosurgery, Carney Institute for Brain Science, Brown University, Providence, RI, USA
| | - Christine N Sang
- Department of Anesthesiology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Joachim Scholz
- Neurocognitive Disorders, Pain and New Indications, Biogen, Cambridge, MA, USA
| | | | - Irene Tracey
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | | | - Jing Wang
- Department of Anesthesiology, Perioperative Care and Pain Medicine, NYU School of Medicine, New York, NY, USA
| | - Tor D Wager
- Department of Psychological and Brain Sciences, Dartmouth College, Hanover, NH, USA
| | - Ajay D Wasan
- Anesthesiology and Perioperative Medicine and Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Mary Ann Pelleymounter
- Division of Translational Research, National Institute of Neurological Disorders and Stroke, NIH, Rockville, MD, USA
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18
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The Radiolabeling of a Gly-Sar Dipeptide Derivative with Flourine-18 and Its Use as a Potential Peptide Transporter PET Imaging Agent. Molecules 2020; 25:molecules25030643. [PMID: 32024310 PMCID: PMC7037988 DOI: 10.3390/molecules25030643] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 01/27/2020] [Accepted: 01/30/2020] [Indexed: 11/23/2022] Open
Abstract
We have developed a novel fluorine-18 radiotracer, dipeptide 1, radiolabeled in two steps from mesylate 3. The initial radiolabeling is achieved in a short reaction time (10 min) and purified through solid-phase extraction (SPE) with modest radiochemical yields (rcy = 10 ± 2%, n = 5) in excellent radiochemical purity (rcp > 99%, n = 5). The de-protection of the tert-butyloxycarbonyl (Boc) and trityl group was achieved with mild heating under acidic conditions to provide 18F-tagged dipeptide 1. Preliminary analysis of 18F-dipeptide 1 was performed to confirm uptake by peptide transporters (PepTs) in human pancreatic carcinoma cell lines Panc1, BxPC3, and ASpc1, which are reported to express the peptide transporter 1 (PepT1). Furthermore, we confirmed in vivo uptake of 18F-dipeptide tracer 1 using microPET/CT in mice harboring subcutaneous flank Panc1, BxPC3, and Aspc1 tumors. In conclusion, we have established the radiolabeling of dipeptide 1 with fluoride-18, and demonstrated its potential as an imaging agent which may have clinical applications for the diagnosis of pancreatic carcinomas.
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19
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Osovizky A, Laster B, Wilson AA, Bloomfield P, Sarusi B, Vasdev N, Bell T, Garcia A, Houle S. New detection configuration for low activity levels of PET tracers during the analysis of plasma samples. Appl Radiat Isot 2019; 151:317-330. [PMID: 31376719 DOI: 10.1016/j.apradiso.2019.05.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 03/21/2019] [Accepted: 05/16/2019] [Indexed: 11/28/2022]
Abstract
A new radio-HPLC detection system for measuring radioactivity in plasma samples during Positron Emission Tomography [PET] studies was developed. It is based on detecting both the positron and one of the annihilation photons. The system focused on improving the measurement of radioactivity concentrations on an unmetabolized positron emitting a radiopharmaceutical [PER] in the presence of its radioactive metabolites, all containing the same positron emitter. This paper presents a new detection configuration that improves the minimal detectible activity (MDA), simplify the measuring systems and reduces the error caused by the metabolites. The detector is based on a plastic scintillator and a BGO scintillation crystal, that produces different light output spectra for signal and noise events. By summing the positron and the annihilated photon light outputs, different spectra are obtained for the metabolite and for the parent compound tracer and for tracer marked by different positron emitting isotopes. This new detection system can improve quantitative analysis of plasma samples. The spectrum change provides up to a three-fold improvement in sensitivity compared to the currently used detection systems that measure only the annihilation coincidence events. Results showed that for 11C the MDA was improved by approximately 520%. Furthermore, it provides the additional advantage of reliability by providing a method for separating the signal and noise readings from the gross detector readout. Accurate reconstruction algorithm of the signal was achieved over a wide measuring range even when the signal was only 5% of the gross measurement.
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Affiliation(s)
- A Osovizky
- Jerry J. Cohen Radiobiology Research Laboratory, Nuclear Engineering Department, Ben-Gurion University of the Negev, Israel; Centre for Addiction and Mental Health, Toronto, Canada; Rotem Industries Ltd, Beer-Sheva, Israel.
| | - B Laster
- Jerry J. Cohen Radiobiology Research Laboratory, Nuclear Engineering Department, Ben-Gurion University of the Negev, Israel
| | - A A Wilson
- Centre for Addiction and Mental Health, Toronto, Canada
| | - P Bloomfield
- Centre for Addiction and Mental Health, Toronto, Canada
| | - B Sarusi
- Rotem Industries Ltd, Beer-Sheva, Israel
| | - N Vasdev
- Centre for Addiction and Mental Health, Toronto, Canada
| | - T Bell
- Centre for Addiction and Mental Health, Toronto, Canada
| | - A Garcia
- Centre for Addiction and Mental Health, Toronto, Canada
| | - S Houle
- Centre for Addiction and Mental Health, Toronto, Canada; University of Toronto, Toronto, Canada
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20
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Emulsion Techniques for the Production of Pharmacological Nanoparticles. Macromol Biosci 2019; 19:e1900063. [DOI: 10.1002/mabi.201900063] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Revised: 04/10/2019] [Indexed: 12/13/2022]
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21
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Mannheim JG, Schmid AM, Schwenck J, Katiyar P, Herfert K, Pichler BJ, Disselhorst JA. PET/MRI Hybrid Systems. Semin Nucl Med 2018; 48:332-347. [PMID: 29852943 DOI: 10.1053/j.semnuclmed.2018.02.011] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Over the last decade, the combination of PET and MRI in one system has proven to be highly successful in basic preclinical research, as well as in clinical research. Nowadays, PET/MRI systems are well established in preclinical imaging and are progressing into clinical applications to provide further insights into specific diseases, therapeutic assessments, and biological pathways. Certain challenges in terms of hardware had to be resolved concurrently with the development of new techniques to be able to reach the full potential of both combined techniques. This review provides an overview of these challenges and describes the opportunities that simultaneous PET/MRI systems can exploit in comparison with stand-alone or other combined hybrid systems. New approaches were developed for simultaneous PET/MRI systems to correct for attenuation of 511 keV photons because MRI does not provide direct information on gamma photon attenuation properties. Furthermore, new algorithms to correct for motion were developed, because MRI can accurately detect motion with high temporal resolution. The additional information gained by the MRI can be employed to correct for partial volume effects as well. The development of new detector designs in combination with fast-decaying scintillator crystal materials enabled time-of-flight detection and incorporation in the reconstruction algorithms. Furthermore, this review lists the currently commercially available systems both for preclinical and clinical imaging and provides an overview of applications in both fields. In this regard, special emphasis has been placed on data analysis and the potential for both modalities to evolve with advanced image analysis tools, such as cluster analysis and machine learning.
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Affiliation(s)
- Julia G Mannheim
- Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center, Eberhard Karls University Tuebingen, Tuebingen, Germany
| | - Andreas M Schmid
- Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center, Eberhard Karls University Tuebingen, Tuebingen, Germany
| | - Johannes Schwenck
- Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center, Eberhard Karls University Tuebingen, Tuebingen, Germany; Department of Nuclear Medicine and Clinical Molecular Imaging, Eberhard Karls University Tuebingen, Tuebingen, Germany
| | - Prateek Katiyar
- Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center, Eberhard Karls University Tuebingen, Tuebingen, Germany
| | - Kristina Herfert
- Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center, Eberhard Karls University Tuebingen, Tuebingen, Germany
| | - Bernd J Pichler
- Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center, Eberhard Karls University Tuebingen, Tuebingen, Germany.
| | - Jonathan A Disselhorst
- Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center, Eberhard Karls University Tuebingen, Tuebingen, Germany
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22
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Evans JD, Jethwa KR, Ost P, Williams S, Kwon ED, Lowe VJ, Davis BJ. Prostate cancer–specific PET radiotracers: A review on the clinical utility in recurrent disease. Pract Radiat Oncol 2018; 8:28-39. [DOI: 10.1016/j.prro.2017.07.011] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 07/12/2017] [Accepted: 07/18/2017] [Indexed: 01/08/2023]
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23
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Yusufi N, Mall S, Bianchi HDO, Steiger K, Reder S, Klar R, Audehm S, Mustafa M, Nekolla S, Peschel C, Schwaiger M, Krackhardt AM, D`Alessandria C. In-depth Characterization of a TCR-specific Tracer for Sensitive Detection of Tumor-directed Transgenic T Cells by Immuno-PET. Am J Cancer Res 2017; 7:2402-2416. [PMID: 28744323 PMCID: PMC5525745 DOI: 10.7150/thno.17994] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 03/22/2017] [Indexed: 12/19/2022] Open
Abstract
A number of different technologies have been developed to monitor in vivo the distribution of gene-modified T cells used in immunotherapy. Nevertheless, in-depth characterization of novel approaches with respect to sensitivity and clinical applicability are so far missing. We have previously described a novel method to track engineered human T cells in tumors using 89Zr-Df-aTCRmu-F(ab')2 targeting the murinized part of the TCR beta domain (TCRmu) of a transgenic TCR. Here, we performed an in-depth in vitro characterization of the tracer in terms of antigen affinity, immunoreactivity, influence on T-cell functionality and stability in vitro and in vivo. Of particular interest, we have developed diverse experimental settings to quantify TCR-transgenic T cells in vivo. Local application of 89Zr-Df-aTCRmu-F(ab')2-labeled T cells in a spot-assay revealed signal detection down to approximately 1.8x104 cells. In a more clinically relevant model, NSG mice were intravenously injected with different numbers of transgenic T cells, followed by injection of the 89Zr-Df-aTCRmu-F(ab')2 tracer, PET/CT imaging and subsequent ex vivo T-cell quantification in the tumor. Using this setting, we defined a comparable detection limit of 1.0x104 T cells. PET signals correlated well to total numbers of transgenic T cells detected ex vivo independently of the engraftment rates observed in different individual experiments. Thus, these findings confirm the high sensitivity of our novel PET/CT T-cell tracking method and provide critical information about the quantity of transgenic T cells in the tumor environment suggesting our technology being highly suitable for further clinical translation.
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24
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Hoffmann SHL, Maurer A, Reck DI, Reischl G, Pichler BJ, Kneilling M, Griessinger CM. Murine Lymphocyte Labeling by 64Cu-Antibody Receptor Targeting for In Vivo Cell Trafficking by PET/CT. J Vis Exp 2017. [PMID: 28518105 DOI: 10.3791/55270] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
This protocol illustrates the production of 64Cu and the chelator conjugation/radiolabeling of a monoclonal antibody (mAb) followed by murine lymphocyte cell culture and 64Cu-antibody receptor targeting of the cells. In vitro evaluation of the radiolabel and non-invasive in vivo cell tracking in an animal model of an airway delayed-type hypersensitivity reaction (DTHR) by PET/CT are described. In detail, the conjugation of a mAb with the chelator 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) is shown. Following the production of radioactive 64Cu, radiolabeling of the DOTA-conjugated mAb is described. Next, the expansion of chicken ovalbumin (cOVA)-specific CD4+ interferon (IFN)-γ-producing T helper cells (cOVA-TH1) and the subsequent radiolabeling of the cOVA-TH1 cells are depicted. Various in vitro techniques are presented to evaluate the effects of 64Cu-radiolabeling on the cells, such as the determination of cell viability by trypan blue exclusion, the staining for apoptosis with Annexin V for flow cytometry, and the assessment of functionality by IFN-γ enzyme-linked immunosorbent assay (ELISA). Furthermore, the determination of the radioactive uptake into the cells and the labeling stability are described in detail. This protocol further describes how to perform cell tracking studies in an animal model for an airway DTHR and, therefore, the induction of cOVA-induced acute airway DHTR in BALB/c mice is included. Finally, a robust PET/CT workflow including image acquisition, reconstruction, and analysis is presented. The 64Cu-antibody receptor targeting approach with subsequent receptor internalization provides high specificity and stability, reduced cellular toxicity, and low efflux rates compared to common PET-tracers for cell labeling, e.g.64Cu-pyruvaldehyde bis(N4-methylthiosemicarbazone) (64Cu-PTSM). Finally, our approach enables non-invasive in vivo cell tracking by PET/CT with an optimal signal-to-background ratio for 48 h. This experimental approach can be transferred to different animal models and cell types with membrane-bound receptors that are internalized.
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Affiliation(s)
- Sabrina H L Hoffmann
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tübingen
| | - Andreas Maurer
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tübingen
| | - Dorothea I Reck
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tübingen
| | - Gerald Reischl
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tübingen
| | - Bernd J Pichler
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tübingen
| | - Manfred Kneilling
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tübingen; Department of Dermatology, Eberhard Karls University Tübingen
| | - Christoph M Griessinger
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tübingen;
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25
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Feng T, Tsui BMW, Li X, Vranesic M, Lodge MA, Gulaldi NCM, Szabo Z. Image-derived and arterial blood sampled input functions for quantitative PET imaging of the angiotensin II subtype 1 receptor in the kidney. Med Phys 2016; 42:6736-44. [PMID: 26520763 DOI: 10.1118/1.4934375] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE The radioligand 11C-KR31173 has been introduced for positron emission tomography (PET) imaging of the angiotensin II subtype 1 receptor in the kidney in vivo. To study the biokinetics of 11C-KR31173 with a compartmental model, the input function is needed. Collection and analysis of arterial blood samples are the established approach to obtain the input function but they are not feasible in patients with renal diseases. The goal of this study was to develop a quantitative technique that can provide an accurate image-derived input function (ID-IF) to replace the conventional invasive arterial sampling and test the method in pigs with the goal of translation into human studies. METHODS The experimental animals were injected with [11C]KR31173 and scanned up to 90 min with dynamic PET. Arterial blood samples were collected for the artery derived input function (AD-IF) and used as a gold standard for ID-IF. Before PET, magnetic resonance angiography of the kidneys was obtained to provide the anatomical information required for derivation of the recovery coefficients in the abdominal aorta, a requirement for partial volume correction of the ID-IF. Different image reconstruction methods, filtered back projection (FBP) and ordered subset expectation maximization (OS-EM), were investigated for the best trade-off between bias and variance of the ID-IF. The effects of kidney uptakes on the quantitative accuracy of ID-IF were also studied. Biological variables such as red blood cell binding and radioligand metabolism were also taken into consideration. A single blood sample was used for calibration in the later phase of the input function. RESULTS In the first 2 min after injection, the OS-EM based ID-IF was found to be biased, and the bias was found to be induced by the kidney uptake. No such bias was found with the FBP based image reconstruction method. However, the OS-EM based image reconstruction was found to reduce variance in the subsequent phase of the ID-IF. The combined use of FBP and OS-EM resulted in reduced bias and noise. After performing all the necessary corrections, the areas under the curves (AUCs) of the AD-IF were close to that of the AD-IF (average AUC ratio=1±0.08) during the early phase. When applied in a two-tissue-compartmental kinetic model, the average difference between the estimated model parameters from ID-IF and AD-IF was 10% which was within the error of the estimation method. CONCLUSIONS The bias of radioligand concentration in the aorta from the OS-EM image reconstruction is significantly affected by radioligand uptake in the adjacent kidney and cannot be neglected for quantitative evaluation. With careful calibrations and corrections, the ID-IF derived from quantitative dynamic PET images can be used as the input function of the compartmental model to quantify the renal kinetics of 11C-KR31173 in experimental animals and the authors intend to evaluate this method in future human studies.
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Affiliation(s)
- Tao Feng
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins School of Medicine, Baltimore, Maryland 21287
| | - Benjamin M W Tsui
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins School of Medicine, Baltimore, Maryland 21287
| | - Xin Li
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins School of Medicine, Baltimore, Maryland 21287
| | - Melin Vranesic
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins School of Medicine, Baltimore, Maryland 21287
| | - Martin A Lodge
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins School of Medicine, Baltimore, Maryland 21287
| | - Nedim C M Gulaldi
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins School of Medicine, Baltimore, Maryland 21287
| | - Zsolt Szabo
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins School of Medicine, Baltimore, Maryland 21287
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Rahman O, Långström B, Halldin C. Alkyl Iodides and [11
C]CO in Nickel-Mediated Cross-Coupling Reactions: Successful Use of Alkyl Electrophiles containing a β Hydrogen Atom in Metal-Mediated [11
C]Carbonylation. ChemistrySelect 2016. [DOI: 10.1002/slct.201600643] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Obaidur Rahman
- Karolinska Institutet; Department of Clinical Neuroscience; Centre for Psychiatric Research; Karolinska University Hospital; 171 76 Stockholm Sweden
- Bencar AB; Dag Hammarsjöldsväg 34B 572 37 Uppsala Sweden
| | - Bengt Långström
- Department of Chemistry; Uppsala University; 751 23 Uppsala Sweden
- Bencar AB; Dag Hammarsjöldsväg 34B 572 37 Uppsala Sweden
| | - Christer Halldin
- Karolinska Institutet; Department of Clinical Neuroscience; Centre for Psychiatric Research; Karolinska University Hospital; 171 76 Stockholm Sweden
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Comparison of the Performances of (18)F-FP-CIT Brain PET/MR and Simultaneous PET/CT: a Preliminary Study. Nucl Med Mol Imaging 2016; 50:219-27. [PMID: 27540426 DOI: 10.1007/s13139-016-0419-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Revised: 04/12/2016] [Accepted: 04/15/2016] [Indexed: 10/21/2022] Open
Abstract
PURPOSE (18)F-FP-CIT [(18)F-fluorinated N-3-fluoropropyl-2-beta-carboxymethoxy-3-beta-(4-iodophenyl) nortropane] has been well established and used for the differential diagnosis of atypical parkinsonian disorders. Recently, combined positron emission tomography (PET)/magnetic resonance (MR) was proposed as a viable alternative to PET/computed tomography (CT). The aim of this study was to compare the performances of conventional (18)F-FP-CIT brain PET/CT and simultaneous PET/MR by visual inspection and quantitative analysis. METHODS Fifteen consecutive patients clinically suspected of having Parkinson's disease were recruited for the study.(18)F-FP-CIT PET was performed during PET/CT and PET/MR. PET/CT image acquisition was started 90 min after intravenous injection of (18)F-FP-CIT and then PET/MR images were acquired. Dopamine transporter (DAT) density in bilateral striatal subregions was assessed visually. Quantitative analyses were performed on bilateral striatal volumes of interest (VOIs) using average standardized uptake values (SUVmeans). Intraclass correlation coefficients (ICCs) and their 95 % confidence intervals (CIs) were assessed to compare PET/CT and PET/MR data. Bland-Altman plots were drawn to perform method-comparisons. RESULTS All subjects showed a preferential decrease in DAT binding in the posterior putamen (PP), with relative sparing of the ventral putamen (VP). Bilateral striatal subregional binding ratio (BR) determined PET/CT and PET/MR demonstrated close interequipment correspondence (BRright caudate - ICC, 0.944; 95 % CI, 0.835-0.981, BRleft caudate - ICC, 0.917; 95 % CI, 0.753-0.972, BRright putamen - ICC, 0.976; 95 % CI, 0.929-0.992 and BRleft putamen - ICC, 0.970; 95 % CI, 0.911-0.990, respectively), and Bland-Altman plots showed interequipment agreement between the two modalities. CONCLUSIONS It is known that MR provides more information about anatomical changes associated with brain diseases and to enable the anatomical allocations of subregions than CT, though this was not observed in the present study. Although the subregional BR of simultaneous PET/MR was comparable to that of PET/CT in Parkinson's disease, our isocontouring method could make bias. A future automated method using standard template study or manual segmentation of putamen/caudate based on MR or CT is needed.
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Kang CS, Wu N, Chen Y, Sun X, Bandara N, Liu D, Lewis MR, Rogers BE, Chong HS. Transferrin conjugates of triazacyclononane-based bifunctional NE3TA chelates for PET imaging: Synthesis, Cu-64 radiolabeling, and in vitro and in vivo evaluation. J Inorg Biochem 2015; 154:60-6. [PMID: 26583705 DOI: 10.1016/j.jinorgbio.2015.10.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 10/09/2015] [Accepted: 10/28/2015] [Indexed: 12/29/2022]
Abstract
Three different polyaminocarboxylate-based bifunctional NE3TA (7-[2-[carboxymethyl)amino]ethyl]-1,4,7-triazacyclononane-1,4-diacetic acid) chelating agents were synthesized for potential use in copper 64-PET imaging applications. The bifunctional chelates were comparatively evaluated using transferrin (Tf) as a model targeting vector that binds to the transferrin receptor overexpressed in many different cancer cells. The transferrin conjugates of the NE3TA-based bifunctional chelates were evaluated for radiolabeling with (64)Cu. In vitro stability and cellular uptake of (64)Cu-radiolabeled conjugates were evaluated in human serum and prostate (PC-3) cancer cells, respectively. Among the three NE3TA-Tf conjugates tested, N-NE3TA-Tf was identified as the best conjugate for radiolabeling with (64)Cu. N-NE3TA-Tf rapidly bound to (64)Cu (>98% radiolabeling efficiency, 1min, RT), and (64)Cu-N-NE3TA-Tf remained stable in human serum for 2days and demonstrated high uptake in PC-3 cancer cells. (64)Cu-N-NE3TA-Tf was shown to have rapid blood clearance and increasing tumor uptake in PC-3 tumor bearing mice over a 24h period. This bifunctional chelate presents highly efficient chelation chemistry with (64)Cu under mild condition that can be applied for radiolabeling of various tumor-specific biomolecules with (64)Cu for potential use in PET imaging applications.
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Affiliation(s)
- Chi Soo Kang
- Department of Biological and Chemical Sciences, Illinois Institute of Technology, Chicago, IL, United States
| | - Ningjie Wu
- Department of Biological and Chemical Sciences, Illinois Institute of Technology, Chicago, IL, United States
| | - Yunwei Chen
- Department of Biological and Chemical Sciences, Illinois Institute of Technology, Chicago, IL, United States
| | - Xiang Sun
- Department of Biological and Chemical Sciences, Illinois Institute of Technology, Chicago, IL, United States
| | - Nilantha Bandara
- Department of Radiation Oncology, Washington University in St. Louis, St. Louis, MO, United States
| | - Dijie Liu
- Department of Veterinary Medicine and Surgery, University of Missouri, Columbia, MO, United States
| | - Michael R Lewis
- Research Service, Harry S. Truman Memorial Veterans' Hospital, United States; Department of Veterinary Medicine and Surgery, University of Missouri, Columbia, MO, United States
| | - Buck E Rogers
- Department of Radiation Oncology, Washington University in St. Louis, St. Louis, MO, United States
| | - Hyun-Soon Chong
- Department of Biological and Chemical Sciences, Illinois Institute of Technology, Chicago, IL, United States.
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Chun KA, Kong E, Cho I. An Incidental Finding of Skull Hemangioma During 18F-FP CIT Brain PET/CT. Clin Nucl Med 2015; 40:e488-9. [DOI: 10.1097/rlu.0000000000000907] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Kastis GA, Gaitanis A, Samartzis AP, Fokas AS. The SRT reconstruction algorithm for semiquantification in PET imaging. Med Phys 2015; 42:5970-82. [DOI: 10.1118/1.4931409] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Kumar A, Zhang S, Hao G, Hassan G, Ramezani S, Sagiyama K, Lo ST, Takahashi M, Sherry AD, Öz OK, Kovacs Z, Sun X. Molecular platform for design and synthesis of targeted dual-modality imaging probes. Bioconjug Chem 2015; 26:549-58. [PMID: 25615011 PMCID: PMC4428032 DOI: 10.1021/acs.bioconjchem.5b00028] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
We report a versatile dendritic structure
based platform for construction
of targeted dual-modality imaging probes. The platform contains multiple
copies of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid
(DOTA) branching out from a 1,4,7-triazacyclononane-N,N′,N″-triacetic
acid (NOTA) core. The specific coordination chemistries of the NOTA
and DOTA moieties offer specific loading of 68/67Ga3+ and Gd3+, respectively, into a common molecular
scaffold. The platform also contains three amino groups which can
potentiate targeted dual-modality imaging of PET/MRI or SPECT/MRI
(PET: positron emission tomography; SPECT: single photon emission
computed tomography; MRI: magnetic resonance imaging) when further
functionalized by targeting vectors of interest. To validate this
design concept, a bimetallic complex was synthesized with six peripheral
Gd-DOTA units and one Ga-NOTA core at the center, whose ion T1 relaxivity per gadolinium atom was measured
to be 15.99 mM–1 s–1 at 20 MHz.
Further, the bimetallic agent demonstrated its anticipated in vivo
stability, tissue distribution, and pharmacokinetic profile when labeled
with 67Ga. When conjugated with a model targeting peptide
sequence, the trivalent construct was able to visualize tumors in
a mouse xenograft model by both PET and MRI via a single dose injection.
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Affiliation(s)
- Amit Kumar
- †Department of Radiology, ‡Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Shanrong Zhang
- †Department of Radiology, ‡Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Guiyang Hao
- †Department of Radiology, ‡Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Gedaa Hassan
- †Department of Radiology, ‡Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Saleh Ramezani
- †Department of Radiology, ‡Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Koji Sagiyama
- †Department of Radiology, ‡Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Su-Tang Lo
- †Department of Radiology, ‡Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Masaya Takahashi
- †Department of Radiology, ‡Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - A Dean Sherry
- †Department of Radiology, ‡Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Orhan K Öz
- †Department of Radiology, ‡Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Zoltan Kovacs
- †Department of Radiology, ‡Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Xiankai Sun
- †Department of Radiology, ‡Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
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Hicks JW, Parkes J, Tong J, Houle S, Vasdev N, Wilson AA. Radiosynthesis and ex vivo evaluation of [(11)C-carbonyl]carbamate- and urea-based monoacylglycerol lipase inhibitors. Nucl Med Biol 2014; 41:688-94. [PMID: 24969632 DOI: 10.1016/j.nucmedbio.2014.05.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 04/16/2014] [Accepted: 05/01/2014] [Indexed: 10/25/2022]
Abstract
INTRODUCTION Monoacylglycerol lipase (MAGL) and fatty acid amide hydrolase (FAAH) are the two primary enzymes that regulate the tone of endocannabinoid signaling. Although new PET radiotracers have been discovered for imaging FAAH in vivo, no such radiotracer exists for imaging MAGL. Here we report the radiosynthesis of five candidate MAGL radiotracers and their ex vivo evaluations in mice and rats. METHODS Candidate carbamate and urea MAGL inhibitors were radiolabeled at the carbonyl position by [(11)C]CO2 fixation. Radiotracers were administered (tail-vein injection) to rodents and brain uptake of radioactivity measured at early and late time points ex vivo. Specificity of uptake was explored by pretreatment with unlabeled inhibitors (2 mg/kg, ip) 30 min prior to radiotracer administration. RESULTS All five candidate MAGL radiotracers were prepared in high specific activity (>65 GBq/μmol) and radiochemical purity (>98%). Moderate brain uptake (0.2-0.8 SUV) was observed for each candidate while pretreatment did not reduce uptake for four of the five tested. For two candidates ([(11)C]12 and [(11)C]14), high retention of radioactivity was observed in the blood (ca. 10 and 4 SUV at 40 min) which was blocked by pretreatment with unlabeled inhibitors. The most promising candidate, [(11)C]18, demonstrated moderate brain uptake (ca. 0.8 SUV) which showed circa 50% blockade by pretreatment with unlabeled 18. CONCLUSION One putative and four reported potent and selective MAGL inhibitors have been radiolabeled via [(11)C]CO2 fixation as radiotracers for this enzyme. Despite the promising in vitro pharmacological profile, none of the five candidate radiotracers exhibited in vivo behavior suitable for PET neuroimaging.
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Affiliation(s)
- Justin W Hicks
- Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada, M5T 1R8; Institute of Medical Science, University of Toronto, Toronto, ON, Canada, M5S 1A8
| | - Jun Parkes
- Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada, M5T 1R8
| | - Junchao Tong
- Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada, M5T 1R8
| | - Sylvain Houle
- Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada, M5T 1R8
| | - Neil Vasdev
- Department of Radiology, Harvard Medical School and Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital, Boston, MA, USA, 02114
| | - Alan A Wilson
- Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada, M5T 1R8; Institute of Medical Science, University of Toronto, Toronto, ON, Canada, M5S 1A8.
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Synthesis and biological evaluation of 99mTc-ECF: a new ethionamide derivative for tuberculosis diagnosis. J Radioanal Nucl Chem 2014. [DOI: 10.1007/s10967-014-3059-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Griessinger CM, Kehlbach R, Bukala D, Wiehr S, Bantleon R, Cay F, Schmid A, Braumüller H, Fehrenbacher B, Schaller M, Eichner M, Sutcliffe JL, Ehrlichmann W, Eibl O, Reischl G, Cherry SR, Röcken M, Pichler BJ, Kneilling M. In Vivo Tracking of Th1 Cells by PET Reveals Quantitative and Temporal Distribution and Specific Homing in Lymphatic Tissue. J Nucl Med 2014; 55:301-7. [DOI: 10.2967/jnumed.113.126318] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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Li T, Qian Y, Ye M, Tang J, Hu H, Shen Y. Synthesis and Properties of a Biodegradable Dendritic Magnetic Resonance Imaging Contrast Agent. CHINESE J CHEM 2014. [DOI: 10.1002/cjoc.201300889] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Non-invasive monitoring of pancreatic tumor progression in the RIP1-Tag2 mouse by magnetic resonance imaging. Mol Imaging Biol 2013; 15:186-93. [PMID: 22752651 DOI: 10.1007/s11307-012-0548-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
PURPOSE Assessing information on tumor progression in the RIP1-Tag2 mouse in vivo is a great challenge because the tumors form spontaneously throughout the pancreas and are difficult to detect with current imaging modalities. In this study, we focused on non-invasive magnetic resonance imaging, providing information on tumor growth. PROCEDURES Tissue relaxation times were measured over time and were compared between tumors and healthy pancreatic tissue. The effects of age and body temperature on these relaxation times, possibly influencing image contrast and therefore detection capabilities, were evaluated. RESULTS Tumors appeared hyperintense in T2-weighted images when they exceeded 0.8 mm in diameter, and both relaxation times showed significantly higher values in tumors than in the healthy pancreas. CONCLUSION Visualization and monitoring of these small tumors in vivo is feasible, even under adverse conditions of permanent gut movement. In the mouse model studied, the relaxation times of tumors differed significantly from healthy pancreatic tissue.
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Molecular imaging of experimental abdominal aortic aneurysms. ScientificWorldJournal 2013; 2013:973150. [PMID: 23737735 PMCID: PMC3655677 DOI: 10.1155/2013/973150] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Accepted: 03/19/2013] [Indexed: 11/18/2022] Open
Abstract
Current laboratory research in the field of abdominal aortic aneurysm (AAA) disease often utilizes small animal experimental models induced by genetic manipulation or chemical application. This has led to the use and development of multiple high-resolution molecular imaging modalities capable of tracking disease progression, quantifying the role of inflammation, and evaluating the effects of potential therapeutics. In vivo imaging reduces the number of research animals used, provides molecular and cellular information, and allows for longitudinal studies, a necessity when tracking vessel expansion in a single animal. This review outlines developments of both established and emerging molecular imaging techniques used to study AAA disease. Beyond the typical modalities used for anatomical imaging, which include ultrasound (US) and computed tomography (CT), previous molecular imaging efforts have used magnetic resonance (MR), near-infrared fluorescence (NIRF), bioluminescence, single-photon emission computed tomography (SPECT), and positron emission tomography (PET). Mouse and rat AAA models will hopefully provide insight into potential disease mechanisms, and the development of advanced molecular imaging techniques, if clinically useful, may have translational potential. These efforts could help improve the management of aneurysms and better evaluate the therapeutic potential of new treatments for human AAA disease.
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Locatelli E, Gil L, Israel LL, Passoni L, Naddaka M, Pucci A, Reese T, Gomez-Vallejo V, Milani P, Matteoli M, Llop J, Lellouche JP, Franchini MC. Biocompatible nanocomposite for PET/MRI hybrid imaging. Int J Nanomedicine 2012; 7:6021-33. [PMID: 23271907 PMCID: PMC3526150 DOI: 10.2147/ijn.s38107] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
A novel nanocarrier system was designed and developed with key components uniquely structured at the nanoscale for early cancer diagnosis and treatment. In order to perform magnetic resonance imaging, hydrophilic superparamagnetic maghemite nanoparticles (NPs) were synthesized and coated with a lipophilic organic ligand. Next, they were entrapped into polymeric NPs made of biodegradable poly(lactic-co-glycolic acid) linked to polyethylene glycol. In addition, resulting NPs have been conjugated on their surface with a 2,2'-(7-(4-((2-aminoethyl)amino)-1-carboxy-4-oxobutyl)-1,4,7-triazonane-1,4-diyl)diacetic acid ligand for subsequent (68)Ga incorporation. A cell-based cytotoxicity assay has been employed to verify the in vitro cell viability of human pancreatic cancer cells exposed to this nanosystem. Finally, in vivo positron emission tomography-computerized tomography biodistribution studies in healthy animals were performed.
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Affiliation(s)
- Erica Locatelli
- Department of Industrial Chemistry Toso Montanari. University of Bologna, Italy
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Miranda DMD, Mamede M, Souza BRD, Almeida Barros AGD, Magno LA, Alvim-Soares A, Rosa DV, Castro CJD, Malloy-Diniz L, Gomez MV, Marco LAD, Correa H, Romano-Silva MA. Molecular medicine: a path towards a personalized medicine. BRAZILIAN JOURNAL OF PSYCHIATRY 2012; 34:82-91. [PMID: 22392394 DOI: 10.1016/s1516-4446(12)70015-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2011] [Accepted: 08/21/2011] [Indexed: 10/27/2022]
Abstract
Psychiatric disorders are among the most common human illnesses; still, the molecular and cellular mechanisms underlying their complex pathophysiology remain to be fully elucidated. Over the past 10 years, our group has been investigating the molecular abnormalities in major signaling pathways involved in psychiatric disorders. Recent evidences obtained by the Instituto Nacional de Ciência e Tecnologia de Medicina Molecular (National Institute of Science and Technology - Molecular Medicine, INCT-MM) and others using behavioral analysis of animal models provided valuable insights into the underlying molecular alterations responsible for many complex neuropsychiatric disorders, suggesting that "defects" in critical intracellular signaling pathways have an important role in regulating neurodevelopment, as well as in pathophysiology and treatment efficacy. Resources from the INCT have allowed us to start doing research in the field of molecular imaging. Molecular imaging is a research discipline that visualizes, characterizes, and quantifies the biologic processes taking place at cellular and molecular levels in humans and other living systems through the results of image within the reality of the physiological environment. In order to recognize targets, molecular imaging applies specific instruments (e.g., PET) that enable visualization and quantification in space and in real-time of signals from molecular imaging agents. The objective of molecular medicine is to individualize treatment and improve patient care. Thus, molecular imaging is an additional tool to achieve our ultimate goal.
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Affiliation(s)
- Debora Marques de Miranda
- Instituto Nacional de Ciência e Tecnologia de Medicina Molecular, Faculdade de Medicina, Universidade Federal de Minas Gerais, Brazil
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Wang H, Stout DB, Taschereau R, Gu Z, Vu NT, Prout DL, Chatziioannou AF. MARS: a mouse atlas registration system based on a planar x-ray projector and an optical camera. Phys Med Biol 2012; 57:6063-77. [PMID: 22968224 DOI: 10.1088/0031-9155/57/19/6063] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
This paper introduces a mouse atlas registration system (MARS), composed of a stationary top-view x-ray projector and a side-view optical camera, coupled to a mouse atlas registration algorithm. This system uses the x-ray and optical images to guide a fully automatic co-registration of a mouse atlas with each subject, in order to provide anatomical reference for small animal molecular imaging systems such as positron emission tomography (PET). To facilitate the registration, a statistical atlas that accounts for inter-subject anatomical variations was constructed based on 83 organ-labeled mouse micro-computed tomography (CT) images. The statistical shape model and conditional Gaussian model techniques were used to register the atlas with the x-ray image and optical photo. The accuracy of the atlas registration was evaluated by comparing the registered atlas with the organ-labeled micro-CT images of the test subjects. The results showed excellent registration accuracy of the whole-body region, and good accuracy for the brain, liver, heart, lungs and kidneys. In its implementation, the MARS was integrated with a preclinical PET scanner to deliver combined PET/MARS imaging, and to facilitate atlas-assisted analysis of the preclinical PET images.
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Affiliation(s)
- Hongkai Wang
- Department of Molecular and Medical Pharmacology, Crump Institute for Molecular Imaging, UCLA, Los Angeles, CA, USA.
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de Miranda DM, Mamede M, de Souza BR, de Almeida Barros AG, Magno LA, Alvim-Soares A, Rosa DV, de Castro CJ, Malloy-Diniz L, Gomez MV, De Marco LA, Correa H, Romano-Silva MA. Molecular medicine: a path towards a personalized medicine. BRAZILIAN JOURNAL OF PSYCHIATRY 2012. [DOI: 10.1590/s1516-44462012000100015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Oh M, Kim JS, Kim JY, Shin KH, Park SH, Kim HO, Moon DH, Oh SJ, Chung SJ, Lee CS. Subregional Patterns of Preferential Striatal Dopamine Transporter Loss Differ in Parkinson Disease, Progressive Supranuclear Palsy, and Multiple-System Atrophy. J Nucl Med 2012; 53:399-406. [DOI: 10.2967/jnumed.111.095224] [Citation(s) in RCA: 190] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Sánchez F, Moliner L, Correcher C, González A, Orero A, Carles M, Soriano A, Rodriguez-Alvarez MJ, Medina LA, Mora F, Benlloch JM. Small animal PET scanner based on monolithic LYSO crystals: Performance evaluation. Med Phys 2012; 39:643-53. [DOI: 10.1118/1.3673771] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Essouissi I, Malek Saied N, Bernard S, Guizani S, Mejri N, Barc C, Ben Hamouda S, Asmi A, Saidi M. 99mTc-N-IFC: a new isoniazid derivative for Mycobacterium diagnostic. RADIOCHIM ACTA 2011. [DOI: 10.1524/ract.2012.1905] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
We present in this work a new technetium-99m-labeled derivative from isoniazid. The labeling was achieved with a double-ligand transfer through the use of a ferrocene derivative. A further referred to as 99mTc-N-IFC (N-Isonicotinamide ferrocene carboxamide labeled with 99mTc), targeting infections in experimental animals, has been synthesized. The N-IFC was chemically synthesized and then labeled with technetium-99m. It has been confirmed through this work that it was obtained with high radiolabelling yield (95%). Radiochemical analyses of 99mTc-N-IFC revealed that the molecule was efficiently labeled with a little free pertechnetate in the preparations containing purified compound. Only 1–2% of the tracer was leached out from the complex at 24 h when incubated in serum at 37 ºC confirmed its high stability. The radiolabeled complex was found to be 10% bound to blood protein, which corresponds to a fast retention advantage. Biodistribution study showed the renal route of excretion and has also demonstrated that our radiolabeled compound is rapidly and significantly accumulated (P<0.5) at infection sites. Thigh model of localized infection was prepared in mice by injecting of BCG (pGFM-11) (fluorexcente BCG) live bacteria in growing phase. The confirmation of the bacteria presence in infection sites has been established through its fluorescence characteristic. The comparison of the 99mTc-N-IFC accumulation at sites of BCG (pGFM-11) infected animals, which is expressed as target-to-non-target ratio, (3.14) with other radiotracers was discussed. This allowed us to consider that 99mTc-N-IFC could be a good radiotracer for mycobacterial infections. Obtained results were in good and encourage to undergo a similar labeling for the Mycobacterium tuberculosis as perspective of this work.
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Affiliation(s)
| | - Nadia Malek Saied
- Unit of Medical, Agricultural and Environmental Techniques Nuclear Applications (CNSTN), 2020 Sidi Thabet, Tunesien
| | - Serge Bernard
- Experimental Infectiology Platform (PFIE3), INRA, Centre of Tours, Frankreich
| | - Sihem Guizani
- Unit of Medical, Agricultural and Environmental Techniques Nuclear Applications (CNSTN), 2020 Sidi Thabet, Tunesien
| | - Najoua Mejri
- Unit of Medical, Agricultural and Environmental Techniques Nuclear Applications (CNSTN), 2020 Sidi Thabet, Tunesien
| | - Celine Barc
- Experimental Infectiology Platform (PFIE3), INRA, Centre of Tours, Frankreich
| | - Salem Ben Hamouda
- Unit of Medical, Agricultural and Environmental Techniques Nuclear Applications (CNSTN), 2020 Sidi Thabet, Tunesien
| | - Amin Asmi
- Unit of Medical, Agricultural and Environmental Techniques Nuclear Applications (CNSTN), 2020 Sidi Thabet, Tunesien
| | - Mouldi Saidi
- Unit of Medical, Agricultural and Environmental Techniques Nuclear Applications (CNSTN), 2020 Sidi Thabet, Tunesien
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Carberry P, Carpenter AP, Kung HF. Fluoride-18 radiolabeling of peptides bearing an aminooxy functional group to a prosthetic ligand via an oxime bond. Bioorg Med Chem Lett 2011; 21:6992-5. [PMID: 22024031 DOI: 10.1016/j.bmcl.2011.09.124] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Revised: 09/26/2011] [Accepted: 09/28/2011] [Indexed: 11/27/2022]
Abstract
We have developed a novel F-18 prosthetic ligand named fluoro-PEG-benzaldehyde (FPBA) 1. [(18)F]-FPBA 1 is formed in situ from its radiolabeled precursor [(18)F]6. Compound 6 is efficiently synthesized in four steps starting from commercially available 6-bromo-3-pyridine carbaldehyde 2. [(18)F]-FPBA was evaluated as a prosthetic ligand to radiolabel three cyclic peptides bearing an aminooxy functional group at the N-terminus position. Acetal [(18)F]6 is purified by either solid-phase extraction (SPE) or reverse-phase HPLC with the overall radiochemical yields (RCY) and radiochemical purity (RCP) in very close agreement. The SPE purification process has the advantage of shorter reaction times (71-87 min for entire reaction sequence), while the use of the reverse-phase HPLC purification process allows the use of up to fifty times less of the expensive synthetic peptides (~ 50 nmol) in the oxime coupling reaction. We have demonstrated an efficient methodology in the production of [(18)F]-FPBA 1 and demonstrated its use as a prosthetic ligand for the labeling of peptides possessing an aminooxy functional group.
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Affiliation(s)
- Patrick Carberry
- Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA
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Carberry P, Lieberman BP, Ploessl K, Choi SR, Haase DN, Kung HF. New F-18 prosthetic group via oxime coupling. Bioconjug Chem 2011; 22:642-53. [PMID: 21452846 DOI: 10.1021/bc1004262] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A novel fluorine-18 prosthetic ligand, 5-(1,3-dioxolan-2-yl)-2-(2-(2-(2-fluoroethoxy)ethoxy)ethoxy)pyridine [(18)F]2, has been synthesized. The prosthetic ligand is formed in high radiochemical yield (rcy = 71 ± 2%, n = 3) with excellent radiochemical purity (rcp = 99 ± 1%, n = 3) in a short reaction time (10 min). [(18)F]2 is a small, neutral, organic complex, easily synthesized in four steps from a readily available starting material. It can be anchored onto a target molecule containing an aminooxy functional group under acidic conditions by way of an oxime bond. We report herein two examples [(18)F]23 and [(18)F]24, potential imaging agents for β-amyloid plaques, which were labeled with this prosthetic group. This approach could be used for labeling proteins and peptides containing an aminooxy group. Biodistribution in male ICR mice for both oxime labeled complexes [(18)F]23 and [(18)F]24 were compared to that of the known β-amyloid plaque indicator, [(18)F]-AV-45, florbetapir 1. Oximes [(18)F]23 and [(18)F]24 are larger in size and therefore should reduce the blood-brain barrier (BBB) penetration. The brain uptake for oxime [(18)F]23 appeared to be reduced, but still retained some capability to cross the BBB. Oxime [(18)F]24 showed promising results after 2 min post injection (0.48% dose/gram); however, the uptake increased after 30 min post injection (0.92% dose/gram) suggesting an in vivo decomposition/metabolism of compound [(18)F]24. We have demonstrated a general protocol for the fluoride-18 labeling with a new prosthetic ligand [(18)F]2 that is tolerant toward several functional groups and is formed via chemoselective oxime coupling.
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Affiliation(s)
- Patrick Carberry
- Department of Radiology, University of Pennsylvania , 3700 Market Street, Room 305, Philadelphia, Pennsylvania 19104, United States
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Beyer T, Freudenberg LS, Czernin J, Townsend DW. The future of hybrid imaging-part 3: PET/MR, small-animal imaging and beyond. Insights Imaging 2011; 2:235-246. [PMID: 22347950 PMCID: PMC3270262 DOI: 10.1007/s13244-011-0085-4] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Revised: 01/04/2011] [Accepted: 02/18/2011] [Indexed: 11/30/2022] Open
Abstract
Since the 1990s, hybrid imaging by means of software and hardware image fusion alike allows the intrinsic combination of functional and anatomical image information. This review summarises in three parts the state of the art of dual-technique imaging with a focus on clinical applications. We will attempt to highlight selected areas of potential improvement of combined imaging technologies and new applications. In this third part, we discuss briefly the origins of combined positron emission tomography (PET)/magnetic resonance imaging (MRI). Unlike PET/computed tomography (CT), PET/MRI started out from developments in small-animal imaging technology, and, therefore, we add a section on advances in dual- and multi-modality imaging technology for small animals. Finally, we highlight a number of important aspects beyond technology that should be addressed for a sustained future of hybrid imaging. In short, we predict that, within 10 years, we may see all existing multi-modality imaging systems in clinical routine, including PET/MRI. Despite the current lack of clinical evidence, integrated PET/MRI may become particularly important and clinically useful in improved therapy planning for neurodegenerative diseases and subsequent response assessment, as well as in complementary loco-regional oncology imaging. Although desirable, other combinations of imaging systems, such as single-photon emission computed tomography (SPECT)/MRI may be anticipated, but will first need to go through the process of viable clinical prototyping. In the interim, a combination of PET and ultrasound may become available. As exciting as these new possible triple-technique—imaging systems sound, we need to be aware that they have to be technologically feasible, applicable in clinical routine and cost-effective.
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Affiliation(s)
- Thomas Beyer
- cmi-experts GmbH, Pestalozzistr 3, 8032 Zürich, Switzerland
- Department of Nuclear Medicine, University Hospital Essen, Essen, Germany
| | - Lutz S. Freudenberg
- Department of Nuclear Medicine, University Hospital Essen, Essen, Germany
- Department of Nuclear Medicine, ZRN, Grevenbroich, Germany
| | - Johannes Czernin
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA USA
| | - David W. Townsend
- Singapore Bioimaging Consortium, 11 Biopolis Way, 02-02 Helios, Singapore, 138667 Singapore
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Andreozzi E, Seo JW, Ferrara K, Louie A. Novel method to label solid lipid nanoparticles with 64cu for positron emission tomography imaging. Bioconjug Chem 2011; 22:808-18. [PMID: 21388194 DOI: 10.1021/bc100478k] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Solid lipid nanoparticles (SLNs) are submicrometer (1-1000 nm) colloidal carriers developed in the past decade as an alternative system to traditional carriers (emulsions, liposomes, and polymeric nanoparticles) for intravenous applications. Because of their potential as drug carriers, there is much interest in understanding the in vivo biodistribution of SLNs following intravenous (i.v.) injection. Positron emission tomography (PET) is an attractive method for investigating biodistribution but requires a radiolabeled compound. In this work, we describe a method to radiolabel SLN for in vivo PET studies. A copper specific chelator, 6-[p-(bromoacetamido)benzyl]-1,4,8,11-tetraazacyclotetradecane-N,N',N'',N'''-tetraacetic acid (BAT), conjugated with a synthetic lipid, was incorporated into the SLN. Following incubation with (64)CuCl(2) for 1 h at 25 °C in 0.1 M NH(4)OAc buffer (pH 5.5), the SLNs (∼150 nm) were successfully radiolabeled with (64)Cu (66.5% radiolabeling yield), exhibiting >95% radiolabeled particles following purification. The (64)Cu-SLNs were delivered intravenously to mice and imaged with PET at 0.5, 3, 20, and 48 h post injection. Gamma counting was utilized post imaging to confirm organ distributions. Tissue radioactivity (% injected dose/gram, %ID/g), obtained by quantitative analysis of the images, suggests that the (64)Cu-SLNs are circulating in the bloodstream after 3 h (blood half-life ∼1.4 h), but are almost entirely cleared by 48 h. PET and gamma counting demonstrate that approximately 5-7%ID/g (64)Cu-SLNs remain in the liver at 48 h post injection. Stability assays confirm that copper remains associated with the SLN over the 48 h time period and that the biodistribution patterns observed are not from free, dissociated copper. Our results indicate that SLNs can be radiolabeled with (64)Cu, and their biodistribution can be quantitatively evaluated by in vivo PET imaging and ex vivo gamma counting.
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Affiliation(s)
- Erica Andreozzi
- Department of Biomedical Engineering, University of California , Davis, California, United States
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The cell labeling efficacy, cytotoxicity and relaxivity of copper-activated MRI/PET imaging contrast agents. Biomaterials 2010; 32:1167-76. [PMID: 21035183 DOI: 10.1016/j.biomaterials.2010.10.013] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2010] [Accepted: 10/06/2010] [Indexed: 02/03/2023]
Abstract
A new class of nanoparticle-based dual-modality positron emission tomography/magnetic resonance imaging (PET/MRI) contrast agents has been developed. The probe consists of a superparamagnetic iron oxide (SPIO) or manganese oxide core coated with 3,4-dihydroxy-D,L-phenylalanine (DL-DOPA). The chelator 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) was conjugated to DOPA termini. The DOTA modified nanoparticles allow chelation of copper for PET imaging. These surface functionalized nanoparticle-based probes have been characterized by various analytical techniques. The cell-labeling efficacy, cytotoxicity and relaxivity of these nanoparticles have been evaluated and compared with the same properties of one of the most commonly utilized MRI contrast agents, Feridex(®). Evidently, this new nanoparticle has a great potential for use in cell tracking with MRI and PET in the absence of transfecting agent. It is noteworthy that there is a sharp increase in r(2) relaxivity of these nanoparticles on coordination with Cu(2+) ions. Thus these iron oxide nanoparticles can also be explored as the smart magnetic resonance (MR) sensor for the detection of micromolar changes in copper concentration for neurodegenerative diseases such as Alzheimer's disease, Menkes and Wilson's diseases, amyotrophic lateral sclerosis and prion diseases.
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Jarrett BR, Correa C, Ma KL, Louie AY. In vivo mapping of vascular inflammation using multimodal imaging. PLoS One 2010; 5:e13254. [PMID: 20949008 PMCID: PMC2952595 DOI: 10.1371/journal.pone.0013254] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2010] [Accepted: 09/08/2010] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Plaque vulnerability to rupture has emerged as a critical correlate to risk of adverse coronary events but there is as yet no clinical method to assess plaque stability in vivo. In the search to identify biomarkers of vulnerable plaques an association has been found between macrophages and plaque stability--the density and pattern of macrophage localization in lesions is indicative of probability to rupture. In very unstable plaques, macrophages are found in high densities and concentrated in the plaque shoulders. Therefore, the ability to map macrophages in plaques could allow noninvasive assessment of plaque stability. We use a multimodality imaging approach to noninvasively map the distribution of macrophages in vivo. The use of multiple modalities allows us to combine the complementary strengths of each modality to better visualize features of interest. Our combined use of Positron Emission Tomography and Magnetic Resonance Imaging (PET/MRI) allows high sensitivity PET screening to identify putative lesions in a whole body view, and high resolution MRI for detailed mapping of biomarker expression in the lesions. METHODOLOGY/PRINCIPAL FINDINGS Macromolecular and nanoparticle contrast agents targeted to macrophages were developed and tested in three different mouse and rat models of atherosclerosis in which inflamed vascular plaques form spontaneously and/or are induced by injury. For multimodal detection, the probes were designed to contain gadolinium (T1 MRI) or iron oxide (T2 MRI), and Cu-64 (PET). PET imaging was utilized to identify regions of macrophage accumulation; these regions were further probed by MRI to visualize macrophage distribution at high resolution. In both PET and MR images the probes enhanced contrast at sites of vascular inflammation, but not in normal vessel walls. MRI was able to identify discrete sites of inflammation that were blurred together at the low resolution of PET. Macrophage content in the lesions was confirmed by histology. CONCLUSIONS/SIGNIFICANCE The multimodal imaging approach allowed high-sensitivity and high-resolution mapping of biomarker distribution and may lead to a clinical method to predict plaque probability to rupture.
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Affiliation(s)
- Benjamin R. Jarrett
- Department of Biomedical Engineering, University of California Davis, Davis, California, United States of America
| | - Carlos Correa
- Department of Computer Science, University of California Davis, Davis, California, United States of America
| | - Kwan Liu Ma
- Department of Computer Science, University of California Davis, Davis, California, United States of America
| | - Angelique Y. Louie
- Department of Biomedical Engineering, University of California Davis, Davis, California, United States of America
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