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Zeng X, Zhang Z, Li D, Huang X, Wang Z, Wang Y, Zhou W, Wang P, Zhu M, Wei Q, Gong H, Wei L. Evaluation of monolithic crystal detector with dual-ended readout utilizing multiplexing method. Phys Med Biol 2024; 69:085003. [PMID: 38484392 DOI: 10.1088/1361-6560/ad3417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 03/14/2024] [Indexed: 04/04/2024]
Abstract
Objective.Monolithic crystal detectors are increasingly being applied in positron emission tomography (PET) devices owing to their excellent depth-of-interaction (DOI) resolution capabilities and high detection efficiency. In this study, we constructed and evaluated a dual-ended readout monolithic crystal detector based on a multiplexing method.Approach.We employed two 12 × 12 silicon photomultiplier (SiPM) arrays for readout, and the signals from the 12 × 12 array were merged into 12 X and 12 Y channels using channel multiplexing. In 2D reconstruction, three methods based on the centre of gravity (COG) were compared, and the concept of thresholds was introduced. Furthermore, a light convolutional neural network (CNN) was employed for testing. To enhance depth localization resolution, we proposed a method by utilizing the mutual information from both ends of the SiPMs. The source width and collimation effect were simulated using GEANT4, and the intrinsic spatial resolution was separated from the measured values.Main results.At an operational voltage of 29 V for the SiPM, an energy resolution of approximately 12.5 % was achieved. By subtracting a 0.8 % threshold from the total energy in every channel, a 2D spatial resolution of approximately 0.90 mm full width at half maximum (FWHM) can be obtained. Furthermore, a higher level of resolution, approximately 0.80 mm FWHM, was achieved using a CNN, with some alleviation of edge effects. With the proposed DOI method, a significant 1.36 mm FWHM average DOI resolution can be achieved. Additionally, it was found that polishing and black coating on the crystal surface yielded smaller edge effects compared to a rough surface with a black coating.Significance.The introduction of a threshold in COG method and a dual-ended readout scheme can lead to excellent spatial resolution for monolithic crystal detectors, which can help to develop PET systems with both high sensitivity and high spatial resolution.
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Affiliation(s)
- Xiangtao Zeng
- Beijing Engineering Research Centre of Radiographic Techniques and Equipment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Jinan Laboratory of Applied Nuclear Science, Jinan 250131, People's Republic of China
- CAEA Centre of Excellence on Nuclear Technology Applications for Nuclear Detection and Imaging, Beijing 100049, People's Republic of China
| | - Zhiming Zhang
- Beijing Engineering Research Centre of Radiographic Techniques and Equipment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Jinan Laboratory of Applied Nuclear Science, Jinan 250131, People's Republic of China
- CAEA Centre of Excellence on Nuclear Technology Applications for Nuclear Detection and Imaging, Beijing 100049, People's Republic of China
| | - Daowu Li
- Beijing Engineering Research Centre of Radiographic Techniques and Equipment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Jinan Laboratory of Applied Nuclear Science, Jinan 250131, People's Republic of China
- CAEA Centre of Excellence on Nuclear Technology Applications for Nuclear Detection and Imaging, Beijing 100049, People's Republic of China
| | - Xianchao Huang
- Beijing Engineering Research Centre of Radiographic Techniques and Equipment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Jinan Laboratory of Applied Nuclear Science, Jinan 250131, People's Republic of China
- CAEA Centre of Excellence on Nuclear Technology Applications for Nuclear Detection and Imaging, Beijing 100049, People's Republic of China
| | - Zhuoran Wang
- Beijing Engineering Research Centre of Radiographic Techniques and Equipment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Jinan Laboratory of Applied Nuclear Science, Jinan 250131, People's Republic of China
- CAEA Centre of Excellence on Nuclear Technology Applications for Nuclear Detection and Imaging, Beijing 100049, People's Republic of China
| | - Yingjie Wang
- Beijing Engineering Research Centre of Radiographic Techniques and Equipment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Jinan Laboratory of Applied Nuclear Science, Jinan 250131, People's Republic of China
- CAEA Centre of Excellence on Nuclear Technology Applications for Nuclear Detection and Imaging, Beijing 100049, People's Republic of China
| | - Wei Zhou
- Beijing Engineering Research Centre of Radiographic Techniques and Equipment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Jinan Laboratory of Applied Nuclear Science, Jinan 250131, People's Republic of China
- CAEA Centre of Excellence on Nuclear Technology Applications for Nuclear Detection and Imaging, Beijing 100049, People's Republic of China
| | - Peilin Wang
- Beijing Engineering Research Centre of Radiographic Techniques and Equipment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Jinan Laboratory of Applied Nuclear Science, Jinan 250131, People's Republic of China
- CAEA Centre of Excellence on Nuclear Technology Applications for Nuclear Detection and Imaging, Beijing 100049, People's Republic of China
| | - Meiling Zhu
- Beijing Engineering Research Centre of Radiographic Techniques and Equipment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Jinan Laboratory of Applied Nuclear Science, Jinan 250131, People's Republic of China
- CAEA Centre of Excellence on Nuclear Technology Applications for Nuclear Detection and Imaging, Beijing 100049, People's Republic of China
| | - Qing Wei
- Beijing Engineering Research Centre of Radiographic Techniques and Equipment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Jinan Laboratory of Applied Nuclear Science, Jinan 250131, People's Republic of China
- CAEA Centre of Excellence on Nuclear Technology Applications for Nuclear Detection and Imaging, Beijing 100049, People's Republic of China
| | - Huixing Gong
- Beijing Engineering Research Centre of Radiographic Techniques and Equipment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Jinan Laboratory of Applied Nuclear Science, Jinan 250131, People's Republic of China
- CAEA Centre of Excellence on Nuclear Technology Applications for Nuclear Detection and Imaging, Beijing 100049, People's Republic of China
| | - Long Wei
- Beijing Engineering Research Centre of Radiographic Techniques and Equipment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Jinan Laboratory of Applied Nuclear Science, Jinan 250131, People's Republic of China
- CAEA Centre of Excellence on Nuclear Technology Applications for Nuclear Detection and Imaging, Beijing 100049, People's Republic of China
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León-Quinto T, Madrigal R, Cabello E, Fimia A, Serna A. Morphological and biochemical responses of a neotropical pest insect to low temperatures. J Therm Biol 2024; 119:103795. [PMID: 38281313 DOI: 10.1016/j.jtherbio.2024.103795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 01/10/2024] [Accepted: 01/14/2024] [Indexed: 01/30/2024]
Abstract
As traditionally cold areas become warmer due to climate change, temperature could no longer be a barrier to the establishment of non-native insects. This is particularly relevant for pest insects from warm and tropical areas, mainly those with some tolerance to moderately low temperatures, which could expand their range into these new locations. From this perspective, in this work we studied the morphological and biochemical responses of the Neotropical pest Paysandisia archon to low temperatures, as part of a possible strategy to colonize new areas. To that end, wild larvae were exposed for 7 days to either low (1 and 5 °C) or ambient (23 °C) temperatures. We then quantified the inner and outer morphological changes, by X-Ray Computer Tomography and Digital Holographic Microscopy, as well as the accumulation of metabolites acting as potential endogenous cryoprotectants, by Spectrophotometry. We found that Paysandisia archon developed a cold-induced response based on different aspects. On the one hand, morphological changes occurred with a significant reduction both in fluids susceptible to freezing and fat body, together with the thickening, hardening and increased roughness of the integument. On the other hand, we found an increase in the hemolymph concentration of cryoprotective substances such as glucose (6-fold) and glycerol (2-fold), while trehalose remained unchanged. Surprisingly, this species did not show any evidence of cold-induced response unless the environmental temperature was remarkably low (1 °C). These results could be useful to improve models predicting the possible spread of such a pest, which should incorporate parameters related to its resistance to low temperatures.
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Affiliation(s)
- Trinidad León-Quinto
- Área de Zoología, Departamento Agroquímica y Medio Ambiente, Universidad Miguel Hernández, E3202-Elche, Alicante, Spain; Instituto de Bioingeniería, Universidad Miguel Hernández, E3202-Elche, Alicante, Spain.
| | - Roque Madrigal
- Departamento de Ciencia de Materiales, Óptica y Tecnología Electrónica, Universidad Miguel Hernández, E3202-Elche, Alicante, Spain.
| | - Esteban Cabello
- Centro de Investigación Operativa, Universidad Miguel Hernández, E3202-Elche, Alicante, Spain.
| | - Antonio Fimia
- Departamento de Ciencia de Materiales, Óptica y Tecnología Electrónica, Universidad Miguel Hernández, E3202-Elche, Alicante, Spain.
| | - Arturo Serna
- Departamento de Física Aplicada, Universidad Miguel Hernández, E3202-Elche, Alicante, Spain.
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Law SH, Ke CC, Chu CS, Liu SH, Weng MC, Ke LY, Chan HC. SPECT/CT imaging for tracking subendothelial retention of electronegative low-density lipoprotein in vivo. Int J Biol Macromol 2023; 250:126069. [PMID: 37536403 DOI: 10.1016/j.ijbiomac.2023.126069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 06/29/2023] [Accepted: 07/28/2023] [Indexed: 08/05/2023]
Abstract
The fifth subfraction of low-density lipoprotein (L5 LDL) can be separated from human LDL using fast-protein liquid chromatography with an anion exchange column. L5 LDL induces vascular endothelial injury both in vitro and in vivo through the lectin-like oxidized LDL receptor-1 (LOX-1). However, no in vivo evidence shows the tendency of L5 LDL deposition on vascular endothelium and links to dysfunction. This study aimed to investigate L5 LDL retention in vivo using SPECT/CT imaging, with Iodine-131 (131I)-labeled and injected into six-month-old apolipoprotein E knockout (apoE-/-) mice through tail veins. Besides, we examined the biodistribution of L5 LDL in tissues and analyzed the intracellular trafficking in human aortic endothelial cells (HAoECs) by confocal microscopy. The impacts of L5 LDL on HAoECs were analyzed using electron microscopy for mitochondrial morphology and western blotting for signaling. Results showed 131I-labeled-L5 was preferentially deposited in the heart and vessels compared to L1 LDL. Furthermore, L5 LDL was co-localized with the mitochondria and associated with mitofusin (MFN1/2) and optic atrophy protein 1 (OPA1) downregulation, leading to mitochondrial fission. In summary, L5 LDL exhibits a propensity for subendothelial retention, thereby promoting endothelial dysfunction and the formation of atherosclerotic lesions.
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Affiliation(s)
- Shi Hui Law
- Department of Medical Laboratory Science and Biotechnology, College of Health Sciences, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Chien-Chih Ke
- Department of Medical Imaging and Radiological Sciences, College of Health Sciences, Kaohsiung Medical University, Taiwan; Drug Development and Value Creation Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Chih-Sheng Chu
- Division of Cardiology, Department of Internal Medicine, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung, Taiwan; Division of Cardiology, Department of International Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Center for Lipid Biosciences, Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
| | - Shu-Hsuan Liu
- Faculty of Health Sciences, Bristol Medical School, Bristol, England, United Kingdom
| | - Mao-Chi Weng
- Isotope Application Division, Institute of Nuclear Energy Research, Taoyuan, Taiwan
| | - Liang-Yin Ke
- Department of Medical Laboratory Science and Biotechnology, College of Health Sciences, Kaohsiung Medical University, Kaohsiung, Taiwan; Center for Lipid Biosciences, Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Graduate Institute of Medicine & Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Drug Development and Value Creation Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan.
| | - Hua-Chen Chan
- Department of Medical Laboratory Science, College of Medicine, I-Shou University, Kaohsiung, Taiwan.
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Liu Z, Zheng C, Zhao N, Huang Y, Chen J, Yang Y. A GPU-accelerated Monte Carlo dose computation engine for small animal radiotherapy. Med Phys 2023; 50:5238-5247. [PMID: 37014307 DOI: 10.1002/mp.16409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 03/07/2023] [Accepted: 03/09/2023] [Indexed: 04/05/2023] Open
Abstract
BACKGROUND Accurate dose computation is critical in precision small animal radiotherapy. The Monte Carlo simulation method is the gold standard for radiation dose computation but has not been widely implemented in practice due to its low computation efficiency. PURPOSE This study aims to develop a GPU-accelerated radiation dose engine (GARDEN) based on the Monte Carlo simulation method for fast and accurate dose computation. METHODS In the GARDEN simulation, Compton scattering, Rayleigh scattering, and photoelectric effect were considered. The Woodcock tracking algorithm and GPU-specific acceleration techniques were used to obtain a high computational efficiency. Benchmark studies against both Geant4 simulations and experimental measurements were performed for various phantoms and beams. Finally, a conformal arc treatment plan was designed for a lung tumor to further evaluate the accuracy and efficiency in small animal radiotherapy. RESULT The engine attained a speed-up of 1232 times in a homogeneous water phantom and 935 times in a water-bone-lung heterogeneous phantom when compared with Geant4. Both the depth-dose curves and cross-sectional dose profiles for various radiation field sizes showed a great match between measurements and the GARDEN calculations. For in vivo dose validation, the differences between calculations and measurements in the mouse thorax and abdomen were 2.50% ± 1.50% and 1.56% ± 1.40%, respectively. The computation time for an arc treatment plan delivered from 36 angles was 2 s at a <1% uncertainty level using an NVIDIA GeForce RTX 2060 SUPER GPU. When compared with Geant4, the 3D gamma comparison passing rate was 98.7% at 2%/0.3 mm criteria. CONCLUSION GARDEN can perform fast and accurate dose computations in heterogeneous tissue environments and is expected to play a vital role in image-guided precision small animal radiotherapy.
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Affiliation(s)
- Zihao Liu
- Department of Engineering and Applied Physics, University of Science and Technology of China, Hefei, Anhui, China
| | - Cheng Zheng
- Department of Engineering and Applied Physics, University of Science and Technology of China, Hefei, Anhui, China
| | - Ning Zhao
- Department of Engineering and Applied Physics, University of Science and Technology of China, Hefei, Anhui, China
| | - Yunwen Huang
- Department of Engineering and Applied Physics, University of Science and Technology of China, Hefei, Anhui, China
- Department of Radiation Oncology, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Jiahao Chen
- Department of Engineering and Applied Physics, University of Science and Technology of China, Hefei, Anhui, China
| | - Yidong Yang
- Department of Engineering and Applied Physics, University of Science and Technology of China, Hefei, Anhui, China
- Department of Radiation Oncology, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
- Ion Medical Research Institute, University of Science and Technology of China, Hefei, Anhui, China
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Simon KS, Coelho LC, Veloso PHDH, Melo-Silva CA, Morais JAV, Longo JPF, Figueiredo F, Viana L, Silva Pereira I, Amado VM, Mortari MR, Bocca AL. Innovative Pre-Clinical Data Using Peptides to Intervene in the Evolution of Pulmonary Fibrosis. Int J Mol Sci 2023; 24:11049. [PMID: 37446227 DOI: 10.3390/ijms241311049] [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: 05/19/2023] [Revised: 06/20/2023] [Accepted: 06/26/2023] [Indexed: 07/15/2023] Open
Abstract
Idiopathic pulmonary fibrosis (IPF) is a progressive, relentless, and deadly disease. Little is known about its pathogenetic mechanisms; therefore, developing efficient pharmacological therapies is challenging. This work aimed to apply a therapeutic alternative using immunomodulatory peptides in a chronic pulmonary fibrosis murine model. BALB/c mice were intratracheally instilled with bleomycin (BLM) and followed for 30 days. The mice were treated with the immune modulatory peptides ToAP3 and ToAP4 every three days, starting on the 5th day post-BLM instillation. ELISA, qPCR, morphology, and respiratory function analyses were performed. The treatment with both peptides delayed the inflammatory process observed in the non-treated group, which showed a fibrotic process with alterations in the production of collagen I, III, and IV that were associated with significant alterations in their ventilatory mechanics. The ToAP3 and ToAP4 treatments, by lung gene modulation patterns, indicated that distinct mechanisms determine the action of peptides. Both peptides controlled the experimental IPF, maintaining the tissue characteristics and standard function properties and regulating fibrotic-associated cytokine production. Data obtained in this work show that the immune response regulation by ToAP3 and ToAP4 can control the alterations that cause the fibrotic process after BLM instillation, making both peptides potential therapeutic alternatives and/or adjuvants for IPF.
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Affiliation(s)
- Karina Smidt Simon
- Department of Cellular Biology, Institute of Biological Sciences, University of Brasilia, Brasilia 70910-900, Brazil
| | - Luísa Coutinho Coelho
- Department of Cellular Biology, Institute of Biological Sciences, University of Brasilia, Brasilia 70910-900, Brazil
| | | | - Cesar Augusto Melo-Silva
- Laboratory of Respiratory Physiology, Medical School, University of Brasilia, Brasilia 70910-900, Brazil
- Hospital of the University of Brasilia, University of Brasilia, Brasilia 70910-900, Brazil
| | | | - João Paulo Figueiró Longo
- Department of Genetics and Morphology, Institute of Biological Sciences, University of Brasilia, Brasilia 70910-900, Brazil
| | - Florencio Figueiredo
- Laboratory of Pathology, Medical School, University of Brasilia, Brasilia 70910-900, Brazil
| | - Leonora Viana
- Laboratory of Pathology, Medical School, University of Brasilia, Brasilia 70910-900, Brazil
| | - Ildinete Silva Pereira
- Department of Cellular Biology, Institute of Biological Sciences, University of Brasilia, Brasilia 70910-900, Brazil
| | - Veronica Moreira Amado
- Laboratory of Respiratory Physiology, Medical School, University of Brasilia, Brasilia 70910-900, Brazil
- Hospital of the University of Brasilia, University of Brasilia, Brasilia 70910-900, Brazil
| | - Marcia Renata Mortari
- Department de Physiological Sciences, Institute of Biological Sciences, University of Brasilia, Brasilia 70910-900, Brazil
| | - Anamelia Lorenzetti Bocca
- Department of Cellular Biology, Institute of Biological Sciences, University of Brasilia, Brasilia 70910-900, Brazil
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Tashima H, Nishina T, Takyu S, Nishikido F, Suga M, Yamaya T. Optimum selection for multi-interaction events in Compton-PET hybrid reconstruction: a Monte Carlo study. Radiol Phys Technol 2023; 16:254-261. [PMID: 36943646 DOI: 10.1007/s12194-023-00714-5] [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: 07/04/2022] [Revised: 03/13/2023] [Accepted: 03/13/2023] [Indexed: 03/23/2023]
Abstract
In Compton PET, that has a scatterer inserted inside a PET ring, there are multi-interaction events that can be treated as both PET and Compton events. A PET event from multi-interaction events that include a Compton event and a photoelectric absorption event or two Compton events can be extracted by applying a PET recovery method. In this study, we aimed to establish a method to maximize image quality by utilizing such redundant events. We conducted brain-scale Monte Carlo simulations of a C-shaped Compton-PET geometry and a whole gamma imaging (WGI) geometry. Images were reconstructed by a hybrid image reconstruction method combining both PET and Compton events. The result showed that the spatial resolution was improved when treated as PET events while keeping the noise level. The effect of improvement was more significant in WGI than in C-shaped Compton PET because the number of events recovered as PET events having more accurate spatial information was much larger in WGI. When the PET-recovered multi-interaction events were also included as Compton events in the hybrid reconstruction, we did not observe any improvement in image quality, while the number of used events was largest. The results suggested that treating events as PET events exclusively was better for image quality.
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Affiliation(s)
- Hideaki Tashima
- National Institutes for Quantum Science and Technology, 4-9-1, Anagawa, Inage-ku, Chiba-shi, Chiba, 263-8555, Japan.
| | - Takumi Nishina
- National Institutes for Quantum Science and Technology, 4-9-1, Anagawa, Inage-ku, Chiba-shi, Chiba, 263-8555, Japan
- Medical Engineering Course, Graduate School of Science and Engineering, Chiba University, 1-33, Yayoicho, Inage-ku, Chiba-shi, Chiba, 263-8522, Japan
| | - Sodai Takyu
- National Institutes for Quantum Science and Technology, 4-9-1, Anagawa, Inage-ku, Chiba-shi, Chiba, 263-8555, Japan
| | - Fumihiko Nishikido
- National Institutes for Quantum Science and Technology, 4-9-1, Anagawa, Inage-ku, Chiba-shi, Chiba, 263-8555, Japan
| | - Mikio Suga
- Medical Engineering Course, Graduate School of Science and Engineering, Chiba University, 1-33, Yayoicho, Inage-ku, Chiba-shi, Chiba, 263-8522, Japan
- Center for Frontier Medical Engineering, Chiba University, 1-33, Yayoicho, Inage-ku, Chiba-shi, Chiba, 263-8522, Japan
| | - Taiga Yamaya
- National Institutes for Quantum Science and Technology, 4-9-1, Anagawa, Inage-ku, Chiba-shi, Chiba, 263-8555, Japan
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Kapoor S, Kala D, Svoboda J, Daněk J, Faridová A, Brnoliaková Z, Mikulecká A, Folbergrová J, Otáhal J. The effect of sulforaphane on perinatal hypoxic-ischemic brain injury in rats. Physiol Res 2022; 71:401-411. [PMID: 35616041 DOI: 10.33549/physiolres.934878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Perinatal hypoxic-ischemic insult (HII) is one of the main devastating causes of morbidity and mortality in newborns. HII induces brain injury which evolves to neurological sequelae later in life. Hypothermia is the only therapeutic approach available capable of diminishing brain impairment after HII. Finding a novel therapeutic method to reduce the severity of brain injury and its consequences is critical in neonatology. The present paper aimed to evaluate the effect of sulforaphane (SFN) pre-treatment on glucose metabolism, neurodegeneration, and functional outcome at the acute, sub-acute, and sub-chronic time intervals in the experimental model of perinatal hypoxic-ischemic insult in rats. To estimate the effect of SFN on brain glucose uptake we have performed 18F-deoxyglucose (FDG) microCT/PET. The activity of FDG was determined in the hippocampus and sensorimotor cortex. Neurodegeneration was assessed by histological analysis of Nissl-stained brain sections. To investigate functional outcomes a battery of behavioral tests was employed. We have shown that although SFN possesses a protective effect on glucose uptake in the ischemic hippocampus 24 h and 1 week after HII, no effect has been observed in the motor cortex. We have further shown that the ischemic hippocampal formation tends to be thinner in HIE and SFN treatment tends to reverse this pattern. We have observed subtle chronic movement deficit after HII detected by ladder rung walking test with no protective effect of SFN. SFN should be thus considered as a potent neuroprotective drug with the capability to interfere with pathophysiological processes triggered by perinatal hypoxic-ischemic insult.
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Affiliation(s)
- S Kapoor
- Centre of Experimental Medicine, Institute of Experimental Pharmacology and Toxicology, Slovak Academy of Sciences, Bratislava, Slovak Republic; Laboratory of Developmental Epileptology, Institute of Physiology of the Czech Academy of Sciences, Czech Republic.
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Freire M, Echegoyen S, Gonzalez-Montoro A, Sanchez F, Gonzalez AJ. Performance evaluation of side-by-side optically coupled monolithic LYSO crystals. Med Phys 2022; 49:5616-5626. [PMID: 35689501 PMCID: PMC9545681 DOI: 10.1002/mp.15792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 05/12/2022] [Accepted: 05/25/2022] [Indexed: 11/12/2022] Open
Abstract
Background Significant interest has been recently shown for using monolithic scintillation crystals in molecular imaging systems, such as positron emission tomography (PET) scanners. Monolithic‐based PET scanners result in a lower cost and higher sensitivity, in contrast to systems based on the more conventional pixellated configuration. The monolithic design allows one to retrieve depth‐of‐interaction information of the impinging 511 keV photons without the need for additional hardware materials or complex positioning algorithms. However, the so‐called edge‐effect inherent to monolithic‐based approaches worsens the detector performance toward the crystal borders due to the truncation of the light distribution, thus decreasing positioning accuracy. Purpose The main goal of this work is to experimentally demonstrate the detector performance improvement when machine‐learning artificial neural‐network (NN) techniques are applied for positioning estimation in multiple monolithic scintillators optically coupled side‐by‐side. Methods In this work, we show the performance evaluation of two LYSO crystals of 33 × 25.4 × 10 mm3 optically coupled by means of a high refractive index adhesive compound (Meltmount, refractive index n = 1.70). A 12 × 12 silicon photomultiplier array has been used as photosensor. For comparison, the same detector configuration was tested for two additional coupling cases: (1) optical grease (n = 1.46) in between crystals, and (2) isolated crystals using black paint with an air gap at the interface (named standard configuration). Regarding 2D photon positioning (XY plane), we have tested two different methods: (1) a machine‐learning artificial NN algorithm and (2) a squared‐charge (SC) centroid technique. Results At the interface region of the detector, the SC method achieved spatial resolutions of 1.7 ± 0.3, 2.4 ± 0.3, and 2.6 ± 0.4 mm full‐width at half‐maximum (FWHM) for the Meltmount, grease, and standard configurations, respectively. These values improve to 1.0 ± 0.2, 1.2 ± 0.2, and 1.2 ± 0.3 mm FWHM when the NN algorithm was employed. Regarding energy performance, resolutions of 18 ± 2%, 20 ± 2%, and 23 ± 3% were obtained at the interface region of the detector for Meltmount, grease, and standard configurations, respectively. Conclusions The results suggest that optically coupling together scintillators with a high refractive index adhesive, in combination with an NN algorithm, reduces edge‐effects and makes it possible to build scanners with almost no gaps in between detectors.
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Affiliation(s)
- Marta Freire
- Instituto de Instrumentación para Imagen Molecular (I3M), Centro Mixto CSIC - Universitat Politècnica de València, Valencia, Spain
| | - Sara Echegoyen
- Instituto de Instrumentación para Imagen Molecular (I3M), Centro Mixto CSIC - Universitat Politècnica de València, Valencia, Spain
| | - Andrea Gonzalez-Montoro
- Instituto de Instrumentación para Imagen Molecular (I3M), Centro Mixto CSIC - Universitat Politècnica de València, Valencia, Spain
| | - Filomeno Sanchez
- Instituto de Instrumentación para Imagen Molecular (I3M), Centro Mixto CSIC - Universitat Politècnica de València, Valencia, Spain
| | - Antonio J Gonzalez
- Instituto de Instrumentación para Imagen Molecular (I3M), Centro Mixto CSIC - Universitat Politècnica de València, Valencia, Spain
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Kuang Z, Wang X, Ren N, Wu S, Zeng T, Niu M, Cong L, Sang Z, Liu Z, Sun T, Hu Z, Liang D, Liu X, Zheng H, Yang Y. Physical and Imaging Performance of SIAT aPET under Different Energy Windows and Timing Windows. Med Phys 2022; 49:1432-1444. [PMID: 35049067 DOI: 10.1002/mp.15455] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 12/20/2021] [Accepted: 12/22/2021] [Indexed: 11/07/2022] Open
Abstract
PURPOSE The performance of small animal PET scanners depends on the energy window (EW) and timing window (TW). In NEMA Standards Publication NU 4-2008, detailed procedures of the performance measurements are defined, but the EW and TW are not specified. In this work, the effects of EW and TW on the physical and imaging performance of SIAT aPET will be evaluated. METHODS First, the flood histogram, energy resolution and timing resolution were measured for a detector of SIAT aPET. Second, the spatial resolutions were measured with different EWs. Third, the sensitivities, the scatter fractions (SFs), and noise equivalent count rates (NECRs) of a mouse-sized phantom and a rat-sized phantom, the recovery coefficients (RCs) of rods of different sizes, and the percentage standard deviation (%STD) of the NEMA image quality phantom were measured for different EWs and TWs. Last, images of a hot rod phantom, a mouse heart and a rat brain were acquired from the scanner with different EWs. RESULTS The SIAT aPET detectors provided good flood histograms such that all but the corner crystals can be resolved even with lower energies of 250-350 keV, an average energy resolution of 21.1±1.9 % and an average timing resolution of 2.63±0.69 ns. The average spatial resolutions obtained with EWs of 250-350 keV and 450-550 keV are 0.68 mm and 0.75 mm. For EWs of 250-750 keV, 350-750 keV, and 450-750 keV with a fixed TW of 12 ns, the sensitivities at center of field of view are 16.0%, 11.9%, and 8.2%, the peak NECRs of a mouse-sized phantom are 355.6 kcps, 324.4 kcps, and 249.4 kcps, and the peak NECRs of a rat-sized phantom are 148.5 kcps, 144.3 kcps, and 117.7 kcps, respectively. For the TWs of 4 ns, 8 ns,12 ns, and 20 ns with a fixed EW of 350-750 keV, the sensitivities at center of field of view are 9.6%, 11.4%, 11.9%, and 12.2%, the peak NECRs of a mouse-sized phantom are 260.1 kcps, 311.5 kcps, 324.4 kcps and 324.9 kcps, and the peak NECRs of a rat-sized phantom are 110.5 kcps, 137.3 kcps,144.3 kcps and 142.6 kcps, respectively. Narrowing the EW and TW improves the RCs of rods of all sizes, and the %STD of images obtained with different EWs and TWs are similar. Rods with diameter down to 0.8 mm can be visually resolved from images of the hot rod phantom obtained with different EWs. Images of mouse heart with high spatial resolution and rat brain with detail brain structure were obtained with different EWs. Images of both phantom and in-vivo animals obtained with different EWs only showed subtle difference. CONCLUSION The performance of SIAT aPET under different EWs and TWs was compared. The EW and TW affect the sensitivity, SF, and NECR, but not the spatial resolution and animal images of SIAT aPET, which imply that careful optimization of the EW and TW is not required. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Zhonghua Kuang
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China.,Shenzhen College of Advanced Technology, University of Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Xiaohui Wang
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Ning Ren
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - San Wu
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Tianyi Zeng
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Ming Niu
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Longhan Cong
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Ziru Sang
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Zheng Liu
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Tao Sun
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Zhanli Hu
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Dong Liang
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Xin Liu
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Hairong Zheng
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Yongfeng Yang
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
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10
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Bandi F, Ilisie V, Vornicu I, Carmona-Galán R, Benlloch JM, Rodríguez-Vázquez Á. Architecture-Level Optimization on Digital Silicon Photomultipliers for Medical Imaging. SENSORS (BASEL, SWITZERLAND) 2021; 22:122. [PMID: 35009665 PMCID: PMC8749722 DOI: 10.3390/s22010122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 12/07/2021] [Accepted: 12/21/2021] [Indexed: 06/14/2023]
Abstract
Silicon photomultipliers (SiPMs) are arrays of single-photon avalanche diodes (SPADs) connected in parallel. Analog silicon photomultipliers are built in custom technologies optimized for detection efficiency. Digital silicon photomultipliers are built in CMOS technology. Although CMOS SPADs are less sensitive, they can incorporate additional functionality at the sensor plane, which is required in some applications for an accurate detection in terms of energy, timestamp, and spatial location. This additional circuitry comprises active quenching and recharge circuits, pulse combining and counting logic, and a time-to-digital converter. This, together with the disconnection of defective SPADs, results in a reduction of the light-sensitive area. In addition, the pile-up of pulses, in space and in time, translates into additional efficiency losses that are inherent to digital SiPMs. The design of digital SiPMs must include some sort of optimization of the pixel architecture in order to maximize sensitivity. In this paper, we identify the most relevant variables that determine the influence of SPAD yield, fill factor loss, and spatial and temporal pile-up in the photon detection efficiency. An optimum of 8% is found for different pixel sizes. The potential benefits of molecular imaging of these optimized and small-sized pixels with independent timestamping capabilities are also analyzed.
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Affiliation(s)
- Franco Bandi
- Organisation Européenne Pour la Recherche Nucléaire, Experimental Physics Department, Esplanade des Particules 1, 1211 Meyrin, Switzerland
| | - Victor Ilisie
- Escuela de Ciencias, Ingeniería y Diseño, Universidad Europea de Valencia, Passeig de l’Albereda, 7, 46010 Valencia, Spain
| | - Ion Vornicu
- Silicon Austria Labs, Frontend Integrated Circuits & Systems and RF Systems, Europastraße 12, 9524 Villach, Austria;
| | - Ricardo Carmona-Galán
- Instituto de Microelectrónica de Sevilla (IMSE-CNM), CSIC-Universidad de Sevilla, 41092 Sevilla, Spain; (R.C.-G.); (Á.R.-V.)
| | - José M. Benlloch
- Institute for Instrumentation in Molecular Imaging (I3M), CSIC-Universitat Politècnica de València, 46022 Valencia, Spain;
| | - Ángel Rodríguez-Vázquez
- Instituto de Microelectrónica de Sevilla (IMSE-CNM), CSIC-Universidad de Sevilla, 41092 Sevilla, Spain; (R.C.-G.); (Á.R.-V.)
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11
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The Effect of Sulphoraphane on Brain Glucose Uptake during Neonatal Hypoxic-Ischemic Encephalopathy in Newborn Rats. EUROPEAN PHARMACEUTICAL JOURNAL 2021. [DOI: 10.2478/afpuc-2021-0013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
Neonatal hypoxic-ischemic insult (HII) is one of the leading causes of morbidity and mortality in newborns. It has long-term consequences and represents a socioeconomic burden. It is an urgent issue in current neonatology. The aim of the present pilot study was to evaluate the possible effect of sulforaphane on brain glucose uptake expressed as 18F-fluorodeoxyglucose (18F-FDG) activity at the acute, subacute, and subchronic time intervals after the experimental perinatal HII in rats. Significant protection has been observed in the hippocampus 5 weeks after the insult as represented by normalisations of interhemispheric ratio of measured 18F-FDG activity. In conclusion, positron emission tomography (PET) with 18F-FDG revealed a protective effect of SFN on glucose metabolism in the subchronic phase after HII. Further research within the field of neonatal HII in newborn rats will be necessary.
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12
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Cheng X, Hu K, Yang D, Shao Y. A compact and lightweight small animal PET with uniform high-resolution for onboard PET/CT image-guided preclinical radiation oncology research. Phys Med Biol 2021; 66. [PMID: 34592731 DOI: 10.1088/1361-6560/ac2bb4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 09/30/2021] [Indexed: 11/12/2022]
Abstract
OBJECTIVE In contrast to clinical radiation therapy (RT) that ubiquitously uses PET/CT image to accurately guide RT, all current commercial animal irradiators can only provide CT image-guided preclinical RT that severely limits their capability for preclinical and compatibility for translational radiation oncology research. To address this problem, we have developed a compact and lightweight PET with uniform, high spatial resolution that is suited to be installed inside an existing animal irradiator for potential onboard PET/CT image-guided preclinical RT research. APPROACH The design focused on the balance of achieving sufficient imaging performance for practical preclinical RT guidance with constrained size and weight. The detector head consists of a ring of 12 detector panels in a dodecagon configuration and 12 front-end electronics boards that are closely attached to the detector panels. The overall size and weight of the detector head are 33.0 cm diameter, 11.0 cm axial length and ∼6.5 kg weight that can be installed inside an existing irradiator. Each detector panel has a 30 × 30 array of 1 × 1 × 20 mm3LYSO scintillators with depth-of-interaction (DOI) measurement. The front-end electronics boards process and convert detected signals to digital signals and transfer them to system electronics and data acquisition located outside the irradiator through low-voltage-differential-signaling cables. MAIN RESULTS The typical energy, DOI and coincidence timing resolutions are around 22.1%, 3.1 mm, and 1.92 ns. The imaging field-of-view (FOV) is 8.0 cm diameter and 3.5 cm axial length. The performance evaluations show a 1.8% sensitivity at the center FOV, uniform ∼1.1 mm resolution within 6 cm diameter FOV, and all rods of 1.0 mm diameter can be clearly resolved from the image of an ultra-micro hot-rods phantom. SIGNIFICANCE Overall, this compact and lightweight PET has demonstrated its designed capability and performance sufficient for providing onboard functional/biological/molecular image to guide the preclinical RT research.
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Affiliation(s)
- Xinyi Cheng
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75057, United States of America
| | - Kun Hu
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75057, United States of America
| | - Dongxu Yang
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75057, United States of America
| | - Yiping Shao
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75057, United States of America
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Wargocka-Matuszewska W, Fiedorowicz K, Rugowska A, Bednarowicz K, Zimna A, Cheda Ł, Hamankiewicz P, Kilian K, Fiedorowicz M, Drabik M, Rozwadowska N, Rogulski Z, Kurpisz M. Molecular imaging of myogenic stem/progenitor cells with [ 18F]-FHBG PET/CT system in SCID mice model of post-infarction heart. Sci Rep 2021; 11:19825. [PMID: 34615887 PMCID: PMC8494811 DOI: 10.1038/s41598-021-98861-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 07/23/2021] [Indexed: 11/08/2022] Open
Abstract
Preclinical and clinical studies have shown that stem cells can promote the regeneration of damaged tissues, but therapeutic protocols need better quality control to confirm the location and number of transplanted cells. This study describes in vivo imaging while assessing reporter gene expression by its binding to a radiolabelled molecule to the respective receptor expressed in target cells. Five mice underwent human skeletal muscle-derived stem/progenitor cell (huSkMDS/PC EF1-HSV-TK) intracardial transplantation after induction of myocardial infarction (MI). The metabolic parameters of control and post-infarction stem progenitor cell-implanted mice were monitored using 2-deoxy-18F-fluorodeoxyglucose ([18F]-FDG) before and after double promotor/reporter probe imaging with 9-(4-18F-fluoro-3-[hydroxymethyl]butyl)guanine ([18F]-FHBG) using positron emission tomography (PET) combined with computed tomography (CT). Standardized uptake values (SUVs) were then calculated based on set regions of interest (ROIs). Experimental animals were euthanized after magnetic resonance imaging (MRI). Molecular [18F]-FHBG imaging of myogenic stem/progenitor cells in control and post-infarction mice confirmed the survival and proliferation of transplanted cells, as shown by an increased or stable signal from the PET apparatus throughout the 5 weeks of monitoring. huSkMDS/PC EF1-HSV-TK transplantation improved cardiac metabolic ([18F]-FDG with PET) and haemodynamic (MRI) parameters. In vivo PET/CT and MRI revealed that the precise use of a promotor/reporter probe incorporated into stem/progenitor cells may improve non-invasive monitoring of targeted cellular therapy in the cardiovascular system.
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Affiliation(s)
- Weronika Wargocka-Matuszewska
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Żwirki i Wigury 101, 02-089, Warsaw, Poland
| | - Katarzyna Fiedorowicz
- Institute of Human Genetics Polish Academy of Science, Strzeszyńska 32, 60-479, Poznan, Poland
| | - Anna Rugowska
- Institute of Human Biology and Evolution, Faculty of Biology Adam, Mickiewicz University, Uniwersytetu Poznańskiego 6, 61-614, Poznan, Poland
| | - Karolina Bednarowicz
- Institute of Human Genetics Polish Academy of Science, Strzeszyńska 32, 60-479, Poznan, Poland
| | - Agnieszka Zimna
- Institute of Human Genetics Polish Academy of Science, Strzeszyńska 32, 60-479, Poznan, Poland
| | - Łukasz Cheda
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Żwirki i Wigury 101, 02-089, Warsaw, Poland
| | - Paulina Hamankiewicz
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Żwirki i Wigury 101, 02-089, Warsaw, Poland
| | - Krzysztof Kilian
- Heavy Ion Laboratory, University of Warsaw, Pasteura 5A, 02-093, Warsaw, Poland
| | - Michał Fiedorowicz
- Mossakowski Medical Research Centre Polish Academy of Science, Pawińskiego 5, 02-106, Warsaw, Poland
| | - Monika Drabik
- Mossakowski Medical Research Centre Polish Academy of Science, Pawińskiego 5, 02-106, Warsaw, Poland
| | - Natalia Rozwadowska
- Institute of Human Genetics Polish Academy of Science, Strzeszyńska 32, 60-479, Poznan, Poland
| | - Zbigniew Rogulski
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Żwirki i Wigury 101, 02-089, Warsaw, Poland.
| | - Maciej Kurpisz
- Institute of Human Genetics Polish Academy of Science, Strzeszyńska 32, 60-479, Poznan, Poland.
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14
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Jaliparthi G, Martone PF, Stolin AV, Raylman RR. Deep residual-convolutional neural networks for event positioning in a monolithic annular PET scanner. Phys Med Biol 2021; 66. [PMID: 34153950 DOI: 10.1088/1361-6560/ac0d0c] [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] [Received: 02/17/2021] [Accepted: 06/21/2021] [Indexed: 11/12/2022]
Abstract
PET scanners based on monolithic pieces of scintillator can potentially produce superior performance characteristics (high spatial resolution and detection sensitivity, for example) compared to conventional PET scanners. Consequently, we initiated development of a preclinical PET system based on a single 7.2 cm long annulus of LYSO, called AnnPET. While this system could facilitate creation of high-quality images, its unique geometry results in optics that can complicate estimation of event positioning in the detector. To address this challenge, we evaluated deep-residual convolutional neural networks (DR-CNN) to estimate the three-dimensional position of annihilation photon interactions. Monte Carlo simulations of the AnnPET scanner were used to replicate the physics, including optics, of the scanner. It was determined that a ten-layer-DR-CNN was most suited to application with AnnPET. The errors between known event positions, and those estimated by this network and those calculated with the commonly used center-of-mass algorithm (COM) were used to assess performance. The mean absolute errors (MAE) for the ten-layer-DR-CNN-based event positions were 0.54 mm, 0.42 mm and 0.45 mm along thex(axial)-,y(transaxial)- andz- (depth-of-interaction) axes, respectively. For COM estimates, the MAEs were 1.22 mm, 1.04 mm and 2.79 mm in thex-,y- andz-directions, respectively. Reconstruction of the network-estimated data with the 3D-FBP algorithm (5 mm source offset) yielded spatial resolutions (full-width-at-half-maximum (FWHM)) of 0.8 mm (radial), 0.7 mm (tangential) and 0.71 mm (axial). Reconstruction of the COM-derived data yielded spatial resolutions (FWHM) of 1.15 mm (radial), 0.96 mm (tangential) and 1.14 mm (axial). These findings demonstrated that use of a ten-layer-DR-CNN with a PET scanner based on a monolithic annulus of scintillator has the potential to produce excellent performance compared to standard analytical methods.
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Affiliation(s)
- Gangadhar Jaliparthi
- Center for Advanced Imaging, Department of Radiology, School of Medicine, West Virginia University, Morgantown, WV, United States of America
| | - Peter F Martone
- Center for Advanced Imaging, Department of Radiology, School of Medicine, West Virginia University, Morgantown, WV, United States of America
| | - Alexander V Stolin
- Center for Advanced Imaging, Department of Radiology, School of Medicine, West Virginia University, Morgantown, WV, United States of America
| | - Raymond R Raylman
- Center for Advanced Imaging, Department of Radiology, School of Medicine, West Virginia University, Morgantown, WV, United States of America
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15
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Cicone F, Denoël T, Gnesin S, Riggi N, Irving M, Jakka G, Schaefer N, Viertl D, Coukos G, Prior JO. Preclinical Evaluation and Dosimetry of [ 111In]CHX-DTPA-scFv78-Fc Targeting Endosialin/Tumor Endothelial Marker 1 (TEM1). Mol Imaging Biol 2021; 22:979-991. [PMID: 31993928 PMCID: PMC7343747 DOI: 10.1007/s11307-020-01479-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Purpose Endosialin/tumor endothelial marker-1 (TEM1) is an attractive theranostic target expressed by the microenvironment of a wide range of tumors, as well as by sarcoma and neuroblastoma cells. We report on the radiolabeling and preclinical evaluation of the scFv78-Fc, a fully human TEM1-targeting antibody fragment cross-reactive with mouse TEM1. Procedures The scFv78-Fc was conjugated with the chelator p-SCN-Bn-CHX-A”-DTPA, followed by labeling with indium-111. The number of chelators per molecule was estimated by mass spectrometry. A conventional saturation assay, extrapolated to infinite antigen concentration, was used to determine the immunoreactive fraction of the radioimmunoconjugate. The radiopharmaceutical biodistribution was assessed in immunodeficient mice grafted with Ewing’s sarcoma RD-ES and neuroblastoma SK-N-AS human TEM1-positive tumors. The full biodistribution studies were preceded by a dose-escalation experiment based on the simultaneous administration of the radiopharmaceutical with increasing amounts of unlabeled scFv78-Fc. Radiation dosimetry extrapolations to human adults were obtained from mouse biodistribution data according to established methodologies and additional assumptions concerning the impact of the tumor antigenic sink in the cross-species translation. Results [111In]CHX-DTPA-scFv78-Fc was obtained with a radiochemical purity > 98 % after 1 h incubation at 42 °C and ultrafiltration. It showed good stability in human serum and > 70 % immunoreactive fraction. Biodistribution data acquired in tumor-bearing mice confirmed fast blood clearance and specific tumor targeting in both xenograft models. The radiopharmaceutical off-target uptake was predominantly abdominal. After a theoretical injection of [111In]CHX-DTPA-scFv78-Fc to the reference person, the organs receiving the highest absorbed dose would be the spleen (0.876 mGy/MBq), the liver (0.570 mGy/MBq) and the kidneys (0.298 mGy/MBq). The total body dose and the effective dose would be 0.058 mGy/MBq and 0.116 mSv/MBq, respectively. Conclusions [111In]CHX-DTPA-scFv78-Fc binds specifically to endosialin/TEM1 in vitro and in vivo. Dosimetry estimates are in the range of other monoclonal antibodies radiolabeled with indium-111. [111In]CHX-DTPA-scFv78-Fc could be potentially translated into clinic. Electronic supplementary material The online version of this article (10.1007/s11307-020-01479-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Francesco Cicone
- Department of Nuclear Medicine and Molecular Imaging, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland. .,Department of Experimental and Clinical Medicine, Unit of Nuclear Medicine, "Magna Graecia" University of Catanzaro, Catanzaro, Italy.
| | - Thibaut Denoël
- Department of Nuclear Medicine and Molecular Imaging, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Silvano Gnesin
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Nicolo Riggi
- Experimental Pathology Service, Institute of Pathology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Melita Irving
- Department of Oncology, Ludwig Institute for Cancer Research, Lausanne Branch, University of Lausanne, CH-1066, Epalinges, Switzerland
| | - Gopinadh Jakka
- Department of Oncology, Ludwig Institute for Cancer Research, Lausanne Branch, University of Lausanne, CH-1066, Epalinges, Switzerland
| | - Niklaus Schaefer
- Department of Nuclear Medicine and Molecular Imaging, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - David Viertl
- Department of Nuclear Medicine and Molecular Imaging, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - George Coukos
- Department of Oncology, Ludwig Institute for Cancer Research, Lausanne Branch, University of Lausanne, CH-1066, Epalinges, Switzerland
| | - John O Prior
- Department of Nuclear Medicine and Molecular Imaging, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
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Overstreet AMC, Grayson BE, Boger A, Bakke D, Carmody EM, Bales CE, Paski SC, Murphy SF, Dethlefs CR, Shannon KJ, Adlaka KR, Wolford CE, Campiti VJ, Raghunandan CV, Seeley RJ, Boone DL. Gastrokine-1, an anti-amyloidogenic protein secreted by the stomach, regulates diet-induced obesity. Sci Rep 2021; 11:9477. [PMID: 33947892 PMCID: PMC8096951 DOI: 10.1038/s41598-021-88928-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 04/19/2021] [Indexed: 12/27/2022] Open
Abstract
Obesity and its sequelae have a major impact on human health. The stomach contributes to obesity in ways that extend beyond its role in digestion, including through effects on the microbiome. Gastrokine-1 (GKN1) is an anti-amyloidogenic protein abundantly and specifically secreted into the stomach lumen. We examined whether GKN1 plays a role in the development of obesity and regulation of the gut microbiome. Gkn1-/- mice were resistant to diet-induced obesity and hepatic steatosis (high fat diet (HFD) fat mass (g) = 10.4 ± 3.0 (WT) versus 2.9 ± 2.3 (Gkn1-/-) p < 0.005; HFD liver mass (g) = 1.3 ± 0.11 (WT) versus 1.1 ± 0.07 (Gkn1-/-) p < 0.05). Gkn1-/- mice also exhibited increased expression of the lipid-regulating hormone ANGPTL4 in the small bowel. The microbiome of Gkn1-/- mice exhibited reduced populations of microbes implicated in obesity, namely Firmicutes of the class Erysipelotrichia. Altered metabolism consistent with use of fat as an energy source was evident in Gkn1-/- mice during the sleep period. GKN1 may contribute to the effects of the stomach on the microbiome and obesity. Inhibition of GKN1 may be a means to prevent obesity.
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Affiliation(s)
- Anne-Marie C Overstreet
- Department of Microbiology and Immunology, Indiana University School of Medicine-South Bend, RCH122, 1234 N. Notre Dame Ave., South Bend, IN, 46617, USA
| | - Bernadette E Grayson
- Division of Endocrinology, Diabetes and Metabolism, Department of Internal Medicine, University of Cincinnati, Cincinnati, OH, USA
- Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, MS, USA
| | - Antonia Boger
- Department of Microbiology and Immunology, Indiana University School of Medicine-South Bend, RCH122, 1234 N. Notre Dame Ave., South Bend, IN, 46617, USA
| | - Danika Bakke
- Department of Microbiology and Immunology, Indiana University School of Medicine-South Bend, RCH122, 1234 N. Notre Dame Ave., South Bend, IN, 46617, USA
| | - Erin M Carmody
- Department of Biology, University of Notre Dame, South Bend, IN, USA
| | - Cayla E Bales
- Department of Biology, University of Notre Dame, South Bend, IN, USA
| | | | - Stephen F Murphy
- Department of Urology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | | | - Kara J Shannon
- Department of Biology, University of Notre Dame, South Bend, IN, USA
| | - Katie R Adlaka
- Department of Biology, University of Notre Dame, South Bend, IN, USA
| | - Claire E Wolford
- Department of Biology, University of Notre Dame, South Bend, IN, USA
| | - Vincent J Campiti
- Department of Microbiology and Immunology, Indiana University School of Medicine-South Bend, RCH122, 1234 N. Notre Dame Ave., South Bend, IN, 46617, USA
| | - Christina V Raghunandan
- Department of Microbiology and Immunology, Indiana University School of Medicine-South Bend, RCH122, 1234 N. Notre Dame Ave., South Bend, IN, 46617, USA
| | - Randy J Seeley
- Division of Endocrinology, Diabetes and Metabolism, Department of Internal Medicine, University of Cincinnati, Cincinnati, OH, USA
- Department of Surgery, University of Michigan Health System, Ann Arbor, MI, USA
| | - David L Boone
- Department of Microbiology and Immunology, Indiana University School of Medicine-South Bend, RCH122, 1234 N. Notre Dame Ave., South Bend, IN, 46617, USA.
- Department of Biology, University of Notre Dame, South Bend, IN, USA.
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Gonzalez-Montoro A, Gonzalez AJ, Pourashraf S, Miyaoka RS, Bruyndonckx P, Chinn G, Pierce LA, Levin CS. Evolution of PET Detectors and Event Positioning Algorithms Using Monolithic Scintillation Crystals. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2021. [DOI: 10.1109/trpms.2021.3059181] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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18
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Groll AN, Levin CS. Instrumentation and Methods to Combine Small-Animal PET With Other Imaging Modalities. Mol Imaging 2021. [DOI: 10.1016/b978-0-12-816386-3.00005-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Abstract
Cerebrovascular disease is a significant cause of cognitive impairment leading to a reduction or loss of functioning, including social and occupational. The connection cause-effect between cerebrovascular disease and cerebral infarction was originally theorized by the studies from Newcastle-Upon-Tyne, England, in the 1960s, where vascular dementia (VaD) was defined as a disease originated from several infarctions that overcome a determined threshold. It differs from Alzheimer's disease (AD), although there are various overlaps in risk factors, symptomatology, the similarity of vascular lesions, and treatment benefits. Nevertheless, AD is one-half of all cases of dementia. Cognitive impairment and dementia (VCID) has recently been proposed to include different entities such as VaD, Vascular cognitive impairment, subcortical (ischemic) VaD, and vascular cognitive disorders. VaD is the most common cause of dementia after AD. Neuroimaging is an essential part of the workup of patients with cognitive decline and in those with suspected VCID it should be used to assess the extent, location, and type of vascular lesions. Computed tomography (CT) or structural magnetic resonance imaging (MRI) are usually used for the diagnosis of vascular diseases of the brain. However, images obtained from new hybrid devices could help the neurologist in the differential diagnosis between various neuropathological entities related to VCID. Single-photon emission computed tomography (SPECT) combined with CT or MRI and positron emission tomography (PET) combined with CT or MRI represent the future of neuroimaging tools as morphological and functional data can be provided simultaneously. New prospects have been developed such as hybrid PET/SPECT/CT, a high-performance prototype able to produce high-quality images but for now suitable only for small animals. Nowadays, PET/CT and PET/MRI are good performance and high-quality instruments, even if the magnetic field of MRI represents a limitation that affects the PET electronics and positron detection ability. SPECT/MRI delineates as a potential and tempting device. It could give us both functional and anatomical details, with the advantage of lack of extra ionizing radiation and high soft-tissue contrast, important features, and considerable auxiliary for differential diagnosis in the variegate word of vascular cognitive impairment. The aim of this review is to summarize the newest viewpoints in hybrid imaging in the diagnosis of VaD and to highlight pros and cons of each methodic.
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Affiliation(s)
| | - Miriam Conte
- Department of Radiological Sciences, Oncology and Anatomical Pathology, Sapienza University of Rome, Rome, Italy
| | - Giuseppe De Vincentis
- Department of Radiological Sciences, Oncology and Anatomical Pathology, Sapienza University of Rome, Rome, Italy
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Morphological response of the red palm weevil, Rhynchophorus ferrugineus, to a transient low temperature analyzed by computer tomography and holographic microscopy. J Therm Biol 2020; 94:102748. [PMID: 33292989 DOI: 10.1016/j.jtherbio.2020.102748] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 09/03/2020] [Accepted: 10/05/2020] [Indexed: 11/21/2022]
Abstract
The red palm weevil (RPW), Rhynchophorus ferrugineus, is one of the worst palm pests worldwide. Our study aims to assess its internal and external morphological response to a sudden but transient decrease in the environmental temperature. Wild pre-pupae were subjected for 7 days to either low (5.0 ± 0.5 °C) or ambient temperature (23 ± 1 °C). Such conditions mimic a thermal anomaly happening in the larval stage most exposed to environmental factors. We quantified the changes undergone at: 1) the internal morphology, by X-Ray Computer Tomography (CT); 2) the 3-D integument' architecture, by Digital Holographic Microscopy (DHM); and 3) the glucose in hemolymph as a potential endogenous cryoprotectant. From X-ray CT we found that both pre-pupae subjected to cold and those remaining at ambient temperature follow a development where their fat body content decreases while a thick and dense cuticle is formed. There was no difference between both groups in the rate of change of fat body/dense tissues. Nevertheless, the cold group presents a slight developmental delay at the level of hemolymph content. Through DHM we again obtained that pre-pupae subjected to cold have not experienced a stop in their development. However, a more obvious developmental delay is now observed in this group at the level of the integumental roughness. Finally, regarding glucose, we found similar levels in control and ambient temperature larvae, while it was clearly increased in 51,7% of those subjected to cold. Our whole results provide morphological and biochemical evidence showing that the larval-pupal transition of the RPW continues almost undisturbed even during the quiescent state induced by a sudden and severe cold event. Nevertheless, a certain developmental delay is observed in both internal and external morphology. Additionally, the increased glucose level only found in the cold group suggests that glucose is part of the RPW cold tolerance strategy.
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Attarwala AA, Hardiansyah D, Romanó C, Jiménez-Franco LD, Roscher M, Wängler B, Glatting G. Performance assessment of the ALBIRA II pre-clinical SPECT S102 system for 99mTc imaging. Ann Nucl Med 2020; 35:111-120. [PMID: 33180260 DOI: 10.1007/s12149-020-01547-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 10/29/2020] [Indexed: 10/23/2022]
Abstract
OBJECTIVE The performance characteristics of the SPECT sub-system S102 of the ALBIRA II PET/SPECT/CT are analyzed for the 80 mm field of view (FOV) to evaluate the potential in-vivo imaging in rats, based on measurements of the system response for the commonly used Technetium-99 m (99mTc) in small animal imaging. METHODS The ALBIRA II tri-modal µPET/SPECT/CT pre-clinical system (Bruker BioSpin, Ettlingen, Germany) was used. The SPECT modality is made up of two opposite gamma cameras (Version S102) with Sodium doped Cesium Iodide (CsI(Na)) single continuous crystal detectors coupled to position-sensitive photomultipliers (PSPMTs). Imaging was performed with the NEMA NU-4 image quality phantom (Data Spectrum Corporation, Durham, USA). Measurements were performed with a starting activity concentration of 4.76 MBq/mL 99mTc. An energy window of 20% at 140 keV was selected in this study. The system offers a 20 mm, 40 mm, 60 mm and an 80 mm field of view (FOV) and in this study the 80 mm FOV was used for all the acquisitions. The data were reconstructed with an ordered subset expectation maximization (OSEM) algorithm. Sensitivity, spatial resolution, count rate linearity, convergence of the algorithm and the recovery coefficients (RC) were analyzed. All analyses were performed with PMOD and MATLAB software. RESULTS The sensitivities measured at the center of the 80 mm FOV with the point source were 23.1 ± 0.3 cps/MBq (single pinhole SPH) and 105.6 ± 5.5 cps/MBq (multi pinhole MPH). The values for the axial, tangential and radial full width at half maximum (FWHM) were 2.51, 2.54, and 2.55 mm with SPH and 2.35, 2.44 and 2.32 mm with MPH, respectively. The corresponding RC values for the 5 mm, 4 mm, 3 mm and 2 mm rods were 0.60 ± 0.28, 0.61 ± 0.24, 0.29 ± 0.11 and 0.20 ± 0.06 with SPH and 0.56 ± 0.20, 0.50 ± 0.18, 0.38 ± 0.09 and 0.23 ± 0.06 with MPH. To obtain quantitative imaging data, the image reconstructions should be performed with 12 iterations. CONCLUSION The ALBIRA II preclinical SPECT sub-system S102 has a favorable sensitivity and spatial resolution for the 80 mm FOV setting for both the SPH and MPH configurations and is a valuable tool for small animal imaging.
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Affiliation(s)
- Ali Asgar Attarwala
- Medical Radiation Physics/Radiation Protection, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, 68167, Mannheim, Germany
| | - Deni Hardiansyah
- Medical Radiation Physics/Radiation Protection, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, 68167, Mannheim, Germany. .,Medical Physics and Biophysics Research Group, Physics Department, Faculty of Mathematics and Natural Sciences (FMIPA), Universitas Indonesia, Depok, 16424, Indonesia.
| | - Chiara Romanó
- Medical Radiation Physics/Radiation Protection, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, 68167, Mannheim, Germany
| | - Luis David Jiménez-Franco
- Medical Radiation Physics/Radiation Protection, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, 68167, Mannheim, Germany.,ABX-CRO Advanced Pharmaceutical Services Forschungsgesellschaft GmbH, 01307, Dresden, Germany
| | - Mareike Roscher
- Molecular Imaging and Radiochemistry, Department for Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim, Heidelberg University, 68167, Mannheim, Germany.,Radiooncology/Radiobiology, German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany
| | - Björn Wängler
- Molecular Imaging and Radiochemistry, Department for Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim, Heidelberg University, 68167, Mannheim, Germany
| | - Gerhard Glatting
- Medical Radiation Physics/Radiation Protection, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, 68167, Mannheim, Germany.,Medical Radiation Physics, Department of Nuclear Medicine, Ulm University, 89081, Ulm, Germany
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Abstract
In the light of ever-increasing demands for PET scanner with better resolvability, higher sensitivity and wide accessibility for noninvasive screening of small structures and physiological processes in laboratory rodents, several dedicated PET scanners were developed and evaluated. Understanding conceptual design constraints pros and cons of different configurations and impact of the major components will be helpful to further establish the crucial role of these miniaturized systems in a broad spectrum of modern research. Hence, a comprehensive review of preclinical PET scanners developed till early 2020 with particular emphasis on innovations in instrumentation and geometrical designs is provided.
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Affiliation(s)
- Mahsa Amirrashedi
- Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Iran; Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran, Iran
| | - Habib Zaidi
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, Geneva CH-1211, Switzerland; Geneva University Neurocenter, Geneva University, Geneva CH-1205, Switzerland; Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen 9700 RB, Netherlands; Department of Nuclear Medicine, University of Southern Denmark, Odense 500, Denmark
| | - Mohammad Reza Ay
- Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Iran; Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran, Iran.
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Toledano M, Toledano-Osorio M, Osorio R, Carrasco-Carmona Á, Gutiérrez-Pérez JL, Gutiérrez-Corrales A, Serrera-Figallo MA, Lynch CD, Torres-Lagares D. Doxycycline and Zinc Loaded Silica-Nanofibrous Polymers as Biomaterials for Bone Regeneration. Polymers (Basel) 2020; 12:polym12051201. [PMID: 32466191 PMCID: PMC7285172 DOI: 10.3390/polym12051201] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 05/12/2020] [Accepted: 05/22/2020] [Indexed: 12/13/2022] Open
Abstract
The main target of bone tissue engineering is to design biomaterials that support bone regeneration and vascularization. Nanostructured membranes of (MMA)1-co-(HEMA)1/(MA)3-co-(HEA)2 loaded with 5% wt of SiO2-nanoparticles (HOOC-Si-Membrane) were doped with zinc (Zn-HOOC-Si-Membrane) or doxycycline (Dox-HOOC-Si-Membrane). Critical bone defects were effectuated on six New Zealand-bred rabbit skulls and covered with the membranes. After six weeks, the bone architecture was evaluated with micro computed tomography. Three histological analyses were utilized to analyse bone regeneration, including von Kossa silver nitrate, toluidine blue and fluorescence. All membrane-treated defects exhibited higher number of osteocytes and bone perimeter than the control group without the membrane. Zn-HOOC-Si-Membranes induced higher new bone and osteoid area than those treated with HOOC-Si-Membranes, and control group, respectively. Zn-HOOC-Si-Membranes and Dox-HOOC-Si-Membranes attained the lowest ratio M1 macrophages/M2 macrophages. Dox-HOOC-Si-Membranes caused the lowest number of osteoclasts, and bone density. At the trabecular new bone, Zn-HOOC-Si-Membranes produced the highest angiogenesis, bone thickness, connectivity, junctions and branches. Zn-HOOC-Si-Membranes enhanced biological activity, attained a balanced remodeling, and achieved the greatest regenerative efficiency after osteogenesis and angiogenesis assessments. The bone-integrated Zn-HOOC-Si-Membranes can be considered as bioactive modulators provoking a M2 macrophages (pro-healing cells) increase, being a potential biomaterial for promoting bone repair.
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Affiliation(s)
- Manuel Toledano
- Dental Materials Section, Faculty of Dentistry, University of Granada, Colegio Máximo de Cartuja s/n, 18071 Granada, Spain; (M.T.); (M.T.-O.); (Á.C.-C.)
| | - Manuel Toledano-Osorio
- Dental Materials Section, Faculty of Dentistry, University of Granada, Colegio Máximo de Cartuja s/n, 18071 Granada, Spain; (M.T.); (M.T.-O.); (Á.C.-C.)
| | - Raquel Osorio
- Dental Materials Section, Faculty of Dentistry, University of Granada, Colegio Máximo de Cartuja s/n, 18071 Granada, Spain; (M.T.); (M.T.-O.); (Á.C.-C.)
- Correspondence: ; Tel.: +34-958243789
| | - Álvaro Carrasco-Carmona
- Dental Materials Section, Faculty of Dentistry, University of Granada, Colegio Máximo de Cartuja s/n, 18071 Granada, Spain; (M.T.); (M.T.-O.); (Á.C.-C.)
| | - José-Luis Gutiérrez-Pérez
- Oral Surgery Section, Faculty of Dentistry, University of Sevilla, Avicena s/n, 41009 Sevilla, Spain; (J.-L.G.-P.); (A.G.-C.); (M.-A.S.-F.); (D.T.-L.)
| | - Aida Gutiérrez-Corrales
- Oral Surgery Section, Faculty of Dentistry, University of Sevilla, Avicena s/n, 41009 Sevilla, Spain; (J.-L.G.-P.); (A.G.-C.); (M.-A.S.-F.); (D.T.-L.)
| | - María-Angeles Serrera-Figallo
- Oral Surgery Section, Faculty of Dentistry, University of Sevilla, Avicena s/n, 41009 Sevilla, Spain; (J.-L.G.-P.); (A.G.-C.); (M.-A.S.-F.); (D.T.-L.)
| | - Christopher D. Lynch
- University Dental School & Hospital/University College Cork, Wilton, T12 E8YV Cork, Ireland;
| | - Daniel Torres-Lagares
- Oral Surgery Section, Faculty of Dentistry, University of Sevilla, Avicena s/n, 41009 Sevilla, Spain; (J.-L.G.-P.); (A.G.-C.); (M.-A.S.-F.); (D.T.-L.)
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Vandenberghe S, Moskal P, Karp JS. State of the art in total body PET. EJNMMI Phys 2020; 7:35. [PMID: 32451783 PMCID: PMC7248164 DOI: 10.1186/s40658-020-00290-2] [Citation(s) in RCA: 142] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 03/25/2020] [Indexed: 12/29/2022] Open
Abstract
The idea of a very sensitive positron emission tomography (PET) system covering a large portion of the body of a patient already dates back to the early 1990s. In the period 2000-2010, only some prototypes with long axial field of view (FOV) have been built, which never resulted in systems used for clinical research. One of the reasons was the limitations in the available detector technology, which did not yet have sufficient energy resolution, timing resolution or countrate capabilities for fully exploiting the benefits of a long axial FOV design. PET was also not yet as widespread as it is today: the growth in oncology, which has become the major application of PET, appeared only after the introduction of PET-CT (early 2000).The detector technology used in most clinical PET systems today has a combination of good energy and timing resolution with higher countrate capabilities and has now been used since more than a decade to build time-of-flight (TOF) PET systems with fully 3D acquisitions. Based on this technology, one can construct total body PET systems and the remaining challenges (data handling, fast image reconstruction, detector cooling) are mostly related to engineering. The direct benefits of long axial FOV systems are mostly related to the higher sensitivity. For single organ imaging, the gain is close to the point source sensitivity which increases linearly with the axial length until it is limited by solid angle and attenuation of the body. The gains for single organ (compared to a fully 3D PET 20-cm axial FOV) are limited to a factor 3-4. But for long objects (like body scans), it increases quadratically with scanner length and factors of 10-40 × higher sensitivity are predicted for the long axial FOV scanner. This application of PET has seen a major increase (mostly in oncology) during the last 2 decades and is now the main type of study in a PET centre. As the technology is available and the full body concept also seems to match with existing applications, the old concept of a total body PET scanner is seeing a clear revival. Several research groups are working on this concept and after showing the potential via extensive simulations; construction of these systems has started about 2 years ago. In the first phase, two PET systems with long axial FOV suitable for large animal imaging were constructed to explore the potential in more experimental settings. Recently, the first completed total body PET systems for human use, a 70-cm-long system, called PennPET Explorer, and a 2-m-long system, called uExplorer, have become reality and first clinical studies have been shown. These results illustrate the large potential of this concept with regard to low-dose imaging, faster scanning, whole-body dynamic imaging and follow-up of tracers over longer periods. This large range of possible technical improvements seems to have the potential to change the current clinical routine and to expand the number of clinical applications of molecular imaging. The J-PET prototype is a prototype system with a long axial FOV built from axially arranged plastic scintillator strips.This paper gives an overview of the recent technical developments with regard to PET scanners with a long axial FOV covering at least the majority of the body (so called total body PET systems). After explaining the benefits and challenges of total body PET systems, the different total body PET system designs proposed for large animal and clinical imaging are described in detail. The axial length is one of the major factors determining the total cost of the system, but there are also other options in detector technology, design and processing for reducing the cost these systems. The limitations and advantages of different designs for research and clinical use are discussed taking into account potential applications and the increased cost of these systems.
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Affiliation(s)
- Stefaan Vandenberghe
- Department of Electronics and Information Systems, MEDISIP, Ghent University-IBiTech, De Pintelaan 185 block B, Ghent, B-9000 Belgium
| | - Pawel Moskal
- Institute of Physics, Jagiellonian University, Krakow, Poland
| | - Joel S. Karp
- Department of Radiology, University of Pennsylvania, Philadelphia, USA
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Freire M, Gonzalez-Montoro A, Sanchez F, Benlloch JM, Gonzalez AJ. Calibration of Gamma Ray Impacts in Monolithic-Based Detectors Using Voronoi Diagrams. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2020. [DOI: 10.1109/trpms.2019.2947716] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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27
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Miyaoka RS, Lehnert A. Small animal PET: a review of what we have done and where we are going. Phys Med Biol 2020; 65. [PMID: 32357344 DOI: 10.1088/1361-6560/ab8f71] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 05/01/2020] [Indexed: 02/07/2023]
Abstract
Small animal research is an essential tool in studying both pharmaceutical biodistributions and disease progression over time. Furthermore, through the rapid development of in vivo imaging technology over the last few decades, small animal imaging (also referred to as preclinical imaging) has become a mainstay for all fields of biologic research and a center point for most preclinical cancer research. Preclinical imaging modalities include optical, MRI and MRS, microCT, small animal PET, ultrasound, and photoacoustic, each with their individual strengths. The strong points of small animal PET are its translatability to the clinic; its quantitative imaging capabilities; its whole-body imaging ability to dynamically trace functional/biochemical processes; its ability to provide useful images with only nano- to pico‑ molar concentrations of administered compounds; and its ability to study animals serially over time. This review paper gives an overview of the development and evolution of small animal PET imaging. It provides an overview of detector designs; system configurations; multimodality PET imaging systems; image reconstruction and analysis tools; and an overview of research and commercially available small animal PET systems. It concludes with a look toward developing technologies/methodologies that will further enhance the impact of small animal PET imaging on medical research in the future.
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Affiliation(s)
- Robert S Miyaoka
- Radiology, University of Washington, Seattle, Washington, UNITED STATES
| | - Adrienne Lehnert
- Radiology, University of Washington, Seattle, Washington, UNITED STATES
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Abstract
Molecular imaging enables both spatial and temporal understanding of the complex biologic systems underlying carcinogenesis and malignant spread. Single-photon emission tomography (SPECT) is a versatile nuclear imaging-based technique with ideal properties to study these processes in vivo in small animal models, as well as to identify potential drug candidates and characterize their antitumor action and potential adverse effects. Small animal SPECT and SPECT-CT (single-photon emission tomography combined with computer tomography) systems continue to evolve, as do the numerous SPECT radiopharmaceutical agents, allowing unprecedented sensitivity and quantitative molecular imaging capabilities. Several of these advances, their specific applications in oncology as well as new areas of exploration are highlighted in this chapter.
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Affiliation(s)
- Benjamin L Franc
- Department of Radiology, Stanford University School of Medicine, 300 Pasteur Drive, H2232, MC 5281, Stanford, CA, 94305-5105, USA.
| | - Youngho Seo
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, USA
| | - Robert Flavell
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, USA
| | - Carina Mari Aparici
- Department of Radiology, Stanford University School of Medicine, 300 Pasteur Drive, H2232, MC 5281, Stanford, CA, 94305-5105, USA
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Abstract
SPECT and PET are nuclear tomographic imaging modalities that visualize functional information based on the accumulation of radioactive tracer molecules. However, SPECT and PET lack anatomical information, which has motivated their combination with an anatomical imaging modality such as CT or MRI. This chapter begins with an overview over the fundamental physics of SPECT and PET followed by a presentation of the respective detector technologies, including detection requirements, principles and different detector concepts. The reader is subsequently provided with an introduction into hybrid imaging concepts, before a dedicated section presents the challenges that arise when hybridizing SPECT or PET with MRI, namely, mutual distortions of the different electromagnetic fields in MRI on the nuclear imaging system and vice versa. The chapter closes with an overview about current hybrid imaging systems of both clinical and preclinical kind. Finally, future developments in hybrid SPECT and PET technology are discussed.
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Affiliation(s)
- Teresa Nolte
- Physics of Molecular Imaging Systems, Experimental Molecular Imaging, RWTH Aachen University, Aachen, Germany
| | - Nicolas Gross-Weege
- Physics of Molecular Imaging Systems, Experimental Molecular Imaging, RWTH Aachen University, Aachen, Germany
| | - Volkmar Schulz
- Physics of Molecular Imaging Systems, Experimental Molecular Imaging, RWTH Aachen University, Aachen, Germany.
- Hyperion Hybrid Imaging Systems GmbH, Aachen, Germany.
- Fraunhofer Institute for Digital Medicine MEVIS, Bremen, Germany.
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Mohammadi I, Castro IFC, Correia PMM, Silva ALM, Veloso JFCA. Minimization of parallax error in positron emission tomography using depth of interaction capable detectors: methods and apparatus. Biomed Phys Eng Express 2019. [DOI: 10.1088/2057-1976/ab4a1b] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Novel non-resorbable polymeric-nanostructured scaffolds for guided bone regeneration. Clin Oral Investig 2019; 24:2037-2049. [PMID: 31493213 DOI: 10.1007/s00784-019-03068-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 08/27/2019] [Indexed: 12/11/2022]
Abstract
OBJECTIVE The aim of this study was to evaluate the bone-regeneration efficiency of novel polymeric nanostructured membranes and the effect of zinc, calcium, titanium, and bone morpho-protein loading on membranes, through an in vivo rabbit model. MATERIAL AND METHODS Nanostructured membranes of methylmethacrylate were loaded with zinc, calcium, TiO2 nanoparticles, and bone-morphogenetic protein (BMP). These membranes covered the bone defects prepared on the skulls of six rabbits. Animals were sacrificed 6 weeks after surgery. Micro computed tomography was used to evaluate bone architecture through BoneJ pluging and ImageJ script. Three histological processing of samples, including von Kossa silver nitrate, toluidine blue, and fluorescence by the deposition of calcein were utilized. RESULTS Zn-membranes (Zn-Ms) promoted the highest amount of new bone and higher bone perimeter than both unloaded and Ti-membranes (Ti-Ms). Ca-membranes (Ca-Ms) attained higher osteoid perimeter and bone perimeter than Zn-Ms. The skeleton analysis showed that Zn-Ms produced more branches and junctions at the trabecular bone than BMP-loaded membranes (BMP-Ms). Samples treated with Ti-Ms showed less bone formation and bony bridging processes. Both Zn-Ms and Ca-Ms achieved higher number of osteoblasts than the control group. BMP-Ms and Ca-Ms originated higher number of blood vessels than Ti-Ms and control group. CONCLUSIONS Zn incorporation in novel nanostructured membranes provided the highest regenerative efficiency for bone healing at the rabbit calvarial defects. CLINICAL RELEVANCE Zn-Ms promoted osteogenesis and enhanced biological activity, as mineralized and osteoid new bone with multiple interconnected ossified trabeculae appeared in close contact with the membrane.
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Cicone F, Gnesin S, Denoël T, Stora T, van der Meulen NP, Müller C, Vermeulen C, Benešová M, Köster U, Johnston K, Amato E, Auditore L, Coukos G, Stabin M, Schaefer N, Viertl D, Prior JO. Internal radiation dosimetry of a 152Tb-labeled antibody in tumor-bearing mice. EJNMMI Res 2019; 9:53. [PMID: 31187358 PMCID: PMC6560118 DOI: 10.1186/s13550-019-0524-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 05/28/2019] [Indexed: 11/10/2022] Open
Abstract
Background Biodistribution studies based on organ harvesting represent the gold standard pre-clinical technique for dose extrapolations. However, sequential imaging is becoming increasingly popular as it allows the extraction of longitudinal data from single animals, and a direct correlation with deterministic radiation effects. We assessed the feasibility of mouse-specific, microPET-based dosimetry of an antibody fragment labeled with the positron emitter 152Tb [(T1/2 = 17.5 h, Eβ+mean = 1140 keV (20.3%)]. Image-based absorbed dose estimates were compared with those obtained from the extrapolation to 152Tb of a classical biodistribution experiment using the same antibody fragment labeled with 111In. 152Tb was produced by proton-induced spallation in a tantalum target, followed by mass separation and cation exchange chromatography. The endosialin-targeting scFv78-Fc fusion protein was conjugated with the chelator p-SCN-Bn-CHX-A”-DTPA, followed by labeling with either 152Tb or 111In. Micro-PET images of four immunodeficient female mice bearing RD-ES tumor xenografts were acquired 4, 24, and 48 h after the i.v. injection of 152Tb-CHX-DTPA-scFv78-Fc. After count/activity camera calibration, time-integrated activity coefficients (TIACs) were obtained for the following compartments: heart, lungs, liver, kidneys, intestines, tumor, and whole body, manually segmented on CT. For comparison, radiation dose estimates of 152Tb-CHX-DTPA-scFv78-Fc were extrapolated from mice dissected 4, 24, 48, and 96 h after the injection of 111In-CHX-DTPA-scFv78-Fc (3–5 mice per group). Imaging-derived and biodistribution-derived organ TIACs were used as input in the 25 g mouse model of OLINDA/EXM® 2.0, after appropriate mass rescaling. Tumor absorbed doses were obtained using the OLINDA2 sphere model. Finally, the relative percent difference (RD%) between absorbed doses obtained from imaging and biodistribution were calculated. Results RD% between microPET-based dosimetry and biodistribution-based dose extrapolations were + 12, − 14, and + 17 for the liver, the kidneys, and the tumors, respectively. Compared to biodistribution, the imaging method significantly overestimates the absorbed doses to the heart and the lungs (+ 89 and + 117% dose difference, respectively). Conclusions MicroPET-based dosimetry of 152Tb is feasible, and the comparison with organ harvesting resulted in acceptable dose discrepancies for body districts that can be segmented on CT. These encouraging results warrant additional validation using radiolabeled biomolecules with a different biodistribution pattern.
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Affiliation(s)
- Francesco Cicone
- Department of Nuclear Medicine and Molecular Imaging, Lausanne University Hospital, Rue du Bugnon 46, CH-1011, Lausanne, CH, Switzerland.
| | - Silvano Gnesin
- Institute of Radiation Physics, Lausanne University Hospital, Lausanne, CH, Switzerland
| | - Thibaut Denoël
- Department of Nuclear Medicine and Molecular Imaging, Lausanne University Hospital, Rue du Bugnon 46, CH-1011, Lausanne, CH, Switzerland
| | | | - Nicholas P van der Meulen
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute (PSI), Villigen, CH, Switzerland.,Laboratory of Radiochemistry, Paul Scherrer Institute (PSI), Villigen, CH, Switzerland
| | - Cristina Müller
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute (PSI), Villigen, CH, Switzerland
| | - Christiaan Vermeulen
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute (PSI), Villigen, CH, Switzerland
| | - Martina Benešová
- Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute (PSI), Villigen, CH, Switzerland
| | - Ulli Köster
- Institut Laue-Langevin, Grenoble, FR, France
| | | | - Ernesto Amato
- Section of Radiological Sciences, Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Messina, IT, Italy
| | - Lucrezia Auditore
- Section of Radiological Sciences, Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Messina, IT, Italy
| | - George Coukos
- Department of Oncology and Ludwig Center for Cancer Research, Lausanne, CH, Switzerland
| | | | - Niklaus Schaefer
- Department of Nuclear Medicine and Molecular Imaging, Lausanne University Hospital, Rue du Bugnon 46, CH-1011, Lausanne, CH, Switzerland
| | - David Viertl
- Department of Nuclear Medicine and Molecular Imaging, Lausanne University Hospital, Rue du Bugnon 46, CH-1011, Lausanne, CH, Switzerland
| | - John O Prior
- Department of Nuclear Medicine and Molecular Imaging, Lausanne University Hospital, Rue du Bugnon 46, CH-1011, Lausanne, CH, Switzerland
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Gonzalez-Montoro A, Gonzalez AJ. Performance comparison of large-area SiPM arrays suitable for gamma ray detectors. Biomed Phys Eng Express 2019. [DOI: 10.1088/2057-1976/ab0f6e] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Nguyen MP, Goorden MC, Kamphuis C, Beekman FJ. Evaluation of pinhole collimator materials for micron-resolution ex vivo SPECT. ACTA ACUST UNITED AC 2019; 64:105017. [DOI: 10.1088/1361-6560/ab1618] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Mannheim JG, Kara F, Doorduin J, Fuchs K, Reischl G, Liang S, Verhoye M, Gremse F, Mezzanotte L, Huisman MC. Standardization of Small Animal Imaging-Current Status and Future Prospects. Mol Imaging Biol 2019; 20:716-731. [PMID: 28971332 DOI: 10.1007/s11307-017-1126-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The benefit of small animal imaging is directly linked to the validity and reliability of the collected data. If the data (regardless of the modality used) are not reproducible and/or reliable, then the outcome of the data is rather questionable. Therefore, standardization of the use of small animal imaging equipment, as well as of animal handling in general, is of paramount importance. In a recent paper, guidance for efficient small animal imaging quality control was offered and discussed, among others, the use of phantoms in setting up a quality control program (Osborne et al. 2016). The same phantoms can be used to standardize image quality parameters for multi-center studies or multi-scanners within center studies. In animal experiments, the additional complexity due to animal handling needs to be addressed to ensure standardized imaging procedures. In this review, we will address the current status of standardization in preclinical imaging, as well as potential benefits from increased levels of standardization.
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Affiliation(s)
- Julia G Mannheim
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tuebingen, Roentgenweg 13, 72076, Tuebingen, Germany.
| | - Firat Kara
- Bio-Imaging Lab, University of Antwerp, Antwerp, Belgium
| | - Janine Doorduin
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Kerstin Fuchs
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tuebingen, Roentgenweg 13, 72076, Tuebingen, Germany
| | - Gerald Reischl
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tuebingen, Roentgenweg 13, 72076, Tuebingen, Germany
| | - Sayuan Liang
- Bio-Imaging Lab, University of Antwerp, Antwerp, Belgium
| | | | - Felix Gremse
- Institute for Experimental Molecular Imaging, RWTH Aachen University Clinic, Aachen, Germany
| | - Laura Mezzanotte
- Optical Molecular Imaging, Department of Radiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Marc C Huisman
- Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands
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Xiong C, Yin D, Li J, Huang Q, Ravoori MK, Kundra V, Zhu H, Yang Z, Lu Y, Li C. Metformin Reduces Renal Uptake of Radiotracers and Protects Kidneys from Radiation-Induced Damage. Mol Pharm 2019; 16:808-815. [PMID: 30608713 DOI: 10.1021/acs.molpharmaceut.8b01091] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Metformin is the most widely prescribed drug for type 2 diabetes. Chemically, metformin is a hydrophilic base that functions as an organic cation, suggesting that it may have the capacity to inhibit the tubular reabsorption of peptide radiotracers. The purpose of this study was to investigate whether metformin could reduce renal uptake of peptidyl radiotracers and serve as a radioprotective agent for peptide receptor radionuclide therapy (PRRT). METHODS We used two radiolabeled peptides: a 68Ga-labeled cyclic (TNYL-RAW) peptide (68Ga-NOTA-c(TNYL-RAW) (NOTA: 1,4,7 triazacyclononane-1,4,7-trisacetic acid) targeting EphB4 receptors and an 111In- or 64Cu-labeled octreotide (111In/64Cu-DOTA-octreotide) (DOTA: 1,4,7,10 triazacyclododecane-1,4,7,10-tetraacetic acid) targeting somatostatin receptors. Each radiotracer was injected intravenously into normal Swiss mice or tumor-bearing nude mice in the presence or absence of metformin administered intravenously or orally. Micropositron emission tomography or microsingle-photon emission computed tomography images were acquired at different times after radiotracer injection, and biodistribution studies were performed at the end of the imaging session. To assess the radioprotective effect of metformin on the kidneys, normal Swiss mice received two doses of 111In-DOTA-octreotidein the presence or absence of metformin, and renal function was analyzed via blood chemistry and histology. RESULTS Intravenous injection of metformin with 68Ga-NOTA-c(TNYL-RAW) or 111In-DOTA-octreotide reduced the renal uptake of the radiotracer by 60% and 35%, respectively, compared to uptake without metformin. These reductions were accompanied by greater uptake in the tumors for both radiolabeled peptides. Moreover, the renal uptake of 111In-DOTA-octreotide was significantly reduced when metformin was administered via oral gavage. Significantly more radioactivity was recovered in the urine collected over a period of 24 h after intravenous injection of 64Cu-DOTA-octreotide in mice that received oral metformin than in mice that received vehicle. Finally, coadministration of 111In-DOTA-octreotide with metformin mitigated radio-nephrotoxicity. CONCLUSION Metformin inhibits kidney uptake of peptidyl radiotracers, protecting the kidney from nephrotoxicity. Further studies are needed to elucidate the mechanisms of these finding and to optimize mitigation of radiation-induced damage to kidney in PRRT.
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Affiliation(s)
| | | | | | | | | | | | - Hua Zhu
- Department of Nuclear Medicine , Peking University Cancer Hospital & Institute , Beijing , 100142 , PR China
| | - Zhi Yang
- Department of Nuclear Medicine , Peking University Cancer Hospital & Institute , Beijing , 100142 , PR China
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Rodriguez-Alvarez MJ, Sanchez F, Soriano A, Moliner L, Sanchez S, Benlloch J. QR-Factorization Algorithm for Computed Tomography (CT): Comparison With FDK and Conjugate Gradient (CG) Algorithms. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2018. [DOI: 10.1109/trpms.2018.2843803] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Zhong Y, Kalantari F, Zhang Y, Shao Y, Wang J. Quantitative 4D-PET reconstruction for small animal using SMEIR-reconstructed 4D-CBCT. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2018; 2:300-306. [PMID: 33778232 DOI: 10.1109/trpms.2018.2814342] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Respiratory motions in small animals PET cause image degradation during reconstruction. This work aims to develop a motion compensated 4D-PET reconstruction method using accurate motion corrections and attenuation corrections from 4D-CBCT images reconstructed using a simultaneous motion estimation and image reconstruction (SMEIR) method. Projections of 4D-CBCT were calculated using a ray-tracing method on a digital 4D rat phantom, and list-mode data of 4D-PET with matched respiratory phases were simulated using the GATE Monte Carlo package. The respiratory rate was set at 1.0 second per cycle with 10 phases of 30 projection images each. 4D-CBCT images were reconstructed using the SMEIR method and motion information and linear attenuation from 4D-CBCT were subsequently used for motion compensated 4D-PET reconstruction and attenuation corrections. We quantitatively evaluate the reconstructed 4D-PET using the errors of tumor volume and standard uptake values of tumors with different sizes. The tumor motion was successfully reconstructed and showed good agreement with the original phantom. The proposed method reduced tumor volume errors and standard uptake value errors. For tumor diameters of 3.0, 4.5, and 6.0 mm, the tumor volume errors are 32.5%, 29.2% and 19.4% respectively with motion compensation and 45.1%, 37.5% and 20.2% respectively without compensation.
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Affiliation(s)
- Yuncheng Zhong
- Medical Physics and Engineering Division in the Department of Radiation Oncology, the University of Texas Southwestern Medical Center, Dallas, TX
| | - Faraz Kalantari
- Medical Physics and Engineering Division in the Department of Radiation Oncology, the University of Texas Southwestern Medical Center, Dallas, TX
| | - You Zhang
- Medical Physics and Engineering Division in the Department of Radiation Oncology, the University of Texas Southwestern Medical Center, Dallas, TX
| | - Yiping Shao
- Medical Physics and Engineering Division in the Department of Radiation Oncology, the University of Texas Southwestern Medical Center, Dallas, TX
| | - Jing Wang
- Medical Physics and Engineering Division in the Department of Radiation Oncology, the University of Texas Southwestern Medical Center, Dallas, TX
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Esquinas PL, Rodríguez-Rodríguez C, Carlos De La Vega J, Bokharaei M, Saatchi K, Shirmohammad M, Häfeli UO, Sossi V, Celler A. 188Re image performance assessment using small animal multi-pinhole SPECT/PET/CT system. Phys Med 2017; 33:26-37. [DOI: 10.1016/j.ejmp.2016.11.105] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Revised: 10/10/2016] [Accepted: 11/14/2016] [Indexed: 02/08/2023] Open
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Laviña B. Brain Vascular Imaging Techniques. Int J Mol Sci 2016; 18:ijms18010070. [PMID: 28042833 PMCID: PMC5297705 DOI: 10.3390/ijms18010070] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 12/13/2016] [Accepted: 12/26/2016] [Indexed: 12/13/2022] Open
Abstract
Recent major improvements in a number of imaging techniques now allow for the study of the brain in ways that could not be considered previously. Researchers today have well-developed tools to specifically examine the dynamic nature of the blood vessels in the brain during development and adulthood; as well as to observe the vascular responses in disease situations in vivo. This review offers a concise summary and brief historical reference of different imaging techniques and how these tools can be applied to study the brain vasculature and the blood-brain barrier integrity in both healthy and disease states. Moreover, it offers an overview on available transgenic animal models to study vascular biology and a description of useful online brain atlases.
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Affiliation(s)
- Bàrbara Laviña
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, 75185 Uppsala, Sweden.
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Silva-Rodríguez J, García-Varela L, López-Arias E, Domínguez-Prado I, Cortés J, Pardo-Montero J, Fernández-Ferreiro A, Ruibal Á, Sobrino T, Aguiar P. Impact of benzodiazepines on brain FDG-PET quantification after single-dose and chronic administration in rats. Nucl Med Biol 2016; 43:827-834. [DOI: 10.1016/j.nucmedbio.2016.09.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 09/02/2016] [Accepted: 09/07/2016] [Indexed: 02/08/2023]
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Denis-Bacelar AM, Cronin SE, Da Pieve C, Paul RL, Eccles SA, Spinks TJ, Box C, Hall A, Sosabowski JK, Kramer-Marek G, Flux GD. Pre-clinical quantitative imaging and mouse-specific dosimetry for 111In-labelled radiotracers. EJNMMI Res 2016; 6:85. [PMID: 27885618 PMCID: PMC5122527 DOI: 10.1186/s13550-016-0238-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 11/14/2016] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Accurate quantification in molecular imaging is essential to improve the assessment of novel drugs and compare the radiobiological effects of therapeutic agents prior to in-human studies. The aim of this study was to investigate the challenges and feasibility of pre-clinical quantitative imaging and mouse-specific dosimetry of 111In-labelled radiotracers. Attenuation, scatter and partial volume effects were studied using phantom experiments, and an activity calibration curve was obtained for varying sphere sizes. Six SK-OV-3-tumour bearing mice were injected with 111In-labelled HER2-targeting monoclonal antibodies (mAbs) (range 5.58-8.52 MBq). Sequential SPECT imaging up to 197 h post-injection was performed using the Albira SPECT/PET/CT pre-clinical scanner. Mice were culled for quantitative analysis of biodistribution studies. The tumour activity, mass and percentage of injected activity per gram of tissue (%IA/g) were calculated at the final scan time point and compared to the values determined from the biodistribution data. Delivered 111In-labelled mAbs tumour absorbed doses were calculated using mouse-specific convolution dosimetry, and absorbed doses for 90Y-labelled mAbs were extrapolated under the assumptions of equivalent injected activities, biological half-lives and uptake distributions as for 111In. RESULTS For the sphere sizes investigated (volume 0.03-1.17 ml), the calibration factor varied by a factor of 3.7, whilst for the range of tumour masses in the mice (41-232 mg), the calibration factor changed by a factor of 2.5. Comparisons between the mice imaging and the biodistribution results showed a statistically significant correlation for the tumour activity (r = 0.999, P < 0.0001) and the tumour mass calculations (r = 0.977, P = 0.0008), whilst no correlation was found for the %IA/g (r = 0.521, P = 0.29). Median tumour-absorbed doses per injected activity of 52 cGy/MBq (range 36-69 cGy/MBq) and 649 cGy/MBq (range 441-950 cGy/MBq) were delivered by 111In-labelled mAbs and extrapolated for 90Y-labelled mAbs, respectively. CONCLUSIONS This study demonstrates the need for multidisciplinary efforts to standardise imaging and dosimetry protocols in pre-clinical imaging. Accurate image quantification can improve the calculation of the activity, %IA/g and absorbed dose. Diagnostic imaging could be used to estimate the injected activities required for therapeutic studies, potentially reducing the number of animals used.
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Affiliation(s)
- Ana M Denis-Bacelar
- Joint Department of Physics, The Institute of Cancer Research and The Royal Marsden Hospital NHS Foundation Trust, London, SM2 5NG, United Kingdom.
| | - Sarah E Cronin
- Joint Department of Physics, The Institute of Cancer Research and The Royal Marsden Hospital NHS Foundation Trust, London, SM2 5NG, United Kingdom
| | - Chiara Da Pieve
- Joint Department of Physics, The Institute of Cancer Research and The Royal Marsden Hospital NHS Foundation Trust, London, SM2 5NG, United Kingdom
| | - Rowena L Paul
- Joint Department of Physics, The Institute of Cancer Research and The Royal Marsden Hospital NHS Foundation Trust, London, SM2 5NG, United Kingdom
| | - Sue A Eccles
- Division of Cancer Therapeutics, The Institute of Cancer Research, London, SM2 5NG, United Kingdom
| | - Terence J Spinks
- Joint Department of Physics, The Institute of Cancer Research and The Royal Marsden Hospital NHS Foundation Trust, London, SM2 5NG, United Kingdom
| | - Carol Box
- Division of Cancer Therapeutics, The Institute of Cancer Research, London, SM2 5NG, United Kingdom
| | - Adrian Hall
- Radiopharmacy Department, The Royal Marsden Hospital NHS Foundation Trust, London, SM2 5PT, United Kingdom
| | - Jane K Sosabowski
- Centre for Molecular Oncology, Barts Cancer Institute, Queen Mary University of London, London, EC1M 6BQ, United Kingdom
| | - Gabriela Kramer-Marek
- Division of Cancer Therapeutics, The Institute of Cancer Research, London, SM2 5NG, United Kingdom
- Division of Radiotherapy and Imaging, The Institute of Cancer Research, London, SM2 5NG, United Kingdom
| | - Glenn D Flux
- Joint Department of Physics, The Institute of Cancer Research and The Royal Marsden Hospital NHS Foundation Trust, London, SM2 5NG, United Kingdom
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Ma Y, Huang J, Song S, Chen H, Zhang Z. Cancer-Targeted Nanotheranostics: Recent Advances and Perspectives. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2016; 12:4936-4954. [PMID: 27150247 DOI: 10.1002/smll.201600635] [Citation(s) in RCA: 118] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 03/22/2016] [Indexed: 05/10/2023]
Abstract
Cancer-targeted nanotechnology is experiencing the trend of finding new materials with multiple functions for imaging and therapeutic applications. With the rapid development of the related fields, there exists a large number of reports regarding theranostic nanomedicine, decreasing the gap between cancer diagnosis and treatment with minimized separate comprehensions. In order to present an overview on the cancer-targeted nanotheranostics, we first describe their essential building blocks, including platforms, therapeutic agents and imaging agents, and then the recently rapidly developed multimodal theranostic systems. Finally we discuss the major challenges and the perspectives of future development of nanotheranostics toward clinical translations and personalized nanomedicine.
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Affiliation(s)
- Yufei Ma
- CAS Key Laboratory of Nano-Bio Interface, Division of Nanobiomedicine, CAS Center for Excellence in Nanoscience, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, 215123, China
| | - Jie Huang
- CAS Key Laboratory of Nano-Bio Interface, Division of Nanobiomedicine, CAS Center for Excellence in Nanoscience, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, 215123, China
| | - Saijie Song
- CAS Key Laboratory of Nano-Bio Interface, Division of Nanobiomedicine, CAS Center for Excellence in Nanoscience, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, 215123, China
| | - Huabing Chen
- Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases, College of Pharmaceutical Sciences, Soochow University, Suzhou, 215123, China.
| | - Zhijun Zhang
- CAS Key Laboratory of Nano-Bio Interface, Division of Nanobiomedicine, CAS Center for Excellence in Nanoscience, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, 215123, China.
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Mejia J, Miranda ACC, Durante ACR, de Oliveira LR, de Barboza MRFF, Rosell KT, Jardim DP, Campos AH, dos Reis MA, Catanoso MF, Galvis-Alonso OY, Cabral FR. Preclinical molecular imaging: development of instrumentation for translational research with small laboratory animals. EINSTEIN-SAO PAULO 2016; 14:408-414. [PMID: 27759832 PMCID: PMC5234755 DOI: 10.1590/s1679-45082016ao3696] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 06/27/2016] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE: To present the result of upgrading a clinical gamma-camera to be used to obtain in vivo tomographic images of small animal organs, and its application to register cardiac, renal and neurological images. METHODS: An updated version of the miniSPECT upgrading device was built, which is composed of mechanical, electronic and software subsystems. The device was attached to a Discovery VH (General Electric Healthcare) gamma-camera, which was retired from the clinical service and installed at the Centro de Imagem Pré-Clínica of the Hospital Israelita Albert Einstein. The combined system was characterized, determining operational parameters, such as spatial resolution, magnification, maximum acceptable target size, number of projections, and acquisition and reconstruction times. RESULTS: Images were obtained with 0.5mm spatial resolution, with acquisition and reconstruction times between 30 and 45 minutes, using iterative reconstruction with 10 to 20 iterations and 4 projection subsets. The system was validated acquiring in vivo tomographic images of the heart, kidneys and brain of normal animals (mice and adult rats), using the radiopharmaceuticals technetium-labeled hexakis-2-methoxy-isobutyl isonitrile (99mTc-Sestamibi), technetium-labeled dimercaptosuccinic acid (99mTc-DMSA) and technetium-labeled hexamethyl propyleneamine oxime (99mTc-HMPAO). CONCLUSION: This kind of application, which consists in the adaptation for an alternative objective of already existing instrumentation, resulted in a low-cost infrastructure option, allowing to carry out large scale in vivo studies with enhanced quality in several areas, such as neurology, nephrology, cardiology, among others. OBJETIVO: Apresentar o resultado da adaptação de uma gama câmara clínica para uso dedicado na obtenção de imagens tomográficas in vivo de órgãos de pequenos animais de experimentação, e de sua aplicação na obtenção de imagens cardíacas, renais e neurológicas. MÉTODOS: Foi construída uma versão atualizada do dispositivo de adaptação miniSPECT, composto por três subsistemas: mecânico, eletrônico e de software. O dispositivo foi montado em uma câmara Discovery VH da General Electric Healthcare, retirada do serviço clínico e instalada no Centro de Imagem Pré-Clínica do Hospital Israelita Albert Einstein. O sistema combinado foi caracterizado, determinando parâmetros de funcionamento como resolução espacial, magnificação, limites de tamanho dos alvos de estudo, número de projeções, tempo de registro e tempo de reconstrução das imagens tomográficas. RESULTADOS: Foram obtidas imagens com resolução espacial de até 0,5mm, com tempos de registro e reconstrução de 30 a 45 minutos, utilizando reconstrução iterativa com 10 a 20 iterações e 4 subconjuntos de projeções. O sistema foi validado obtendo imagens tomográficas in vivo do coração, dos rins e do cérebro de animais normais (camundongos e ratos adultos), utilizando os radiofármacos hexaquis-2-metoxi-isobutil-isonitrila marcado com 99mTc (Sestamibi-99mTc), ácido dimercaptosuccínico marcado com 99mTc (DMSA-99mTc) e hexametil-propileno-amina-oxima marcada com 99mTc (HMPAO-99mTc). CONCLUSÃO: Este tipo de aplicação, que consiste na adaptação para um objetivo alternativo de instrumentação já existente, constituiu-se em uma opção de infraestrutura de baixo custo, que permite realizar estudos in vivo em larga escala, com qualidade aprimorada, em áreas diversas, como neurologia, nefrologia, cardiologia, entre outras.
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Affiliation(s)
- Jorge Mejia
- Hospital Israelita Albert Einstein, São Paulo, SP, Brazil
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Pajak MZ, Volgyes D, Pimlott SL, Salvador CC, Asensi AS, McKeown C, Waldeck J, Anderson KI. NEMA NU4-2008 Performance Evaluation of Albira: A Two-Ring Small-Animal PET System Using Continuous LYSO Crystals. ACTA ACUST UNITED AC 2016. [DOI: 10.2174/1874220301603010012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Goals:This paper presents the performance review based on a dual-ring Positron Emission Tomography (PET) scanner being a part of Bruker Albira: a multi-modal small-animal imaging platform. Each ring of Albira PET contains eight detectors arranged as octagon, and each detector is built using a single continuous lutetium-yttrium oxyorthosilicate crystal and multi-anode photo multiplier tube. In two-ring configuration, the scanner covers 94.4 mm in axial- and 80´80 mm in trans-axial direction, which is sufficient to acquire images of small animals (e.g.mice) without the need of moving the animal bed during the scan.Methods:All measurements and majority of data processing were performed according to the NEMA NU4-2008 standard with one exception. Due to the scanner geometry, the spatial resolution test was reconstructed using iterative algorithm instead of the analytical one. The main performance characteristics were compared with those of the other PET sub-systems of tri-modal small-animal scanners.Results:The measured spatial resolution at the centre of the axial field of view in radial, tangential and axial directions was 1.72, 1.70 and 2.45 mm, respectively. The scatter fraction for the mouse-like phantom was 9.8% and for the rat-like phantom, 21.8%. The maximum absolute sensitivity was 5.30%. Finally, the recovery co-efficients for 5, 4, 3, 2, 1 mm diameter rods in image quality phantom were: 0.90, 0.77, 0.66, 0.30 and 0.05, respectively.Conclusion:The Bruker Albira is a versatile small-animal multi-modal device that can be used for variety of studies. Overall the PET sub-system provides a good spatial resolution coupled with better-than average sensitivity and the ability to produce good quality animal images when administering low activities.
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Pfister J, Summer D, Rangger C, Petrik M, von Guggenberg E, Minazzi P, Giovenzana GB, Aloj L, Decristoforo C. Influence of a novel, versatile bifunctional chelator on theranostic properties of a minigastrin analogue. EJNMMI Res 2015; 5:74. [PMID: 26669693 PMCID: PMC4679714 DOI: 10.1186/s13550-015-0154-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Accepted: 12/10/2015] [Indexed: 01/21/2023] Open
Abstract
Background 6-[Bis(carboxymethyl)amino]-1,4-bis(carboxymethyl)-6-methyl-1,4-diazepane (AAZTA ) is a promising chelator with potential advantages over 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) for radiopharmaceutical applications. Its mesocyclic structure enables fast radiolabelling under mild conditions with trivalent metals including not only 68Ga for positron emission tomography (PET) but also 177Lu and 111In for single-photon emission computed tomography (SPECT) and radionuclide therapy. Here, we describe the evaluation of a bifunctional AAZTA derivative conjugated to a model minigastrin derivative as a potential theranostic agent. Methods An AAZTA derivative with an aliphatic C9 chain as linker was coupled to a minigastrin, namely [AAZTA0, D-Glu1, desGlu2–6]-minigastrin (AAZTA-MG), and labelled with 68Ga, 177Lu and 111In. The characterisation in vitro included stability studies in different media and determination of logD (octanol/PBS). Affinity determination (IC50) and cell uptake studies were performed in A431-CCK2R cells expressing the human CCK2 receptor. μPET/CT and ex vivo biodistribution studies were performed in CCK2 tumour xenograft-bearing nude mice and normal mice. Results AAZTA-MG showed high radiochemical yields for 68Ga (>95 %), 177Lu (>98 %) and 111In (>98 %). The logD value of −3.7 for both [68Ga]- and [177Lu]-AAZTA-MG indicates a highly hydrophilic character. Stability tests showed overall high stability in solution with some degradation in human plasma for [68Ga]- and transchelation towards DTPA for and [177Lu]-AAZTA-MG. An IC50 value of 10.0 nM was determined, which indicates a high affinity for the CCK2 receptor. Specific cell uptake after 60 min was >7.5 % for [68Ga]-AAZTA-MG and >9.5 % for [177Lu]-AAZTA-MG, comparable to other DOTA-MG-analogues. μPET/CT studies in CCK2 receptor tumour xenografted mice not only revealed high selective accumulation in A431-CCK2R positive tumours of 68Ga-labelled AAZTA-MG (1.5 % ID/g in 1 h post injection) but also higher blood levels as corresponding DOTA-analogues. The 111In-labelled peptide had a tumour uptake of 1.7 % ID/g. Biodistribution in normal mice with the [177Lu]-AAZTA-MG showed a considerable uptake in intestine (7.3 % ID/g) and liver (1.5 % ID/g). Conclusion Overall, AAZTA showed interesting properties as bifunctional chelator for peptides providing mild radiolabelling conditions for both 68Ga and trivalent metals having advantages over the currently used chelator DOTA. Studies are ongoing to further investigate in vivo targeting properties and stability issues and the influence of spacer length on biodistribution of AAZTA. Electronic supplementary material The online version of this article (doi:10.1186/s13550-015-0154-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Joachim Pfister
- Department of Nuclear Medicine, Innsbruck Medical University, Anichstrasse 35, A-6020, Innsbruck, Austria
| | - Dominik Summer
- Department of Nuclear Medicine, Innsbruck Medical University, Anichstrasse 35, A-6020, Innsbruck, Austria
| | - Christine Rangger
- Department of Nuclear Medicine, Innsbruck Medical University, Anichstrasse 35, A-6020, Innsbruck, Austria
| | - Milos Petrik
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University Olomouc, Olomouc, Czech Republic
| | - Elisabeth von Guggenberg
- Department of Nuclear Medicine, Innsbruck Medical University, Anichstrasse 35, A-6020, Innsbruck, Austria
| | | | - Giovanni B Giovenzana
- CAGE Chemicals srl, Novara, Italy.,DSF, Università del Piemonte Orientale "A. Avogadro", Novara, Italy
| | - Luigi Aloj
- Division of Nuclear Medicine, Istituto Nazionale Tumori, "Fondazione G. Pascale"-IRCCS, Napoli, Italy
| | - Clemens Decristoforo
- Department of Nuclear Medicine, Innsbruck Medical University, Anichstrasse 35, A-6020, Innsbruck, Austria.
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Performance characteristics of a novel clustered multi-pinhole technology for simultaneous high-resolution SPECT/PET. Ann Nucl Med 2015; 29:460-6. [DOI: 10.1007/s12149-015-0966-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Accepted: 03/19/2015] [Indexed: 11/26/2022]
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Balsara RD, Chapman SE, Sander IM, Donahue DL, Liepert L, Castellino FJ, Leevy WM. Non-invasive imaging and analysis of cerebral ischemia in living rats using positron emission tomography with 18F-FDG. J Vis Exp 2014. [PMID: 25590998 PMCID: PMC4354491 DOI: 10.3791/51495] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Stroke is the third leading cause of death among Americans 65 years of age or older1. The quality of life for patients who suffer from a stroke fails to return to normal in a large majority of patients2, which is mainly due to current lack of clinical treatment for acute stroke. This necessitates understanding the physiological effects of cerebral ischemia on brain tissue over time and is a major area of active research. Towards this end, experimental progress has been made using rats as a preclinical model for stroke, particularly, using non-invasive methods such as 18F-fluorodeoxyglucose (FDG) coupled with Positron Emission Tomography (PET) imaging3,10,17. Here we present a strategy for inducing cerebral ischemia in rats by middle cerebral artery occlusion (MCAO) that mimics focal cerebral ischemia in humans, and imaging its effects over 24 hr using FDG-PET coupled with X-ray computed tomography (CT) with an Albira PET-CT instrument. A VOI template atlas was subsequently fused to the cerebral rat data to enable a unbiased analysis of the brain and its sub-regions4. In addition, a method for 3D visualization of the FDG-PET-CT time course is presented. In summary, we present a detailed protocol for initiating, quantifying, and visualizing an induced ischemic stroke event in a living Sprague-Dawley rat in three dimensions using FDG-PET.
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Affiliation(s)
- Rashna D Balsara
- W. M. Keck Center for Transgene Research, University of Notre Dame; Department of Chemistry and Biochemistry, University of Notre Dame
| | - Sarah E Chapman
- Notre Dame Integrated Imaging Facility, University of Notre Dame
| | - Ian M Sander
- Department of Biological Sciences, University of Notre Dame
| | | | - Lucas Liepert
- Department of Biological Sciences, University of Notre Dame
| | - Francis J Castellino
- W. M. Keck Center for Transgene Research, University of Notre Dame; Department of Chemistry and Biochemistry, University of Notre Dame
| | - W Matthew Leevy
- Notre Dame Integrated Imaging Facility, University of Notre Dame; Department of Biological Sciences, University of Notre Dame; Harper Cancer Research Institute, University of Notre Dame;
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Petrik M, Vlckova A, Novy Z, Urbanek L, Haas H, Decristoforo C. Selected ⁶⁸Ga-siderophores versus ⁶⁸Ga-colloid and ⁶⁸Ga-citrate: biodistribution and small animal imaging in mice. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 2014; 159:60-6. [PMID: 25363728 DOI: 10.5507/bp.2014.052] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 09/30/2014] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND (68)Ga-triacetylfusarinine C (TAFC) and (68)Ga-ferrioxamine E (FOXE) show great potential to be used as highly sensitive and selective tracers for Aspergillus infection imaging. Here we report on a comparison of the ex vivo biodistribution and small animal imaging of (68)Ga-TAFC and (68)Ga-FOXE versus (68)Ga-colloid and (68)Ga-citrate as unspecific control in mice. METHODS The radiochemical purity of tested (68)Ga labelled tracers was determined by RP-HPLC or ITLC-SG. Ex vivo biodistribution was studied in normal DBA/2 mice 30 min and 90 min p.i. Static and dynamic imaging were performed using µPET/CT. RESULTS (68)Ga-TAFC and (68)Ga-FOXE showed rapid renal excretion and low blood values even 90 min p.i. (68)Ga-TAFC showed almost no retention in other organs while (68)Ga-FOXE displayed some uptake in gastrointestinal tract. (68)Ga-colloid and (68)Ga-citrate revealed significantly different ex vivo biodistribution. (68)Ga-colloid showed pronounced radioactivity retention in the liver, while (68)Ga-citrate displayed high blood values and significant retention of radioactivity in highly perfused organs. CONCLUSIONS From the results, both (68)Ga-TAFC and (68)Ga-FOXE have excellent and significantly different in vivo behaviour compared to (68)Ga-colloid and (68)Ga-citrate. (68)Ga-TAFC in particular confirmed its great potential use as a specific tracer for Aspergillus infection imaging.
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Affiliation(s)
- Milos Petrik
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University Olomouc, Czech Republic
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Gammon ST, Foje N, Brewer EM, Owers E, Downs CA, Budde MD, Leevy WM, Helms MN. Preclinical anatomical, molecular, and functional imaging of the lung with multiple modalities. Am J Physiol Lung Cell Mol Physiol 2014; 306:L897-914. [DOI: 10.1152/ajplung.00007.2014] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In vivo imaging is an important tool for preclinical studies of lung function and disease. The widespread availability of multimodal animal imaging systems and the rapid rate of diagnostic contrast agent development have empowered researchers to noninvasively study lung function and pulmonary disorders. Investigators can identify, track, and quantify biological processes over time. In this review, we highlight the fundamental principles of bioluminescence, fluorescence, planar X-ray, X-ray computed tomography, magnetic resonance imaging, and nuclear imaging modalities (such as positron emission tomography and single photon emission computed tomography) that have been successfully employed for the study of lung function and pulmonary disorders in a preclinical setting. The major principles, benefits, and applications of each imaging modality and technology are reviewed. Limitations and the future prospective of multimodal imaging in pulmonary physiology are also discussed. In vivo imaging bridges molecular biological studies, drug design and discovery, and the imaging field with modern medical practice, and, as such, will continue to be a mainstay in biomedical research.
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Affiliation(s)
- Seth T. Gammon
- Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Nathan Foje
- Department of Biological Sciences, Notre Dame Integrated Imaging Facility, Notre Dame, Indiana
| | - Elizabeth M. Brewer
- Department of Pediatrics Center for Cystic Fibrosis and Airways Disease Research, Emory University, Atlanta, Georgia
| | - Elizabeth Owers
- Department of Biological Sciences, Notre Dame Integrated Imaging Facility, Notre Dame, Indiana
| | - Charles A. Downs
- Nell Hodgson Woodruff School of Nursing, Emory University, Atlanta, Georgia; and
| | - Matthew D. Budde
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - W. Matthew Leevy
- Department of Biological Sciences, Notre Dame Integrated Imaging Facility, Notre Dame, Indiana
| | - My N. Helms
- Department of Pediatrics Center for Cystic Fibrosis and Airways Disease Research, Emory University, Atlanta, Georgia
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