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Vrachliotis A, Gaitanis A, Protonotarios NE, Kastis GA, Costaridou L. Noninvasive Quantification of Glucose Metabolism in Mice Myocardium Using the Spline Reconstruction Technique. J Imaging 2024; 10:170. [PMID: 39057741 PMCID: PMC11278115 DOI: 10.3390/jimaging10070170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2024] [Revised: 06/25/2024] [Accepted: 07/12/2024] [Indexed: 07/28/2024] Open
Abstract
The spline reconstruction technique (SRT) is a fast algorithm based on a novel numerical implementation of an analytic representation of the inverse Radon transform. The purpose of this study was to compare the SRT, filtered back-projection (FBP), and the Tera-Tomo 3D algorithm for various iteration numbers, using small-animal dynamic PET data obtained from a Mediso nanoScan® PET/CT scanner. For this purpose, Patlak graphical kinetic analysis was employed to noninvasively quantify the myocardial metabolic rate of glucose (MRGlu) in seven male C57BL/6 mice (n=7). All analytic reconstructions were performed via software for tomographic image reconstruction. The analysis of all PET-reconstructed images was conducted with PMOD software (version 3.506, PMOD Technologies LLC, Fällanden, Switzerland) using the inferior vena cava as the image-derived input function. Statistical significance was determined by employing the one-way analysis of variance test. The results revealed that the differences between the values of MRGlu obtained via SRT versus FBP, and the variants of he Tera-Tomo 3D algorithm were not statistically significant (p > 0.05). Overall, the SRT appears to perform similarly to the other algorithms investigated, providing a valid alternative analytic method for preclinical dynamic PET studies.
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Affiliation(s)
- Alexandros Vrachliotis
- Department of Medical Physics, School of Medicine, University of Patras, 26504 Patras, Greece; (A.V.); (L.C.)
- Clinical, Experimental Surgery & Translational Research, Biomedical Research Foundation (BRFAA), Academy of Athens, 4 Soranou Ephessiou, 11527 Athens, Greece;
| | - Anastasios Gaitanis
- Clinical, Experimental Surgery & Translational Research, Biomedical Research Foundation (BRFAA), Academy of Athens, 4 Soranou Ephessiou, 11527 Athens, Greece;
| | - Nicholas E. Protonotarios
- Mathematics Research Center, Academy of Athens, 11527 Athens, Greece;
- Institute of Nuclear & Radiological Sciences & Technology, Energy & Safety, National Center for Scientific Research “Demokritos”, 15341 Athens, Greece
| | - George A. Kastis
- Mathematics Research Center, Academy of Athens, 11527 Athens, Greece;
- Institute of Nuclear & Radiological Sciences & Technology, Energy & Safety, National Center for Scientific Research “Demokritos”, 15341 Athens, Greece
| | - Lena Costaridou
- Department of Medical Physics, School of Medicine, University of Patras, 26504 Patras, Greece; (A.V.); (L.C.)
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Optimization of Spatial Resolution and Image Reconstruction Parameters for the Small-Animal Metis™ PET/CT System. ELECTRONICS 2022. [DOI: 10.3390/electronics11101542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Purpose: The aim of this study was to investigate the optimization of the spatial resolution and image reconstruction parameters related to image quality in an iterative reconstruction algorithm for the small-animal Metis™ PET/CT system. Methods: We used a homemade Derenzo phantom to evaluate the image quality using visual assessment, the signal-to-noise ratio, the contrast, the coefficient of variation, and the contrast-to-noise ratio of the 0.8 mm hot rods of eight slices in the center of the phantom PET images. A healthy mouse study was performed to analyze the influence of the optimal reconstruction parameters and the Gaussian post-filter FWHM. Results: In the phantom study, the image quality was the best when the phantom was placed at the end, keeping the central axis parallel to the X-axis of the system, and selecting between 30 and 40 iterations, a 0.314 mm reconstructed voxel size, and a 1.57 mm Gaussian post-filter FWHM. The optimization of the spatial resolution could reach 0.6 mm. In the animal study, it was suitable to choose a voxel size of 0.472 mm, between 30 and 40 iterations, and a 2.36 mm Gaussian post-filter FWHM. Conclusions: Our results indicate that the optimal imaging conditions and reconstruction parameters are very necessary to obtain high-resolution images and quantitative accuracy, especially for the high-precision recognition of tiny lesions.
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Vrachliotis A, Kastis GA, Protonotarios NE, Fokas AS, Nekolla SG, Anagnostopoulos CD, Costaridou L, Gaitanis A. Evaluation of the spline reconstruction technique for preclinical PET imaging. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2022; 217:106668. [PMID: 35176596 DOI: 10.1016/j.cmpb.2022.106668] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 12/27/2021] [Accepted: 01/26/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND AND OBJECTIVE The Spline Reconstruction Technique (SRT) is a fast algorithm based on a novel numerical implementation of an analytic representation of the inverse Radon transform. The purpose of this study is to provide a comparison between SRT, Filtered Back-Projection (FBP), Ordered Subset Expectation Maximization 2D (2D-OSEM), and the Tera-Tomo 3D algorithm, using phantom data at various acquisition durations as well as small-animal data obtained from the Mediso nanoScan® PET/CT scanner. METHODS For this purpose, the "NEMA NU 4-2008 standards" protocol was employed at five different realizations and acquisition durations. In addition to the image quality metrics described by the NEMA protocol, Cold Region Contrast was also considered as a figure-of-merit. Furthermore, Cold Region Contrast was measured in the myocardial infarction region of six male Wistar rats. The volumetric defect quantification was assessed with dedicated computer software. Lastly, plots of Recovery Coefficient and Spill-Over Ratio as a function of the Percentage Standard Deviation were generated, after smoothing the phantom reconstructions with four different Gaussian filters. Statistical significance was determined by employing the Kruskal-Wallis test or One-way Analysis of Variance depending on the normality of the variable's distribution. RESULTS The present study revealed that, at the expense of slightly increased noise in the reconstructed images, SRT resulted in higher Recovery Coefficient values for small hot regions of interest, when compared with FBP and 2D-OSEM at all acquisition durations. Furthermore, SRT reconstructed images exhibit higher Recovery Coefficient values, for all hot regions of interest, when compared to the other 2D algorithms at short acquisition durations. In both phantom and animal studies, SRT achieved a significant improvement over 2D-OSEM for the Spill-Over Ratio and the Cold Region Contrast. These advantages were maintained even after comparing the algorithms at equal noise levels. The Tera-Tomo 3D algorithm (4 subsets, iterations≥ 13) performed significantly better compared to the other algorithms for all figures-of-merit. No statistically significant differences regarding the myocardial defect size were observed between the algorithms investigated. CONCLUSIONS Overall, SRT appears that could be useful for the quantification of small hot regions of interest, cold regions of interest, as well as in low-count imaging applications.
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Affiliation(s)
- Alexandros Vrachliotis
- Department of Medical Physics, School of Medicine, University of Patras, Patras 26504, Greece; Clinical, Experimental Surgery and Translational Research, Biomedical Research Foundation, Academy of Athens (BRFAA), Athens 11527, Greece
| | - George A Kastis
- Mathematics Research Center, Academy of Athens, Athens 11527, Greece; Institute of Nuclear & Radiological Sciences & Technology, Energy & Safety, National Center for Scientific Research "Demokritos", 15341 Athens, Greece
| | - Nicholas E Protonotarios
- Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge CB30WA, United Kingdom
| | - Athanasios S Fokas
- Mathematics Research Center, Academy of Athens, Athens 11527, Greece; Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge CB30WA, United Kingdom
| | - Stephan G Nekolla
- Klinikum rechts der Isar, Department of Nuclear Medicine and DZHK (German Centre for Cardiovascular Research), Technical University Munich, Partner Site Munich Heart Alliance, Munich 80336, Germany
| | - Constantinos D Anagnostopoulos
- Clinical, Experimental Surgery and Translational Research, Biomedical Research Foundation, Academy of Athens (BRFAA), Athens 11527, Greece
| | - Lena Costaridou
- Department of Medical Physics, School of Medicine, University of Patras, Patras 26504, Greece
| | - Anastasios Gaitanis
- Clinical, Experimental Surgery and Translational Research, Biomedical Research Foundation, Academy of Athens (BRFAA), Athens 11527, Greece.
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Reconstruction of Preclinical PET Images via Chebyshev Polynomial Approximation of the Sinogram. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12073335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Over the last decades, there has been an increasing interest in dedicated preclinical imaging modalities for research in biomedicine. Especially in the case of positron emission tomography (PET), reconstructed images provide useful information of the morphology and function of an internal organ. PET data, stored as sinograms, involve the Radon transform of the image under investigation. The analytical approach to PET image reconstruction incorporates the derivative of the Hilbert transform of the sinogram. In this direction, in the present work we present a novel numerical algorithm for the inversion of the Radon transform based on Chebyshev polynomials of the first kind. By employing these polynomials, the computation of the derivative of the Hilbert transform of the sinogram is significantly simplified. Extending the mathematical setting of previous research based on Chebyshev polynomials, we are able to efficiently apply our new Chebyshev inversion scheme for the case of analytic preclinical PET image reconstruction. We evaluated our reconstruction algorithm on projection data from a small-animal image quality (IQ) simulated phantom study, in accordance with the NEMA NU 4-2008 standards protocol. In particular, we quantified our reconstructions via the image quality metrics of percentage standard deviation, recovery coefficient, and spill-over ratio. The projection data employed were acquired for three different Poisson noise levels: 100% (NL1), 50% (NL2), and 20% (NL3) of the total counts, respectively. In the uniform region of the IQ phantom, Chebyshev reconstructions were consistently improved over filtered backprojection (FBP), in terms of percentage standard deviation (up to 29% lower, depending on the noise level). For all rods, we measured the contrast-to-noise-ratio, indicating an improvement of up to 68% depending on the noise level. In order to compare our reconstruction method with FBP, at equal noise levels, plots of recovery coefficient and spill-over ratio as functions of the percentage standard deviation were generated, after smoothing the NL3 reconstructions with three different Gaussian filters. When post-smoothing was applied, Chebyshev demonstrated recovery coefficient values up to 14% and 42% higher, for rods 1–3 mm and 4–5 mm, respectively, compared to FBP, depending on the smoothing sigma values. Our results indicate that our Chebyshev-based analytic reconstruction method may provide PET reconstructions that are comparable to FBP, thus yielding a good alternative to standard analytic preclinical PET reconstruction methods.
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Kurochkin MA, German SV, Abalymov A, Vorontsov DА, Gorin DA, Novoselova MV. Sentinel lymph node detection by combining nonradioactive techniques with contrast agents: State of the art and prospects. JOURNAL OF BIOPHOTONICS 2022; 15:e202100149. [PMID: 34514735 DOI: 10.1002/jbio.202100149] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 08/21/2021] [Accepted: 09/09/2021] [Indexed: 06/13/2023]
Abstract
The status of sentinel lymph nodes (SLNs) has a substantial prognostic value because these nodes are the first place where cancer cells accumulate along their spreading route. Routine SLN biopsy ("gold standard") involves peritumoral injections of radiopharmaceuticals, such as technetium-99m, which has obvious disadvantages. This review examines the methods used as "gold standard" analogs to diagnose SLNs. Nonradioactive preoperative and intraoperative methods of SLN detection are analyzed. Promising photonic tools for SLNs detection are reviewed, including NIR-I/NIR-II fluorescence imaging, photoswitching dyes for SLN detection, in vivo photoacoustic detection, imaging and biopsy of SLNs. Also are discussed methods of SLN detection by magnetic resonance imaging, ultrasonic imaging systems including as combined with photoacoustic imaging, and methods based on the magnetometer-aided detection of superparamagnetic nanoparticles. The advantages and disadvantages of nonradioactive SLN-detection methods are shown. The review concludes with prospects for the use of conservative diagnostic methods in combination with photonic tools.
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Affiliation(s)
| | - Sergey V German
- Skolkovo Institute of Science and Technology, Moscow, Russia
- Institute of Spectroscopy of the Russian Academy of Sciences, Moscow, Russia
| | | | - Dmitry А Vorontsov
- State Budgetary Institution of Health Care of Nizhny Novgorod "Nizhny Novgorod Regional Clinical Oncological Dispensary", Nizhny Novgorod, Russia
| | - Dmitry A Gorin
- Skolkovo Institute of Science and Technology, Moscow, Russia
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Chomet M, Schreurs M, Vos R, Verlaan M, Kooijman EJ, Poot AJ, Boellaard R, Windhorst AD, van Dongen GA, Vugts DJ, Huisman MC, Beaino W. Performance of nanoScan PET/CT and PET/MR for quantitative imaging of 18F and 89Zr as compared with ex vivo biodistribution in tumor-bearing mice. EJNMMI Res 2021; 11:57. [PMID: 34117946 PMCID: PMC8197690 DOI: 10.1186/s13550-021-00799-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 06/02/2021] [Indexed: 12/29/2022] Open
Abstract
INTRODUCTION The assessment of ex vivo biodistribution is the preferred method for quantification of radiotracers biodistribution in preclinical models, but is not in line with current ethics on animal research. PET imaging allows for noninvasive longitudinal evaluation of tracer distribution in the same animals, but systemic comparison with ex vivo biodistribution is lacking. Our aim was to evaluate the potential of preclinical PET imaging for accurate tracer quantification, especially in tumor models. METHODS NEMA NU 4-2008 phantoms were filled with 11C, 68Ga, 18F, or 89Zr solutions and scanned in Mediso nanoPET/CT and PET/MR scanners until decay. N87 tumor-bearing mice were i.v. injected with either [18F]FDG (~ 14 MBq), kept 50 min under anesthesia followed by imaging for 20 min, or with [89Zr]Zr-DFO-NCS-trastuzumab (~ 5 MBq) and imaged 3 days post-injection for 45 min. After PET acquisition, animals were killed and organs of interest were collected and measured in a γ-counter to determine tracer uptake levels. PET data were reconstructed using TeraTomo reconstruction algorithm with attenuation and scatter correction and regions of interest were drawn using Vivoquant software. PET imaging and ex vivo biodistribution were compared using Bland-Altman plots. RESULTS In phantoms, the highest recovery coefficient, thus the smallest partial volume effect, was obtained with 18F for both PET/CT and PET/MR. Recovery was slightly lower for 11C and 89Zr, while the lowest recovery was obtained with 68Ga in both scanners. In vivo, tumor uptake of the 18F- or 89Zr-labeled tracer proved to be similar irrespective whether quantified by either PET/CT and PET/MR or ex vivo biodistribution with average PET/ex vivo ratios of 0.8-0.9 and a deviation of 10% or less. Both methods appeared less congruent in the quantification of tracer uptake in healthy organs such as brain, kidney, and liver, and depended on the organ evaluated and the radionuclide used. CONCLUSIONS Our study suggests that PET quantification of 18F- and 89Zr-labeled tracers is reliable for the evaluation of tumor uptake in preclinical models and a valuable alternative technique for ex vivo biodistribution. However, PET and ex vivo quantification require fully described experimental and analytical procedures for reliability and reproducibility.
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Affiliation(s)
- Marion Chomet
- Amsterdam UMC, Vrije Universiteit Amsterdam, Radiology & Nuclear Medicine, Cancer Center Amsterdam, De Boelelaan 1117, Amsterdam 1081 HV, The Netherlands
| | - Maxime Schreurs
- Amsterdam UMC, Vrije Universiteit Amsterdam, Radiology & Nuclear Medicine, Cancer Center Amsterdam, De Boelelaan 1117, Amsterdam 1081 HV, The Netherlands
| | - Ricardo Vos
- Amsterdam UMC, Vrije Universiteit Amsterdam, Radiology & Nuclear Medicine, Cancer Center Amsterdam, De Boelelaan 1117, Amsterdam 1081 HV, The Netherlands
| | - Mariska Verlaan
- Amsterdam UMC, Vrije Universiteit Amsterdam, Radiology & Nuclear Medicine, Cancer Center Amsterdam, De Boelelaan 1117, Amsterdam 1081 HV, The Netherlands
| | - Esther J Kooijman
- Amsterdam UMC, Vrije Universiteit Amsterdam, Radiology & Nuclear Medicine, Cancer Center Amsterdam, De Boelelaan 1117, Amsterdam 1081 HV, The Netherlands
| | - Alex J Poot
- Amsterdam UMC, Vrije Universiteit Amsterdam, Radiology & Nuclear Medicine, Cancer Center Amsterdam, De Boelelaan 1117, Amsterdam 1081 HV, The Netherlands
| | - Ronald Boellaard
- Amsterdam UMC, Vrije Universiteit Amsterdam, Radiology & Nuclear Medicine, Cancer Center Amsterdam, De Boelelaan 1117, Amsterdam 1081 HV, The Netherlands
| | - Albert D Windhorst
- Amsterdam UMC, Vrije Universiteit Amsterdam, Radiology & Nuclear Medicine, Cancer Center Amsterdam, De Boelelaan 1117, Amsterdam 1081 HV, The Netherlands
| | - Guus Ams van Dongen
- Amsterdam UMC, Vrije Universiteit Amsterdam, Radiology & Nuclear Medicine, Cancer Center Amsterdam, De Boelelaan 1117, Amsterdam 1081 HV, The Netherlands
| | - Danielle J Vugts
- Amsterdam UMC, Vrije Universiteit Amsterdam, Radiology & Nuclear Medicine, Cancer Center Amsterdam, De Boelelaan 1117, Amsterdam 1081 HV, The Netherlands
| | - Marc C Huisman
- Amsterdam UMC, Vrije Universiteit Amsterdam, Radiology & Nuclear Medicine, Cancer Center Amsterdam, De Boelelaan 1117, Amsterdam 1081 HV, The Netherlands
| | - Wissam Beaino
- Amsterdam UMC, Vrije Universiteit Amsterdam, Radiology & Nuclear Medicine, Cancer Center Amsterdam, De Boelelaan 1117, Amsterdam 1081 HV, The Netherlands.
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Teuho J, Riehakainen L, Honkaniemi A, Moisio O, Han C, Tirri M, Liu S, Grönroos TJ, Liu J, Wan L, Liang X, Ling Y, Hua Y, Roivainen A, Knuuti J, Xie Q, Teräs M, D'Ascenzo N, Klén R. Evaluation of image quality with four positron emitters and three preclinical PET/CT systems. EJNMMI Res 2020; 10:155. [PMID: 33301074 PMCID: PMC7728905 DOI: 10.1186/s13550-020-00724-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 10/21/2020] [Indexed: 01/19/2023] Open
Abstract
Background We investigated the image quality of 11C, 68Ga, 18F and 89Zr, which have different positron fractions, physical half-lifes and positron ranges. Three small animal positron emission tomography/computed tomography (PET/CT) systems were used in the evaluation, including the Siemens Inveon, RAYCAN X5 and Molecubes β-cube. The evaluation was performed on a single scanner level using the national electrical manufacturers association (NEMA) image quality phantom and analysis protocol. Acquisitions were performed with the standard NEMA protocol for 18F and using a radionuclide-specific acquisition time for 11C, 68Ga and 89Zr. Images were assessed using percent recovery coefficient (%RC), percentage standard deviation (%STD), image uniformity (%SD), spill-over ratio (SOR) and evaluation of image quantification.
Results 68Ga had the lowest %RC (< 62%) across all systems. 18F had the highest maximum %RC (> 85%) and lowest %STD for the 5 mm rod across all systems. For 11C and 89Zr, the maximum %RC was close (> 76%) to the %RC with 18F. A larger SOR were measured in water with 11C and 68Ga compared to 18F on all systems. SOR in air reflected image reconstruction and data correction performance. Large variation in image quantification was observed, with maximal errors of 22.73% (89Zr, Inveon), 17.54% (89Zr, RAYCAN) and − 14.87% (68Ga, Molecubes). Conclusions The systems performed most optimal in terms of NEMA image quality parameters when using 18F, where 11C and 89Zr performed slightly worse than 18F. The performance was least optimal when using 68Ga, due to large positron range. The large quantification differences prompt optimization not only by terms of image quality but also quantification. Further investigation should be performed to find an appropriate calibration and harmonization protocol and the evaluation should be conducted on a multi-scanner and multi-center level.
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Affiliation(s)
- Jarmo Teuho
- Turku PET Centre, University of Turku, Turku, Finland. .,Turku PET Centre, Turku University Hospital, Turku, Finland.
| | | | | | - Olli Moisio
- Turku PET Centre, University of Turku, Turku, Finland
| | - Chunlei Han
- Turku PET Centre, Turku University Hospital, Turku, Finland
| | - Marko Tirri
- Turku PET Centre, University of Turku, Turku, Finland.,Department of Biomedicine, University of Turku, Turku, Finland
| | - Shihao Liu
- RaySolution Digital Medical Imaging Co., Ltd, Ezhou, People's Republic of China
| | - Tove J Grönroos
- Turku PET Centre, University of Turku, Turku, Finland.,MediCity Research Laboratory, University of Turku, Turku, Finland
| | - Jie Liu
- School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, People's Republic of China
| | - Lin Wan
- School of Software Engineering, Huazhong University of Science and Technology, Wuhan, People's Republic of China
| | - Xiao Liang
- School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, People's Republic of China
| | - Yiqing Ling
- School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, People's Republic of China
| | - Yuexuan Hua
- School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, People's Republic of China
| | - Anne Roivainen
- Turku PET Centre, University of Turku, Turku, Finland.,Turku PET Centre, Turku University Hospital, Turku, Finland.,Turku Center for Disease Modeling, University of Turku, Turku, Finland
| | - Juhani Knuuti
- Turku PET Centre, University of Turku, Turku, Finland.,Turku PET Centre, Turku University Hospital, Turku, Finland
| | - Qingguo Xie
- School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, People's Republic of China.,Department of Medical Physics and Engineering, Istituto Neurologico Mediterraneo NEUROMED I.R.C.C.S., Pozzilli, Italy.,Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, China
| | - Mika Teräs
- Department of Biomedicine, University of Turku, Turku, Finland.,Department of Medical Physics, Turku University Hospital, Turku, Finland
| | - Nicola D'Ascenzo
- School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, People's Republic of China.,Department of Medical Physics and Engineering, Istituto Neurologico Mediterraneo NEUROMED I.R.C.C.S., Pozzilli, Italy
| | - Riku Klén
- Turku PET Centre, University of Turku, Turku, Finland
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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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Meester EJ, Krenning BJ, de Swart J, Segbers M, Barrett HE, Bernsen MR, Van der Heiden K, de Jong M. Perspectives on Small Animal Radionuclide Imaging; Considerations and Advances in Atherosclerosis. Front Med (Lausanne) 2019; 6:39. [PMID: 30915335 PMCID: PMC6421263 DOI: 10.3389/fmed.2019.00039] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 02/11/2019] [Indexed: 12/20/2022] Open
Abstract
This review addresses nuclear SPECT and PET imaging in small animals in relation to the atherosclerotic disease process, one of our research topics of interest. Imaging of atherosclerosis in small animal models is challenging, as it operates at the limits of current imaging possibilities regarding sensitivity, and spatial resolution. Several topics are discussed, including technical considerations that apply to image acquisition, reconstruction, and analysis. Moreover, molecules developed for or applied in these small animal nuclear imaging studies are listed, including target-directed molecules, useful for imaging organs or tissues that have elevated expression of the target compared to other tissues, and molecules that serve as substrates for metabolic processes. Differences between animal models and human pathophysiology that should be taken into account during translation from animal to patient as well as differences in tracer behavior in animal vs. man are also described. Finally, we give a future outlook on small animal radionuclide imaging in atherosclerosis, followed by recommendations. The challenges and solutions described might be applicable to other research fields of health and disease as well.
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Affiliation(s)
- Eric J Meester
- Department of Radiology and Nuclear Medicine, Erasmus Medical Center, Rotterdam, Netherlands.,Department of Biomedical Engineering, Thorax Center, Erasmus Medical Center, Rotterdam, Netherlands
| | - B J Krenning
- Department of Cardiology, Thorax Center, Erasmus Medical Center, Rotterdam, Netherlands
| | - J de Swart
- Department of Radiology and Nuclear Medicine, Erasmus Medical Center, Rotterdam, Netherlands
| | - M Segbers
- Department of Radiology and Nuclear Medicine, Erasmus Medical Center, Rotterdam, Netherlands
| | - H E Barrett
- Department of Radiology and Nuclear Medicine, Erasmus Medical Center, Rotterdam, Netherlands.,Department of Biomedical Engineering, Thorax Center, Erasmus Medical Center, Rotterdam, Netherlands
| | - M R Bernsen
- Department of Radiology and Nuclear Medicine, Erasmus Medical Center, Rotterdam, Netherlands
| | - K Van der Heiden
- Department of Biomedical Engineering, Thorax Center, Erasmus Medical Center, Rotterdam, Netherlands
| | - Marion de Jong
- Department of Radiology and Nuclear Medicine, Erasmus Medical Center, Rotterdam, Netherlands
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Freesmeyer M, Kuehnel C, Opfermann T, Niksch T, Wiegand S, Stolz R, Huonker R, Witte OW, Winkens T. The Use of Ostrich Eggs for In Ovo Research: Making Preclinical Imaging Research Affordable and Available. J Nucl Med 2018; 59:1901-1906. [PMID: 29934406 DOI: 10.2967/jnumed.118.210310] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 05/31/2018] [Indexed: 12/11/2022] Open
Abstract
In ovo studies are a valuable option in preclinical research, but imaging studies are severely limited by the costs of dedicated equipment needed for small-sized eggs. We sought to verify the feasibility of using larger, ostrich, eggs (Struthio camelus) for imaging on the PET/CT scanners used for routine clinical investigations. Methods: Ostrich eggs were incubated until shortly before hatching, prepared for intravitelline venous injection of contrast medium or radiotracer, and imaged using native CT, contrast-enhanced CT, and PET/CT. Any technical adaptations that were needed to improve the outcome were noted. Results: Of the 34 eggs initially incubated, 12 became fully available for imaging of embryonal development. In ovo imaging with conventional PET/CT not only was feasible but also provided images of good quality, including on dynamic PET imaging. Conclusion: In ovo imaging with ostrich eggs and routine clinical scanners may allow broader application of this field of preclinical research, obviating costly dedicated equipment and reducing the number of animals needed for classic animal research. Further experiments are warranted to refine this novel approach, especially to reduce motion artifacts and improve monitoring of viability.
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Affiliation(s)
| | | | - Thomas Opfermann
- Clinic of Nuclear Medicine, Jena University Hospital, Jena, Germany
| | - Tobias Niksch
- Clinic of Nuclear Medicine, Jena University Hospital, Jena, Germany
| | - Steffen Wiegand
- Clinic of Nuclear Medicine, Jena University Hospital, Jena, Germany
| | - Ronny Stolz
- Leibniz Institute of Photonic Technology, Jena, Germany
| | - Ralph Huonker
- Biomagnetic Center, Hans Berger Department of Neurology, Jena University Hospital, Jena, Germany; and
| | - Otto W Witte
- Biomagnetic Center, Hans Berger Department of Neurology, Jena University Hospital, Jena, Germany; and.,Hans Berger Department of Neurology, Jena University Hospital, Jena, Germany
| | - Thomas Winkens
- Clinic of Nuclear Medicine, Jena University Hospital, Jena, Germany
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