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Ebrahimi S, Lundström E, Batasin SJ, Hedlund E, Stålberg K, Ehman EC, Sheth VR, Iranpour N, Loubrie S, Schlein A, Rakow-Penner R. Application of PET/MRI in Gynecologic Malignancies. Cancers (Basel) 2024; 16:1478. [PMID: 38672560 PMCID: PMC11048306 DOI: 10.3390/cancers16081478] [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: 02/24/2024] [Revised: 03/23/2024] [Accepted: 03/27/2024] [Indexed: 04/28/2024] Open
Abstract
The diagnosis, treatment, and management of gynecologic malignancies benefit from both positron emission tomography/computed tomography (PET/CT) and MRI. PET/CT provides important information on the local extent of disease as well as diffuse metastatic involvement. MRI offers soft tissue delineation and loco-regional disease involvement. The combination of these two technologies is key in diagnosis, treatment planning, and evaluating treatment response in gynecological malignancies. This review aims to assess the performance of PET/MRI in gynecologic cancer patients and outlines the technical challenges and clinical advantages of PET/MR systems when specifically applied to gynecologic malignancies.
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Affiliation(s)
- Sheida Ebrahimi
- Department of Radiology, University of California San Diego, La Jolla, CA 92093, USA
| | - Elin Lundström
- Department of Radiology, University of California San Diego, La Jolla, CA 92093, USA
- Department of Surgical Sciences, Radiology, Uppsala University, 751 85 Uppsala, Sweden
- Center for Medical Imaging, Uppsala University Hospital, 751 85 Uppsala, Sweden
| | - Summer J. Batasin
- Department of Radiology, University of California San Diego, La Jolla, CA 92093, USA
| | - Elisabeth Hedlund
- Department of Surgical Sciences, Radiology, Uppsala University, 751 85 Uppsala, Sweden
| | - Karin Stålberg
- Department of Women’s and Children’s Health, Uppsala University, 751 85 Uppsala, Sweden
| | - Eric C. Ehman
- Department of Radiology, Mayo Clinic, Rochester, MN 55905, USA
| | - Vipul R. Sheth
- Department of Radiology, Stanford University, Palo Alto, CA 94305, USA; (V.R.S.)
| | - Negaur Iranpour
- Department of Radiology, Stanford University, Palo Alto, CA 94305, USA; (V.R.S.)
| | - Stephane Loubrie
- Department of Radiology, University of California San Diego, La Jolla, CA 92093, USA
| | - Alexandra Schlein
- Department of Radiology, University of California San Diego, La Jolla, CA 92093, USA
| | - Rebecca Rakow-Penner
- Department of Radiology, University of California San Diego, La Jolla, CA 92093, USA
- Department of Bioengineering, University of California San Diego, La Jolla, CA 92093, USA
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Li C, Scheins J, Tellmann L, Issa A, Wei L, Shah NJ, Lerche C. Fast 3D kernel computation method for positron range correction in PET. Phys Med Biol 2023; 68. [PMID: 36595256 DOI: 10.1088/1361-6560/acaa84] [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: 08/19/2022] [Accepted: 12/09/2022] [Indexed: 12/13/2022]
Abstract
Objective. The positron range is a fundamental, detector-independent physical limitation to spatial resolution in positron emission tomography (PET) as it causes a significant blurring of underlying activity distribution in the reconstructed images. A major challenge for positron range correction methods is to provide accurate range kernels that inherently incorporate the generally inhomogeneous stopping power, especially at tissue boundaries. In this work, we propose a novel approach to generate accurate three-dimensional (3D) blurring kernels both in homogenous and heterogeneous media to improve PET spatial resolution.Approach. In the proposed approach, positron energy deposition was approximately tracked along straight paths, depending on the positron stopping power of the underlying material. The positron stopping power was derived from the attenuation coefficient of 511 keV gamma photons according to the available PET attenuation maps. Thus, the history of energy deposition is taken into account within the range of kernels. Special emphasis was placed on facilitating the very fast computation of the positron annihilation probability in each voxel.Results. Positron path distributions of18F in low-density polyurethane were in high agreement with Geant4 simulation at an annihilation probability larger than 10-2∼ 10-3of the maximum annihilation probability. The Geant4 simulation was further validated with measured18F depth profiles in these polyurethane phantoms. The tissue boundary of water with cortical bone and lung was correctly modeled. Residual artifacts from the numerical computations were in the range of 1%. The calculated annihilation probability in voxels shows an overall difference of less than 20% compared to the Geant4 simulation.Significance. The proposed method is expected to significantly improve spatial resolution for non-standard isotopes by providing sufficiently accurate range kernels, even in the case of significant tissue inhomogeneities.
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Affiliation(s)
- Chong Li
- Institute of Neuroscience and Medicine, INM-4, Forschungszentrum GmbH, Jülich, Germany.,Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Jürgen Scheins
- Institute of Neuroscience and Medicine, INM-4, Forschungszentrum GmbH, Jülich, Germany
| | - Lutz Tellmann
- Institute of Neuroscience and Medicine, INM-4, Forschungszentrum GmbH, Jülich, Germany
| | - Ahlam Issa
- Institute of Neuroscience and Medicine, INM-4, Forschungszentrum GmbH, Jülich, Germany.,Department of Neurology, RWTH Aachen University, Aachen, Germany.,JARA-BRAIN-Translational Medicine, RWTH Aachen University, Aachen, Germany
| | - Long Wei
- Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, People's Republic of China
| | - N Jon Shah
- Institute of Neuroscience and Medicine, INM-4, Forschungszentrum GmbH, Jülich, Germany.,Institute of Neuroscience and Medicine, INM-11, Forschungszentrum GmbH, Jülich, Germany.,Department of Neurology, RWTH Aachen University, Aachen, Germany.,JARA-BRAIN-Translational Medicine, RWTH Aachen University, Aachen, Germany
| | - Christoph Lerche
- Institute of Neuroscience and Medicine, INM-4, Forschungszentrum GmbH, Jülich, Germany
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Meng X, Liu H, Li H, Wang S, Sun H, Wang F, Ding J, He L, Chen X, Jin L, Dong Y, Zhu H, Yang Z. Evaluating the impact of different positron emitters on the performance of a clinical PET/MR system. Med Phys 2022; 49:2642-2651. [PMID: 35106784 DOI: 10.1002/mp.15513] [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: 07/26/2021] [Revised: 10/27/2021] [Accepted: 01/06/2022] [Indexed: 11/07/2022] Open
Abstract
PURPOSE The positron range and prompt gamma emission are distinctive with different positron emitters. The performance assessment of an integrated PET/MR scanner with these positron emitters is required for related applications, as the magnetic field interferes with the positron propagation. Such an assessment is to be performed on the United Imaging uPMR 790 integrated PET/MR system. METHODS The performance measurement methods were modified based on NEMA NU 2-2012, involving 18 F, 64 Cu, 68 Ga, 89 Zr, and 124 I as positron emitters. The NEMA IEC phantom was used for evaluations of image qualities. An agarose cap was wrapped around the point source for tissue-simulating spatial resolution measurement. The count rate performance was assessed with selected positron emitters. Images of a 3D-printed Derenzo phantom and representative patients were also acquired. RESULTS The image quality measurement showed that all five positron emitters were suitable for the PET/MR system studied. However, due to the magnetic field, the image of the point source showed an elongated comet-tail feature, which could be eliminated by a tissue-simulating cap. This effect is more obvious in 124 I and 68 Ga, due to their long positron ranges. The imaging ability with various positron emitters was further validated with the count rate assessment, the Derenzo phantom, and the clinical images. CONCLUSIONS Different positron emitters could be effectively imaged by the PET/MR system tested. The resolution measurement strategy proposed could be applied to measure PET spatial resolution in the magnetic field. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Xiangxi Meng
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Key Laboratory for Research and Evaluation of Radiopharmaceuticals (National Medical Products Administration), Department of Nuclear Medicine, Beijing Cancer Hospital & Institute, Beijing, China
| | - Hui Liu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Key Laboratory for Research and Evaluation of Radiopharmaceuticals (National Medical Products Administration), Department of Nuclear Medicine, Beijing Cancer Hospital & Institute, Beijing, China.,United Imaging Healthcare, Shanghai, China
| | - Hui Li
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Key Laboratory for Research and Evaluation of Radiopharmaceuticals (National Medical Products Administration), Department of Nuclear Medicine, Beijing Cancer Hospital & Institute, Beijing, China.,Department of Nuclear Medicine, Peking University Third Hospital, Beijing, China
| | - Shujing Wang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Key Laboratory for Research and Evaluation of Radiopharmaceuticals (National Medical Products Administration), Department of Nuclear Medicine, Beijing Cancer Hospital & Institute, Beijing, China
| | - Hongwei Sun
- Central Research Institute, United Imaging Healthcare, Beijing, China
| | - Feng Wang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Key Laboratory for Research and Evaluation of Radiopharmaceuticals (National Medical Products Administration), Department of Nuclear Medicine, Beijing Cancer Hospital & Institute, Beijing, China
| | - Jin Ding
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Key Laboratory for Research and Evaluation of Radiopharmaceuticals (National Medical Products Administration), Department of Nuclear Medicine, Beijing Cancer Hospital & Institute, Beijing, China
| | - Liuchun He
- United Imaging Healthcare, Shanghai, China
| | - Xin Chen
- United Imaging Healthcare, Shanghai, China
| | - Lujia Jin
- Institute of Medical Technology, Peking University Health Science Center, Peking University, Beijing, China
| | - Yun Dong
- United Imaging Healthcare, Shanghai, China
| | - Hua Zhu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Key Laboratory for Research and Evaluation of Radiopharmaceuticals (National Medical Products Administration), Department of Nuclear Medicine, Beijing Cancer Hospital & Institute, Beijing, China
| | - Zhi Yang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Key Laboratory for Research and Evaluation of Radiopharmaceuticals (National Medical Products Administration), Department of Nuclear Medicine, Beijing Cancer Hospital & Institute, Beijing, China
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4
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George KJH, Borjian S, Cross MC, Hicks JW, Schaffer P, Kovacs MS. Expanding the PET radioisotope universe utilizing solid targets on small medical cyclotrons. RSC Adv 2021; 11:31098-31123. [PMID: 35498914 PMCID: PMC9041346 DOI: 10.1039/d1ra04480j] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 08/25/2021] [Indexed: 12/17/2022] Open
Abstract
Molecular imaging with medical radioisotopes enables the minimally-invasive monitoring of aberrant biochemical, cellular and tissue-level processes in living subjects. The approach requires the administration of radiotracers composed of radioisotopes attached to bioactive molecules, the pairing of which considers several aspects of the radioisotope in addition to the biological behavior of the targeting molecule to which it is attached. With the advent of modern cellular and biochemical techniques, there has been a virtual explosion in potential disease recognition antigens as well as targeting moieties, which has subsequently opened new applications for a host of emerging radioisotopes with well-matched properties. Additionally, the global radioisotope production landscape has changed rapidly, with reactor-based production and its long-defined, large-scale centralized manufacturing and distribution paradigm shifting to include the manufacture and distribution of many radioisotopes via a worldwide fleet of cyclotrons now in operation. Cyclotron-based radioisotope production has become more prevalent given the commercial availability of instruments, coupled with the introduction of new target hardware, process automation and target manufacturing methods. These advances enable sustained, higher-power irradiation of solid targets that allow hospital-based radiopharmacies to produce a suite of radioisotopes that drive research, clinical trials, and ultimately clinical care. Over the years, several different radioisotopes have been investigated and/or selected for radiolabeling due to favorable decay characteristics (i.e. a suitable half-life, high probability of positron decay, etc.), well-elucidated chemistry, and a feasible production framework. However, longer-lived radioisotopes have surged in popularity given recent regulatory approvals and incorporation of radiopharmaceuticals into patient management within the medical community. This review focuses on the applications, nuclear properties, and production and purification methods for some of the most frequently used/emerging positron-emitting, solid-target-produced radioisotopes that can be manufactured using small-to-medium size cyclotrons (≤24 MeV).
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Affiliation(s)
- K J H George
- Lawson Health Research Institute 268 Grosvenor Street London ON N6A 4V2 Canada
- Medical Biophysics, Western University 1151 Richmond Street N. London ON N6A 5C1 Canada
| | - S Borjian
- ARTMS 301-4475 Wayburn Drive Burnaby BC V5G 4X4 Canada
| | - M C Cross
- ARTMS 301-4475 Wayburn Drive Burnaby BC V5G 4X4 Canada
| | - J W Hicks
- Lawson Health Research Institute 268 Grosvenor Street London ON N6A 4V2 Canada
- Medical Biophysics, Western University 1151 Richmond Street N. London ON N6A 5C1 Canada
| | - P Schaffer
- Life Sciences, TRIUMF 4004 Wesbrook Mall Vancouver BC V6T 2A3 Canada
- ARTMS 301-4475 Wayburn Drive Burnaby BC V5G 4X4 Canada
- Radiology, University of British Columbia 2775 Laurel St Vancouver BC V5Z 1M9 Canada
- Chemistry, Simon Fraser University 8888 University Dr Burnaby BC V5A 1S6 Canada
| | - M S Kovacs
- Lawson Health Research Institute 268 Grosvenor Street London ON N6A 4V2 Canada
- Medical Biophysics, Western University 1151 Richmond Street N. London ON N6A 5C1 Canada
- Medical Imaging, Western University 1151 Richmond Street N. London ON N6A 5C1 Canada
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Caribé PRRV, Vandenberghe S, Diogo A, Pérez-Benito D, Efthimiou N, Thyssen C, D'Asseler Y, Koole M. Monte Carlo Simulations of the GE Signa PET/MR for Different Radioisotopes. Front Physiol 2020; 11:525575. [PMID: 33041852 PMCID: PMC7522581 DOI: 10.3389/fphys.2020.525575] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 08/13/2020] [Indexed: 12/28/2022] Open
Abstract
NEMA characterization of PET systems is generally based on 18F because it is the most relevant radioisotope for the clinical use of PET. 18F has a half-life of 109.7 min and decays into stable 18O via β+ emission with a probability of over 96% and a maximum positron energy of 0.633 MeV. Other commercially available PET radioisotopes, such as 82Rb and 68Ga have more complex decay schemes with a variety of prompt gammas, which can directly fall into the energy window and induce false coincidence detections by the PET scanner.
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Affiliation(s)
- Paulo R R V Caribé
- Medical Imaging and Signal Processing - MEDISIP, Ghent University, Ghent, Belgium
| | - Stefaan Vandenberghe
- Medical Imaging and Signal Processing - MEDISIP, Ghent University, Ghent, Belgium
| | - André Diogo
- Faculty of Sciences of the University of Lisbon (FCUL), Lisbon, Portugal
| | - David Pérez-Benito
- Bioengineering and Aerospace Department, Universidad Carlos III de Madrid, Madrid, Spain
| | - Nikos Efthimiou
- Department of Physics, University of York, York, United Kingdom
| | - Charlotte Thyssen
- Medical Imaging and Signal Processing - MEDISIP, Ghent University, Ghent, Belgium
| | - Yves D'Asseler
- Department of Diagnostic Sciences, Faculty of Medicine, Ghent University, Ghent, Belgium
| | - Michel Koole
- Nuclear Medicine and Molecular Imaging, Department of Imaging & Pathology, KU Leuven, Leuven, Belgium
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6
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Coenen HH, Ermert J. Expanding PET-applications in life sciences with positron-emitters beyond fluorine-18. Nucl Med Biol 2020; 92:241-269. [PMID: 32900582 DOI: 10.1016/j.nucmedbio.2020.07.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 07/09/2020] [Indexed: 12/20/2022]
Abstract
Positron-emission-tomography (PET) has become an indispensable diagnostic tool in modern nuclear medicine. Its outstanding molecular imaging features allow repetitive studies on one individual and with high sensitivity, though no interference. Rather few positron-emitters with near favourable physical properties, i.e. carbon-11 and fluorine-18, furnished most studies in the beginning, preferably if covalently bound as isotopic label of small molecules. With the advancement of PET-devices the scope of in vivo research in life sciences and especially that of medical applications expanded, and other than "standard" PET-nuclides received increasing significance, like the radiometals copper-64 and gallium-68. Especially during the last decades, positron-emitters of other chemical elements have gotten into the focus of interest, concomitant with the technical advancements in imaging and radionuclide production. With known nuclear imaging properties and main production methods of emerging positron-emitters their usefulness for medical application is promising and even proven for several ones already. Unfortunate decay properties could be corrected for, and β+-emitters, especially with a longer half-life, provided new possibilities for application where slower processes are of importance. Further on, (bio)chemical features of positron-emitters of other elements, among there many metals, not only expanded the field of classical clinical investigations, but also opened up new fields of application. Appropriately labelled peptides, proteins and nanoparticles lend itself as newer probes for PET-imaging, e.g. in theragnostic or PET/MR hybrid imaging. Furthermore, the potential of non-destructive in-vivo imaging with positron-emission-tomography directs the view on further areas of life sciences. Thus, exploiting the excellent methodology for basic research on molecular biochemical functions and processes is increasingly encouraged as well in areas outside of health, such as plant and environmental sciences.
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Affiliation(s)
- Heinz H Coenen
- Institut für Neurowissenschaften und Medizin, INM-5, Nuklearchemie, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany.
| | - Johannes Ermert
- Institut für Neurowissenschaften und Medizin, INM-5, Nuklearchemie, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany.
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Qaim SM, Scholten B, Spahn I, Neumaier B. Positron-emitting radionuclides for applications, with special emphasis on their production methodologies for medical use. RADIOCHIM ACTA 2019. [DOI: 10.1515/ract-2019-3154] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Abstract
A survey of the positron-emitting radionuclides over the whole mass range of the Periodic Table of Elements was carried out. As already known, positrons are preferably emitted from light mass neutron deficient radionuclides. Their emission from heavier mass nuclides is rather rare. The applications of positron annihilation in three areas, namely materials research, plant physiology and medical diagnosis, are reported. The methods of production of positron emitters are discussed, with emphasis on radionuclides presently attracting more attention in theranostics and multimodal imaging. Some future perspectives of radionuclide development technologies are considered.
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Affiliation(s)
- Syed M. Qaim
- Institut für Neurowissenschaften und Medizin, INM-5: Nuklearchemie , Forschungszentrum Jülich GmbH , 52425 Jülich , Germany
| | - Bernhard Scholten
- Institut für Neurowissenschaften und Medizin, INM-5: Nuklearchemie , Forschungszentrum Jülich GmbH , 52425 Jülich , Germany
| | - Ingo Spahn
- Institut für Neurowissenschaften und Medizin, INM-5: Nuklearchemie , Forschungszentrum Jülich GmbH , 52425 Jülich , Germany
| | - Bernd Neumaier
- Institut für Neurowissenschaften und Medizin, INM-5: Nuklearchemie , Forschungszentrum Jülich GmbH , 52425 Jülich , Germany
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NEMA NU 2-2007 performance characteristics of GE Signa integrated PET/MR for different PET isotopes. EJNMMI Phys 2019; 6:11. [PMID: 31273558 PMCID: PMC6609673 DOI: 10.1186/s40658-019-0247-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Accepted: 06/14/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Fully integrated PET/MR systems are being used frequently in clinical research and routine. National Electrical Manufacturers Association (NEMA) characterization of these systems is generally done with 18F which is clinically the most relevant PET isotope. However, other PET isotopes, such as 68Ga and 90Y, are gaining clinical importance as they are of specific interest for oncological applications and for follow-up of 90Y-based radionuclide therapy. These isotopes have a complex decay scheme with a variety of prompt gammas in coincidence. 68Ga and 90Y have higher positron energy and, because of the larger positron range, there may be interference with the magnetic field of the MR compared to 18F. Therefore, it is relevant to determine the performance of PET/MR for these clinically relevant and commercially available isotopes. METHODS NEMA NU 2-2007 performance measurements were performed for characterizing the spatial resolution, sensitivity, image quality, and the accuracy of attenuation and scatter corrections for 18F, 68Ga, and 90Y. Scatter fraction and noise equivalent count rate (NECR) tests were performed using 18F and 68Ga. All phantom data were acquired on the GE Signa integrated PET/MR system, installed in UZ Leuven, Belgium. RESULTS 18F, 68Ga, and 90Y NEMA performance tests resulted in substantially different system characteristics. In comparison with 18F, the spatial resolution is about 1 mm larger in the axial direction for 68Ga and no significative effect was found for 90Y. The impact of this lower resolution is also visible in the recovery coefficients of the smallest spheres of 68Ga in image quality measurements, where clearly lower values are obtained. For 90Y, the low number of counts leads to a large variability in the image quality measurements. The primary factor for the sensitivity change is the scale factor related to the positron emission fraction. There is also an impact on the peak NECR, which is lower for 68Ga than for 18F and appears at higher activities. CONCLUSIONS The system performance of GE Signa integrated PET/MR was substantially different, in terms of NEMA spatial resolution, image quality, and NECR for 68Ga and 90Y compared to 18F. But these differences are compensated by the PET/MR scanner technologies and reconstructions methods.
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Neuner I, Rajkumar R, Brambilla CR, Ramkiran S, Ruch A, Orth L, Farrher E, Mauler J, Wyss C, Kops ER, Scheins J, Tellmann L, Lang M, Ermert J, Dammers J, Neumaier B, Lerche C, Heekeren K, Kawohl W, Langen KJ, Herzog H, Shah NJ. Simultaneous PET-MR-EEG: Technology, Challenges and Application in Clinical Neuroscience. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2019. [DOI: 10.1109/trpms.2018.2886525] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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10
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Caldeira L, Rota Kops E, Yun SD, da Silva N, Mauler J, Weirich C, Scheins J, Herzog H, Tellmann L, Lohmann P, Langen KJ, Lerche C, Shah NJ. The Jülich Experience With Simultaneous 3T MR-BrainPET: Methods and Technology. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2019. [DOI: 10.1109/trpms.2018.2863953] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Mannheim JG, Schmid AM, Schwenck J, Katiyar P, Herfert K, Pichler BJ, Disselhorst JA. PET/MRI Hybrid Systems. Semin Nucl Med 2018; 48:332-347. [PMID: 29852943 DOI: 10.1053/j.semnuclmed.2018.02.011] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Over the last decade, the combination of PET and MRI in one system has proven to be highly successful in basic preclinical research, as well as in clinical research. Nowadays, PET/MRI systems are well established in preclinical imaging and are progressing into clinical applications to provide further insights into specific diseases, therapeutic assessments, and biological pathways. Certain challenges in terms of hardware had to be resolved concurrently with the development of new techniques to be able to reach the full potential of both combined techniques. This review provides an overview of these challenges and describes the opportunities that simultaneous PET/MRI systems can exploit in comparison with stand-alone or other combined hybrid systems. New approaches were developed for simultaneous PET/MRI systems to correct for attenuation of 511 keV photons because MRI does not provide direct information on gamma photon attenuation properties. Furthermore, new algorithms to correct for motion were developed, because MRI can accurately detect motion with high temporal resolution. The additional information gained by the MRI can be employed to correct for partial volume effects as well. The development of new detector designs in combination with fast-decaying scintillator crystal materials enabled time-of-flight detection and incorporation in the reconstruction algorithms. Furthermore, this review lists the currently commercially available systems both for preclinical and clinical imaging and provides an overview of applications in both fields. In this regard, special emphasis has been placed on data analysis and the potential for both modalities to evolve with advanced image analysis tools, such as cluster analysis and machine learning.
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Affiliation(s)
- Julia G Mannheim
- Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center, Eberhard Karls University Tuebingen, Tuebingen, Germany
| | - Andreas M Schmid
- Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center, Eberhard Karls University Tuebingen, Tuebingen, Germany
| | - Johannes Schwenck
- Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center, Eberhard Karls University Tuebingen, Tuebingen, Germany; Department of Nuclear Medicine and Clinical Molecular Imaging, Eberhard Karls University Tuebingen, Tuebingen, Germany
| | - Prateek Katiyar
- Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center, Eberhard Karls University Tuebingen, Tuebingen, Germany
| | - Kristina Herfert
- Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center, Eberhard Karls University Tuebingen, Tuebingen, Germany
| | - Bernd J Pichler
- Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center, Eberhard Karls University Tuebingen, Tuebingen, Germany.
| | - Jonathan A Disselhorst
- Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center, Eberhard Karls University Tuebingen, Tuebingen, Germany
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13
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Cabello J, Ziegler SI. Advances in PET/MR instrumentation and image reconstruction. Br J Radiol 2018; 91:20160363. [PMID: 27376170 PMCID: PMC5966194 DOI: 10.1259/bjr.20160363] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Revised: 06/26/2016] [Accepted: 06/29/2016] [Indexed: 12/15/2022] Open
Abstract
The combination of positron emission tomography (PET) and MRI has attracted the attention of researchers in the past approximately 20 years in small-animal imaging and more recently in clinical research. The combination of PET/MRI allows researchers to explore clinical and research questions in a wide number of fields, some of which are briefly mentioned here. An important number of groups have developed different concepts to tackle the problems that PET instrumentation poses to the exposition of electromagnetic fields. We have described most of these research developments in preclinical and clinical experiments, including the few commercial scanners available. From the software perspective, an important number of algorithms have been developed to address the attenuation correction issue and to exploit the possibility that MRI provides for motion correction and quantitative image reconstruction, especially parametric modelling of radiopharmaceutical kinetics. In this work, we give an overview of some exemplar applications of simultaneous PET/MRI, together with technological hardware and software developments.
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Affiliation(s)
- Jorge Cabello
- Nuklearmedizinische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Sibylle I Ziegler
- Nuklearmedizinische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
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Breunig K, Spahn I, Hermanne A, Spellerberg S, Scholten B, Coenen HH. Cross section measurements of 75As(α,xn)76,77,78Br and 75As(α,x)74As nuclear reactions using the monitor radionuclides 67Ga and 66Ga for beam evaluation. RADIOCHIM ACTA 2017. [DOI: 10.1515/ract-2016-2593] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
For the production of the medically interesting radionuclides 76Br and 77Br cross sections of α-particle induced reactions on arsenic, leading to the formation of 76,77,78Br as well as to the non-isotopic impurity 74As, were measured from their thresholds up to 37 MeV. Sediments of elemental arsenic were used as targets and irradiated, using the established stacked-foil technique. In order to remove discrepancies of the existing literature data, the cross section ratios of the monitor nuclides 67Ga/66Ga were used for determination of the α-particle energies as well as the effective beam current through all the stacks, thus inferring the experimental cross sections. Compared with the available excitation functions the new data indicate slightly divergent curve shapes. In the case of 76Br the excitation function seems to be shifted to somewhat lower α-particle energies, and also the maximum cross section of the formation of 77Br tends to be slightly lower compared with the curve recommended to date. In the case of a re-evaluation, these new data should be taken into account, as they may contribute to enhance the accuracy of the excitation functions.
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Affiliation(s)
- Katharina Breunig
- Institute for Neuroscience and Medicine, INM-5: Nuclear Chemistry , Forschungszentrum Jülich , Jülich , Germany
| | - Ingo Spahn
- Institute for Neuroscience and Medicine, INM-5: Nuclear Chemistry , Forschungszentrum Jülich , Jülich , Germany
| | - Alex Hermanne
- Cyclotron Laboratory , Vrije Universiteit Brussel (VUB) , Brussels , Belgium
| | - Stefan Spellerberg
- Institute for Neuroscience and Medicine, INM-5: Nuclear Chemistry , Forschungszentrum Jülich , Jülich , Germany
| | - Bernhard Scholten
- Institute for Neuroscience and Medicine, INM-5: Nuclear Chemistry , Forschungszentrum Jülich , Jülich , Germany
| | - Heinz H. Coenen
- Institute for Neuroscience and Medicine, INM-5: Nuclear Chemistry , Forschungszentrum Jülich , Jülich , Germany
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Electrodynamics and radiofrequency antenna concepts for human magnetic resonance at 23.5 T (1 GHz) and beyond. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2016; 29:641-56. [PMID: 27097905 DOI: 10.1007/s10334-016-0559-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 04/04/2016] [Accepted: 04/06/2016] [Indexed: 10/21/2022]
Abstract
OBJECTIVE This work investigates electrodynamic constraints, explores RF antenna concepts and examines the transmission fields (B 1 (+) ) and RF power deposition of dipole antenna arrays for (1)H magnetic resonance of the human brain at 1 GHz (23.5 T). MATERIALS AND METHODS Electromagnetic field (EMF) simulations are performed in phantoms with average tissue simulants for dipole antennae using discrete frequencies [300 MHz (7.0 T) to 3 GHz (70.0 T)]. To advance to a human setup EMF simulations are conducted in anatomical human voxel models of the human head using a 20-element dipole array operating at 1 GHz. RESULTS Our results demonstrate that transmission fields suitable for (1)H MR of the human brain can be achieved at 1 GHz. An increase in transmit channel density around the human head helps to enhance B 1 (+) in the center of the brain. The calculated relative increase in specific absorption rate at 23.5 versus 7.0 T was below 1.4 (in-phase phase setting) and 2.7 (circular polarized phase setting) for the dipole antennae array. CONCLUSION The benefits of multi-channel dipole antennae at higher frequencies render MR at 23.5 T feasible from an electrodynamic standpoint. This very preliminary finding opens the door on further explorations that might be catalyzed into a 20-T class human MR system.
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Ko GB, Yoon HS, Kim KY, Lee MS, Yang BY, Jeong JM, Lee DS, Song IC, Kim SK, Kim D, Lee JS. Simultaneous Multiparametric PET/MRI with Silicon Photomultiplier PET and Ultra-High-Field MRI for Small-Animal Imaging. J Nucl Med 2016; 57:1309-15. [PMID: 27081173 DOI: 10.2967/jnumed.115.170019] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 03/11/2016] [Indexed: 12/18/2022] Open
Abstract
UNLABELLED Visualization of biologic processes at molecular and cellular levels has revolutionized the understanding and treatment of human diseases. However, no single biomedical imaging modality provides complete information, resulting in the emergence of multimodal approaches. Combining state-of-the-art PET and MRI technologies without loss of system performance and overall image quality can provide opportunities for new scientific and clinical innovations. Here, we present a multiparametric PET/MR imager based on a small-animal dedicated, high-performance, silicon photomultiplier (SiPM) PET system and a 7-T MR scanner. METHODS A SiPM-based PET insert that has the peak sensitivity of 3.4% and center volumetric resolution of 1.92/0.53 mm(3) (filtered backprojection/ordered-subset expectation maximization) was developed. The SiPM PET insert was placed between the mouse body transceiver coil and gradient coil of a 7-T small-animal MRI scanner for simultaneous PET/MRI. Mutual interference between the MRI and SiPM PET systems was evaluated using various MR pulse sequences. A cylindric corn oil phantom was scanned to assess the effects of the SiPM PET on the MR image acquisition. To assess the influence of MRI on the PET imaging functions, several PET performance indicators including scintillation pulse shape, flood image quality, energy spectrum, counting rate, and phantom image quality were evaluated with and without the application of MR pulse sequences. Simultaneous mouse PET/MRI studies were also performed to demonstrate the potential and usefulness of the multiparametric PET/MRI in preclinical applications. RESULTS Excellent performance and stability of the PET system were demonstrated, and the PET/MRI combination did not result in significant image quality degradation of either modality. Finally, simultaneous PET/MRI studies in mice demonstrated the feasibility of the developed system for evaluating the biochemical and cellular changes in a brain tumor model and facilitating the development of new multimodal imaging probes. CONCLUSION We developed a multiparametric imager with high physical performance and good system stability and demonstrated its feasibility for small-animal experiments, suggesting its usefulness for investigating in vivo molecular interactions of metabolites, and cross-validation studies of both PET and MRI.
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Affiliation(s)
- Guen Bae Ko
- Department of Nuclear Medicine, Seoul National University, Seoul, Korea Department of Biomedical Sciences, Seoul National University, Seoul, Korea
| | - Hyun Suk Yoon
- Department of Nuclear Medicine, Seoul National University, Seoul, Korea Department of Biomedical Sciences, Seoul National University, Seoul, Korea
| | - Kyeong Yun Kim
- Department of Nuclear Medicine, Seoul National University, Seoul, Korea Department of Biomedical Sciences, Seoul National University, Seoul, Korea
| | - Min Sun Lee
- Department of Nuclear Medicine, Seoul National University, Seoul, Korea Interdisciplinary Program in Radiation Applied Life Science, Seoul National University, Seoul, Korea
| | - Bo Yeun Yang
- Department of Nuclear Medicine, Seoul National University, Seoul, Korea Institute of Radiation Medicine, Medical Research Center, Seoul National University, Seoul, Korea
| | - Jae Min Jeong
- Department of Nuclear Medicine, Seoul National University, Seoul, Korea Department of Biomedical Sciences, Seoul National University, Seoul, Korea Interdisciplinary Program in Radiation Applied Life Science, Seoul National University, Seoul, Korea Institute of Radiation Medicine, Medical Research Center, Seoul National University, Seoul, Korea
| | - Dong Soo Lee
- Department of Nuclear Medicine, Seoul National University, Seoul, Korea Interdisciplinary Program in Radiation Applied Life Science, Seoul National University, Seoul, Korea Institute of Radiation Medicine, Medical Research Center, Seoul National University, Seoul, Korea Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Suwon, Korea
| | - In Chan Song
- Institute of Radiation Medicine, Medical Research Center, Seoul National University, Seoul, Korea Department of Radiology, Seoul National University, Seoul, Korea
| | - Seok-Ki Kim
- Department of Nuclear Medicine, National Cancer Center, Goyang, Korea; and Molecular Imaging and Therapy Branch, National Cancer Center, Goyang, Korea
| | - Daehong Kim
- Molecular Imaging and Therapy Branch, National Cancer Center, Goyang, Korea
| | - Jae Sung Lee
- Department of Nuclear Medicine, Seoul National University, Seoul, Korea Department of Biomedical Sciences, Seoul National University, Seoul, Korea Interdisciplinary Program in Radiation Applied Life Science, Seoul National University, Seoul, Korea Institute of Radiation Medicine, Medical Research Center, Seoul National University, Seoul, Korea
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Bertolli O, Eleftheriou A, Cecchetti M, Camarlinghi N, Belcari N, Tsoumpas C. PET iterative reconstruction incorporating an efficient positron range correction method. Phys Med 2016; 32:323-30. [DOI: 10.1016/j.ejmp.2015.11.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 11/03/2015] [Accepted: 11/14/2015] [Indexed: 10/22/2022] Open
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Abstract
Multimodal imaging has led to a more detailed exploration of different physiologic processes with integrated PET/MR imaging being the most recent entry. Although the clinical need is still questioned, it is well recognized that it represents one of the most active and promising fields of medical imaging research in terms of software and hardware. The hardware developments have moved from small detector components to high-performance PET inserts and new concepts in full systems. Conversely, the software focuses on the efficient performance of necessary corrections without the use of CT data. The most recent developments in both directions are reviewed.
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Affiliation(s)
- Charalampos Tsoumpas
- Division of Biomedical Imaging, Faculty of Medicine and Health, University of Leeds, 8.001a, Worsley Building, Clarendon Way, Leeds LS2 9JT, UK
| | - Dimitris Visvikis
- LaTIM UMR 1101, INSERM, University of Brest, Bat 1, 1er etage, 5 avenue Foch, Brest 29609, France
| | - George Loudos
- Department of Biomedical Engineering, Technological Educational Institute of Athens, Ag. Spiridonos 28, Egaleo, Athens 12210, Greece.
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Kolb A, Sauter AW, Eriksson L, Vandenbrouke A, Liu CC, Levin C, Pichler BJ, Rafecas M. Shine-Through in PET/MR Imaging: Effects of the Magnetic Field on Positron Range and Subsequent Image Artifacts. J Nucl Med 2015; 56:951-4. [DOI: 10.2967/jnumed.114.147637] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 01/19/2015] [Indexed: 11/16/2022] Open
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Huang SY, Savic D, Yang J, Shrestha U, Seo Y. The Effect of Magnetic Field on Positron Range and Spatial Resolution in an Integrated Whole-Body Time-Of-Flight PET/MRI System. IEEE NUCLEAR SCIENCE SYMPOSIUM CONFERENCE RECORD. NUCLEAR SCIENCE SYMPOSIUM 2014; 2014. [PMID: 27076778 DOI: 10.1109/nssmic.2014.7431006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Simultaneous imaging systems combining positron emission tomography (PET) and magnetic resonance imaging (MRI) have been actively investigated. A PET/MR imaging system (GE Healthcare) comprised of a time-of-flight (TOF) PET system utilizing silicon photomultipliers (SiPMs) and 3-tesla (3T) MRI was recently installed at our institution. The small-ring (60 cm diameter) TOF PET subsystem of this PET/MRI system can generate images with higher spatial resolution compared with conventional PET systems. We have examined theoretically and experimentally the effect of uniform magnetic fields on the spatial resolution for high-energy positron emitters. Positron emitters including 18F, 124I, and 68Ga were simulated in water using the Geant4 Monte Carlo toolkit in the presence of a uniform magnetic field (0, 3, and 7 Tesla). The positron annihilation position was tracked to determine the 3D spatial distribution of the 511-keV gammy ray emission. The full-width at tenth maximum (FWTM) of the positron point spread function (PSF) was determined. Experimentally, 18F and 68Ga line source phantoms in air and water were imaged with an investigational PET/MRI system and a PET/CT system to investigate the effect of magnetic field on the spatial resolution of PET. The full-width half maximum (FWHM) of the line spread function (LSF) from the line source was determined as the system spatial resolution. Simulations and experimental results show that the in-plane spatial resolution was slightly improved at field strength as low as 3 Tesla, especially when resolving signal from high-energy positron emitters in the air-tissue boundary.
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Affiliation(s)
- Shih-Ying Huang
- Physics Research Laboratory, Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA 94143
| | - Dragana Savic
- Physics Research Laboratory, Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA 94143
| | - Jaewon Yang
- Physics Research Laboratory, Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA 94143
| | - Uttam Shrestha
- Physics Research Laboratory, Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA 94143
| | - Youngho Seo
- Physics Research Laboratory, Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA 94143
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Multimodal neuroimaging in humans at 9.4 T: a technological breakthrough towards an advanced metabolic imaging scanner. Brain Struct Funct 2014; 220:1867-84. [PMID: 25017191 DOI: 10.1007/s00429-014-0843-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Accepted: 07/02/2014] [Indexed: 10/25/2022]
Abstract
The aim of this paper is twofold: firstly, to explore the potential of simultaneously acquiring multimodal MR-PET-EEG data in a human 9.4 T scanner to provide a platform for metabolic brain imaging. Secondly, to demonstrate that the three modalities are complementary, with MRI providing excellent structural and functional imaging, PET providing quantitative molecular imaging, and EEG providing superior temporal resolution. A 9.4 T MRI scanner equipped with a PET insert and a commercially available EEG device was used to acquire in vivo proton-based images, spectra, and sodium- and oxygen-based images with MRI, EEG signals from a human subject in a static 9.4 T magnetic field, and demonstrate hybrid MR-PET capability in a rat model. High-resolution images of the in vivo human brain with an isotropic resolution of 0.5 mm and post-mortem brain images of the cerebellum with an isotropic resolution of 320 µm are presented. A (1)H spectrum was also acquired from 2 × 2 × 2 mm voxel in the brain allowing 12 metabolites to be identified. Imaging based on sodium and oxygen is demonstrated with isotropic resolutions of 2 and 5 mm, respectively. Auditory evoked potentials measured in a static field of 9.4 T are shown. Finally, hybrid MR-PET capability at 9.4 T in the human scanner is demonstrated in a rat model. Initial progress on the road to 9.4 T multimodal MR-PET-EEG is illustrated. Ultra-high resolution structural imaging, high-resolution images of the sodium distribution and proof-of-principle (17)O data are clearly demonstrated. Further, simultaneous MR-PET data are presented without artefacts and EEG data successfully corrected for the cardioballistic artefact at 9.4 T are presented.
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