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Siva NK, Bauer C, Glover C, Stolin A, Chandi S, Melnick H, Marano G, Parker B, Mandich M, Lewis JW, Qi J, Gao S, Nott K, Majewski S, Brefczynski-Lewis JA. Real-time motion-enabling positron emission tomography of the brain of upright ambulatory humans. COMMUNICATIONS MEDICINE 2024; 4:117. [PMID: 38872007 PMCID: PMC11176317 DOI: 10.1038/s43856-024-00547-2] [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: 03/30/2022] [Accepted: 06/05/2024] [Indexed: 06/15/2024] Open
Abstract
BACKGROUND Mobile upright PET devices have the potential to enable previously impossible neuroimaging studies. Currently available options are imagers with deep brain coverage that severely limit head/body movements or imagers with upright/motion enabling properties that are limited to only covering the brain surface. METHODS In this study, we test the feasibility of an upright, motion-compatible brain imager, our Ambulatory Motion-enabling Positron Emission Tomography (AMPET) helmet prototype, for use as a neuroscience tool by replicating a variant of a published PET/fMRI study of the neurocorrelates of human walking. We validate our AMPET prototype by conducting a walking movement paradigm to determine motion tolerance and assess for appropriate task related activity in motor-related brain regions. Human participants (n = 11 patients) performed a walking-in-place task with simultaneous AMPET imaging, receiving a bolus delivery of F18-Fluorodeoxyglucose. RESULTS Here we validate three pre-determined measure criteria, including brain alignment motion artifact of less than <2 mm and functional neuroimaging outcomes consistent with existing walking movement literature. CONCLUSIONS The study extends the potential and utility for use of mobile, upright, and motion-tolerant neuroimaging devices in real-world, ecologically-valid paradigms. Our approach accounts for the real-world logistics of an actual human participant study and can be used to inform experimental physicists, engineers and imaging instrumentation developers undertaking similar future studies. The technical advances described herein help set new priorities for facilitating future neuroimaging devices and research of the human brain in health and disease.
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Affiliation(s)
- Nanda K Siva
- Department of Neuroscience, West Virginia University, P.O. Box 9303, Morgantown, WV, USA
| | | | - Colson Glover
- Department of Neuroscience, West Virginia University, P.O. Box 9303, Morgantown, WV, USA
| | - Alexander Stolin
- Department of Neuroscience, West Virginia University, P.O. Box 9303, Morgantown, WV, USA
| | - Sonia Chandi
- Department of Neuroscience, West Virginia University, P.O. Box 9303, Morgantown, WV, USA
| | - Helen Melnick
- Department of Neuroscience, West Virginia University, P.O. Box 9303, Morgantown, WV, USA
| | - Gary Marano
- Department of Neuroscience, West Virginia University, P.O. Box 9303, Morgantown, WV, USA
| | - Benjamin Parker
- Department of Neuroscience, West Virginia University, P.O. Box 9303, Morgantown, WV, USA
| | - MaryBeth Mandich
- Department of Neuroscience, West Virginia University, P.O. Box 9303, Morgantown, WV, USA
| | - James W Lewis
- Department of Neuroscience, West Virginia University, P.O. Box 9303, Morgantown, WV, USA
| | - Jinyi Qi
- Department of Biomedical Engineering, University of California, Davis, Davis, CA, USA
| | - Si Gao
- Department of Neuroscience, West Virginia University, P.O. Box 9303, Morgantown, WV, USA
| | - Kaylee Nott
- Department of Neuroscience, West Virginia University, P.O. Box 9303, Morgantown, WV, USA
| | - Stan Majewski
- Department of Biomedical Engineering, University of California, Davis, Davis, CA, USA
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Alstrup AKO, Dollerup MR, Simonsen MIT, Vendelbo MH. Preclinical Imaging Studies: Protocols, Preparation, Anesthesia, and Animal Care. Semin Nucl Med 2023; 53:570-576. [PMID: 36858906 DOI: 10.1053/j.semnuclmed.2023.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 02/01/2023] [Indexed: 03/03/2023]
Abstract
Today preclinical PET imaging connects laboratory research with clinical applications. Here PET clearly bridges the gap, as nearly identical imaging protocols can be applied to both animal and humans. However, some hurdles exist and researchers must be careful, partly because the animals are usually anesthetized during the scans, while human volunteers are awake. This review is based on our own experiences of some of the most important pitfalls and how to overcome them. This includes how studies should be designed, how to select the right anesthesia and monitoring. The choice of anesthesia is quite crucial, as it may have a greater influence on the results than the effect of the tested procedures. Monitoring is necessary, as the animals cannot fully maintain homeostasis during anesthesia, and reliable results are dependent on a stable physiology. Additionally, it is important to note that rodents, in particular, are prone to rapidly becoming hypothermic. Thus, the selection of an appropriate anesthetic and monitoring protocol is crucial for both obtaining accurate results and ensuring animal welfare. Prior to imaging, catheters for tracer administration and, if necessary, blood sampling should be implanted. The administration of tracers should be done in a manner that minimizes interference with the scans, and the same applies to any serial blood sampling. The limited blood volume and organ size of rodents should also be taken into consideration when planning experiments. Finally, if the animal needs to be awakened after the scan, proper care must be taken to ensure their welfare.
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Affiliation(s)
- Aage K O Alstrup
- Department of Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark; Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
| | - Mie R Dollerup
- Department of Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark
| | - Mette I T Simonsen
- Department of Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark
| | - Mikkel H Vendelbo
- Department of Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark; Department of Biomedicine, Aarhus University, Aarhus, Denmark
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3
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Iriki A, Tramacere A. “Natural Laboratory Complex” for novel primate neuroscience. Front Integr Neurosci 2022; 16:927605. [PMID: 36274659 PMCID: PMC9581230 DOI: 10.3389/fnint.2022.927605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Accepted: 08/23/2022] [Indexed: 11/25/2022] Open
Abstract
We propose novel strategies for primate experimentation that are ethically valuable and pragmatically useful for cognitive neuroscience and neuropsychiatric research. Specifically, we propose Natural Laboratory Complex or Natural Labs, which are a combination of indoor-outdoor structures for studying free moving and socially housed primates in natural or naturalistic environment. We contend that Natural Labs are pivotal to improve primate welfare, and at the same time to implement longitudinal and socio-ecological studies of primate brain and behavior. Currently emerging advanced technologies and social systems (including recent COVID-19 induced “remote” infrastructures) can speed-up cognitive neuroscience approaches in freely behaving animals. Experimental approaches in natural(istic) settings are not in competition with conventional approaches of laboratory investigations, and could establish several benefits at the ethical, experimental, and economic levels.
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Affiliation(s)
- Atsushi Iriki
- Laboratory for Symbolic Cognitive Development, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
- *Correspondence: Atsushi Iriki,
| | - Antonella Tramacere
- Department of Philosophy and Communication Studies, University of Bologna, Bologna, Italy
- Department of Cultural and Linguistic Evolution, Max Planck Institute for the Science of Human History, Jena, Germany
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4
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Wei S, Joshi N, Salerno M, Ouellette D, Saleh L, Delorenzo C, Woody C, Schlyer D, Purschke ML, Pratte JF, Junnarkar S, Budassi M, Cao T, Fried J, Karp JS, Vaska P. PET Imaging of Leg Arteries for Determining the Input Function in PET/MRI Brain Studies Using a Compact, MRI-Compatible PET System. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2022; 6:583-591. [PMID: 36212108 PMCID: PMC9541963 DOI: 10.1109/trpms.2021.3111841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
In this study, we used a compact, high-resolution, and MRI-compatible PET camera (VersaPET) to assess the feasibility of measuring the image-derived input function (IDIF) from arteries in the leg with the ultimate goal of enabling fully quantitative PET brain imaging without blood sampling. We used this approach in five 18F-FDG PET/MRI brain studies in which the input function was also acquired using the gold standard of serial arterial blood sampling. After accounting for partial volume, dispersion, and calibration effects, we compared the metabolic rates of glucose (MRglu) quantified from VersaPET IDIFs in 80 brain regions to those using the gold standard and achieved a bias and variability of <5% which is within the range of reported test-retest values for this type of study. We also achieved a strong linear relationship (R2 >0.97) against the gold standard across regions. The results of this preliminary study are promising and support further studies to optimize methods, validate in a larger cohort, and extend to the modeling of other radiotracers.
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Affiliation(s)
- Shouyi Wei
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - Nandita Joshi
- Department of Electrical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - Michael Salerno
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - David Ouellette
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - Lemise Saleh
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - Christine Delorenzo
- Department of Psychiatry and Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | - Craig Woody
- Department of Physics, Brookhaven National Laboratory, Upton, NY, USA
| | - David Schlyer
- Department of Physics, Brookhaven National Laboratory, Upton, NY, USA
| | | | - Jean-Francois Pratte
- Interdisciplinary Institute for Technological Innovation, Université de Sherbrooke, Sherbrooke, Canada
| | | | - Michael Budassi
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA
| | | | - Jack Fried
- Department of Physics, Brookhaven National Laboratory, Upton, NY, USA
| | - Joel S. Karp
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Paul Vaska
- Department of Biomedical Engineering and Radiology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, USA
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5
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Miranda A, Bertoglio D, Stroobants S, Staelens S, Verhaeghe J. Translation of Preclinical PET Imaging Findings: Challenges and Motion Correction to Overcome the Confounding Effect of Anesthetics. Front Med (Lausanne) 2021; 8:753977. [PMID: 34746189 PMCID: PMC8569248 DOI: 10.3389/fmed.2021.753977] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 09/27/2021] [Indexed: 11/13/2022] Open
Abstract
Preclinical brain positron emission tomography (PET) in animals is performed using anesthesia to avoid movement during the PET scan. In contrast, brain PET scans in humans are typically performed in the awake subject. Anesthesia is therefore one of the principal limitations in the translation of preclinical brain PET to the clinic. This review summarizes the available literature supporting the confounding effect of anesthesia on several PET tracers for neuroscience in preclinical small animal scans. In a second part, we present the state-of-the-art methodologies to circumvent this limitation to increase the translational significance of preclinical research, with an emphasis on motion correction methods. Several motion tracking systems compatible with preclinical scanners have been developed, each one with its advantages and limitations. These systems and the novel experimental setups they can bring to preclinical brain PET research are reviewed here. While technical advances have been made in this field, and practical implementations have been demonstrated, the technique should become more readily available to research centers to allow for a wider adoption of the motion correction technique for brain research.
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Affiliation(s)
- Alan Miranda
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium
| | - Daniele Bertoglio
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium
| | - Sigrid Stroobants
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium.,University Hospital Antwerp, Antwerp, Belgium
| | - Steven Staelens
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium
| | - Jeroen Verhaeghe
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium
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6
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Schaart DR. Physics and technology of time-of-flight PET detectors. Phys Med Biol 2021; 66. [PMID: 33711831 DOI: 10.1088/1361-6560/abee56] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 03/12/2021] [Indexed: 01/04/2023]
Abstract
The imaging performance of clinical positron emission tomography (PET) systems has evolved impressively during the last ∼15 years. A main driver of these improvements has been the introduction of time-of-flight (TOF) detectors with high spatial resolution and detection efficiency, initially based on photomultiplier tubes, later silicon photomultipliers. This review aims to offer insight into the challenges encountered, solutions developed, and lessons learned during this period. Detectors based on fast, bright, inorganic scintillators form the scope of this work, as these are used in essentially all clinical TOF-PET systems today. The improvement of the coincidence resolving time (CRT) requires the optimization of the entire detection chain and a sound understanding of the physics involved facilitates this effort greatly. Therefore, the theory of scintillation detector timing is reviewed first. Once the fundamentals have been set forth, the principal detector components are discussed: the scintillator and the photosensor. The parameters that influence the CRT are examined and the history, state-of-the-art, and ongoing developments are reviewed. Finally, the interplay between these components and the optimization of the overall detector design are considered. Based on the knowledge gained to date, it appears feasible to improve the CRT from the values of 200-400 ps achieved by current state-of-the-art TOF-PET systems to about 100 ps or less, even though this may require the implementation of advanced methods such as time resolution recovery. At the same time, it appears unlikely that a system-level CRT in the order of ∼10 ps can be reached with conventional scintillation detectors. Such a CRT could eliminate the need for conventional tomographic image reconstruction and a search for new approaches to timestamp annihilation photons with ultra-high precision is therefore warranted. While the focus of this review is on timing performance, it attempts to approach the topic from a clinically driven perspective, i.e. bearing in mind that the ultimate goal is to optimize the value of PET in research and (personalized) medicine.
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Affiliation(s)
- Dennis R Schaart
- Delft University of Technology, Radiation Science & Technology dept., section Medical Physics & Technology, Mekelweg 15, 2629 JB Delft, The Netherlands
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7
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D'Elia A, Schiavi S, Soluri A, Massari R, Soluri A, Trezza V. Role of Nuclear Imaging to Understand the Neural Substrates of Brain Disorders in Laboratory Animals: Current Status and Future Prospects. Front Behav Neurosci 2020; 14:596509. [PMID: 33362486 PMCID: PMC7759612 DOI: 10.3389/fnbeh.2020.596509] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 11/23/2020] [Indexed: 12/18/2022] Open
Abstract
Molecular imaging, which allows the real-time visualization, characterization and measurement of biological processes, is becoming increasingly used in neuroscience research. Scintigraphy techniques such as single photon emission computed tomography (SPECT) and positron emission tomography (PET) provide qualitative and quantitative measurement of brain activity in both physiological and pathological states. Laboratory animals, and rodents in particular, are essential in neuroscience research, providing plenty of models of brain disorders. The development of innovative high-resolution small animal imaging systems together with their radiotracers pave the way to the study of brain functioning and neurotransmitter release during behavioral tasks in rodents. The assessment of local changes in the release of neurotransmitters associated with the performance of a given behavioral task is a turning point for the development of new potential drugs for psychiatric and neurological disorders. This review addresses the role of SPECT and PET small animal imaging systems for a better understanding of brain functioning in health and disease states. Brain imaging in rodent models faces a series of challenges since it acts within the boundaries of current imaging in terms of sensitivity and spatial resolution. Several topics are discussed, including technical considerations regarding the strengths and weaknesses of both technologies. Moreover, the application of some of the radioligands developed for small animal nuclear imaging studies is discussed. Then, we examine the changes in metabolic and neurotransmitter activity in various brain areas during task-induced neural activation with special regard to the imaging of opioid, dopaminergic and cannabinoid receptors. Finally, we discuss the current status providing future perspectives on the most innovative imaging techniques in small laboratory animals. The challenges and solutions discussed here might be useful to better understand brain functioning allowing the translation of preclinical results into clinical applications.
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Affiliation(s)
- Annunziata D'Elia
- Institute of Biochemistry and Cell Biology, National Research Council of Italy (CNR), Rome, Italy.,Section of Biomedical Sciences and Technologies, Department of Science, University "Roma Tre", Rome, Italy
| | - Sara Schiavi
- Section of Biomedical Sciences and Technologies, Department of Science, University "Roma Tre", Rome, Italy
| | - Andrea Soluri
- Institute of Biochemistry and Cell Biology, National Research Council of Italy (CNR), Rome, Italy
| | - Roberto Massari
- Institute of Biochemistry and Cell Biology, National Research Council of Italy (CNR), Rome, Italy
| | - Alessandro Soluri
- Institute of Biochemistry and Cell Biology, National Research Council of Italy (CNR), Rome, Italy
| | - Viviana Trezza
- Section of Biomedical Sciences and Technologies, Department of Science, University "Roma Tre", Rome, Italy
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8
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Bergel A, Tiran E, Deffieux T, Demené C, Tanter M, Cohen I. Adaptive modulation of brain hemodynamics across stereotyped running episodes. Nat Commun 2020; 11:6193. [PMID: 33273463 PMCID: PMC7713412 DOI: 10.1038/s41467-020-19948-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 11/06/2020] [Indexed: 12/14/2022] Open
Abstract
During locomotion, theta and gamma rhythms are essential to ensure timely communication between brain structures. However, their metabolic cost and contribution to neuroimaging signals remain elusive. To finely characterize neurovascular interactions during locomotion, we simultaneously recorded mesoscale brain hemodynamics using functional ultrasound (fUS) and local field potentials (LFP) in numerous brain structures of freely-running overtrained rats. Locomotion events were reliably followed by a surge in blood flow in a sequence involving the retrosplenial cortex, dorsal thalamus, dentate gyrus and CA regions successively, with delays ranging from 0.8 to 1.6 seconds after peak speed. Conversely, primary motor cortex was suppressed and subsequently recruited during reward uptake. Surprisingly, brain hemodynamics were strongly modulated across trials within the same recording session; cortical blood flow sharply decreased after 10-20 runs, while hippocampal responses strongly and linearly increased, particularly in the CA regions. This effect occurred while running speed and theta activity remained constant and was accompanied by an increase in the power of hippocampal, but not cortical, high-frequency oscillations (100-150 Hz). Our findings reveal distinct vascular subnetworks modulated across fast and slow timescales and suggest strong hemodynamic adaptation, despite the repetition of a stereotyped behavior.
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Affiliation(s)
- Antoine Bergel
- Sorbonne Université, CNRS, INSERM, Institut de Biologie Paris Seine-Neuroscience, 75005, Paris, France.
- Physique pour la Médecine Paris, INSERM U1273, ESPCI Paris, CNRS FRE 2031, PSL Université Recherche, Paris, France.
| | - Elodie Tiran
- Physique pour la Médecine Paris, INSERM U1273, ESPCI Paris, CNRS FRE 2031, PSL Université Recherche, Paris, France
| | - Thomas Deffieux
- Physique pour la Médecine Paris, INSERM U1273, ESPCI Paris, CNRS FRE 2031, PSL Université Recherche, Paris, France
| | - Charlie Demené
- Physique pour la Médecine Paris, INSERM U1273, ESPCI Paris, CNRS FRE 2031, PSL Université Recherche, Paris, France
| | - Mickaël Tanter
- Physique pour la Médecine Paris, INSERM U1273, ESPCI Paris, CNRS FRE 2031, PSL Université Recherche, Paris, France.
| | - Ivan Cohen
- Sorbonne Université, CNRS, INSERM, Institut de Biologie Paris Seine-Neuroscience, 75005, Paris, France.
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9
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Benveniste H, Lee H, Ozturk B, Chen X, Koundal S, Vaska P, Tannenbaum A, Volkow ND. Glymphatic Cerebrospinal Fluid and Solute Transport Quantified by MRI and PET Imaging. Neuroscience 2020; 474:63-79. [PMID: 33248153 DOI: 10.1016/j.neuroscience.2020.11.014] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 11/04/2020] [Accepted: 11/07/2020] [Indexed: 12/13/2022]
Abstract
Over the past decade there has been an enormous progress in our understanding of fluid and solute transport in the central nervous system (CNS). This is due to a number of factors, including important developments in whole brain imaging technology and computational fluid dynamics analysis employed for the elucidation of glymphatic transport function in the live animal and human brain. In this paper, we review the technical aspects of dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) in combination with administration of Gd-based tracers into the cerebrospinal fluid (CSF) for tracking glymphatic solute and fluid transport in the CNS as well as lymphatic drainage. Used in conjunction with advanced computational processing methods including optimal mass transport analysis, one gains new insights into the biophysical forces governing solute transport in the CNS which leads to intriguing new research directions. Considering drainage pathways, we review the novel T1 mapping technique for quantifying glymphatic transport and cervical lymph node drainage concurrently in the same subject. We provide an overview of knowledge gleaned from DCE-MRI studies of glymphatic transport and meningeal lymphatic drainage. Finally, we introduce positron emission tomography (PET) and CSF administration of radiotracers as an alternative method to explore other pharmacokinetic aspects of CSF transport into brain parenchyma as well as efflux pathways.
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Affiliation(s)
- Helene Benveniste
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, United States; Department of Biomedical Engineering, Yale School of Medicine, New Haven, CT, United States.
| | - Hedok Lee
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, United States
| | - Burhan Ozturk
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, United States
| | - Xinan Chen
- Departments of Computer Science and Applied Mathematics & Statistics, Stony Brook University, Stony Brook, NY, United States
| | - Sunil Koundal
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, United States
| | - Paul Vaska
- Department of Radiology and Biomedical Engineering, Renaissance School of Medicine at Stony Brook University, Stony Brook, NY, United States
| | - Allen Tannenbaum
- Departments of Computer Science and Applied Mathematics & Statistics, Stony Brook University, Stony Brook, NY, United States
| | - Nora D Volkow
- Laboratory for Neuroimaging, NIAAA, Bethesda, MD, United States
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10
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Wei S, Vaska P. Evaluation of quantitative, efficient image reconstruction for VersaPET, a compact PET system. Med Phys 2020; 47:2852-2868. [PMID: 32219853 DOI: 10.1002/mp.14158] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 03/13/2020] [Accepted: 03/13/2020] [Indexed: 11/09/2022] Open
Abstract
PURPOSE Previously we developed a high-resolution positron emission tomography (PET) system-VersaPET-characterized by a block geometry with relatively large axial and transaxial interblock gaps and a compact geometry susceptible to parallax blurring effects. In this work, we report the qualitative and quantitative evaluation of a graphic processing unit (GPU)-accelerated maximum-likelihood by expectation-maximization (MLEM) image reconstruction framework for VersaPET which features accurate system geometry and projection space point-spread-function (PSF) modeling. METHODS We combined the ray-tracing module from software for tomographic image reconstruction (STIR), an open-source PET image reconstruction package, with VersaPET's exact block geometry for the geometric system matrix. Point-spread-function modeling of crystal penetration and scattering was achieved by a custom Monte-Carlo simulation for projection space blurring in all dimensions. We also parallelized the reconstruction in GPU taking advantage of the system's symmetry for PSF computation. To investigate the effects of PSF width, we generated and studied multiple kernels between one that reflects the true LYSO density in the MC simulation and another that reflects geometry only (no PSF). GATE simulations of hot and cold-sphere phantoms with spheres of different sizes, real microDerenzo phantom, and human blood vessel data were used to characterize the quantitative and qualitative performances of the reconstruction. RESULTS Reconstruction with an accurate system geometry effectively improved image quality compared to STIR (version 3.0) which assumes an idealized system geometry. Reconstructions of GATE-simulated hot-sphere phantom data showed that all PSF kernels achieved superior performance in contrast recovery and bias reduction compared to using no PSF, but may introduce edge artifact and lumped background noise pattern depending on the width of PSF kernels. Cold-sphere phantom simulation results also indicated improvement in contrast recovery and quantification with PSF modeling (compared to no PSF) for 5 and 10 mm cold spheres. Real microDerenzo phantom images with the PSF kernel that reflects the true LYSO density showed degraded resolving power of small sectors that could be resolved more clearly by underestimated PSF kernels, which is consistent with recent literature despite differences in scanner geometries and in approaches to system model estimation. The human vessel results resemble those of the hot-sphere phantom simulation with the PSF kernel that reflects the true LYSO density achieving the highest peak in the time activity curve (TAC) and similar lumped noise pattern. CONCLUSIONS We fully evaluated a practical MLEM reconstruction framework that we developed for VersaPET in terms of qualitative and quantitative performance. Different PSF kernels may be adopted for improving the results of specific imaging tasks but the underlying reasons for the variation in optimal kernel for the real and simulation studies requires further study.
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Affiliation(s)
- Shouyi Wei
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Paul Vaska
- Departments of Biomedical Engineering and Radiology, Renaissance School of Medicine at Stony Brook University, Stony Brook, NY, 11794, USA
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11
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Peeters LM, Missault S, Keliris AJ, Keliris GA. Combining designer receptors exclusively activated by designer drugs and neuroimaging in experimental models: A powerful approach towards neurotheranostic applications. Br J Pharmacol 2020; 177:992-1002. [PMID: 31658365 PMCID: PMC7042113 DOI: 10.1111/bph.14885] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 09/13/2019] [Accepted: 09/16/2019] [Indexed: 11/30/2022] Open
Abstract
The combination of chemogenetics targeting specific brain cell populations with in vivo imaging techniques provides scientists with a powerful new tool to study functional neural networks at the whole-brain scale. A number of recent studies indicate the potential of this approach to increase our understanding of brain function in health and disease. In this review, we discuss the employment of a specific chemogenetic tool, designer receptors exclusively activated by designer drugs, in conjunction with non-invasive neuroimaging techniques such as PET and MRI. We highlight the utility of using this multiscale approach in longitudinal studies and its ability to identify novel brain circuits relevant to behaviour that can be monitored in parallel. In addition, some identified shortcomings in this technique and more recent efforts to overcome them are also presented. Finally, we discuss the translational potential of designer receptors exclusively activated by designer drugs in neuroimaging and the promise it holds for future neurotheranostic applications.
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12
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Kobayashi T, Islam T, Sato M, Ohkura M, Nakai J, Hayashi Y, Okamoto H. Wide and Deep Imaging of Neuronal Activities by a Wearable NeuroImager Reveals Premotor Activity in the Whole Motor Cortex. Sci Rep 2019; 9:8366. [PMID: 31182818 PMCID: PMC6557893 DOI: 10.1038/s41598-019-44146-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 05/09/2019] [Indexed: 12/04/2022] Open
Abstract
Wearable technologies for functional whole brain imaging in freely moving animals would advance our understanding of cognitive processing and adaptive behavior. Fluorescence imaging can visualize the activity of individual neurons in real time, but conventional microscopes have limited sample coverage in both the width and depth of view. Here we developed a novel head-mounted laser camera (HLC) with macro and deep-focus lenses that enable fluorescence imaging at cellular resolution for comprehensive imaging in mice expressing a layer- and cell type-specific calcium probe. We visualized orientation selectivity in individual excitatory neurons across the whole visual cortex of one hemisphere, and cell assembly expressing the premotor activity that precedes voluntary movement across the motor cortex of both hemispheres. Including options for multiplex and wireless interfaces, our wearable, wide- and deep-imaging HLC technology could enable simple and economical mapping of neuronal populations underlying cognition and behavior.
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Affiliation(s)
- Takuma Kobayashi
- Laboratory for Neural Circuit Dynamics of Decision Making, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan.
| | - Tanvir Islam
- Laboratory for Neural Circuit Dynamics of Decision Making, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan
| | - Masaaki Sato
- Graduate School of Science and Engineering, Saitama University, Wako, Saitama, 338-8570, Japan.,Brain and Body System Science Institute, Saitama University, Wako, Saitama, 338-8570, Japan.,Laboratory for Mental Biology, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan
| | - Masamichi Ohkura
- Graduate School of Science and Engineering, Saitama University, Wako, Saitama, 338-8570, Japan.,Brain and Body System Science Institute, Saitama University, Wako, Saitama, 338-8570, Japan
| | - Junichi Nakai
- Graduate School of Science and Engineering, Saitama University, Wako, Saitama, 338-8570, Japan.,Brain and Body System Science Institute, Saitama University, Wako, Saitama, 338-8570, Japan
| | - Yasunori Hayashi
- Brain and Body System Science Institute, Saitama University, Wako, Saitama, 338-8570, Japan.,RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan.,Department of Pharmacology, Kyoto University Graduate School of Medicine, Kyoto, 606-8501, Japan
| | - Hitoshi Okamoto
- Laboratory for Neural Circuit Dynamics of Decision Making, RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan.
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13
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Cannella N, Ubaldi M, Masi A, Bramucci M, Roberto M, Bifone A, Ciccocioppo R. Building better strategies to develop new medications in Alcohol Use Disorder: Learning from past success and failure to shape a brighter future. Neurosci Biobehav Rev 2019; 103:384-398. [PMID: 31112713 DOI: 10.1016/j.neubiorev.2019.05.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 05/10/2019] [Accepted: 05/15/2019] [Indexed: 12/11/2022]
Abstract
Alcohol Use Disorder (AUD) is a chronic disease that develops over the years. The complexity of the neurobiological processes contributing to the emergence of AUD and the neuroadaptive changes occurring during disease progression make it difficult to improve treatments. On the other hand, this complexity offers researchers the possibility to explore new targets. Over years of intense research several molecules were tested in AUD; in most cases, despite promising preclinical data, the clinical efficacy appeared insufficient to justify futher development. A prototypical example is that of corticotropin releasing factor type 1 receptor (CRF1R) antagonists that showed significant effectiveness in animal models of AUD but were largely ineffective in humans. The present article attempts to analyze the most recent venues in the development of new medications in AUD with a focus on the most promising drug targets under current exploration. Moreover, we delineate the importance of using a more integrated translational framework approach to correlate preclinical findings and early clinical data to enhance the probability to validate biological targets of interest.
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Affiliation(s)
- Nazzareno Cannella
- School of Pharmacy, Pharmacology Unit, University of Camerino, 62032 Camerino, Italy
| | - Massimo Ubaldi
- School of Pharmacy, Pharmacology Unit, University of Camerino, 62032 Camerino, Italy
| | - Alessio Masi
- School of Pharmacy, Pharmacology Unit, University of Camerino, 62032 Camerino, Italy
| | - Massimo Bramucci
- School of Pharmacy, Pharmacology Unit, University of Camerino, 62032 Camerino, Italy
| | - Marisa Roberto
- The Scripps Research Institute, Department of Neuroscience, La Jolla, CA, USA
| | - Angelo Bifone
- Center for Neuroscience and Cognitive Systems @UniTn, Istituto Italiano di Tecnologia, Corso Bettini 31, 38068 Rovereto, Italy; Department of Molecular Biotechnology and Health Science, University of Torino, Italy
| | - Roberto Ciccocioppo
- School of Pharmacy, Pharmacology Unit, University of Camerino, 62032 Camerino, Italy.
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14
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Ammour L, Heymes J, Bautista M, Fieux S, Gensolen F, Kachel M, Dubois A, Lefebvre F, Pain F, Pangaud P, Pinot L, Baudot J, Gisquet-Verrier P, Laniece P, Morel C, Zimmer L, Verdier MA. MAPSSIC, a Novel CMOS Intracerebral Positrons Probe for Deep Brain Imaging in Awake and Freely Moving Rats: A Monte Carlo Study. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2019. [DOI: 10.1109/trpms.2018.2881301] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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15
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PET imaging of freely moving interacting rats. Neuroimage 2019; 191:560-567. [DOI: 10.1016/j.neuroimage.2019.02.064] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 02/06/2019] [Accepted: 02/25/2019] [Indexed: 11/18/2022] Open
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16
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Salerno M, Ferrer E, Wei S, Li X, Gao W, Ouellette D, Balanoff A, Vaska P. Behavioral neuroimaging in birds using PET. J Neurosci Methods 2019; 317:157-164. [PMID: 30710608 DOI: 10.1016/j.jneumeth.2019.01.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 01/17/2019] [Accepted: 01/29/2019] [Indexed: 11/16/2022]
Abstract
BACKGROUND Birds comprise the most diverse group of terrestrial vertebrates. This success likely is related to the evolution of powered flight over 75 mya. Modern approaches for studying brain function, however, have yet to be fully adapted and applied to birds, especially as they relate to specific behaviors including flight. New method: We have developed a comprehensive set of in vivo experimental methods utilizing PET imaging with F-18 labeled fluorodeoxyglucose (FDG) to study regional changes in metabolism specifically related to flight, yet applicable to other behaviors as well. It incorporates approaches for selection of species, behavioral/imaging paradigm, animal preparation, radiotracer injection route, image quantification, and image analysis via an enhanced brain atlas. We also carried out preliminary modeling studies to better understand tracer kinetics. RESULTS The methods were successful in identifying brain regions statistically associated with flight using only 8 animals. Peak brain uptake of FDG between birds and rodents is similar despite much higher blood glucose levels in birds. We also confirmed that brain uptake of FDG steadily decreases after the initial peak and provide evidence that it may be related to greater dephosphorylation of FDG phosphate than that observed in mammals. Comparison with existing methods: FDG PET has been used in only a few studies of the bird brain. We introduce a new species, more realistic flight behavior, paired (test/retest) design, and improved quantification and analysis approaches. CONCLUSIONS The proposed imaging protocol is non-invasive yet sensitive to regional metabolic changes in the bird brain related to behavior.
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Affiliation(s)
- Michael Salerno
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, 11794-5230, USA
| | - Elizabeth Ferrer
- Department of Anatomical Sciences, Stony Brook University, Stony Brook, NY, 11794-8081, USA
| | - Shouyi Wei
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, 11794-5230, USA
| | - Xiang Li
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, 11794-5230, USA
| | - Wenrong Gao
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, 11794-5230, USA
| | - David Ouellette
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, 11794-5230, USA
| | - Amy Balanoff
- Johns Hopkins University, Center for Functional Anatomy and Evolution, Baltimore, MD, 21205, USA; American Museum of Natural History, Division of Paleontology, New York, NY, 10024, USA.
| | - Paul Vaska
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, 11794-5230, USA; Department of Radiology, Renaissance School of Medicine at Stony Brook University, Stony Brook, NY, USA.
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17
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Gabrielson K, Maronpot R, Monette S, Mlynarczyk C, Ramot Y, Nyska A, Sysa-Shah P. In Vivo Imaging With Confirmation by Histopathology for Increased Rigor and Reproducibility in Translational Research: A Review of Examples, Options, and Resources. ILAR J 2018; 59:80-98. [PMID: 30541081 PMCID: PMC6645176 DOI: 10.1093/ilar/ily010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 07/18/2018] [Indexed: 12/13/2022] Open
Abstract
Preclinical noninvasive imaging can be an indispensable tool for studying animal models of disease. In vivo imaging to assess anatomical, functional, and molecular features requires verification by a comparison to the macroscopic and microscopic morphological features, since all noninvasive in vivo imaging methods have much lower resolution than standard histopathology. Comprehensive pathological evaluation of the animal model is underutilized; yet, many institutions have veterinary or human pathologists with necessary comparative pathology expertise. By performing a rigorous comparison to gross or histopathology for image interpretation, these trained individuals can assist scientists with the development of the animal model, experimental design, and evaluation of the in vivo imaging data. These imaging and pathology corroboration studies undoubtedly increase scientific rigor and reproducibility in descriptive and hypothesis-driven research. A review of case examples including ultrasound, nuclear, optical, and MRI is provided to illustrate how a wide range of imaging modalities data can be confirmed by gross or microscopic pathology. This image confirmation and authentication will improve characterization of the model and may contribute to decreasing costs and number of animals used and to more rapid translation from preclinical animal model to the clinic.
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Affiliation(s)
- Kathleen Gabrielson
- Departments of Molecular and Comparative Pathology and Pathology School of Medicine, Environmental Health Engineering Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland
| | | | - Sébastien Monette
- Laboratory of Comparative Pathology, Memorial Sloan Kettering Cancer Center, The Rockefeller University, Weill Cornell Medicine, New York, New York
| | - Coraline Mlynarczyk
- Department of Medicine, Division of Hematology & Medical Oncology and the Meyer Cancer Center, Weill Cornell Medicine, New York, New York
| | - Yuval Ramot
- Department of Dermatology, Hadassah—Hebrew University Medical Center, Kiryat Hadassah, Jerusalem, Israel
| | - Abraham Nyska
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel and Toxicologic Pathology, Timrat, Israel
| | - Polina Sysa-Shah
- Department of Radiology, Miller Research Building Molecular Imaging Service Center, Johns Hopkins University, Baltimore, Maryland
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18
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Kyme AZ, Angelis GI, Eisenhuth J, Fulton RR, Zhou V, Hart G, Popovic K, Akhtar M, Ryder WJ, Clemens KJ, Balleine BW, Parmar A, Pascali G, Perkins G, Meikle SR. Open-field PET: Simultaneous brain functional imaging and behavioural response measurements in freely moving small animals. Neuroimage 2018; 188:92-101. [PMID: 30502443 DOI: 10.1016/j.neuroimage.2018.11.051] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 11/01/2018] [Accepted: 11/27/2018] [Indexed: 10/27/2022] Open
Abstract
A comprehensive understanding of how the brain responds to a changing environment requires techniques capable of recording functional outputs at the whole-brain level in response to external stimuli. Positron emission tomography (PET) is an exquisitely sensitive technique for imaging brain function but the need for anaesthesia to avoid motion artefacts precludes concurrent behavioural response studies. Here, we report a technique that combines motion-compensated PET with a robotically-controlled animal enclosure to enable simultaneous brain imaging and behavioural recordings in unrestrained small animals. The technique was used to measure in vivo displacement of [11C]raclopride from dopamine D2 receptors (D2R) concurrently with changes in the behaviour of awake, freely moving rats following administration of unlabelled raclopride or amphetamine. The timing and magnitude of [11C]raclopride displacement from D2R were reliably estimated and, in the case of amphetamine, these changes coincided with a marked increase in stereotyped behaviours and hyper-locomotion. The technique, therefore, allows simultaneous measurement of changes in brain function and behavioural responses to external stimuli in conscious unrestrained animals, giving rise to important applications in behavioural neuroscience.
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Affiliation(s)
- Andre Z Kyme
- Biomedical Engineering, School of Aerospace, Mechanical & Mechatronic Engineering, Faculty of Engineering and IT, The University of Sydney, Sydney, NSW, 2006, Australia; Imaging Physics Laboratory, Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2006, Australia; Faculty of Health Sciences, The University of Sydney, Sydney, NSW, 2006, Australia.
| | - Georgios I Angelis
- Imaging Physics Laboratory, Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2006, Australia; Faculty of Health Sciences, The University of Sydney, Sydney, NSW, 2006, Australia
| | - John Eisenhuth
- Faculty of Health Sciences, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Roger R Fulton
- Imaging Physics Laboratory, Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2006, Australia; Faculty of Health Sciences, The University of Sydney, Sydney, NSW, 2006, Australia; Department of Medical Physics, Westmead Hospital, Sydney, NSW, 2145, Australia
| | - Victor Zhou
- Imaging Physics Laboratory, Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Genevra Hart
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Kata Popovic
- Imaging Physics Laboratory, Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2006, Australia; Faculty of Health Sciences, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Mahmood Akhtar
- Imaging Physics Laboratory, Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2006, Australia; Faculty of Health Sciences, The University of Sydney, Sydney, NSW, 2006, Australia
| | - William J Ryder
- Imaging Physics Laboratory, Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2006, Australia; Faculty of Health Sciences, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Kelly J Clemens
- School of Psychology, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Bernard W Balleine
- Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Arvind Parmar
- Imaging Physics Laboratory, Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2006, Australia; Australian Nuclear Science and Technology Organisation, Sydney, NSW, 2234, Australia
| | - Giancarlo Pascali
- Imaging Physics Laboratory, Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2006, Australia; Australian Nuclear Science and Technology Organisation, Sydney, NSW, 2234, Australia
| | - Gary Perkins
- Australian Nuclear Science and Technology Organisation, Sydney, NSW, 2234, Australia
| | - Steven R Meikle
- Imaging Physics Laboratory, Brain and Mind Centre, The University of Sydney, Sydney, NSW, 2006, Australia; Faculty of Health Sciences, The University of Sydney, Sydney, NSW, 2006, Australia
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19
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Miranda A, Glorie D, Bertoglio D, Vleugels J, De Bruyne G, Stroobants S, Staelens S, Verhaeghe J. Awake 18F-FDG PET Imaging of Memantine-Induced Brain Activation and Test-Retest in Freely Running Mice. J Nucl Med 2018; 60:844-850. [PMID: 30442754 PMCID: PMC6581220 DOI: 10.2967/jnumed.118.218669] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 11/05/2018] [Indexed: 11/16/2022] Open
Abstract
PET scans of the mouse brain are usually performed with anesthesia to immobilize the animal. However, it is desirable to avoid the confounding factor of anesthesia in mouse-brain response. Methods: We developed and validated brain PET imaging of awake, freely moving mice. Head-motion tracking was performed using radioactive point-source markers, and we used the tracking information for PET-image motion correction. Regional 18F-FDG brain uptake in a test, retest, and memantine-challenge study was measured in awake (n = 8) and anesthetized (n = 8) C57BL/6 mice. An awake uptake period was considered for the anesthesia scans. Results: Awake (motion-corrected) PET images showed an 18F-FDG uptake pattern comparable to the pattern of anesthetized mice. The test–retest variability (represented by the intraclass correlation coefficient) of the regional SUV quantification in the awake animals (0.424–0.555) was marginally lower than that in the anesthetized animals (intraclass correlation coefficient, 0.491–0.629) over the different regions. The increased memantine-induced 18F-FDG uptake was more pronounced in awake (+63.6%) than in anesthetized (+24.2%) animals. Additional behavioral information, acquired for awake animals, showed increased motor activity on a memantine challenge (total distance traveled, 18.2 ± 5.28 m) compared with test–retest (6.49 ± 2.21 m). Conclusion: The present method enables brain PET imaging on awake mice, thereby avoiding the confounding effects of anesthesia on the PET reading. It allows the simultaneous measurement of behavioral information during PET acquisitions. The method does not require any additional hardware, and it can be deployed in typical high-throughput scan protocols.
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Affiliation(s)
- Alan Miranda
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium
| | - Dorien Glorie
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium
| | - Daniele Bertoglio
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium
| | - Jochen Vleugels
- Product Development, University of Antwerp, Antwerp, Belgium; and
| | - Guido De Bruyne
- Product Development, University of Antwerp, Antwerp, Belgium; and
| | - Sigrid Stroobants
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium.,University Hospital Antwerp, Antwerp, Belgium
| | - Steven Staelens
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium
| | - Jeroen Verhaeghe
- Molecular Imaging Center Antwerp, University of Antwerp, Antwerp, Belgium
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20
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Estimation of and correction for finite motion sampling errors in small animal PET rigid motion correction. Med Biol Eng Comput 2018; 57:505-518. [PMID: 30242596 PMCID: PMC6347657 DOI: 10.1007/s11517-018-1899-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 09/14/2018] [Indexed: 11/23/2022]
Abstract
Motion tracking with finite time sampling causing an associated unknown residual motion between two motion measurements is one of the factors contributing to resolution loss in small animal PET motion correction. The aim of this work is (i) to provide a means to estimate the effect of the finite motion sampling on the spatial resolution of the motion correction reconstructions and (ii) to correct for this residual motion thereby minimizing resolution loss. We calculate a tailored spatially variant deconvolution kernel from the measured motion data which is then used to deconvolve the motion corrected image using a 3D Richardson-Lucy algorithm. A simulation experiment of numerical phantoms as well as a microDerenzo phantom experiment wherein the phantom was manually moved at different speeds was performed to assess the performance of our proposed method. In the motion corrected images of the microDerenzo phantom there was an average rod FWHM differences between the slow and fast motion cases of 9.7%. This difference was reduced to 5.8% after applying the residual motion deconvolution. In awake animal experiments, the proposed method can serve to mitigate the finite sampling factor degrading the spatial resolution as well as the resolution differences between fast-moving and slow-moving animals. Motion correction of positron emission tomography (PET) scans of moving subjects can be performed by measuring the motion of the subject during the PET scan with an optical tracking camera. The motion tracking data obtained from the tracking camera is then used to correct the PET image reconstructions for motion. Due to finite time sampling of the motion data, the motion corrected reconstructions suffer from loss of spatial resolution. In the proposed method, a spatially variant deconvolution kernel is calculated from the motion tracking data, which is then used to correct the motion-corrected PET reconstructions for the blurring effect of the finite motion sampling through a Richardson-Lucy deconvolution. ![]()
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21
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Madru R, Budassi M, Benveniste H, Lee H, Smith SD, Schlyer DJ, Vaska P, Knutsson L, Strand SE. Simultaneous Preclinical Positron Emission Tomography-Magnetic Resonance Imaging Study of Lymphatic Drainage of Chelator-Free 64Cu-Labeled Nanoparticles. Cancer Biother Radiopharm 2018; 33:213-220. [PMID: 30036073 DOI: 10.1089/cbr.2017.2412] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Hybrid positron emission tomography (PET)-magnetic resonance imaging (MRI) systems have been taken in use as new clinical diagnostic tools including detection and therapy planning of cancer. To reduce the amount of contrast agents injected in patients while fully benefitting both modalities, dual-modality probes are required. MATERIAL AND METHODS This study was first aimed at developing a hybrid PET-MRI probe by labeling superparamagnetic iron oxide nanoparticles (SPIONs) with 64Cu using a fast and chelator-free conjugation method, and second, to demonstrate the ability of the agent to target sentinel lymph nodes (SLNs) in vivo using simultaneous PET-MRI imaging. RESULTS High labeling efficiency of 97% produced within 10-15 min was demonstrated at room temperature. 64Cu-SPIONs were chemically stable in mouse serum for 24 h and after intradermal injection in the hind paw of C57BL/6J mice, demonstrated specific accumulation in the SLN. Simultaneous PET-MRI clearly demonstrated visualization of 64Cu-SPIONs, in dynamic and static imaging sequences up to 24 h after administration. CONCLUSION The use of a single hybrid probe and simultaneous hybrid imaging provides an efficient, complementary integration of quantitation and is expected to improve preoperative planning and intraoperative guidance of cancer treatments.
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Affiliation(s)
- Renata Madru
- 1 Department of Clinical Sciences Lund, Medical Radiation Physics, Lund University , Lund, Sweden
| | - Michael Budassi
- 2 Department of Biomedical Engineering, Stony Brook University , Stony Brook, New York.,3 Department of Biosciences, Brookhaven National Laboratory , Brookhaven, New York
| | - Helene Benveniste
- 4 Department of Anesthesiology, Yale University , New Haven, Connecticut
| | - Hedok Lee
- 4 Department of Anesthesiology, Yale University , New Haven, Connecticut
| | - S David Smith
- 3 Department of Biosciences, Brookhaven National Laboratory , Brookhaven, New York
| | - David J Schlyer
- 3 Department of Biosciences, Brookhaven National Laboratory , Brookhaven, New York
| | - Paul Vaska
- 2 Department of Biomedical Engineering, Stony Brook University , Stony Brook, New York
| | - Linda Knutsson
- 1 Department of Clinical Sciences Lund, Medical Radiation Physics, Lund University , Lund, Sweden
| | - Sven-Erik Strand
- 1 Department of Clinical Sciences Lund, Medical Radiation Physics, Lund University , Lund, Sweden .,5 Department of Clinical Sciences Lund, Oncology and Pathology, Lund University , Lund, Sweden
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22
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Abstract
PET scanners are sophisticated and highly sensitive biomedical imaging devices that can produce highly quantitative images showing the 3-dimensional distribution of radiotracers inside the body. PET scanners are commonly integrated with x-ray CT or MRI scanners in hybrid devices that can provide both molecular imaging (PET) and anatomical imaging (CT or MRI). Despite decades of development, significant opportunities still exist to make major improvements in the performance of PET systems for a variety of clinical and research tasks. These opportunities stem from new ideas and concepts, as well as a range of enabling technologies and methodologies. In this paper, we review current state of the art in PET instrumentation, detectors and systems, describe the major limitations in PET as currently practiced, and offer our own personal insights into some of the recent and emerging technological innovations that we believe will impact the field. Our focus is on the technical aspects of PET imaging, specifically detectors and system design, and the opportunity and necessity to move closer to PET systems for diagnostic patient use and in vivo biomedical research that truly approach the physical performance limits while remaining mindful of imaging time, radiation dose, and cost. However, other key endeavors, which are not covered here, including innovations in reconstruction and modeling methodology, radiotracer development, and expanding the range of clinical and research applications, also will play an equally important, if not more important, role in defining the future of the field.
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Affiliation(s)
- Eric Berg
- Department of Biomedical Engineering, University of California, Davis, CA
| | - Simon R Cherry
- Department of Biomedical Engineering, University of California, Davis, CA.; Department of Radiology, University of California, Davis, CA.
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23
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Gold MEL, Norell MA, Budassi M, Vaska P, Schulz D. Rapid 18F-FDG Uptake in Brain of Awake, Behaving Rat and Anesthetized Chicken has Implications for Behavioral PET Studies in Species With High Metabolisms. Front Behav Neurosci 2018; 12:115. [PMID: 29922136 PMCID: PMC5996747 DOI: 10.3389/fnbeh.2018.00115] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 05/18/2018] [Indexed: 11/30/2022] Open
Abstract
Brain-behavior studies using 18F-FDG PET aim to reveal brain regions that become active during behavior. In standard protocols, 18F-FDG is injected, the behavior is executed during 30–60 min of tracer uptake, and then the animal is anesthetized and scanned. Hence, the uptake of 18F-FDG is not itself observed and could, in fact, be complete in very little time. This has implications for behavioral studies because uptake is assumed to reflect concurrent behavior. Here, we utilized a new, miniature PET scanner termed RatCAP to measure uptake simultaneously with behavior. We employed a novel injection protocol in which we administered 18F-FDG (i.v.) four times over two 2 h to allow for repeated measurements and the correlation of changes in uptake and behavioral activity. Furthermore, using standard PET methods, we explored the effects of injection route on uptake time in chickens, a model for avians, for which PET studies are just beginning. We found that in the awake, behaving rat most of the 18F-FDG uptake occurred within minutes and overlapped to a large extent with 18F-FDG data taken from longer uptake periods. By contrast, behavior which occurred within minutes of the 18F-FDG infusion differed markedly from the behavior that occurred during later uptake periods. Accordingly, we found that changes in 18F-FDG uptake in the striatum, motor cortex and cerebellum relative to different reference regions significantly predicted changes in behavioral activity during the scan, if the time bins used for correlation were near the injection times of 18F-FDG. However, when morphine was also injected during the scan, which completely abolished behavioral activity for over 50 min, a large proportion of the variance in behavioral activity was also explained by the uptake data from the entire scan. In anesthetized chickens, tracer uptake was complete in about 80 min with s.c. injection, but 8 min with i.v. injection. In conclusion, uptake time needs to be taken into account to more accurately correlate PET and behavioral data in mammals and avians. Additionally, RatCAP together with multiple, successive injections of 18F-FDG may be useful to explore changes in uptake over time in relation to changes in behavior.
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Affiliation(s)
- Maria E L Gold
- Division of Paleontology, American Museum of Natural History, New York, NY, United States.,Department of Anatomical Sciences, Stony Brook University, Stony Brook, NY, United States.,Department of Biology, Suffolk University, Boston, MA, United States
| | - Mark A Norell
- Division of Paleontology, American Museum of Natural History, New York, NY, United States
| | - Michael Budassi
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, United States
| | - Paul Vaska
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, United States.,Department of Radiology, Stony Brook University, Stony Brook, NY, United States.,Biosciences Department, Brookhaven National Laboratory, Upton, NY, United States
| | - Daniela Schulz
- Department of Psychology, Yeditepe University, Istanbul, Turkey
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Ngernsutivorakul T, White TS, Kennedy RT. Microfabricated Probes for Studying Brain Chemistry: A Review. Chemphyschem 2018; 19:1128-1142. [PMID: 29405568 PMCID: PMC6996029 DOI: 10.1002/cphc.201701180] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Indexed: 12/13/2022]
Abstract
Probe techniques for monitoring in vivo chemistry (e.g., electrochemical sensors and microdialysis sampling probes) have significantly contributed to a better understanding of neurotransmission in correlation to behaviors and neurological disorders. Microfabrication allows construction of neural probes with high reproducibility, scalability, design flexibility, and multiplexed features. This technology has translated well into fabricating miniaturized neurochemical probes for electrochemical detection and sampling. Microfabricated electrochemical probes provide a better control of spatial resolution with multisite detection on a single compact platform. This development allows the observation of heterogeneity of neurochemical activity precisely within the brain region. Microfabricated sampling probes are starting to emerge that enable chemical measurements at high spatial resolution and potential for reducing tissue damage. Recent advancement in analytical methods also facilitates neurochemical monitoring at high temporal resolution. Furthermore, a positive feature of microfabricated probes is that they can be feasibly built with other sensing and stimulating platforms including optogenetics. Such integrated probes will empower researchers to precisely elucidate brain function and develop novel treatments for neurological disorders.
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Affiliation(s)
| | - Thomas S. White
- Macromolecular Science and Engineering, University of Michigan, 3003E, NCRC Building 28, 2800 Plymouth Rd., Ann Arbor, MI 48109
| | - Robert T. Kennedy
- Department of Chemistry, University of Michigan, 930 N. University Ave, Ann Arbor, MI 48109
- Department of Pharmacology, University of Michigan, 1150 W. Medical Center Drive, Ann Arbor, MI 48109
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Angelis GI, Gillam JE, Kyme AZ, Fulton RR, Meikle SR. Image-based modelling of residual blurring in motion corrected small animal PET imaging using motion dependent point spread functions. Biomed Phys Eng Express 2018. [DOI: 10.1088/2057-1976/aab922] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Salabert AS, Mora-Ramirez E, Beaurain M, Alonso M, Fontan C, Tahar HB, Boizeau ML, Tafani M, Bardiès M, Payoux P. Evaluation of [ 18F]FNM biodistribution and dosimetry based on whole-body PET imaging of rats. Nucl Med Biol 2017; 59:1-8. [PMID: 29413751 DOI: 10.1016/j.nucmedbio.2017.12.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 12/05/2017] [Accepted: 12/17/2017] [Indexed: 11/25/2022]
Abstract
INTRODUCTION The aim of this work was to study the biodistribution, metabolism and radiation dosimetry of rats injected with [18F]FNM using PET/CT images. This novel radiotracer targeting NMDA receptor has potential for investigation for neurological and psychiatric diseases. METHODS Free fraction and stability in fresh human plasma were determined in vitro. PET/CT was performed on anesthetized rats. Organs were identified and 3D volumes of interest (VOIs) were manually drawn on the CT in the center of each organ. Time activity curves (TACs) were created with these VOIs, enabling the calculation of residence times. To confirm these values, ex vivo measurements of organs were performed. Plasma and urine were also collected to study in vivo metabolism. Data was extrapolated to humans, effective doses were estimated using ICRP-60 and ICRP-89 dosimetric models and absorbed doses were estimated using OLINDA/EXM V1.0 and OLINDA/EXM V2.0 (which use weighting factors from ICRP-103 to do the calculations). RESULTS The [18F]FNM was stable in human plasma and the diffusible free fraction was 53%. As with memantine, this tracer is poorly metabolized in vivo. Ex vivo distributions validated PET/CT data as well as demonstrating a decrease of radiotracer uptake in the brain due to anesthesia. Total effective dose was around 6.11 μSv/MBq and 4.65 μSv/MBq for female and male human dosimetric models, respectively. CONCLUSIONS This study shows that the presented compound exhibits stability in plasma and plasma protein binding very similar to memantine. Its dosimetry shows that it is suitable for use in humans due to a low total effective dose compared to other PET radiotracers.
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Affiliation(s)
- Anne-Sophie Salabert
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, France; University Hospital, Radiopharmacy Unit, Toulouse, France.
| | - Erick Mora-Ramirez
- Inserm, UMR1037 CRCT, F-31000 Toulouse, France; Université Toulouse III-Paul Sabatier, UMR1037 CRCT, F-31000 Toulouse, France; Universidad de Costa Rica, CICANUM-Escuela de Física, San José, Costa Rica.
| | - Marie Beaurain
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, France; University Hospital, Radiopharmacy Unit, Toulouse, France.
| | - Mathieu Alonso
- University Hospital, Radiopharmacy Unit, Toulouse, France.
| | | | - Hafid Belhadj Tahar
- Research and Expertise Group, French Association for the Promotion of Medical Research (AFPREMED), Toulouse, France.
| | - Marie Laure Boizeau
- Advanced Technology Institute in Life Sciences (ITAV), Centre National de la Recherche Scientifique-Université Paul Sabatier Toulouse III (CNRS-UPS), Université Paul Sabatier Toulouse III (UPS), Université de ToulouseToulouse, France.
| | - Mathieu Tafani
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, France; University Hospital, Radiopharmacy Unit, Toulouse, France.
| | - Manuel Bardiès
- Inserm, UMR1037 CRCT, F-31000 Toulouse, France; Université Toulouse III-Paul Sabatier, UMR1037 CRCT, F-31000 Toulouse, France.
| | - Pierre Payoux
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, France; University Hospital, Nuclear Medicine Unit, Toulouse, France.
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Wong YC, Ilkova T, van Wijk RC, Hartman R, de Lange ECM. Development of a population pharmacokinetic model to predict brain distribution and dopamine D2 receptor occupancy of raclopride in non-anesthetized rat. Eur J Pharm Sci 2017; 111:514-525. [PMID: 29106979 DOI: 10.1016/j.ejps.2017.10.031] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 09/13/2017] [Accepted: 10/22/2017] [Indexed: 12/11/2022]
Abstract
BACKGROUND Raclopride is a selective antagonist of the dopamine D2 receptor. It is one of the most frequently used in vivo D2 tracers (at low doses) for assessing drug-induced receptor occupancy (RO) in animals and humans. It is also commonly used as a pharmacological blocker (at high doses) to occupy the available D2 receptors and antagonize the action of dopamine or drugs on D2 in preclinical studies. The aims of this study were to comprehensively evaluate its pharmacokinetic (PK) profiles in different brain compartments and to establish a PK-RO model that could predict the brain distribution and RO of raclopride in the freely moving rat using a LC-MS based approach. METHODS Rats (n=24) received a 10-min IV infusion of non-radiolabeled raclopride (1.61μmol/kg, i.e. 0.56mg/kg). Plasma and the brain tissues of striatum (with high density of D2 receptors) and cerebellum (with negligible amount of D2 receptors) were collected. Additional microdialysis experiments were performed in some rats (n=7) to measure the free drug concentration in the extracellular fluid of the striatum and cerebellum. Raclopride concentrations in all samples were analyzed by LC-MS. A population PK-RO model was constructed in NONMEM to describe the concentration-time profiles in the unbound plasma, brain extracellular fluid and brain tissue compartments and to estimate the RO based on raclopride-D2 receptor binding kinetics. RESULTS In plasma raclopride showed a rapid distribution phase followed by a slower elimination phase. The striatum tissue concentrations were consistently higher than that of cerebellum tissue throughout the whole experimental period (10-h) due to higher non-specific tissue binding and D2 receptor binding in the striatum. Model-based simulations accurately predicted the literature data on rat plasma PK, brain tissue PK and D2 RO at different time points after intravenous or subcutaneous administration of raclopride at tracer dose (RO <10%), sub-pharmacological dose (RO 10%-30%) and pharmacological dose (RO >30%). CONCLUSION For the first time a predictive model that could describe the quantitative in vivo relationship between dose, PK and D2 RO of raclopride in non-anesthetized rat was established. The PK-RO model could facilitate the selection of optimal dose and dosing time when raclopride is used as tracer or as pharmacological blocker in various rat studies. The LC-MS based approach, which doses and quantifies a non-radiolabeled tracer, could be useful in evaluating the systemic disposition and brain kinetics of tracers.
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Affiliation(s)
- Yin Cheong Wong
- Division of Pharmacology, Cluster Systems Pharmacology, Leiden Academic Center for Drug Research, Leiden University, Leiden, The Netherlands
| | - Trayana Ilkova
- Division of Pharmacology, Cluster Systems Pharmacology, Leiden Academic Center for Drug Research, Leiden University, Leiden, The Netherlands
| | - Rob C van Wijk
- Division of Pharmacology, Cluster Systems Pharmacology, Leiden Academic Center for Drug Research, Leiden University, Leiden, The Netherlands
| | - Robin Hartman
- Division of Pharmacology, Cluster Systems Pharmacology, Leiden Academic Center for Drug Research, Leiden University, Leiden, The Netherlands
| | - Elizabeth C M de Lange
- Division of Pharmacology, Cluster Systems Pharmacology, Leiden Academic Center for Drug Research, Leiden University, Leiden, The Netherlands.
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The brain during free movement - What can we learn from the animal model. Brain Res 2017; 1716:3-15. [PMID: 28893579 DOI: 10.1016/j.brainres.2017.09.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 08/11/2017] [Accepted: 09/04/2017] [Indexed: 11/21/2022]
Abstract
Animals, just like humans, can freely move. They do so for various important reasons, such as finding food and escaping predators. Observing these behaviors can inform us about the underlying cognitive processes. In addition, while humans can convey complicated information easily through speaking, animals need to move their bodies to communicate. This has prompted many creative solutions by animal neuroscientists to enable studying the brain during movement. In this review, we first summarize how animal researchers record from the brain while an animal is moving, by describing the most common neural recording techniques in animals and how they were adapted to record during movement. We further discuss the challenge of controlling or monitoring sensory input during free movement. However, not only is free movement a necessity to reflect the outcome of certain internal cognitive processes in animals, it is also a fascinating field of research since certain crucial behavioral patterns can only be observed and studied during free movement. Therefore, in a second part of the review, we focus on some key findings in animal research that specifically address the interaction between free movement and brain activity. First, focusing on walking as a fundamental form of free movement, we discuss how important such intentional movements are for understanding processes as diverse as spatial navigation, active sensing, and complex motor planning. Second, we propose the idea of regarding free movement as the expression of a behavioral state. This view can help to understand the general influence of movement on brain function. Together, the technological advancements towards recording from the brain during movement, and the scientific questions asked about the brain engaged in movement, make animal research highly valuable to research into the human "moving brain".
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Kyme AZ, Judenhofer MS, Gong K, Bec J, Selfridge A, Du J, Qi J, Cherry SR, Meikle SR. Open-field mouse brain PET: design optimisation and detector characterisation. Phys Med Biol 2017; 62:6207-6225. [PMID: 28475491 DOI: 10.1088/1361-6560/aa7171] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
'Open-field' PET, in which an animal is free to move within an enclosed space during imaging, is a very promising advance for neuroscientific research. It provides a key advantage over conventional imaging under anesthesia by enabling functional changes in the brain to be correlated with an animal's behavioural response to environmental or pharmacologic stimuli. Previously we have demonstrated the feasibility of open-field imaging of rats using motion compensation techniques applied to a commercially available PET scanner. However, this approach of 'retro-fitting' motion compensation techniques to an existing system is limited by the inherent geometric and performance constraints of the system. The goal of this project is to develop a purpose-built PET scanner with geometry, motion tracking and imaging performance tailored and optimised for open-field imaging of the mouse brain. The design concept is a rail-based sliding tomograph which moves according to the animal's motion. Our specific aim in this work was to evaluate candidate scanner designs and characterise the performance of a depth-of-interaction detector module for the open-field system. We performed Monte Carlo simulations to estimate and compare the sensitivity and spatial resolution performance of four scanner geometries: a ring, parallel plate, and two box variants. Each system was based on a detector block consisting of a 23 × 23 array of 0.785 × 0.785 × 20 mm3 LSO crystals (overall dim. 19.6 × 19.6 × 20 mm). We found that a DoI resolution capability of 3 mm was necessary to achieve approximately uniform sub-millimetre spatial resolution throughout the FoV for all scanners except the parallel-plate geometry. With this DoI performance, the sensitivity advantage afforded by the box geometry with overlapping panels (16% peak absolute sensitivity, a 36% improvement over the ring design) suggests this unconventional design is best suited for imaging the mouse brain. We also built and characterised the block detector modelled in the simulations, including a dual-ended readout based on 6 × 6 arrays of through-silicon-via silicon photomultipliers (active area 84%) for DoI estimation. Identification of individual crystals in the flood map was excellent, energy resolution varied from 12.4% ± 0.6% near the centre to 24.4% ± 3.4% at the ends of the crystal, and the average DoI resolution was 2.8 mm ± 0.35 mm near the central depth (10 mm) and 3.5 mm ± 1.0 mm near the ends. Timing resolution was 1.4 ± 0.14 ns. Therefore, the DoI detector module meets the target specifications for the application and will be used as the basis for a prototype open-field mouse PET scanner.
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Affiliation(s)
- Andre Z Kyme
- Department of Biomedical Engineering, University of California, Davis CA 95616, United States of America. Faculty of Health Sciences and Brain & Mind Centre, University of Sydney, Sydney, Australia. Faculty of Engineering, School of AMME, University of Sydney, Sydney, Australia
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Miranda A, Staelens S, Stroobants S, Verhaeghe J. Fast and Accurate Rat Head Motion Tracking With Point Sources for Awake Brain PET. IEEE TRANSACTIONS ON MEDICAL IMAGING 2017; 36:1573-1582. [PMID: 28207390 DOI: 10.1109/tmi.2017.2667889] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
To avoid the confounding effects of anesthesia and immobilization stress in rat brain positron emission tomography (PET), motion tracking-based unrestrained awake rat brain imaging is being developed. In this paper, we propose a fast and accurate rat headmotion tracking method based on small PET point sources. PET point sources (3-4) attached to the rat's head are tracked in image space using 15-32-ms time frames. Our point source tracking (PST) method was validated using a manually moved microDerenzo phantom that was simultaneously tracked with an optical tracker (OT) for comparison. The PST method was further validated in three awake [18F]FDG rat brain scans. Compared with the OT, the PST-based correction at the same frame rate (31.2 Hz) reduced the reconstructed FWHM by 0.39-0.66 mm for the different tested rod sizes of the microDerenzo phantom. The FWHM could be further reduced by another 0.07-0.13 mm when increasing the PST frame rate (66.7 Hz). Regional brain [18F]FDG uptake in the motion corrected scan was strongly correlated ( ) with that of the anesthetized reference scan for all three cases ( ). The proposed PST method allowed excellent and reproducible motion correction in awake in vivo experiments. In addition, there is no need of specialized tracking equipment or additional calibrations to be performed, the point sources are practically imperceptible to the rat, and PST is ideally suitable for small bore scanners, where optical tracking might be challenging.
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Rivnay J, Wang H, Fenno L, Deisseroth K, Malliaras GG. Next-generation probes, particles, and proteins for neural interfacing. SCIENCE ADVANCES 2017; 3:e1601649. [PMID: 28630894 PMCID: PMC5466371 DOI: 10.1126/sciadv.1601649] [Citation(s) in RCA: 224] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 04/18/2017] [Indexed: 05/18/2023]
Abstract
Bidirectional interfacing with the nervous system enables neuroscience research, diagnosis, and therapy. This two-way communication allows us to monitor the state of the brain and its composite networks and cells as well as to influence them to treat disease or repair/restore sensory or motor function. To provide the most stable and effective interface, the tools of the trade must bridge the soft, ion-rich, and evolving nature of neural tissue with the largely rigid, static realm of microelectronics and medical instruments that allow for readout, analysis, and/or control. In this Review, we describe how the understanding of neural signaling and material-tissue interactions has fueled the expansion of the available tool set. New probe architectures and materials, nanoparticles, dyes, and designer genetically encoded proteins push the limits of recording and stimulation lifetime, localization, and specificity, blurring the boundary between living tissue and engineered tools. Understanding these approaches, their modality, and the role of cross-disciplinary development will support new neurotherapies and prostheses and provide neuroscientists and neurologists with unprecedented access to the brain.
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Affiliation(s)
- Jonathan Rivnay
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA
- Palo Alto Research Center, Palo Alto, CA 94304, USA
- Corresponding author.
| | - Huiliang Wang
- Departments of Bioengineering and Psychiatry, Stanford University, Stanford, CA 94305, USA
| | - Lief Fenno
- Departments of Bioengineering and Psychiatry, Stanford University, Stanford, CA 94305, USA
| | - Karl Deisseroth
- Departments of Bioengineering and Psychiatry, Stanford University, Stanford, CA 94305, USA
| | - George G. Malliaras
- Department of Bioelectronics, École Nationale Supérieure des Mines, CMP-EMSE, MOC, Gardanne 13541, France
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Lauber DT, Fülöp A, Kovács T, Szigeti K, Máthé D, Szijártó A. State of the art in vivo imaging techniques for laboratory animals. Lab Anim 2017; 51:465-478. [PMID: 28948893 DOI: 10.1177/0023677217695852] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In recent decades, imaging devices have become indispensable tools in the basic sciences, in preclinical research and in modern drug development. The rapidly evolving high-resolution in vivo imaging technologies provide a unique opportunity for studying biological processes of living organisms in real time on a molecular level. State of the art small-animal imaging modalities provide non-invasive images rich in quantitative anatomical and functional information, which renders longitudinal studies possible allowing precise monitoring of disease progression and response to therapy in models of different diseases. The number of animals in a scientific investigation can be substantially reduced using imaging techniques, which is in full compliance with the ethical endeavours for the 3R (reduction, refinement, replacement) policies formulated by Russell and Burch; furthermore, biological variability can be alleviated, as each animal serves as its own control. The most suitable and commonly used imaging modalities for in vivo small-animal imaging are optical imaging (OI), ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI), and finally the methods of nuclear medicine: positron emission tomography (PET) and single photon emission computed tomography (SPECT).
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Affiliation(s)
- David Tibor Lauber
- 1 Hepato-Pancreatico-Biliary Surgery Research Center Hungary, 1st Department of Surgery, Semmelweis University, Budapest, Hungary
| | - András Fülöp
- 1 Hepato-Pancreatico-Biliary Surgery Research Center Hungary, 1st Department of Surgery, Semmelweis University, Budapest, Hungary
| | - Tibor Kovács
- 1 Hepato-Pancreatico-Biliary Surgery Research Center Hungary, 1st Department of Surgery, Semmelweis University, Budapest, Hungary
- 2 Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
| | - Krisztián Szigeti
- 2 Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
| | - Domokos Máthé
- 2 Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
- 3 CROmed Translational Research Centers Ltd, Budapest, Hungary
| | - Attila Szijártó
- 1 Hepato-Pancreatico-Biliary Surgery Research Center Hungary, 1st Department of Surgery, Semmelweis University, Budapest, Hungary
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Miranda A, Staelens S, Stroobants S, Verhaeghe J. Markerless rat head motion tracking using structured light for brain PET imaging of unrestrained awake small animals. Phys Med Biol 2017; 62:1744-1758. [PMID: 28102175 DOI: 10.1088/1361-6560/aa5a46] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Preclinical positron emission tomography (PET) imaging in small animals is generally performed under anesthesia to immobilize the animal during scanning. More recently, for rat brain PET studies, methods to perform scans of unrestrained awake rats are being developed in order to avoid the unwanted effects of anesthesia on the brain response. Here, we investigate the use of a projected structure stereo camera to track the motion of the rat head during the PET scan. The motion information is then used to correct the PET data. The stereo camera calculates a 3D point cloud representation of the scene and the tracking is performed by point cloud matching using the iterative closest point algorithm. The main advantage of the proposed motion tracking is that no intervention, e.g. for marker attachment, is needed. A manually moved microDerenzo phantom experiment and 3 awake rat [18F]FDG experiments were performed to evaluate the proposed tracking method. The tracking accuracy was 0.33 mm rms. After motion correction image reconstruction, the microDerenzo phantom was recovered albeit with some loss of resolution. The reconstructed FWHM of the 2.5 and 3 mm rods increased with 0.94 and 0.51 mm respectively in comparison with the motion-free case. In the rat experiments, the average tracking success rate was 64.7%. The correlation of relative brain regional [18F]FDG uptake between the anesthesia and awake scan reconstructions was increased from on average 0.291 (not significant) before correction to 0.909 (p < 0.0001) after motion correction. Markerless motion tracking using structured light can be successfully used for tracking of the rat head for motion correction in awake rat PET scans.
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Affiliation(s)
- Alan Miranda
- Molecular Imaging Center Antwerp, University of Antwerp, Universiteitsplein 1, 2610 Antwerp, Belgium
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Lever SZ, Fan KH, Lever JR. Tactics for preclinical validation of receptor-binding radiotracers. Nucl Med Biol 2017; 44:4-30. [PMID: 27755986 PMCID: PMC5161541 DOI: 10.1016/j.nucmedbio.2016.08.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Revised: 08/24/2016] [Accepted: 08/24/2016] [Indexed: 12/20/2022]
Abstract
INTRODUCTION Aspects of radiopharmaceutical development are illustrated through preclinical studies of [125I]-(E)-1-(2-(2,3-dihydrobenzofuran-5-yl)ethyl)-4-(iodoallyl)piperazine ([125I]-E-IA-BF-PE-PIPZE), a radioligand for sigma-1 (σ1) receptors, coupled with examples from the recent literature. Findings are compared to those previously observed for [125I]-(E)-1-(2-(2,3-dimethoxy-5-yl)ethyl)-4-(iodoallyl)piperazine ([125I]-E-IA-DM-PE-PIPZE). METHODS Syntheses of E-IA-BF-PE-PIPZE and [125I]-E-IA-BF-PE-PIPZE were accomplished by standard methods. In vitro receptor binding studies and autoradiography were performed, and binding potential was predicted. Measurements of lipophilicity and protein binding were obtained. In vivo studies were conducted in mice to evaluate radioligand stability, as well as specific binding to σ1 sites in brain, brain regions and peripheral organs in the presence and absence of potential blockers. RESULTS E-IA-BF-PE-PIPZE exhibited high affinity and selectivity for σ1 receptors (Ki = 0.43 ± 0.03 nM, σ2/σ1 = 173). [125I]-E-IA-BF-PE-PIPZE was prepared in good yield and purity, with high specific activity. Radioligand binding provided dissociation (koff) and association (kon) rate constants, along with a measured Kd of 0.24 ± 0.01 nM and Bmax of 472 ± 13 fmol/mg protein. The radioligand proved suitable for quantitative autoradiography in vitro using brain sections. Moderate lipophilicity, Log D7.4 2.69 ± 0.28, was determined, and protein binding was 71 ± 0.3%. In vivo, high initial whole brain uptake, >6% injected dose/g, cleared slowly over 24 h. Specific binding represented 75% to 93% of total binding from 15 min to 24 h. Findings were confirmed and extended by regional brain biodistribution. Radiometabolites were not observed in brain (1%). CONCLUSIONS Substitution of dihydrobenzofuranylethyl for dimethoxyphenethyl increased radioligand affinity for σ1 receptors by 16-fold. While high specific binding to σ1 receptors was observed for both radioligands in vivo, [125I]-E-IA-BF-PE-PIPZE displayed much slower clearance kinetics than [125I]-E-IA-DM-PE-PIPZE. Thus, minor structural modifications of σ1 receptor radioligands lead to major differences in binding properties in vitro and in vivo.
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Affiliation(s)
- Susan Z Lever
- Department of Chemistry, University of Missouri, Columbia, MO, USA; University of Missouri Research Reactor Center, Columbia, MO, USA.
| | - Kuo-Hsien Fan
- Department of Chemistry, University of Missouri, Columbia, MO, USA
| | - John R Lever
- Department of Radiology, University of Missouri, Columbia, MO, USA; Research Service, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, USA.
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Abstract
Birds have evolved behavioral and morphological adaptations for powered flight. Many aspects of this transition are unknown, including the neuroanatomical changes that made flight possible [1]. To understand how the avian brain drives this complex behavior, we utilized positron emission tomography (PET) scanning and the tracer (18)F-fluorodeoxyglucose (FDG) to document regional metabolic activity in the brain associated with a variety of locomotor behaviors. FDG studies are typically employed in rats [2] though the technology has been applied to birds [3]. We examined whole-brain function in European Starlings (Sturnus vulgaris), trained to fly in a wind tunnel while metabolizing the tracer. Drawing on predictions from early anatomical studies [4], we hypothesized increased metabolic activity in the Wulst and functionally related visual brain regions during flight. We found that flight behaviors correlated positively with entopallia and Wulst activity, but negatively with thalamic activity.
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Spangler-Bickell MG, de Laat B, Fulton R, Bormans G, Nuyts J. The effect of isoflurane on 18F-FDG uptake in the rat brain: a fully conscious dynamic PET study using motion compensation. EJNMMI Res 2016; 6:86. [PMID: 27888500 PMCID: PMC5124015 DOI: 10.1186/s13550-016-0242-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 11/17/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In preclinical positron emission tomography (PET) studies an anaesthetic is used to ensure that the animal does not move during the scan. However, anaesthesia may have confounding effects on the drug or tracer kinetics under study, and the nature of these effects is usually not known. METHOD We have implemented a protocol for tracking the rigid motion of the head of a fully conscious rat during a PET scan and performing a motion compensated list-mode reconstruction of the data. Using this technique we have conducted eight rat studies to investigate the effect of isoflurane on the uptake of 18F-FDG in the brain, by comparing conscious and unconscious scans. RESULTS Our results indicate that isoflurane significantly decreases the whole brain uptake, as well as decreasing the relative regional FDG uptake in the cortex, diencephalon, and inferior colliculi, while increasing it in the vestibular nuclei. No statistically significant changes in FDG uptake were observed in the cerebellum and striata. CONCLUSION The applied event-based motion compensation technique allowed for the investigation of the effect of isoflurane on FDG uptake in the rat brain using fully awake and unrestrained rats, scanned dynamically from the moment of injection. A significant effect of the anaesthesia was observed in various regions of the brain.
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Affiliation(s)
- Matthew G Spangler-Bickell
- Department of Imaging and Pathology, KU Leuven - University of Leuven, Nuclear Medicine & Molecular Imaging, Medical Imaging Research Center (MIRC), Leuven, Belgium.
| | - Bart de Laat
- Department of Imaging and Pathology, KU Leuven - University of Leuven, Nuclear Medicine & Molecular Imaging, Medical Imaging Research Center (MIRC), Leuven, Belgium
| | - Roger Fulton
- Brain & Mind Centre and the Faculty of Health Sciences, University of Sydney, Sydney, Australia.,Department of Nuclear Medicine, Westmead Hospital, Sydney, Australia
| | - Guy Bormans
- Department of Radiopharmacy, KU Leuven, Leuven, Belgium
| | - Johan Nuyts
- Department of Imaging and Pathology, KU Leuven - University of Leuven, Nuclear Medicine & Molecular Imaging, Medical Imaging Research Center (MIRC), Leuven, Belgium
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Schmidtlein CR, Turner JN, Thompson MO, Mandal KC, Häggström I, Zhang J, Humm JL, Feiglin DH, Krol A. Initial performance studies of a wearable brain positron emission tomography camera based on autonomous thin-film digital Geiger avalanche photodiode arrays. J Med Imaging (Bellingham) 2016; 4:011003. [PMID: 27921074 DOI: 10.1117/1.jmi.4.1.011003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 10/20/2016] [Indexed: 11/14/2022] Open
Abstract
Using analytical and Monte Carlo modeling, we explored performance of a lightweight wearable helmet-shaped brain positron emission tomography (PET), or BET camera, based on thin-film digital Geiger avalanche photodiode arrays with Lutetium-yttrium oxyorthosilicate (LYSO) or [Formula: see text] scintillators for imaging in vivo human brain function of freely moving and acting subjects. We investigated a spherical cap BET and cylindrical brain PET (CYL) geometries with 250-mm diameter. We also considered a clinical whole-body (WB) LYSO PET/CT scanner. The simulated energy resolutions were 10.8% (LYSO) and 3.3% ([Formula: see text]), and the coincidence window was set at 2 ns. The brain was simulated as a water sphere of uniform F-18 activity with a radius of 100 mm. We found that BET achieved [Formula: see text] better noise equivalent count (NEC) performance relative to the CYL and [Formula: see text] than WB. For 10-mm-thick [Formula: see text] equivalent mass systems, LYSO (7-mm thick) had [Formula: see text] higher NEC than [Formula: see text]. We found that [Formula: see text] scintillator crystals achieved [Formula: see text] full-width-half-maximum spatial resolution without parallax errors. Additionally, our simulations showed that LYSO generally outperformed [Formula: see text] for NEC unless the timing resolution for [Formula: see text] was considerably smaller than that presently used for LYSO, i.e., well below 300 ps.
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Affiliation(s)
- Charles R Schmidtlein
- Memorial Sloan Kettering Cancer Center , Department of Medical Physics, 1250 First Avenue, New York, New York 10065, United States
| | - James N Turner
- State University of New York at Binghamton , Department of Small Scale Systems, Vestal Parkway East, P.O. Box 6000, Binghamton, New York 13902, United States
| | - Michael O Thompson
- Cornell University , Department of Materials Science and Engineering, 328 Bard Hall, Ithaca, New York 14853-1501, United States
| | - Krishna C Mandal
- University of South Carolina , Department of Electrical Engineering, Main Street, Swearingen Engineering Building 301, Columbia, South Carolina 29208, United States
| | - Ida Häggström
- Memorial Sloan Kettering Cancer Center , Department of Medical Physics, 1250 First Avenue, New York, New York 10065, United States
| | - Jiahan Zhang
- State University of New York Upstate Medical University , Department of Radiology, Syracuse, New York 13210, United States
| | - John L Humm
- Memorial Sloan Kettering Cancer Center , Department of Medical Physics, 1250 First Avenue, New York, New York 10065, United States
| | - David H Feiglin
- State University of New York Upstate Medical University , Department of Radiology, Syracuse, New York 13210, United States
| | - Andrzej Krol
- State University of New York Upstate Medical University, Department of Radiology, Syracuse, New York 13210, United States; State University of New York Upstate Medical University, Department of Pharmacology, 750 E. Adams Street, Syracuse, New York 13210, United States
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Spangler-Bickell MG, Zhou L, Kyme AZ, De Laat B, Fulton RR, Nuyts J. Optimising rigid motion compensation for small animal brain PET imaging. Phys Med Biol 2016; 61:7074-7091. [PMID: 27648644 DOI: 10.1088/0031-9155/61/19/7074] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Motion compensation (MC) in PET brain imaging of awake small animals is attracting increased attention in preclinical studies since it avoids the confounding effects of anaesthesia and enables behavioural tests during the scan. A popular MC technique is to use multiple external cameras to track the motion of the animal's head, which is assumed to be represented by the motion of a marker attached to its forehead. In this study we have explored several methods to improve the experimental setup and the reconstruction procedures of this method: optimising the camera-marker separation; improving the temporal synchronisation between the motion tracker measurements and the list-mode stream; post-acquisition smoothing and interpolation of the motion data; and list-mode reconstruction with appropriately selected subsets. These techniques have been tested and verified on measurements of a moving resolution phantom and brain scans of an awake rat. The proposed techniques improved the reconstructed spatial resolution of the phantom by 27% and of the rat brain by 14%. We suggest a set of optimal parameter values to use for awake animal PET studies and discuss the relative significance of each parameter choice.
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Affiliation(s)
- Matthew G Spangler-Bickell
- Department of Imaging and Pathology, KU Leuven-University of Leuven, Nuclear Medicine & Molecular Imaging, Medical Imaging Research Center (MIRC), Belgium
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Bauer CE, Brefczynski-Lewis J, Marano G, Mandich MB, Stolin A, Martone P, Lewis JW, Jaliparthi G, Raylman RR, Majewski S. Concept of an upright wearable positron emission tomography imager in humans. Brain Behav 2016; 6:e00530. [PMID: 27688946 PMCID: PMC5036439 DOI: 10.1002/brb3.530] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 05/19/2016] [Accepted: 06/12/2016] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND Positron Emission Tomography (PET) is traditionally used to image patients in restrictive positions, with few devices allowing for upright, brain-dedicated imaging. Our team has explored the concept of wearable PET imagers which could provide functional brain imaging of freely moving subjects. To test feasibility and determine future considerations for development, we built a rudimentary proof-of-concept prototype (Helmet_PET) and conducted tests in phantoms and four human volunteers. METHODS Twelve Silicon Photomultiplier-based detectors were assembled in a ring with exterior weight support and an interior mechanism that could be adjustably fitted to the head. We conducted brain phantom tests as well as scanned four patients scheduled for diagnostic F(18-) FDG PET/CT imaging. For human subjects the imager was angled such that field of view included basal ganglia and visual cortex to test for typical resting-state pattern. Imaging in two subjects was performed ~4 hr after PET/CT imaging to simulate lower injected F(18-) FDG dose by taking advantage of the natural radioactive decay of the tracer (F(18) half-life of 110 min), with an estimated imaging dosage of 25% of the standard. RESULTS We found that imaging with a simple lightweight ring of detectors was feasible using a fraction of the standard radioligand dose. Activity levels in the human participants were quantitatively similar to standard PET in a set of anatomical ROIs. Typical resting-state brain pattern activation was demonstrated even in a 1 min scan of active head rotation. CONCLUSION To our knowledge, this is the first demonstration of imaging a human subject with a novel wearable PET imager that moves with robust head movements. We discuss potential research and clinical applications that will drive the design of a fully functional device. Designs will need to consider trade-offs between a low weight device with high mobility and a heavier device with greater sensitivity and larger field of view.
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Affiliation(s)
- Christopher E Bauer
- Center for Advanced Imaging West Virginia University Morgantown WV USA; Department of Radiology West Virginia University Morgantown WV USA; Center for Neuroscience West Virginia University Morgantown WV USA
| | - Julie Brefczynski-Lewis
- Center for Advanced Imaging West Virginia University Morgantown WV USA; Center for Neuroscience West Virginia University Morgantown WV USA; Department of Physiology and Pharmacology West Virginia University Morgantown WV USA
| | - Gary Marano
- Center for Advanced Imaging West Virginia University Morgantown WV USA; Department of Radiology West Virginia University Morgantown WV USA
| | - Mary-Beth Mandich
- Division of Physical Therapy Department of Human Performance West Virginia University Morgantown WV USA
| | - Alexander Stolin
- Center for Advanced Imaging West Virginia University Morgantown WV USA; Department of Radiology West Virginia University Morgantown WV USA
| | - Peter Martone
- Center for Advanced Imaging West Virginia University Morgantown WV USA; Department of Radiology West Virginia University Morgantown WV USA
| | - James W Lewis
- Center for Neuroscience West Virginia University Morgantown WV USA; Department of Neurobiology and Anatomy West Virginia University Morgantown WV USA
| | - Gangadhar Jaliparthi
- Center for Advanced Imaging West Virginia University Morgantown WV USA; Department of Radiology West Virginia University Morgantown WV USA
| | - Raymond R Raylman
- Center for Advanced Imaging West Virginia University Morgantown WV USA; Department of Radiology West Virginia University Morgantown WV USA
| | - Stan Majewski
- Department of Radiology and Medical Imaging University of Virginia Charlottesville VA USA
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Tang J, Dai X, Jiang H. Wearable scanning photoacoustic brain imaging in behaving rats. JOURNAL OF BIOPHOTONICS 2016; 9:570-575. [PMID: 26777064 DOI: 10.1002/jbio.201500311] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2015] [Revised: 12/29/2015] [Accepted: 12/30/2015] [Indexed: 06/05/2023]
Abstract
A wearable scanning photoacoustic imaging (wPAI) system is presented for noninvasive brain study in behaving rats. This miniaturized wPAI system consists of four pico linear servos and a single transducer-based PAI probe. It has a dimension of 50 mm × 35 mm × 40 mm, and a weight of 26 g excluding cablings. Phantom evaluation shows that wPAI achieves a lateral resolution of ∼0.5 mm and an axial resolution of ∼0.1 mm at a depth of up to 11 mm. Its imaging ability is also tested in a behaving rat, and the results indicate that wPAI is able to image blood vessels at a depth of up to 5 mm with intact scalp and skull. With its noninvasive, deep penetration, and functional imaging ability in behaving animals, wPAI can be used for behavior, cognition, and preclinical brain disease studies.
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Affiliation(s)
- Jianbo Tang
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA
| | - Xianjin Dai
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA
| | - Huabei Jiang
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA.
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Wearable 3-D Photoacoustic Tomography for Functional Brain Imaging in Behaving Rats. Sci Rep 2016; 6:25470. [PMID: 27146026 PMCID: PMC4857106 DOI: 10.1038/srep25470] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 04/18/2016] [Indexed: 01/11/2023] Open
Abstract
Understanding the relationship between brain function and behavior remains a major challenge in neuroscience. Photoacoustic tomography (PAT) is an emerging technique that allows for noninvasive in vivo brain imaging at micrometer-millisecond spatiotemporal resolution. In this article, a novel, miniaturized 3D wearable PAT (3D-wPAT) technique is described for brain imaging in behaving rats. 3D-wPAT has three layers of fully functional acoustic transducer arrays. Phantom imaging experiments revealed that the in-plane X-Y spatial resolutions were ~200 μm for each acoustic detection layer. The functional imaging capacity of 3D-wPAT was demonstrated by mapping the cerebral oxygen saturation via multi-wavelength irradiation in behaving hyperoxic rats. In addition, we demonstrated that 3D-wPAT could be used for monitoring sensory stimulus-evoked responses in behaving rats by measuring hemodynamic responses in the primary visual cortex during visual stimulation. Together, these results show the potential of 3D-wPAT for brain study in behaving rodents.
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Abstract
Optogenetic methodology enables direct targeting of specific neural circuit elements for inhibition or excitation while spanning timescales from the acute (milliseconds) to the chronic (many days or more). Although the impact of this temporal versatility and cellular specificity has been greater for basic science than clinical research, it is natural to ask whether the dynamic patterns of neural circuit activity discovered to be causal in adaptive or maladaptive behaviors could become targets for treatment of neuropsychiatric diseases. Here, we consider the landscape of ideas related to therapeutic targeting of circuit dynamics. Specifically, we highlight optical, ultrasonic, and magnetic concepts for the targeted control of neural activity, preclinical/clinical discovery opportunities, and recently reported optogenetically guided clinical outcomes.
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Affiliation(s)
| | - Emily Ferenczi
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Karl Deisseroth
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA.
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43
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Chang L, Hu J, Chen F, Chen Z, Shi J, Yang Z, Li Y, Lee LJ. Nanoscale bio-platforms for living cell interrogation: current status and future perspectives. NANOSCALE 2016; 8:3181-3206. [PMID: 26745513 DOI: 10.1039/c5nr06694h] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The living cell is a complex entity that dynamically responds to both intracellular and extracellular environments. Extensive efforts have been devoted to the understanding intracellular functions orchestrated with mRNAs and proteins in investigation of the fate of a single-cell, including proliferation, apoptosis, motility, differentiation and mutations. The rapid development of modern cellular analysis techniques (e.g. PCR, western blotting, immunochemistry, etc.) offers new opportunities in quantitative analysis of RNA/protein expression up to a single cell level. The recent entries of nanoscale platforms that include kinds of methodologies with high spatial and temporal resolution have been widely employed to probe the living cells. In this tutorial review paper, we give insight into background introduction and technical innovation of currently reported nanoscale platforms for living cell interrogation. These highlighted technologies are documented in details within four categories, including nano-biosensors for label-free detection of living cells, nanodevices for living cell probing by intracellular marker delivery, high-throughput platforms towards clinical current, and the progress of microscopic imaging platforms for cell/tissue tracking in vitro and in vivo. Perspectives for system improvement were also discussed to solve the limitations remains in current techniques, for the purpose of clinical use in future.
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Affiliation(s)
- Lingqian Chang
- NSF Nanoscale Science and Engineering Center (NSEC), The Ohio State University, Columbus, OH 43212, USA.
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44
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Thanos PK, Restif C, O'Rourke JR, Lam CY, Metaxas D. Mouse Social Interaction Test (MoST): a quantitative computer automated analysis of behavior. J Neural Transm (Vienna) 2015; 124:3-11. [PMID: 26704381 DOI: 10.1007/s00702-015-1487-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 11/16/2015] [Indexed: 10/22/2022]
Abstract
Rodents are the most commonly used preclinical model of human disease assessing the mechanism(s) involved as well as the role of genetics, epigenetics, and pharmacotherapy on this disease as well as identifying vulnerability factors and risk assessment for disease critical in the development of improved treatment strategies. Unfortunately, the majority of rodent preclinical studies utilize single housed approaches where animals are either entirely housed and tested in solitary environments or group housed but tested in solitary environments. This approach, however, ignores the important contribution of social interaction and social behavior. Social interaction in rodents is found to be a major criterion for the ethological validity of rodent species-specific behavioral characteristics (Zurn et al. 2007; Analysis 2011). It is also well established that there is significant and growing number of reports, which illustrates the important role of social environment and social interaction in all diseases, with particularly significance in all neuropsychiatric diseases. Thus, it is imperative that research studies be able to add large-scale evaluations of social interaction and behavior in mice and benefit from automated tracking of behaviors and measurements by removing user bias and by quantifying aspects of behaviors that cannot be assessed by a human observer. Single mouse setups have been used routinely, but cannot be easily extended to multiple-animal studies where social behavior is key, e.g., autism, depression, anxiety, substance and non-substance addictive disorders, aggression, sexual behavior, or parenting. While recent efforts are focusing on multiple-animal tracking alone, a significant limitation remains the lack of insightful measures of social interactions. We present a novel, non-invasive single camera-based automated tracking method described as Mouse Social Test (MoST) and set of measures designed for estimating the interactions of multiple mice at the same time in the same environment interacting freely. Our results show measurement of social interactions and designed to be adaptable and applicable to most existing home cage systems used in research, and provide a greater level of detailed analysis of social behavior than previously possible. The present study describes social behaviors assessed in a home cage environment setup containing six mice that interact freely over long periods of time, and we illustrate how these measures can be interpreted and combined to classify rodent social behaviors. In addition, we illustrate how these measures can be interpreted and combined to classify and analyze comprehensively rodent behaviors involved in several neuropsychiatric diseases as well as provide opportunity for the basic research of rodent behavior previously not possible.
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Affiliation(s)
- Panayotis K Thanos
- Behavioral Neuropharmacology and Neuroimaging Lab, Research Institute on Addictions, University at Buffalo, Buffalo, NY, 14203, USA.
| | - Christophe Restif
- Center for Computational Biomedicine Imaging and Computation, Rutgers University, New Brunswick, NJ, 08904, USA
| | - Joseph R O'Rourke
- Behavioral Neuropharmacology and Neuroimaging Lab, Research Institute on Addictions, University at Buffalo, Buffalo, NY, 14203, USA
| | - Chiu Yin Lam
- Behavioral Neuropharmacology and Neuroimaging Lab, Research Institute on Addictions, University at Buffalo, Buffalo, NY, 14203, USA
| | - Dimitris Metaxas
- Center for Computational Biomedicine Imaging and Computation, Rutgers University, New Brunswick, NJ, 08904, USA
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Takuwa H, Maeda J, Ikoma Y, Tokunaga M, Wakizaka H, Uchida S, Kanno I, Taniguchi J, Ito H, Higuchi M. [(11)C]Raclopride binding in the striatum of minimally restrained and free-walking awake mice in a positron emission tomography study. Synapse 2015; 69:600-6. [PMID: 26360510 DOI: 10.1002/syn.21864] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 09/07/2015] [Accepted: 09/08/2015] [Indexed: 11/09/2022]
Abstract
Anesthesia and restraint stress have profound impacts on brain functions, including neural activity and cerebrovascular function, possibly influencing functional and neurochemical positron emission tomography (PET) imaging data. For circumventing this effect, we developed an experimental system enabling PET imaging of free-walking awake mice with minimal restraints by fixing the head to a holder. The applicability of this system was investigated by performing PET imaging of D2 dopamine receptors with [(11)C]raclopride under the following three different conditions: (1) free-walking awake state; (2) 1.5% isoflurane anesthesia; and (3) whole-body restraint without anesthesia. [(11)C]raclopride binding potential (BP(ND)) values under isoflurane anesthesia and restrained awake state were significantly lower than under free-walking awake state (P < 0.01). Heart rates in restrained awake mice were significantly higher than those in free-walking awake mice (P < 0.01), suggesting that free-walking awake state minimized restraint stress during the PET scan. [(11)C] raclopride-PET with methamphetamine (METH) injection was also performed in awake and anesthetized mice. METH-induced reduction of [(11)C]raclopride BP(ND) in anesthetized mice showed a trend to be less than that in free-walking awake mice, implying that pharmacological modulation of dopaminergic transmissions could be sensitively captured by PET imaging of free-walking awake mice. We concluded that our system is of utility as an in vivo assaying platform for studies of brain functions and neurotransmission elements in small animals, such as those modeling neuropsychiatric disorders.
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Affiliation(s)
- Hiroyuki Takuwa
- Department of Biophysics Program, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Chiba, 263-8555, Japan
| | - Jun Maeda
- Department of Molecular Neuroimaging, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Chiba, 263-8555, Japan
| | - Yoko Ikoma
- Department of Biophysics Program, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Chiba, 263-8555, Japan
| | - Masaki Tokunaga
- Department of Molecular Neuroimaging, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Chiba, 263-8555, Japan
| | - Hidekatsu Wakizaka
- Department of Biophysics Program, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Chiba, 263-8555, Japan
| | - Shouko Uchida
- Department of Biophysics Program, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Chiba, 263-8555, Japan
| | - Iwao Kanno
- Department of Biophysics Program, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Chiba, 263-8555, Japan
| | - Junko Taniguchi
- Department of Biophysics Program, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Chiba, 263-8555, Japan
| | - Hiroshi Ito
- Department of Biophysics Program, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Chiba, 263-8555, Japan.,Advanced Clinical Research Center, Fukushima Global Medical Science Center, Fukushima Medical University, Hikariga-Oka, Fukushima, 960-1295, Japan
| | - Makoto Higuchi
- Department of Molecular Neuroimaging, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Chiba, 263-8555, Japan
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Hubeau M, Steppe K. Plant-PET Scans: In Vivo Mapping of Xylem and Phloem Functioning. TRENDS IN PLANT SCIENCE 2015; 20:676-685. [PMID: 26440436 DOI: 10.1016/j.tplants.2015.07.008] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Revised: 07/06/2015] [Accepted: 07/29/2015] [Indexed: 05/23/2023]
Abstract
Medical imaging techniques are rapidly expanding in the field of plant sciences. Positron emission tomography (PET) is advancing as a powerful functional imaging technique to decipher in vivo the function of xylem water flow (with (15)O or (18)F), phloem sugar flow (with (11)C or (18)F), and the importance of their strong coupling. However, much remains to be learned about how water flow and sugar distribution are coordinated in intact plants, both under present and future climate regimes. We propose to use PET analysis of plants (plant-PET) to visualize and generate these missing data about integrated xylem and phloem transport. These insights are crucial to understanding how a given environment will affect plant physiological processes and growth.
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Affiliation(s)
- Michiel Hubeau
- Laboratory of Plant Ecology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Kathy Steppe
- Laboratory of Plant Ecology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium.
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Balasse L, Maerk J, Pain F, Genoux A, Fieux S, Lefebvre F, Morel C, Gisquet-Verrier P, Lanièce P, Zimmer L. PIXSIC: A Wireless Intracerebral Radiosensitive Probe in Freely Moving Rats. Mol Imaging 2015. [DOI: 10.2310/7290.2015.00020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Laure Balasse
- From IMNC, CNRS, Université Paris Diderot, Université Paris Sud, Orsay, France; Lyon Neuroscience Research Center, INSERM, CNRS, Université Claude Bernard Lyon 1, France; Aix Marseille Université, CNRS/IN2P3, CPPM UMR 7346, Marseille, France; Paris Sud Neuroscience Center, CNRS, Universiteé Paris Sud, Orsay, France; and Hospices Civils de Lyon, Lyon, France
| | - Julia Maerk
- From IMNC, CNRS, Université Paris Diderot, Université Paris Sud, Orsay, France; Lyon Neuroscience Research Center, INSERM, CNRS, Université Claude Bernard Lyon 1, France; Aix Marseille Université, CNRS/IN2P3, CPPM UMR 7346, Marseille, France; Paris Sud Neuroscience Center, CNRS, Universiteé Paris Sud, Orsay, France; and Hospices Civils de Lyon, Lyon, France
| | - Frédéric Pain
- From IMNC, CNRS, Université Paris Diderot, Université Paris Sud, Orsay, France; Lyon Neuroscience Research Center, INSERM, CNRS, Université Claude Bernard Lyon 1, France; Aix Marseille Université, CNRS/IN2P3, CPPM UMR 7346, Marseille, France; Paris Sud Neuroscience Center, CNRS, Universiteé Paris Sud, Orsay, France; and Hospices Civils de Lyon, Lyon, France
| | - Aurelie Genoux
- From IMNC, CNRS, Université Paris Diderot, Université Paris Sud, Orsay, France; Lyon Neuroscience Research Center, INSERM, CNRS, Université Claude Bernard Lyon 1, France; Aix Marseille Université, CNRS/IN2P3, CPPM UMR 7346, Marseille, France; Paris Sud Neuroscience Center, CNRS, Universiteé Paris Sud, Orsay, France; and Hospices Civils de Lyon, Lyon, France
| | - Sylvain Fieux
- From IMNC, CNRS, Université Paris Diderot, Université Paris Sud, Orsay, France; Lyon Neuroscience Research Center, INSERM, CNRS, Université Claude Bernard Lyon 1, France; Aix Marseille Université, CNRS/IN2P3, CPPM UMR 7346, Marseille, France; Paris Sud Neuroscience Center, CNRS, Universiteé Paris Sud, Orsay, France; and Hospices Civils de Lyon, Lyon, France
| | - Françoise Lefebvre
- From IMNC, CNRS, Université Paris Diderot, Université Paris Sud, Orsay, France; Lyon Neuroscience Research Center, INSERM, CNRS, Université Claude Bernard Lyon 1, France; Aix Marseille Université, CNRS/IN2P3, CPPM UMR 7346, Marseille, France; Paris Sud Neuroscience Center, CNRS, Universiteé Paris Sud, Orsay, France; and Hospices Civils de Lyon, Lyon, France
| | - Christian Morel
- From IMNC, CNRS, Université Paris Diderot, Université Paris Sud, Orsay, France; Lyon Neuroscience Research Center, INSERM, CNRS, Université Claude Bernard Lyon 1, France; Aix Marseille Université, CNRS/IN2P3, CPPM UMR 7346, Marseille, France; Paris Sud Neuroscience Center, CNRS, Universiteé Paris Sud, Orsay, France; and Hospices Civils de Lyon, Lyon, France
| | - Pascale Gisquet-Verrier
- From IMNC, CNRS, Université Paris Diderot, Université Paris Sud, Orsay, France; Lyon Neuroscience Research Center, INSERM, CNRS, Université Claude Bernard Lyon 1, France; Aix Marseille Université, CNRS/IN2P3, CPPM UMR 7346, Marseille, France; Paris Sud Neuroscience Center, CNRS, Universiteé Paris Sud, Orsay, France; and Hospices Civils de Lyon, Lyon, France
| | - Philippe Lanièce
- From IMNC, CNRS, Université Paris Diderot, Université Paris Sud, Orsay, France; Lyon Neuroscience Research Center, INSERM, CNRS, Université Claude Bernard Lyon 1, France; Aix Marseille Université, CNRS/IN2P3, CPPM UMR 7346, Marseille, France; Paris Sud Neuroscience Center, CNRS, Universiteé Paris Sud, Orsay, France; and Hospices Civils de Lyon, Lyon, France
| | - Luc Zimmer
- From IMNC, CNRS, Université Paris Diderot, Université Paris Sud, Orsay, France; Lyon Neuroscience Research Center, INSERM, CNRS, Université Claude Bernard Lyon 1, France; Aix Marseille Université, CNRS/IN2P3, CPPM UMR 7346, Marseille, France; Paris Sud Neuroscience Center, CNRS, Universiteé Paris Sud, Orsay, France; and Hospices Civils de Lyon, Lyon, France
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Tang J, Xi L, Zhou J, Huang H, Zhang T, Carney PR, Jiang H. Noninvasive high-speed photoacoustic tomography of cerebral hemodynamics in awake-moving rats. J Cereb Blood Flow Metab 2015; 35:1224-32. [PMID: 26082016 PMCID: PMC4527999 DOI: 10.1038/jcbfm.2015.138] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 04/10/2015] [Accepted: 05/06/2015] [Indexed: 11/09/2022]
Abstract
We present a noninvasive method of photoacoustic tomography (PAT) for imaging cerebral hemodynamics in awake-moving rats. The wearable PAT (wPAT) system has a size of 15 mm in height and 33 mm in diameter, and a weight of ~8 g (excluding cabling). The wPAT achieved an imaging rate of 3.33 frames/s with a lateral resolution of 243 μm. Animal experiments were designed to show wPAT feasibility for imaging cerebral hemodynamics on awake-moving animals. Results showed that the cerebral oxy-hemoglobin and deoxy-hemoglobin changed significantly in response to hyperoxia; and, after the injection of pentylenetetrazol (PTZ), cerebral blood volume changed faster over time and larger in amplitude for rats in awake-moving state compared with rats under anesthesia. By providing a light-weight, high-resolution technology for in vivo monitoring of cerebral hemodynamics in awake-behaving animals, it will be possible to develop a comprehensive understanding on how activity alters hemodynamics in normal and diseased states.
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Affiliation(s)
- Jianbo Tang
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida, USA
| | - Lei Xi
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida, USA
| | - Junli Zhou
- Department of Pediatrics, University of Florida, Gainesville, Florida, USA
| | - Hua Huang
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida, USA
| | - Tao Zhang
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida, USA
| | - Paul R Carney
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida, USA
- Department of Pediatrics, University of Florida, Gainesville, Florida, USA
- Department of Neurology, University of Florida, Gainesville, Florida, USA
- Department of Neuroscience, University of Florida, Gainesville, Florida, USA
| | - Huabei Jiang
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida, USA
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49
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Real-time imaging of brain activity in freely moving rats using functional ultrasound. Nat Methods 2015; 12:873-8. [DOI: 10.1038/nmeth.3482] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 06/11/2015] [Indexed: 01/09/2023]
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50
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Edmunds KJ, Gargiulo P. Imaging Approaches in Functional Assessment of Implantable Myogenic Biomaterials and Engineered Muscle Tissue. Eur J Transl Myol 2015; 25:4847. [PMID: 26913149 PMCID: PMC4749010 DOI: 10.4081/ejtm.2015.4847] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Accepted: 01/21/2015] [Indexed: 12/13/2022] Open
Abstract
The fields of tissue engineering and regenerative medicine utilize implantable biomaterials and engineered tissues to regenerate damaged cells or replace lost tissues. There are distinct challenges in all facets of this research, but functional assessments and monitoring of such complex environments as muscle tissues present the current strategic priority. Many extant methods for addressing these questions result in the destruction or alteration of tissues or cell populations under investigation. Modern advances in non-invasive imaging modalities present opportunities to rethink some of the anachronistic methods, however, their standard employment may not be optimal when considering advancements in myology. New image analysis protocols and/or combinations of established modalities need to be addressed. This review focuses on efficacies and limitations of available imaging modalities to the functional assessment of implantable myogenic biomaterials and engineered muscle tissues.
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Affiliation(s)
- Kyle J. Edmunds
- Institute for Biomedical and Neural Engineering, University of Reykjavík
| | - Paolo Gargiulo
- Institute for Biomedical and Neural Engineering, University of Reykjavík
- University Hospital Landspítali, Reykjavík, Iceland
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