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Enhanced spatial resolution in magnetic resonance imaging by dynamic nuclear polarization at 5 K. Proc Natl Acad Sci U S A 2022; 119:e2201644119. [PMID: 35605126 DOI: 10.1073/pnas.2201644119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
SignificanceAlthough MRI is a powerful method for visualizing features within organisms and materials, the relatively low signal-to-noise ratio (SNR) of the NMR signals that are used to construct an image makes MRI with isotropic spatial resolution below 3.0 μm impractical at room temperature. Here we show that SNR enhancements available from a combination of low temperatures and dynamic nuclear polarization allow MRI with 1.7-μm isotropic resolution. These results may enable informative MRI studies of eukaryotic cells, cell clusters, and small tissue samples.
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2
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Zeng C, Chen Z, Yang H, Fan Y, Fei L, Chen X, Zhang M. Advanced high resolution three-dimensional imaging to visualize the cerebral neurovascular network in stroke. Int J Biol Sci 2022; 18:552-571. [PMID: 35002509 PMCID: PMC8741851 DOI: 10.7150/ijbs.64373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 10/28/2021] [Indexed: 11/05/2022] Open
Abstract
As an important method to accurately and timely diagnose stroke and study physiological characteristics and pathological mechanism in it, imaging technology has gone through more than a century of iteration. The interaction of cells densely packed in the brain is three-dimensional (3D), but the flat images brought by traditional visualization methods show only a few cells and ignore connections outside the slices. The increased resolution allows for a more microscopic and underlying view. Today's intuitive 3D imagings of micron or even nanometer scale are showing its essentiality in stroke. In recent years, 3D imaging technology has gained rapid development. With the overhaul of imaging mediums and the innovation of imaging mode, the resolution has been significantly improved, endowing researchers with the capability of holistic observation of a large volume, real-time monitoring of tiny voxels, and quantitative measurement of spatial parameters. In this review, we will summarize the current methods of high-resolution 3D imaging applied in stroke.
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Affiliation(s)
- Chudai Zeng
- Department of Neurology, Xiangya Hospital of Central South University, Changsha, Hunan, China, 410008.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China, 410008
| | - Zhuohui Chen
- Department of Neurology, Xiangya Hospital of Central South University, Changsha, Hunan, China, 410008.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China, 410008
| | - Haojun Yang
- Department of Neurology, Xiangya Hospital of Central South University, Changsha, Hunan, China, 410008.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China, 410008
| | - Yishu Fan
- Department of Neurology, Xiangya Hospital of Central South University, Changsha, Hunan, China, 410008.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China, 410008
| | - Lujing Fei
- Department of Neurology, Xiangya Hospital of Central South University, Changsha, Hunan, China, 410008.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China, 410008
| | - Xinghang Chen
- Department of Neurology, Xiangya Hospital of Central South University, Changsha, Hunan, China, 410008.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China, 410008
| | - Mengqi Zhang
- Department of Neurology, Xiangya Hospital of Central South University, Changsha, Hunan, China, 410008.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China, 410008
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3
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Sivelli G, Conley GM, Herrera C, Marable K, Rodriguez KJ, Bollwein H, Sudano MJ, Brugger J, Simpson AJ, Boero G, Grisi M. NMR spectroscopy of a single mammalian early stage embryo. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2022; 335:107142. [PMID: 34999310 DOI: 10.1016/j.jmr.2021.107142] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 12/22/2021] [Accepted: 12/26/2021] [Indexed: 06/14/2023]
Abstract
The resolving power, chemical sensitivity and non-invasive nature of NMR have made it an established technique for in vivo studies of large organisms both for research and clinical applications. NMR would clearly be beneficial for analysis of entities at the microscopic scale of about 1 nL (the nanoliter scale), typical of early development of mammalian embryos, microtissues and organoids: the scale where the building blocks of complex organisms could be observed. However, the handling of such small samples (about 100 µm) and sensitivity issues have prevented a widespread adoption of NMR. In this article we show how these limitations can be overcome to obtain NMR spectra of a mammalian embryo in its early stage. To achieve this we employ ultra-compact micro-chip technologies in combination with 3D-printed micro-structures. Such device is packaged for use as plug & play sensor and it shows sufficient sensitivity to resolve NMR signals from individual bovine pre-implantation embryos. The embryos in this study are obtained through In Vitro Fertilization (IVF) techniques, transported cryopreserved to the NMR laboratory, and measured shortly after thawing. In less than 1 h these spherical samples of just 130-190 µm produce distinct spectral peaks, largely originating from lipids contained inside them. We further observe how the spectra vary from one sample to another despite their optical and morphological similarities, suggesting that the method can further develop into a non-invasive embryo assay for selection prior to embryo transfer.
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Affiliation(s)
| | | | - Carolina Herrera
- Clinic of Reproductive Medicine, Department for Farm Animals, University of Zurich, 8057 Zurich, Switzerland
| | | | - Kyle J Rodriguez
- Microsystems Laboratory, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Heinrich Bollwein
- Clinic of Reproductive Medicine, Department for Farm Animals, University of Zurich, 8057 Zurich, Switzerland
| | - Mateus J Sudano
- Department of Genetics and Evolution, Federal University of São Carlos, São Carlos, SP, Brazil
| | - Jürgen Brugger
- Microsystems Laboratory, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Andre J Simpson
- Environmental NMR Center, University of Toronto, Scarborough Campus, 1265 Military Trail, Toronto M1C1A5, Canada
| | - Giovanni Boero
- Environmental NMR Center, University of Toronto, Scarborough Campus, 1265 Military Trail, Toronto M1C1A5, Canada
| | - Marco Grisi
- Annaida Technologies SA, Lausanne, Switzerland.
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4
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Wapler MC, Testud F, Hucker P, Leupold J, von Elverfeldt D, Zaitsev M, Wallrabe U. MR-compatible optical microscope for in-situ dual-mode MR-optical microscopy. PLoS One 2021; 16:e0250903. [PMID: 33970948 PMCID: PMC8109821 DOI: 10.1371/journal.pone.0250903] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 04/15/2021] [Indexed: 11/18/2022] Open
Abstract
We present the development of a dual-mode imaging platform that combines optical microscopy with magnetic resonance microscopy. Our microscope is designed to operate inside a 9.4T small animal scanner with the option to use a 72mm bore animal RF coil or different integrated linear micro coils. With a design that minimizes the magnetic distortions near the sample, we achieved a field inhomogeneity of 19 ppb RMS. We further integrated a waveguide in the optical layout for the electromagnetic shielding of the camera, which minimizes the noise increase in the MR and optical images below practical relevance. The optical layout uses an adaptive lens for focusing, 2 × 2 modular combinations of objectives with 0.6mm to 2.3mm field of view and 4 configurable RGBW illumination channels and achieves a plano-apochromatic optical aberration correction with 0.6μm to 2.3μm resolution. We present the design, implementation and characterization of the prototype including the general optical and MR-compatible design strategies, a knife-edge optical characterization and different concurrent imaging demonstrations.
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Affiliation(s)
- Matthias C. Wapler
- Department of Microsystemes Engineering (IMTEK), Laborarory for Microactuators, University of Freiburg, Freiburg, Germany
| | - Frederik Testud
- Center for Diagnostic and Therapeutic Radiology, Medical Physics, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Patrick Hucker
- Center for Diagnostic and Therapeutic Radiology, Medical Physics, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Jochen Leupold
- Center for Diagnostic and Therapeutic Radiology, Medical Physics, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Dominik von Elverfeldt
- Center for Diagnostic and Therapeutic Radiology, Medical Physics, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Maxim Zaitsev
- Center for Diagnostic and Therapeutic Radiology, Medical Physics, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center for High-Field Magnetic Resonance, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Ulrike Wallrabe
- Department of Microsystemes Engineering (IMTEK), Laborarory for Microactuators, University of Freiburg, Freiburg, Germany
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5
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Huang Q, Garrett A, Bose S, Blocker S, Rios AC, Clevers H, Shen X. The frontier of live tissue imaging across space and time. Cell Stem Cell 2021; 28:603-622. [PMID: 33798422 PMCID: PMC8034393 DOI: 10.1016/j.stem.2021.02.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
What you see is what you get-imaging techniques have long been essential for visualization and understanding of tissue development, homeostasis, and regeneration, which are driven by stem cell self-renewal and differentiation. Advances in molecular and tissue modeling techniques in the last decade are providing new imaging modalities to explore tissue heterogeneity and plasticity. Here we describe current state-of-the-art imaging modalities for tissue research at multiple scales, with a focus on explaining key tradeoffs such as spatial resolution, penetration depth, capture time/frequency, and moieties. We explore emerging tissue modeling and molecular tools that improve resolution, specificity, and throughput.
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Affiliation(s)
- Qiang Huang
- Department of Pediatric Surgery, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710004 Shaanxi, China; Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC 27708, USA
| | - Aliesha Garrett
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC 27708, USA
| | - Shree Bose
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC 27708, USA
| | - Stephanie Blocker
- Center for In Vitro Microscopy, Duke University, Durham, NC 27708, USA
| | - Anne C Rios
- Princess Máxima Center for Pediatric Oncology, Utrecht 3584, the Netherlands; Department of Cancer Research, Oncode Institute, Hubrecht Institute-KNAW Utrecht, Utrecht 3584, the Netherlands
| | - Hans Clevers
- Princess Máxima Center for Pediatric Oncology, Utrecht 3584, the Netherlands; Department of Cancer Research, Oncode Institute, Hubrecht Institute-KNAW Utrecht, Utrecht 3584, the Netherlands; Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW) and University Medical Center (UMC) Utrecht, Utrecht 3584, the Netherlands
| | - Xiling Shen
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC 27708, USA.
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6
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Flint JJ, Menon K, Hansen B, Forder J, Blackband SJ. Visualization of live, mammalian neurons during Kainate-infusion using magnetic resonance microscopy. Neuroimage 2020; 219:116997. [PMID: 32492508 PMCID: PMC7510773 DOI: 10.1016/j.neuroimage.2020.116997] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 05/25/2020] [Accepted: 05/26/2020] [Indexed: 01/30/2023] Open
Abstract
Since its first description and development in the late 20th century, diffusion magnetic resonance imaging (dMRI) has proven useful in describing the microstructural details of biological tissues. Signal generated from the protons of water molecules undergoing Brownian motion produces contrast based on the varied diffusivity of tissue types. Images employing diffusion contrast were first used to describe the diffusion characteristics of tissues, later used to describe the fiber orientations of white matter through tractography, and most recently proposed as a functional contrast method capable of delineating neuronal firing in the active brain. Thanks to the molecular origins of its signal source, diffusion contrast is inherently useful at describing features of the microenvironment; however, limitations in achievable resolution in magnetic resonance imaging (MRI) scans precluded direct visualization of tissue microstructure for decades following MRI's inception as an imaging modality. Even after advancements in MRI hardware had permitted the visualization of mammalian cells, these specialized systems could only accommodate fixed specimens that prohibited the observation and characterization of physiological processes. The goal of the current study was to visualize cellular structure and investigate the subcellular origins of the functional diffusion contrast mechanism (DfMRI) in living, mammalian tissue explants. Using a combination of ultra-high field spectrometers, micro radio frequency (RF) coils, and an MRI-compatible superfusion device, we are able to report the first live, mammalian cells-α-motor neurons-visualized with magnetic resonance microscopy (MRM). We are also able to report changes in the apparent diffusion of the stratum oriens within the hippocampus-a layer comprised primarily of pyramidal cell axons and basal dendrites-and the spinal cord's ventral horn following exposure to kainate.
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Affiliation(s)
- Jeremy J Flint
- Department of Neuroscience, University of Florida, Gainesville, FL, USA; McKnight Brain Institute, University of Florida, Gainesville, FL, USA.
| | - Kannan Menon
- Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA; McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | - Brian Hansen
- Center of Functionally Integrative Neuroscience, Aarhus University, Denmark
| | - John Forder
- Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA; Department of Radiology, University of Florida, Gainesville, FL, USA; McKnight Brain Institute, University of Florida, Gainesville, FL, USA; National High Magnetic Field Laboratory, Tallahassee, FL, USA
| | - Stephen J Blackband
- Department of Neuroscience, University of Florida, Gainesville, FL, USA; McKnight Brain Institute, University of Florida, Gainesville, FL, USA; Center for Structural Biology, University of Florida, Gainesville, FL, USA; National High Magnetic Field Laboratory, Tallahassee, FL, USA
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7
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van Schadewijk R, Krug JR, Shen D, Sankar Gupta KBS, Vergeldt FJ, Bisseling T, Webb AG, Van As H, Velders AH, de Groot HJM, Alia A. Magnetic Resonance Microscopy at Cellular Resolution and Localised Spectroscopy of Medicago truncatula at 22.3 Tesla. Sci Rep 2020; 10:971. [PMID: 31969628 PMCID: PMC6976659 DOI: 10.1038/s41598-020-57861-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 12/18/2019] [Indexed: 01/30/2023] Open
Abstract
Interactions between plants and the soil’s microbial & fungal flora are crucial for the health of soil ecosystems and food production. Microbe-plant interactions are difficult to investigate in situ due to their intertwined relationship involving morphology and metabolism. Here, we describe an approach to overcome this challenge by elucidating morphology and the metabolic profile of Medicago truncatula root nodules using Magnetic Resonance (MR) Microscopy, at the highest magnetic field strength (22.3 T) currently available for imaging. A home-built solenoid RF coil with an inner diameter of 1.5 mm was used to study individual root nodules. A 3D imaging sequence with an isotropic resolution of (7 μm)3 was able to resolve individual cells, and distinguish between cells infected with rhizobia and uninfected cells. Furthermore, we studied the metabolic profile of cells in different sections of the root nodule using localised MR spectroscopy and showed that several metabolites, including betaine, asparagine/aspartate and choline, have different concentrations across nodule zones. The metabolite spatial distribution was visualised using chemical shift imaging. Finally, we describe the technical challenges and outlook towards future in vivo MR microscopy of nodules and the plant root system.
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Affiliation(s)
- Remco van Schadewijk
- Solid-state NMR, Leiden Institute of Chemistry, Faculty of Science, Leiden University, Einsteinweg 55, Leiden, 2333 CC, The Netherlands
| | - Julia R Krug
- Laboratory of Biophysics, Wageningen University & Research, Stippeneng 4, Wageningen, 6708 WE, The Netherlands.,Laboratory of BioNanoTechnology, Wageningen University & Research, Bornse Weilanden 9, Wageningen, 6708 WG, The Netherlands
| | - Defeng Shen
- Laboratory of Molecular Biology, Wageningen University & Research, Droevendaalsesteeg 1, Wageningen, 6708 PB, The Netherlands
| | - Karthick B S Sankar Gupta
- Solid-state NMR, Leiden Institute of Chemistry, Faculty of Science, Leiden University, Einsteinweg 55, Leiden, 2333 CC, The Netherlands
| | - Frank J Vergeldt
- Laboratory of Biophysics, Wageningen University & Research, Stippeneng 4, Wageningen, 6708 WE, The Netherlands
| | - Ton Bisseling
- Laboratory of Molecular Biology, Wageningen University & Research, Droevendaalsesteeg 1, Wageningen, 6708 PB, The Netherlands
| | - Andrew G Webb
- C.J. Gorter Center for High Field MRI, Radiology department, Leiden University Medical Centre, Leiden University, Leiden, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Henk Van As
- Laboratory of Biophysics, Wageningen University & Research, Stippeneng 4, Wageningen, 6708 WE, The Netherlands
| | - Aldrik H Velders
- Laboratory of BioNanoTechnology, Wageningen University & Research, Bornse Weilanden 9, Wageningen, 6708 WG, The Netherlands
| | - Huub J M de Groot
- Solid-state NMR, Leiden Institute of Chemistry, Faculty of Science, Leiden University, Einsteinweg 55, Leiden, 2333 CC, The Netherlands
| | - A Alia
- Solid-state NMR, Leiden Institute of Chemistry, Faculty of Science, Leiden University, Einsteinweg 55, Leiden, 2333 CC, The Netherlands. .,Institute for Medical Physics and Biophysics, Leipzig University, Härtelstraße 16/18, Leipzig, 04107, Germany.
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Hesse L, Bunk K, Leupold J, Speck T, Masselter T. Structural and functional imaging of large and opaque plant specimens. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:3659-3678. [PMID: 31188449 DOI: 10.1093/jxb/erz186] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 04/08/2019] [Indexed: 05/20/2023]
Abstract
Three- and four-dimensional imaging techniques are a prerequisite for spatially resolving the form-structure-function relationships in plants. However, choosing the right imaging method is a difficult and time-consuming process as the imaging principles, advantages and limitations, as well as the appropriate fields of application first need to be compared. The present study aims to provide an overview of three imaging methods that allow for imaging opaque, large and thick (>5 mm, up to several centimeters), hierarchically organized plant samples that can have complex geometries. We compare light microscopy of serial thin sections followed by 3D reconstruction (LMTS3D) as an optical imaging technique, micro-computed tomography (µ-CT) based on ionizing radiation, and magnetic resonance imaging (MRI) which uses the natural magnetic properties of a sample for image acquisition. We discuss the most important imaging principles, advantages, and limitations, and suggest fields of application for each imaging technique (LMTS, µ-CT, and MRI) with regard to static (at a given time; 3D) and dynamic (at different time points; quasi 4D) structural and functional plant imaging.
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Affiliation(s)
- Linnea Hesse
- Plant Biomechanics Group and Botanic Garden, University of Freiburg, Freiburg, Germany
- Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT), Freiburg, Germany
| | - Katharina Bunk
- Plant Biomechanics Group and Botanic Garden, University of Freiburg, Freiburg, Germany
- Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT), Freiburg, Germany
| | - Jochen Leupold
- Department of Radiology, Medical Physics, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Thomas Speck
- Plant Biomechanics Group and Botanic Garden, University of Freiburg, Freiburg, Germany
- Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT), Freiburg, Germany
- Cluster of Excellence livMatS @ FIT - Freiburg Center for Interactive Materials and Bioinspired Technologies, University of Freiburg, Germany
| | - Tom Masselter
- Plant Biomechanics Group and Botanic Garden, University of Freiburg, Freiburg, Germany
- Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT), Freiburg, Germany
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Chen HY, Tycko R. Temperature-Dependent Nuclear Spin Relaxation Due to Paramagnetic Dopants Below 30 K: Relevance to DNP-Enhanced Magnetic Resonance Imaging. J Phys Chem B 2018; 122:11731-11742. [PMID: 30277390 DOI: 10.1021/acs.jpcb.8b07958] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Dynamic nuclear polarization (DNP) can increase nuclear magnetic resonance (NMR) signal strengths by factors of 100 or more at low temperatures. In magnetic resonance imaging (MRI), signal enhancements from DNP potentially lead to enhancements in image resolution. However, the paramagnetic dopants required for DNP also reduce nuclear spin relaxation times, producing signal losses that may cancel the signal enhancements from DNP. Here we investigate the dependence of 1H NMR relaxation times, including T1ρ and T2, under conditions of Lee-Goldburg 1H-1H decoupling and pulsed spin locking, on temperature and dopant concentration in frozen solutions that contain the trinitroxide compound DOTOPA. We find that relaxation times become longer at temperatures below 10 K, where DOTOPA electron spins become strongly polarized at equilibrium in a 9.39 T magnetic field. We show that the dependences of relaxation times on temperature and DOTOPA concentration can be reproduced qualitatively (although not quantitatively) by detailed simulations of magnetic field fluctuations due to flip-flop transitions in a system of dipole-coupled electron spin magnetic moments. These results have implications for ongoing attempts to reach submicron resolution in inductively detected MRI at very low temperatures.
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Affiliation(s)
- Hsueh-Ying Chen
- Laboratory of Chemical Physics National Institute of Diabetes and Digestive and Kidney Diseases , National Institutes of Health , Bethesda , Maryland 20892-0520 , United States
| | - Robert Tycko
- Laboratory of Chemical Physics National Institute of Diabetes and Digestive and Kidney Diseases , National Institutes of Health , Bethesda , Maryland 20892-0520 , United States
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Chen HY, Tycko R. Low-temperature magnetic resonance imaging with 2.8 μm isotropic resolution. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 287:47-55. [PMID: 29288890 PMCID: PMC5803441 DOI: 10.1016/j.jmr.2017.12.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 12/18/2017] [Accepted: 12/20/2017] [Indexed: 05/16/2023]
Abstract
We demonstrate the feasibility of high-resolution 1H magnetic resonance imaging (MRI) at low temperatures by obtaining an MRI image of 20 μm diameter glass beads in glycerol/water at 28 K with 2.8 μm isotropic resolution. The experiments use a recently-described MRI apparatus (Moore and Tycko, 2015) with minor modifications. The sample is contained within a radio-frequency microcoil with 150 μm inner diameter. Sensitivity is additionally enhanced by paramagnetic doping, optimization of the sample temperature, three-dimensional phase-encoding of k-space data, pulsed spin-lock detection of 1H nuclear magnetic resonance signals, and spherical sampling of k-space. We verify that the actual image resolution is 2.7 ± 0.3 μm by quantitative comparisons of experimental and calculated images. Our imaging approach is compatible with dynamic nuclear polarization, providing a path to significantly higher resolution in future experiments.
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Affiliation(s)
- Hsueh-Ying Chen
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0520, USA
| | - Robert Tycko
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0520, USA.
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11
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Kikuchi J, Ito K, Date Y. Environmental metabolomics with data science for investigating ecosystem homeostasis. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2018; 104:56-88. [PMID: 29405981 DOI: 10.1016/j.pnmrs.2017.11.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 11/19/2017] [Accepted: 11/19/2017] [Indexed: 05/08/2023]
Abstract
A natural ecosystem can be viewed as the interconnections between complex metabolic reactions and environments. Humans, a part of these ecosystems, and their activities strongly affect the environments. To account for human effects within ecosystems, understanding what benefits humans receive by facilitating the maintenance of environmental homeostasis is important. This review describes recent applications of several NMR approaches to the evaluation of environmental homeostasis by metabolic profiling and data science. The basic NMR strategy used to evaluate homeostasis using big data collection is similar to that used in human health studies. Sophisticated metabolomic approaches (metabolic profiling) are widely reported in the literature. Further challenges include the analysis of complex macromolecular structures, and of the compositions and interactions of plant biomass, soil humic substances, and aqueous particulate organic matter. To support the study of these topics, we also discuss sample preparation techniques and solid-state NMR approaches. Because NMR approaches can produce a number of data with high reproducibility and inter-institution compatibility, further analysis of such data using machine learning approaches is often worthwhile. We also describe methods for data pretreatment in solid-state NMR and for environmental feature extraction from heterogeneously-measured spectroscopic data by machine learning approaches.
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Affiliation(s)
- Jun Kikuchi
- RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan; Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan; Graduate School of Bioagricultural Sciences, Nagoya University, 1 Furo-cho, Chikusa-ku, Nagoya, Aichi 464-0810, Japan.
| | - Kengo Ito
- RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan; Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Yasuhiro Date
- RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan; Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
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12
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Anders J, Handwerker J, Ortmanns M, Boero G. A low-power high-sensitivity single-chip receiver for NMR microscopy. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 266:41-50. [PMID: 27011023 DOI: 10.1016/j.jmr.2016.03.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 03/08/2016] [Accepted: 03/09/2016] [Indexed: 06/05/2023]
Abstract
In this paper, we present a fully-integrated receiver for NMR microscopy applications manufactured in a 0.13μm CMOS technology. The design co-integrates a 10-turn planar detection coil together with a complete quadrature, low-IF downconversion receiver on a single chip, which operates from a single 1.5V supply with a total power dissipation of 18mW. The detector's measured time-domain spin sensitivity is 3×10(13)(1)Hspins/Hz at 7T. Additionally, the paper discusses two important aspects of NMR microscopy using planar detection coils: the link between the detection coil's spin sensitivity and the achievable image SNR and the correction of image artifacts induced by the inhomogeneous sensitivity profile of planar detection coils. More specifically, we derive analytical expressions for both the theoretical image SNR as a function of the coil's spin sensitivity and the sensitivity correction for a known coil sensitivity profile in CTI MR imaging experiments. Both expressions are validated using measured data in the imaging section of the paper. Thanks to the improved spin sensitivity of the utilized integrated receiver chip compared to a previously presented design, we were able to obtain sensitivity corrected images in a 7T spectroscopy magnet with isotropic resolutions of 9.6μm and 5μm with single-shot SNRs of 37 and 15 in relatively short imaging times of 4.4h and 24h, respectively.
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Affiliation(s)
- Jens Anders
- University of Ulm, Institute of Microelectronics, Albert-Einstein-Allee 43, D-89081 Ulm, Germany; Ecole Polytechnique Federale de Lausanne (EPFL), Institute of Microengineering, Station 17, CH-1015 Lausanne, Switzerland.
| | - Jonas Handwerker
- University of Ulm, Institute of Microelectronics, Albert-Einstein-Allee 43, D-89081 Ulm, Germany
| | - Maurits Ortmanns
- University of Ulm, Institute of Microelectronics, Albert-Einstein-Allee 43, D-89081 Ulm, Germany
| | - Giovanni Boero
- Ecole Polytechnique Federale de Lausanne (EPFL), Institute of Microengineering, Station 17, CH-1015 Lausanne, Switzerland
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Moore E, Tycko R. Micron-scale magnetic resonance imaging of both liquids and solids. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2015; 260:1-9. [PMID: 26397215 PMCID: PMC4628880 DOI: 10.1016/j.jmr.2015.09.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 08/31/2015] [Accepted: 09/02/2015] [Indexed: 05/16/2023]
Abstract
We describe and demonstrate a novel apparatus for magnetic resonance imaging (MRI), suitable for imaging of both liquid and solid samples with micron-scale isotropic resolution. The apparatus includes a solenoidal radio-frequency microcoil with 170 μm inner diameter and a set of planar gradient coils, all wound by hand and supported on a series of stacked sapphire plates. The design ensures efficient heat dissipation during gradient pulses and also facilitates disassembly, sample changes, and reassembly. To demonstrate liquid state (1)H MRI, we present an image of polystyrene beads within CuSO4-doped water, contained within a capillary tube with 100 μm inner diameter, with 5.0 μm isotropic resolution. To demonstrate solid state (1)H MRI, we present an image of NH4Cl particles within the capillary tube, with 8.0 μm isotropic resolution. High-resolution solid state MRI is enabled by frequency-switched Lee-Goldburg decoupling, with an effective rotating frame field amplitude of 289 kHz. At room temperature, pulsed gradients of 4 T/m (i.e., 170 Hz/μm for (1)H MRI) are achievable in all three directions with currents of 10 A or less. The apparatus is contained within a variable-temperature liquid helium cryostat, which will allow future efforts to obtain MRI images at low temperatures with signal enhancement by dynamic nuclear polarization.
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Affiliation(s)
- Eric Moore
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0520, USA
| | - Robert Tycko
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0520, USA.
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Göbel K, Gruschke OG, Leupold J, Kern JS, Has C, Bruckner-Tuderman L, Hennig J, von Elverfeldt D, Baxan N, Korvink JG. Phased-array of microcoils allows MR microscopy ofex vivohuman skin samples at 9.4 T. Skin Res Technol 2014; 21:61-8. [DOI: 10.1111/srt.12157] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/08/2014] [Indexed: 11/28/2022]
Affiliation(s)
- K. Göbel
- Department of Radiology; Medical Physics; University Medical Center Freiburg; Freiburg Germany
| | - O. G. Gruschke
- Laboratory of Simulation; IMTEK; University of Freiburg; Freiburg Germany
| | - J. Leupold
- Department of Radiology; Medical Physics; University Medical Center Freiburg; Freiburg Germany
| | - J. S. Kern
- Department of Dermatology; University Medical Center Freiburg; Freiburg Germany
| | - C. Has
- Department of Dermatology; University Medical Center Freiburg; Freiburg Germany
| | | | - J. Hennig
- Department of Radiology; Medical Physics; University Medical Center Freiburg; Freiburg Germany
| | - D. von Elverfeldt
- Department of Radiology; Medical Physics; University Medical Center Freiburg; Freiburg Germany
| | - N. Baxan
- Bruker BioSpin MRI GmbH; Ettlingen Germany
| | - J. G. Korvink
- Laboratory of Simulation; IMTEK; University of Freiburg; Freiburg Germany
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Watzlaw J, Glöggler S, Blümich B, Mokwa W, Schnakenberg U. Stacked planar micro coils for single-sided NMR applications. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2013; 230:176-185. [PMID: 23545292 DOI: 10.1016/j.jmr.2013.02.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2012] [Revised: 01/31/2013] [Accepted: 02/22/2013] [Indexed: 06/02/2023]
Abstract
This paper describes planar micro structured coils fabricated in a novel multilayer assembly for single-sided NMR experiments. By arranging the coil's turns in both lateral and vertical directions, all relevant coil parameters can be tailored to a specific application. To this end, we implemented an optimization algorithm based on simulations applying finite element methods (FEMs), which maximizes the coil's sensitivity and thus signal-to-noise ratio (SNR) while incorporating boundary conditions such as the coil's electrical properties and a localized sensitivity needed for single-sided applications. Utilizing thin-film technology and microstructuring techniques, the planar character is kept by a sub-millimeter overall thickness. The coils are adapted to the Profile NMR-MOUSE® magnet with a homogeneous slice of about 200 μm in height and a uniform depth gradient of about 20T/m. The final design of a coil with 20 turns, separated in four layers with five turns each, and an outer dimension of 4×4 mm(2) is able to measure a sample volume almost five times smaller than that of a state-of-the-art 14×16 mm(2) Profile NMR-MOUSE® coil with the same SNR. This allows for volume-limited measurements with high SNR and enables different future developments. The minimal dead time of 4 μs facilitates further improvements of the SNR by echo adding techniques and the characterization of samples with short T2 relaxation times. Measurements on solid polymers like polyethylene (PE) and polypropylene (PP) with T2 components as short as 200 μs approve the overall beneficial coil properties. Furthermore the ability to perform depth profiling with microscopic resolution is demonstrated.
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Affiliation(s)
- Jan Watzlaw
- Institut für Werkstoffe der Elektrotechnik (IWE), Chair 1, RWTH Aachen University, Sommerfeldstraße 24, 52074 Aachen, Germany.
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McDougall MP, Wright SM. A parallel imaging approach to wide-field MR microscopy. Magn Reson Med 2012; 68:850-6. [PMID: 22139858 PMCID: PMC3319189 DOI: 10.1002/mrm.23258] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Revised: 08/26/2011] [Accepted: 09/24/2011] [Indexed: 11/08/2022]
Abstract
Magnetic resonance microscopy, suggested in the earliest papers on MRI, has always been limited by the low signal-to-noise ratio resulting from the small voxel size. Magnetic resonance microscopy has largely been enabled by the use of microcoils that provide the signal-to-noise ratio improvement required to overcome this limitation. Concomitant with the small coils is a small field-of-view, which limits the use of magnetic resonance microscopy as a histological tool or for imaging large regions in general. This article describes initial results in wide field-of-view magnetic resonance microscopy using a large array of narrow, parallel coils, which provides a signal-to-noise ratio enhancement as well as the ability to use parallel imaging techniques. Comparison images made between a volume coil and the proposed technique demonstrate reductions in imaging time of more than 100 with no loss in signal-to-noise ratio or resolution.
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Affiliation(s)
- Mary Preston McDougall
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas, USA.
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Rivera DS, Cohen MS, Clark WG, Chu AC, Nunnally RL, Smith J, Mills D, Judy JW. An implantable RF solenoid for magnetic resonance microscopy and microspectroscopy. IEEE Trans Biomed Eng 2012; 59:2118-25. [PMID: 22156945 PMCID: PMC4497577 DOI: 10.1109/tbme.2011.2178239] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Miniature solenoids routinely enhance small volume nuclear magnetic resonance imaging and spectroscopy; however, no such techniques exist for patients. We present an implantable microcoil for diverse clinical applications, with a microliter coil volume. The design is loosely based on implantable depth electrodes, in which a flexible tube serves as the substrate, and a metal stylet is inserted into the tube during implantation. The goal is to provide enhanced signal-to-noise ratio (SNR) of structures that are not easily accessed by surface coils. The first-generation prototype was designed for implantation up to 2 cm, and provided initial proof-of-concept for microscopy. Subsequently, we optimized the design to minimize the influence of lead inductances, and to thereby double the length of the implantable depth (4 cm). The second-generation design represents an estimated SNR improvement of over 30% as compared to the original design when extended to 4 cm. Impedance measurements indicate that the device is stable for up to 24 h in body temperature saline. We evaluated the SNR and MR-related heating of the device at 3T. The implantable microcoil can differentiate fat and water peaks, and resolve submillimeter features.
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Affiliation(s)
- Debra S. Rivera
- Department of Neurophysics, Max Planck Institute, Leipzig 04103, Germany
| | - Mark S. Cohen
- Department of Psychiatry, University of California, Los Angeles, CA 94607 USA
| | - W. Gilbert Clark
- Department of Physics and Astronomy, University of California, Los Angeles, CA 94607 USA
| | - Allen C. Chu
- Department of Electrical Engineering, University of California, Los Angeles, CA 94607 USA. He is now with Agilent
| | - Ray L. Nunnally
- Robert and Beverly Lewis Center for Neuroimaging, University of Oregon, Eugene, OR 97403-1279 USA. He is now with The Coil Company, Parker, CO 80134 USA
| | - Jolinda Smith
- Robert and Beverly Lewis Center for Neuroimaging, University of Oregon, Eugene, OR 97403-1279 USA
| | - Dixie Mills
- Harvard Vanguard Medical Associates, Affiliate of Atrius Health Kenmore, Boston, MA 02466 USA
| | - Jack W. Judy
- Microsystems Technology Office, Defense Advanced Research Projects Agency, Washington, DC 20001 USA, and also with the Department of Electrical Engineering and the Neuroengineering Interdepartmental Program, University of California, Los Angeles, CA 94607 USA
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Jelescu IO, Boulant N, Le Bihan D, Ciobanu L. Experimental demonstration of diffusion signal enhancement in 2D DESIRE images. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2012; 218:44-48. [PMID: 22578554 DOI: 10.1016/j.jmr.2012.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Revised: 03/10/2012] [Accepted: 03/12/2012] [Indexed: 05/31/2023]
Abstract
In magnetic resonance microscopy based on conventional Fourier encoding techniques, molecular self-diffusion leads to a loss in signal to noise ratio while also limiting the spatial resolution. As opposed to standard diffusion-weighted sequences, the DESIRE (Diffusion Enhancement of SIgnal and REsolution) method gains signal through diffusion via a signal difference measurement, corresponding to the total number of spins saturated by a localized pulse applied for a given amount of time. The higher the diffusion coefficient at that location, the larger the number of spins effectively saturated and thus the higher the difference in signal. While the method has been previously demonstrated in 1D, the availability of higher magnetic fields and gradient strengths has recently brought its development within reach in 2D. Here we report the implementation of 2D DESIRE and the first experimental evaluation of enhancements in water and thin silicone oil. Enhancement levels obtained by saturating a 60 μm diameter region (effectively ~140 μm) and allowing diffusion lengths of 28 μm or 7 μm, respectively, are consistent with theoretical predictions. The typical enhancement values are 100% in water and 20% in silicone oil.
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Affiliation(s)
- Ileana O Jelescu
- NeuroSpin, Commissariat à l'Energie Atomique et aux Energies Alternatives, 91191 Gif-sur-Yvette, France.
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Borisjuk L, Rolletschek H, Neuberger T. Surveying the plant's world by magnetic resonance imaging. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2012; 70:129-46. [PMID: 22449048 DOI: 10.1111/j.1365-313x.2012.04927.x] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Understanding the way in which plants develop, grow and interact with their environment requires tools capable of a high degree of both spatial and temporal resolution. Magnetic resonance imaging (MRI), a technique which is able to visualize internal structures and metabolites, has the great virtue that it is non-invasive and therefore has the potential to monitor physiological processes occurring in vivo. The major aim of this review is to attract plant biologists to MRI by explaining its advantages and wide range of possible applications for solving outstanding issues in plant science. We discuss the challenges and opportunities of MRI in the study of plant physiology and development, plant-environment interactions, biodiversity, gene functions and metabolism. Overall, it is our view that the potential benefit of harnessing MRI for plant research purposes is hard to overrate.
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Affiliation(s)
- Ljudmilla Borisjuk
- Leibniz-Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstraße 3, Gatersleben, Germany.
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20
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de Carvalho Alegro M, Valotta Silva A, Yumi Bando S, de Deus Lopes R, Martins de Castro LH, Hungtsu W, Moreira-Filho CA, Amaro E. Texture analysis of high resolution MRI allows discrimination between febrile and afebrile initial precipitating injury in mesial temporal sclerosis. Magn Reson Med 2012; 68:1647-53. [PMID: 22287318 DOI: 10.1002/mrm.24174] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 12/12/2011] [Accepted: 12/29/2011] [Indexed: 01/10/2023]
Abstract
A computational pipeline combining texture analysis and pattern classification algorithms was developed for investigating associations between high-resolution MRI features and histological data. This methodology was tested in the study of dentate gyrus images of sclerotic hippocampi resected from refractory epilepsy patients. Images were acquired using a simple surface coil in a 3.0T MRI scanner. All specimens were subsequently submitted to histological semiquantitative evaluation. The computational pipeline was applied for classifying pixels according to: a) dentate gyrus histological parameters and b) patients' febrile or afebrile initial precipitating insult history. The pipeline results for febrile and afebrile patients achieved 70% classification accuracy, with 78% sensitivity and 80% specificity [area under the reader observer characteristics (ROC) curve: 0.89]. The analysis of the histological data alone was not sufficient to achieve significant power to separate febrile and afebrile groups. Interesting enough, the results from our approach did not show significant correlation with histological parameters (which per se were not enough to classify patient groups). These results showed the potential of adding computational texture analysis together with classification methods for detecting subtle MRI signal differences, a method sufficient to provide good clinical classification. A wide range of applications of this pipeline can also be used in other areas of medical imaging.
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Affiliation(s)
- Maryana de Carvalho Alegro
- Brain Institute/Dep. Radiology-Hospital Israelita Albert Einstein, Integrated Systems Laboratory, Escola Politécnica da Universidade de São Paulo, São Paulo, SP, Brazil
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21
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Weber H, Baxan N, Paul D, Maclaren J, Schmidig D, Mohammadzadeh M, Hennig J, von Elverfeldt D. Microcoil-based MRI: feasibility study and cell culture applications using a conventional animal system. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2011; 24:137-45. [PMID: 21331647 DOI: 10.1007/s10334-011-0244-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2010] [Revised: 01/10/2011] [Accepted: 01/24/2011] [Indexed: 12/22/2022]
Abstract
OBJECT The aim of this study was to demonstrate the feasibility of MR microimaging on a conventional 9.4 T horizontal animal MRI system using commercial available microcoils in combination with only minor modifications to the system, thereby opening this field to a larger community. MATERIALS AND METHODS Commercially available RF microcoils designed for high-resolution NMR spectrometers were used in combination with a custom-made probehead. For this purpose, changes within the transmit chain and modifications to the adjustment routines and image acquisition sequences were made, all without requiring expensive hardware. To investigate the extent to which routine operation and high-resolution imaging is possible, the quality of phantom images was analysed. Surface and solenoidal microcoils were characterized with regard to their sensitive volume and signal-to-noise ratio. In addition, the feasibility of using planar microcoils to achieve high-resolution images of living glioma cells labelled with MnCl(2) was investigated. RESULTS The setup presented in this work allows routine acquisition of high-quality images with high SNR and isotropic resolutions up to 10 μm within an acceptable measurement time. CONCLUSION This study demonstrates that MR microscopy can be applied at low cost on animal MR imaging systems, which are in widespread use. The successful imaging of living glioma cells indicates that the technique promises to be a useful tool in biomedical research.
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Affiliation(s)
- Hans Weber
- Medical Physics, Department of Radiology, University Medical Center Freiburg, Breisacher Str. 60a, 79106, Freiburg, Germany.
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Hoerr V, Purea A, Faber C. NMR separation of intra- and extracellular compounds based on intermolecular coherences. Biophys J 2011; 99:2336-43. [PMID: 20923669 DOI: 10.1016/j.bpj.2010.06.068] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2010] [Revised: 06/24/2010] [Accepted: 06/28/2010] [Indexed: 11/25/2022] Open
Abstract
NMR spectroscopy is a powerful tool for detection and characterization of chemical compounds in biological systems. Its application in pharmaceutical studies in cell cultures, however, has been hampered by the enormous technical challenges in separating intra- from extracellular amounts of one substance. We introduce a novel approach to separate intra- from extracellular NMR signal based on the detection of intermolecular zero-quantum coherences in presence of a chemical shift agent. In a sample of large cells in culture, the investigation of cellular uptake of pharmacological substances becomes feasible. The addition of 10 mM Tm-DOTP to a suspension of 100 Xenopus laevis oocytes resulted in sufficient separation of resonance frequencies between intra- and extracellular water. Upon selective excitation of either intra- or extracellular water signal, only intra- or extracellular components were observed, respectively. The presented localization technique provides intrinsic averaging over a large number of cells, resulting in a significant signal gain. The method works on standard NMR spectrometers, which are available at most scientific research institutions today. On a high-resolution NMR system with a cryoprobe, a 20-fold sensitivity gain was observed as compared to conventionally localized NMR spectroscopy of a single X. laevis oocyte on dedicated NMR microscopes.
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Affiliation(s)
- Verena Hoerr
- Department of Experimental Physics , University of Würzburg, Würzburg, Germany
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Laistler E, Loewe R, Moser E. Magnetic resonance microimaging of human skin vasculature in vivo at 3 Tesla. Magn Reson Med 2011; 65:1718-23. [PMID: 21254205 DOI: 10.1002/mrm.22743] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Revised: 11/04/2010] [Accepted: 11/07/2010] [Indexed: 11/07/2022]
Abstract
MRI can be used to investigate human skin microvasculature in vivo, provided adequate spatial resolution. Therefore, the sensitivity of the experiment has to be optimized to achieve sufficient signal-to-noise ratio (SNR) within reasonable measurement time to minimize motion artifacts, improve patient comfort and save costs. In this work, the high sensitivity of a 15 mm surface coil and the signal strength of a 3 Tesla scanner, together with a three-dimensional gradient echo sequence and post-processing have been combined to obtain high SNR. Images of human skin with isotropic spatial resolution of 100 μm were acquired within 10 min and the cutaneous vasculature could be visualized in 3D [Correction made here after initial online publication.], based on three averaged scans. The presented method can be used for diagnosis and, due to its non-invasiveness, treatment monitoring of vascular pathologies in the skin, such as inflammation, vascular malformation, or neoangiogenesis in superficial tumors.
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Affiliation(s)
- Elmar Laistler
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
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Thurber KR, Tycko R. Prospects for sub-micron solid state nuclear magnetic resonance imaging with low-temperature dynamic nuclear polarization. Phys Chem Chem Phys 2010; 12:5779-85. [PMID: 20458431 PMCID: PMC2883786 DOI: 10.1039/c0cp00157k] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We evaluate the feasibility of (1)H nuclear magnetic resonance (NMR) imaging with sub-micron voxel dimensions using a combination of low temperatures and dynamic nuclear polarization (DNP). Experiments are performed on nitroxide-doped glycerol-water at 9.4 T and temperatures below 40 K, using a 30 mW tunable microwave source for DNP. With DNP at 7 K, a 0.5 microL sample yields a (1)H NMR signal-to-noise ratio of 770 in two scans with pulsed spin-lock detection and after 80 db signal attenuation. With reasonable extrapolations, we infer that (1)H NMR signals from 1 microm(3) voxel volumes should be readily detectable, and voxels as small as 0.03 microm(3) may eventually be detectable. Through homonuclear decoupling with a frequency-switched Lee-Goldburg spin echo technique, we obtain 830 Hz (1)H NMR linewidths at low temperatures, implying that pulsed field gradients equal to 0.4 G/d or less would be required during spatial encoding dimensions of an imaging sequence, where d is the resolution in each dimension.
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Affiliation(s)
- Kent R. Thurber
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520
| | - Robert Tycko
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520
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Thurber KR, Yau WM, Tycko R. Low-temperature dynamic nuclear polarization at 9.4 T with a 30 mW microwave source. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2010; 204:303-13. [PMID: 20392658 PMCID: PMC2874615 DOI: 10.1016/j.jmr.2010.03.016] [Citation(s) in RCA: 128] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2010] [Revised: 03/11/2010] [Accepted: 03/18/2010] [Indexed: 05/05/2023]
Abstract
Dynamic nuclear polarization (DNP) can provide large signal enhancements in nuclear magnetic resonance (NMR) by transfer of polarization from electron spins to nuclear spins. We discuss several aspects of DNP experiments at 9.4 T (400 MHz resonant frequency for (1)H, 264 GHz for electron spins in organic radicals) in the 7-80K temperature range, using a 30 mW, frequency-tunable microwave source and a quasi-optical microwave bridge for polarization control and low-loss microwave transmission. In experiments on frozen glycerol/water doped with nitroxide radicals, DNP signal enhancements up to a factor of 80 are observed (relative to (1)H NMR signals with thermal equilibrium spin polarization). The largest sensitivity enhancements are observed with a new triradical dopant, DOTOPA-TEMPO. Field modulation with a 10 G root-mean-squared amplitude during DNP increases the nuclear spin polarizations by up to 135%. Dependencies of (1)H NMR signal amplitudes, nuclear spin relaxation times, and DNP build-up times on the dopant and its concentration, temperature, microwave power, and modulation frequency are reported and discussed. The benefits of low-temperature DNP can be dramatic: the (1)H spin polarization is increased approximately 1000-fold at 7 K with DNP, relative to thermal polarization at 80K.
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Affiliation(s)
- Kent R. Thurber
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0520
| | - Wai-Ming Yau
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0520
| | - Robert Tycko
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0520
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Mano S, Miwa T, Nishikawa SI, Mimura T, Nishimura M. Seeing is believing: on the use of image databases for visually exploring plant organelle dynamics. PLANT & CELL PHYSIOLOGY 2009; 50:2000-2014. [PMID: 19755394 DOI: 10.1093/pcp/pcp128] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Organelle dynamics vary dramatically depending on cell type, developmental stage and environmental stimuli, so that various parameters, such as size, number and behavior, are required for the description of the dynamics of each organelle. Imaging techniques are superior to other techniques for describing organelle dynamics because these parameters are visually exhibited. Therefore, as the results can be seen immediately, investigators can more easily grasp organelle dynamics. At present, imaging techniques are emerging as fundamental tools in plant organelle research, and the development of new methodologies to visualize organelles and the improvement of analytical tools and equipment have allowed the large-scale generation of image and movie data. Accordingly, image databases that accumulate information on organelle dynamics are an increasingly indispensable part of modern plant organelle research. In addition, image databases are potentially rich data sources for computational analyses, as image and movie data reposited in the databases contain valuable and significant information, such as size, number, length and velocity. Computational analytical tools support image-based data mining, such as segmentation, quantification and statistical analyses, to extract biologically meaningful information from each database and combine them to construct models. In this review, we outline the image databases that are dedicated to plant organelle research and present their potential as resources for image-based computational analyses.
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Affiliation(s)
- Shoji Mano
- Department of Cell Biology, National Institute for Basic Biology, Okazaki, 444-8585, Japan
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27
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Gonzalez-Lara LE, Xu X, Hofstetrova K, Pniak A, Brown A, Foster PJ. In vivo magnetic resonance imaging of spinal cord injury in the mouse. J Neurotrauma 2009; 26:753-62. [PMID: 19397403 DOI: 10.1089/neu.2008.0704] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The feasibility of performing high-resolution in vivo magnetic resonance imaging (MRI) to visualize the injured mouse spinal cord using a three-dimensional (3D)-FIESTA (fast imaging employing steady state acquisition) pulse sequence, in a clip compression injury model, is presented. Images were acquired using a 3-Tesla clinical whole-body MR system equipped with a high-performance gradient coil insert. High-resolution mouse cord images were used to detect and monitor the cord lesions for 6 weeks after spinal cord injury (SCI). The epicenter of the injury appeared as a region of mixed signal intensities on day 2 post-SCI. Regions of signal hypointensity appeared at the lesion site by 2 weeks post-SCI and became more apparent with time. In some mice, large cyst-like lesions were detected rostral to the lesion epicenter, as early as 2 weeks post-SCI, and increased in volume with time. In addition, MRI was used to detect and monitor iron-labeled mesenchymal stem cells (MSCs) after their transplantation into the injured cord. MSCs appeared as large, obvious regions of signal loss in the cord, which decreased in size over time.
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Moco S, Schneider B, Vervoort J. Plant Micrometabolomics: The Analysis of Endogenous Metabolites Present in a Plant Cell or Tissue. J Proteome Res 2009; 8:1694-703. [DOI: 10.1021/pr800973r] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Sofia Moco
- Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, and Max-Planck-Institute for Chemical Ecology, Beutenberg Campus, Hans-Knöll-Str. 8, D-07745 Jena, Germany
| | - Bernd Schneider
- Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, and Max-Planck-Institute for Chemical Ecology, Beutenberg Campus, Hans-Knöll-Str. 8, D-07745 Jena, Germany
| | - Jacques Vervoort
- Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, and Max-Planck-Institute for Chemical Ecology, Beutenberg Campus, Hans-Knöll-Str. 8, D-07745 Jena, Germany
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Kherlopian AR, Song T, Duan Q, Neimark MA, Po MJ, Gohagan JK, Laine AF. A review of imaging techniques for systems biology. BMC SYSTEMS BIOLOGY 2008; 2:74. [PMID: 18700030 PMCID: PMC2533300 DOI: 10.1186/1752-0509-2-74] [Citation(s) in RCA: 157] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2008] [Accepted: 08/12/2008] [Indexed: 11/10/2022]
Abstract
This paper presents a review of imaging techniques and of their utility in system biology. During the last decade systems biology has matured into a distinct field and imaging has been increasingly used to enable the interplay of experimental and theoretical biology. In this review, we describe and compare the roles of microscopy, ultrasound, CT (Computed Tomography), MRI (Magnetic Resonance Imaging), PET (Positron Emission Tomography), and molecular probes such as quantum dots and nanoshells in systems biology. As a unified application area among these different imaging techniques, examples in cancer targeting are highlighted.
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Affiliation(s)
- Armen R Kherlopian
- Department of Biomedical Engineering, Columbia University, New York, NY, USA.
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Strick DS, Nunnally RL, Smith JC, Clark W, Mills DJ, Cohen MS, Judy JW. Towards a microcoil for intracranial and intraductal MR microscopy. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2008; 2008:2047-50. [PMID: 19163097 PMCID: PMC3196548 DOI: 10.1109/iembs.2008.4649594] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Implantable RF-coils have enabled sub-mm resolution magnetic resonance images (MRI) of deep structures. Scaling down the size of RF coils has similarly provided a gain in signal-to-noise ratio in nuclear-magnetic-resonance spectroscopy. By combining both approaches we designed, fabricated, and imaged with an implantable microcoil catheter. While typical implantable catheters use a transverse magnetization, the axial magnetization of the microcoil provides improved sensitivity and allows visualization of the tissue beyond the distal end of the catheter. The microcoil catheter was designed with a diameter of 1 mm for future integration with intracranial devices, and for intraductal use in breast oncology. We modified the NMR-microcoil design to allow implantation of the RF coil, by winding the microcoil on medical-grade silicone tubing and incorporating leads on the catheter to connect circuit components. In order to achieve proper turn spacing, we coated copper wire with 25 microm of biocompatible polymer (Parylene C). Tuning and matching circuitry insured that the impedance of the RF coil was approximately 50 ohm at the operating frequency for 3-T proton MR applications. A duplexer was used to enable use of the microcoil catheter as a transceiver. Experimental verification of the coil design was achieved through ex vivo imaging of neural tissue. As expected, the microcoil catheter provided microscale images with 20-microm in-plane-resolution and 170-microm-thick slices. While 3-T MRI typically provides 1 to 30 voxels per-cubic-millimeter, in this paper we report that the MRI microcoil can provide hundreds, and even thousands of voxels in the same volume.
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Affiliation(s)
- Debra S Strick
- Biomedical Engineering Interdepartmental program, University of California, LA 90095, USA.
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Ginefri JC, Poirier-Quinot M, Girard O, Darrasse L. Technical aspects: Development, manufacture and installation of a cryo-cooled HTS coil system for high-resolution in-vivo imaging of the mouse at 1.5T. Methods 2007; 43:54-67. [PMID: 17720564 DOI: 10.1016/j.ymeth.2007.03.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2006] [Revised: 01/30/2007] [Accepted: 03/27/2007] [Indexed: 11/23/2022] Open
Abstract
Signal-to-noise ratio improvement is of major importance to achieve microscopic spatial resolution in magnetic resonance experiments. Magnetic resonance imaging of small animals is particularly concerned since it typically requires voxels of less than (100 microm)(3) to observe the small anatomical structures having size reduction by a factor of more than 10 as compared to human being. The signal-to-noise ratio can be increased by working at high static magnetic field strengths, but the biomedical interest of such high-field systems may be limited due to field-dependent contrast mechanisms and severe technological difficulties. An alternative approach that allows working in clinical imaging system is to improve the sensitivity of the radio-frequency receiver coil. This can be done using small cryogenically operated coils made either of copper or high-temperature superconducting material. We report the technological development of cryo-cooled superconducting coils for high-resolution imaging in a whole-body magnetic resonance scanner operating at 1.5 T. The technological background supporting this development is first addressed, including HTS coil design, simulation tools, cryogenic mean description and electrical characterization procedure. To illustrate the performances of superconducting coils for magnetic resonance imaging at intermediate field strength, in-vivo mouse images of various anatomic sites acquired with a 12 mm diameter cryo-cooled superconducting coil are presented.
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McDowell AF, Adolphi NL. Operating nanoliter scale NMR microcoils in a 1 tesla field. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2007; 188:74-82. [PMID: 17627856 DOI: 10.1016/j.jmr.2007.06.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2007] [Revised: 06/15/2007] [Accepted: 06/19/2007] [Indexed: 05/16/2023]
Abstract
Microcoil probes enclosing sample volumes of 1.2, 3.3, 7.0, and 81 nanoliters are constructed as nuclear magnetic resonance (NMR) detectors for operation in a 1 tesla permanent magnet. The probes for the three smallest volumes utilize a novel auxiliary tuning inductor for which the design criteria are given. The signal-to-noise ratio (SNR) and line width of water samples are measured. Based on the measured DC resistance of the microcoils, together with the calculated radio frequency (RF) resistance of the tuning inductor, the SNR is calculated and shown to agree with the measured values. The details of the calculations indicate that the auxiliary inductor does not degrade the NMR probe performance. The diameter of the wire used to construct the microcoils is shown to affect the signal line widths.
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Affiliation(s)
- Andrew F McDowell
- ABQMR, Inc., 2301 Yale Boulevard SE, Suite C-2, Albuquerque, NM 87106, USA
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McDougall MP, Wright SM. Investigation of coil phase compensation in 3D imaging at very high acceleration factors. J Magn Reson Imaging 2007; 25:1305-11. [PMID: 17520730 DOI: 10.1002/jmri.20938] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
PURPOSE To investigate the confounding effect of the coil phase in highly accelerated parallel imaging with small coils, contextualize the effect in terms of single-echo acquisition (SEA) imaging, and show that it can be managed in the case of 3D imaging. MATERIALS AND METHODS The effects of the coil phase variations in a 64-channel array of surface microcoils were modeled. Fully encoded 64 x 128 x 64 (N(phase enc) x N(readout) x N(slice enc)) 3D data sets were obtained, from which factor of 64 accelerated 3D image sets (1 x 128 x 64 each) were extracted from single phase-encoding lines, each representing a different phase compensation value. RESULTS A comparison of the SEA images indicates that the choice of a compromise value for phase compensation successfully enabled a straightforward extension of SEA imaging to three dimensions. The use of the single compromise compensation value in the 3D acquisition resulted in a signal-to-noise ratio (SNR) penalty ranging from 6% to 41% through the slab when compared to the highest SNR possible using any phase compensation value. CONCLUSION The coil-related phase shift issues inherent to highly accelerated imaging will require further study, but this work indicates the general nature of the problem and, more auspiciously, shows that it can be mitigated for at least this application.
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Affiliation(s)
- Mary Preston McDougall
- Department of Electrical Engineering, Texas A&M University, 3120 TAMU, College Station, TX 77843, USA.
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Preparation and characterisation of a novel buoyancy and refractive index matched oil-in-water emulsion. Colloids Surf A Physicochem Eng Asp 2007. [DOI: 10.1016/j.colsurfa.2007.01.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Fan LS, Hsu SSH, Jin JD, Hsieh CY, Lin WC, Hao HC, Cheng HL, Hsueh KC, Lee CZ. Miniaturization of Magnetic Resonance Microsystem Components for 3D Cell Imaging. ACTA ACUST UNITED AC 2007. [DOI: 10.1109/isscc.2007.373346] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Pohlmann A, Möller M, Decker H, Schreiber WG. MRI of tarantulas: morphological and perfusion imaging. Magn Reson Imaging 2006; 25:129-35. [PMID: 17222724 DOI: 10.1016/j.mri.2006.08.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2005] [Accepted: 08/19/2006] [Indexed: 11/29/2022]
Abstract
This paper describes a study performed to evaluate the feasibility of using a 1.5-T whole-body magnetic resonance imaging (MRI) equipment, in combination with pharmacokinetic modeling, to obtain in vivo information about the morphology and perfusion of tarantulas (Eurypelma californicum). MRI was performed on three tarantulas using spin-echo sequences for morphological imaging and a rapid spoiled gradient-echo sequence for dynamic imaging during and after contrast medium (CM; Gd-DTPA) injection. Signal enhancement in dynamic measurements was evaluated with a pharmacokinetic two-compartment model. Spin-echo images showed morphological structures well. Dynamic images were of sufficient quality and allowed a model analysis of CM kinetics, which provides information about regional perfusion. In conclusion, morphological and dynamic contrast-enhanced MRI of tarantulas is feasible with a conventional clinical scanner. Studies of this kind are therefore possible without a dedicated high-field animal scanner.
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Affiliation(s)
- Andreas Pohlmann
- Section of Medical Physics, Department of Diagnostic and Interventional Radiology, Johannes Gutenberg University Hospital, 55131 Mainz, Germany
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Pinkernelle J, Teichgräber U, Neumann F, Lehmkuhl L, Ricke J, Scholz R, Jordan A, Bruhn H. Imaging of single human carcinoma cells in vitro using a clinical whole-body magnetic resonance scanner at 3.0 T. Magn Reson Med 2005; 53:1187-92. [PMID: 15844140 DOI: 10.1002/mrm.20455] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The purpose of the present study was to examine whether single human carcinoma cells labeled with iron oxide nanoparticles could be detected by magnetic resonance (MR) imaging on a clinical 3-T scanner using a surface coil only. WiDr human colon carcinoma cells were loaded with two kinds of iron oxide nanoparticles differing by coating and size: aminosilan-coated (MagForce) and carboxy-dextran-coated particles (Resovist). The latter were preferred by the colon carcinoma cell line used here and taken up much faster (12 h) than the smaller carboxydextran-coated Resovist (48 h). Labeled single carcinoma cells, distributed in an agarose gel in a monodisperse layer as controlled by light microscopy, became detectable as punctuate signal extinctions when using a small circularly polarized surface coil in conjunction with a T(2)*-weighted GE sequence at 3 T. The threshold for the detectability of labeled colon carcinoma cells ranged at a load of 4-5 mug iron/10(6) cells. Obviating the need for special hardware additions, this study opens a new lane for single-cell tracking on clinical 3-T MR scanners amenable to patient studies.
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Affiliation(s)
- Jens Pinkernelle
- Klinik für Strahlenheilkunde, CVK, Charité University Medicine Berlin, Germany.
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Tyszka JM, Fraser SE, Jacobs RE. Magnetic resonance microscopy: recent advances and applications. Curr Opin Biotechnol 2005; 16:93-9. [PMID: 15722021 DOI: 10.1016/j.copbio.2004.11.004] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Magnetic resonance microscopy is receiving increased attention as more researchers in the biological sciences are turning to non-invasive imaging to characterize development, perturbations, phenotypes and pathologies in model organisms ranging from amphibian embryos to adult rodents and even plants. The limits of spatial resolution are being explored as hardware improvements address the need for increased sensitivity. Recent developments include in vivo cell tracking, restricted diffusion imaging, functional magnetic resonance microscopy and three-dimensional mouse atlases. Important applications are also being developed outside biology in the fields of fluid mechanics, geology and chemistry.
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Affiliation(s)
- J Michael Tyszka
- Biological Imaging Center, Division of Biology, California Institute of Technology, 2Q Broad 114-96, 1200 East California Boulevard, Pasadena, CA 91125, USA.
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Henkelman RM, Chen XJ, Sled JG. Disease phenotyping: structural and functional readouts. PROGRESS IN DRUG RESEARCH. FORTSCHRITTE DER ARZNEIMITTELFORSCHUNG. PROGRES DES RECHERCHES PHARMACEUTIQUES 2005; 62:151-84. [PMID: 16329257 DOI: 10.1007/3-7643-7426-8_5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Affiliation(s)
- R Mark Henkelman
- Mouse Imaging Centre (MICe), Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, Ontario, Canada MSG 1X8.
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Ciobanu L, Webb AG, Pennington CH. Signal enhancement by diffusion: experimental observation of the "DESIRE" effect. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2004; 170:252-256. [PMID: 15388088 DOI: 10.1016/j.jmr.2004.07.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2004] [Revised: 06/29/2004] [Indexed: 05/24/2023]
Abstract
Inadequate signal-to-noise ratio is a major factor limiting applications of magnetic resonance microscopy. The "Diffusion Enhancement of Signal and Resolution" (DESIRE) scheme promises potential sensitivity enhancements of between one and three orders of magnitude, but images using this mechanism have not been shown to date. Here, we report the first images obtained using the DESIRE method, and obtain excellent agreement between numerical simulations and experimental data with signal-to-noise enhancements of close to one order of magnitude.
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Affiliation(s)
- Luisa Ciobanu
- Biomedical Imaging Center, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, IL, USA.
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