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Stecker IR, Bdaiwi AS, Niedbalski PJ, Chatterjee N, Hossain MM, Cleveland ZI. Impact of undersampling on preclinical lung T 2* mapping with 3D radial UTE MRI at 7 T. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2024; 365:107741. [PMID: 39089222 PMCID: PMC11357708 DOI: 10.1016/j.jmr.2024.107741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 06/28/2024] [Accepted: 07/11/2024] [Indexed: 08/03/2024]
Abstract
Lung diseases are almost invariably heterogeneous and progressive, making it imperative to capture temporally and spatially explicit information to understand the disease initiation and progression. Imaging the lung with MRI-particularly in the preclinical setting-has historically been challenging because of relatively low lung tissue density, rapid cardiac and respiratory motion, and rapid transverse (T2*) relaxation. These limitations can largely be mitigated using ultrashort-echo-time (UTE) sequences, which are intrinsically robust to motion and avoid significant T2* decay. A significant disadvantage of common radial UTE sequences is that they require inefficient, center-out k-space sampling, resulting in long acquisition times relative to conventional Cartesian sequences. Therefore, pulmonary images acquired with radial UTE are often undersampled to reduce acquisition time. However, undersampling reduces image SNR, introduces image artifacts, and degrades true image resolution. The level of undersampling is further increased if offline gating techniques like retrospective gating are employed, because only a portion (∼40-50%) of the data is used in the final image reconstruction. Here, we explore the impact of undersampling on SNR and T2* mapping in mouse lung imaging using simulation and in-vivo data. Increased scatter in both metrics was noticeable at around 50% sampling. Parenchymal apparent SNR only decreased slightly (average decrease ∼ 1.4) with as little as 10% sampling. Apparent T2* remained similar across undersampling levels, but it became significantly increased (p < 0.05) below 80% sampling. These trends suggest that undersampling can generate quantifiable, but moderate changes in the apparent value of T2*. Moreover, these approaches to assess the impact of undersampling are straightforward to implement and can readily be expanded to assess the quantitative impact of other MR acquisition and reconstruction parameters.
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Affiliation(s)
- Ian R Stecker
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, United States; Center for Pulmonary Imaging Research, Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
| | - Abdullah S Bdaiwi
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, United States; Center for Pulmonary Imaging Research, Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
| | - Peter J Niedbalski
- Center for Pulmonary Imaging Research, Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
| | - Neelakshi Chatterjee
- Division of Biostatistics and Bioinformatics, Department of Environmental and Public Health Sciences, College of Medicine, University of Cincinnati, Cincinnati, OH, United States; Division of Biostatistics and Epidemiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
| | - Md M Hossain
- Division of Biostatistics and Epidemiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States; Department of Pediatrics, University of Cincinnati, Cincinnati, OH, United States
| | - Zackary I Cleveland
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, United States; Center for Pulmonary Imaging Research, Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States; Department of Pediatrics, University of Cincinnati, Cincinnati, OH, United States; Imaging Research Center, Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States.
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2
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Murray A, Gow AJ, Venosa A, Andres J, Malaviya R, Adler D, Yurkow E, Laskin JD, Laskin DL. Assessment of mustard vesicant lung injury and anti-TNF-α efficacy in rodents using live-animal imaging. Ann N Y Acad Sci 2020; 1480:246-256. [PMID: 33165947 DOI: 10.1111/nyas.14525] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 10/13/2020] [Accepted: 10/13/2020] [Indexed: 01/17/2023]
Abstract
Nitrogen mustard (NM) causes acute lung injury, which progresses to fibrosis. This is associated with a macrophage-dominant inflammatory response and the production of proinflammatory/profibrotic mediators, including tumor necrosis factor alpha (TNF-α). Herein, we refined magnetic resonance imaging (MRI) and computed tomography (CT) imaging methodologies to track the progression of NM-induced lung injury in rodents and assess the efficacy of anti-TNF-α antibody in mitigating toxicity. Anti-TNF-α antibody was administered to rats (15 mg/kg, every 8 days, intravenously) beginning 30 min after treatment with phosphate-buffered saline control or NM (0.125 mg/kg, intratracheally). Animals were imaged by MRI and CT prior to exposure and 1-28 days postexposure. Using MRI, we characterized acute lung injury and fibrosis by quantifying high-signal lung volume, which represents edema, inflammation, and tissue consolidation; these pathologies were found to persist for 28 days following NM exposure. CT scans were used to assess structural components of the lung and to register changes in tissue radiodensities. CT scans showed that in control animals, total lung volume increased with time. Treatment of rats with NM caused loss of lung volume; anti-TNF-α antibody mitigated this decrease. These studies demonstrate that MRI and CT can be used to monitor lung disease and the impact of therapeutic intervention.
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Affiliation(s)
- Alexa Murray
- Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, New Jersey
| | - Andrew J Gow
- Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, New Jersey
| | - Alessandro Venosa
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah
| | - Jaclynn Andres
- Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, New Jersey
| | - Rama Malaviya
- Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, New Jersey
| | - Derek Adler
- Molecular Imaging Center, Rutgers University, Piscataway, New Jersey
| | - Edward Yurkow
- Molecular Imaging Center, Rutgers University, Piscataway, New Jersey
| | - Jeffrey D Laskin
- Department of Environmental and Occupational Health, School of Public Health, Rutgers University, Piscataway, New Jersey
| | - Debra L Laskin
- Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, New Jersey
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Niedbalski PJ, Cochran AS, Akinyi TG, Thomen RP, Fugate EM, Lindquist DM, Pratt RG, Cleveland ZI. Preclinical hyperpolarized 129 Xe MRI: ventilation and T 2 * mapping in mouse lungs at 7 T using multi-echo flyback UTE. NMR IN BIOMEDICINE 2020; 33:e4302. [PMID: 32285574 PMCID: PMC7702724 DOI: 10.1002/nbm.4302] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 02/28/2020] [Accepted: 03/07/2020] [Indexed: 05/13/2023]
Abstract
Fast apparent transverse relaxation (short T2 *) is a common obstacle when attempting to perform quantitative 1 H MRI of the lungs. While T2 * times are longer for pulmonary hyperpolarized (HP) gas functional imaging (in particular for gaseous 129 Xe), T2 * can still lead to quantitative inaccuracies for sequences requiring longer echo times (such as diffusion weighted images) or longer readout duration (such as spiral sequences). This is especially true in preclinical studies, where high magnetic fields lead to shorter relaxation times than are typically seen in human studies. However, the T2 * of HP 129 Xe in the most common animal model of human disease (mice) has not been reported. Herein, we present a multi-echo radial flyback imaging sequence and use it to measure HP 129 Xe T2 * at 7 T under a variety of respiratory conditions. This sequence mitigates the impact of T1 relaxation outside the animal by using multiple gradient-refocused echoes to acquire images at a number of effective echo times for each RF excitation. After validating the sequence using a phantom containing water doped with superparamagnetic iron oxide nanoparticles, we measured the 129 Xe T2 * in vivo for 10 healthy C57Bl/6 J mice and found T2 * ~ 5 ms in the lung airspaces. Interestingly, T2 * was relatively constant over all experimental conditions, and varied significantly with sex, but not age, mass, or the O2 content of the inhaled gas mixture. These results are discussed in the context of T2 * relaxation within porous media.
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Affiliation(s)
- Peter J. Niedbalski
- Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229
| | - Alexander S. Cochran
- Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH 45221
| | - Teckla G. Akinyi
- Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH 45221
| | - Robert P. Thomen
- Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229
| | - Elizabeth M. Fugate
- Imaging Research Center, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229
| | - Diana M. Lindquist
- Imaging Research Center, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Ronald G. Pratt
- Imaging Research Center, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229
| | - Zackary I. Cleveland
- Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH 45221
- Imaging Research Center, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
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4
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Holden NE, Coplen TB, Böhlke JK, Tarbox LV, Benefield J, de Laeter JR, Mahaffy PG, O’Connor G, Roth E, Tepper DH, Walczyk T, Wieser ME, Yoneda S. IUPAC Periodic Table of the Elements and Isotopes (IPTEI) for the Education Community (IUPAC Technical Report). PURE APPL CHEM 2018. [DOI: 10.1515/pac-2015-0703] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Abstract
The IUPAC (International Union of Pure and Applied Chemistry) Periodic Table of the Elements and Isotopes (IPTEI) was created to familiarize students, teachers, and non-professionals with the existence and importance of isotopes of the chemical elements. The IPTEI is modeled on the familiar Periodic Table of the Chemical Elements. The IPTEI is intended to hang on the walls of chemistry laboratories and classrooms. Each cell of the IPTEI provides the chemical name, symbol, atomic number, and standard atomic weight of an element. Color-coded pie charts in each element cell display the stable isotopes and the relatively long-lived radioactive isotopes having characteristic terrestrial isotopic compositions that determine the standard atomic weight of each element. The background color scheme of cells categorizes the 118 elements into four groups: (1) white indicates the element has no standard atomic weight, (2) blue indicates the element has only one isotope that is used to determine its standard atomic weight, which is given as a single value with an uncertainty, (3) yellow indicates the element has two or more isotopes that are used to determine its standard atomic weight, which is given as a single value with an uncertainty, and (4) pink indicates the element has a well-documented variation in its atomic weight, and the standard atomic weight is expressed as an interval. An element-by-element review accompanies the IPTEI and includes a chart of all known stable and radioactive isotopes for each element. Practical applications of isotopic measurements and technologies are included for the following fields: forensic science, geochronology, Earth-system sciences, environmental science, and human health sciences, including medical diagnosis and treatment.
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Affiliation(s)
- Norman E. Holden
- National Nuclear Data Center, Brookhaven National Laboratory , Upton, NY , USA
| | | | | | | | | | | | | | | | - Etienne Roth
- Commissariat à l’énergie atomique (CEA) , Gif-sur-Yvette, France
| | | | - Thomas Walczyk
- Department of Chemistry , National University of Singapore , Singapore , Singapore
| | - Michael E. Wieser
- Department of Physics and Astronomy , University of Calgary , Calgary , Canada
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5
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Cleveland ZI, Zhou YM, Akinyi TG, Dunn RS, Davidson CR, Guo J, Woods JC, Hardie WD. Magnetic resonance imaging of disease progression and resolution in a transgenic mouse model of pulmonary fibrosis. Am J Physiol Lung Cell Mol Physiol 2017; 312:L488-L499. [PMID: 28130263 PMCID: PMC5407091 DOI: 10.1152/ajplung.00458.2016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 12/15/2016] [Accepted: 01/19/2017] [Indexed: 01/17/2023] Open
Abstract
Pulmonary fibrosis contributes to morbidity and mortality in a range of diseases, and there are no approved therapies for reversing its progression. To understand the mechanisms underlying pulmonary fibrosis and assess potential therapies, mouse models are central to basic and translational research. Unfortunately, metrics commonly used to assess murine pulmonary fibrosis require animals to be grouped and euthanized, increasing experimental difficulty and cost. We examined the ability of magnetic resonance imaging (MRI) to noninvasively assess lung fibrosis progression and resolution in a doxycycline (Dox) regulatable, transgenic mouse model that overexpresses transforming growth factor-α (TGF-α) under control of a lung-epithelial-specific promoter. During 7 wk of Dox treatment, fibrotic lesions were readily observed as high-signal tissue. Mean weighted signal and percent signal volume were found to be the most robust MRI-derived measures of fibrosis, and these metrics correlated significantly with pleural thickness, histology scores, and hydroxyproline content (R = 0.75-0.89). When applied longitudinally, percent high signal volume increased by 1.5% wk-1 (P < 0.001) and mean weighted signal increased at a rate of 0.0065 wk-1 (P = 0.0062). Following Dox treatment, lesions partially resolved, with percent high signal volume decreasing by -3.2% wk-1 (P = 0.0034) and weighted mean signal decreasing at -0.015 wk-1 (P = 0.0028). Additionally, longitudinal MRI revealed dynamic remodeling in a subset of lesions, a previously unobserved behavior in this model. These results demonstrate MRI can noninvasively assess experimental lung fibrosis progression and resolution and provide unique insights into its pathobiology.
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Affiliation(s)
- Zackary I Cleveland
- Center for Pulmonary Imaging Research, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio;
- Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio
- Imaging Research Center, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Yu M Zhou
- Center for Pulmonary Imaging Research, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
- University of Cincinnati College of Medicine, Cincinnati, Ohio; and
| | - Teckla G Akinyi
- Center for Pulmonary Imaging Research, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, Ohio
| | - R Scott Dunn
- Imaging Research Center, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Cynthia R Davidson
- Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Jinbang Guo
- Center for Pulmonary Imaging Research, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
- Department of Physics, Washington University, St. Louis, Missouri
| | - Jason C Woods
- Center for Pulmonary Imaging Research, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
- Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
- Imaging Research Center, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
- Department of Physics, Washington University, St. Louis, Missouri
| | - William D Hardie
- Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
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6
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Lilburn DML, Hughes-Riley T, Six JS, Stupic KF, Shaw DE, Pavlovskaya GE, Meersmann T. Validating excised rodent lungs for functional hyperpolarized xenon-129 MRI. PLoS One 2013; 8:e73468. [PMID: 24023683 PMCID: PMC3758272 DOI: 10.1371/journal.pone.0073468] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Accepted: 07/21/2013] [Indexed: 12/15/2022] Open
Abstract
Ex vivo rodent lung models are explored for physiological measurements of respiratory function with hyperpolarized (hp) (129)Xe MRI. It is shown that excised lung models allow for simplification of the technical challenges involved and provide valuable physiological insights that are not feasible using in vivo MRI protocols. A custom designed breathing apparatus enables MR images of gas distribution on increasing ventilation volumes of actively inhaled hp (129)Xe. Straightforward hp (129)Xe MRI protocols provide residual lung volume (RV) data and permit for spatially resolved tracking of small hp (129)Xe probe volumes during the inhalation cycle. Hp (129)Xe MRI of lung function in the excised organ demonstrates the persistence of post mortem airway responsiveness to intravenous methacholine challenges. The presented methodology enables physiology of lung function in health and disease without additional regulatory approval requirements and reduces the technical and logistical challenges with hp gas MRI experiments. The post mortem lung functional data can augment histological measurements and should be of interest for drug development studies.
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Affiliation(s)
- David M. L. Lilburn
- Sir Peter Mansfield Magnetic Resonance Centre, School of Clinical Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Theodore Hughes-Riley
- Sir Peter Mansfield Magnetic Resonance Centre, School of Clinical Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Joseph S. Six
- Sir Peter Mansfield Magnetic Resonance Centre, School of Clinical Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Karl F. Stupic
- Sir Peter Mansfield Magnetic Resonance Centre, School of Clinical Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Dominick E. Shaw
- Nottingham Respiratory Research Unit, Nottingham City Hospital, Nottingham, United Kingdom
| | - Galina E. Pavlovskaya
- Sir Peter Mansfield Magnetic Resonance Centre, School of Clinical Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Thomas Meersmann
- Sir Peter Mansfield Magnetic Resonance Centre, School of Clinical Sciences, University of Nottingham, Nottingham, United Kingdom
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7
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Fox MS, Ouriadov A, Santyr GE. Comparison of hyperpolarized 3
He and 129
Xe MRI for the measurement of absolute ventilated lung volume in rats. Magn Reson Med 2013; 71:1130-6. [DOI: 10.1002/mrm.24746] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Matthew S. Fox
- Department of Physics and Astronomy; Western University; London Canada
- Imaging Research Laboratories; Robarts Research Institute, Western University; London Canada
| | - Alexei Ouriadov
- Imaging Research Laboratories; Robarts Research Institute, Western University; London Canada
| | - Giles E. Santyr
- Imaging Research Laboratories; Robarts Research Institute, Western University; London Canada
- Depts. of Medical Biophysics and Medical Imaging; Western University; London Canada
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8
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Lilburn DM, Pavlovskaya GE, Meersmann T. Perspectives of hyperpolarized noble gas MRI beyond 3He. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2013; 229:173-86. [PMID: 23290627 PMCID: PMC3611600 DOI: 10.1016/j.jmr.2012.11.014] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 11/12/2012] [Accepted: 11/15/2012] [Indexed: 05/29/2023]
Abstract
Nuclear Magnetic Resonance (NMR) studies with hyperpolarized (hp) noble gases are at an exciting interface between physics, chemistry, materials science and biomedical sciences. This paper intends to provide a brief overview and outlook of magnetic resonance imaging (MRI) with hp noble gases other than hp (3)He. A particular focus are the many intriguing experiments with (129)Xe, some of which have already matured to useful MRI protocols, while others display high potential for future MRI applications. Quite naturally for MRI applications the major usage so far has been for biomedical research but perspectives for engineering and materials science studies are also provided. In addition, the prospects for surface sensitive contrast with hp (83)Kr MRI is discussed.
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Affiliation(s)
| | | | - Thomas Meersmann
- University of Nottingham, School of Clinical Sciences, Sir Peter Mansfield Magnetic Resonance Centre, Nottingham NG7 2RD, United Kingdom
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9
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Kalber TL, Campbell-Washburn AE, Siow BM, Sage E, Price AN, Ordidge KL, Walker-Samuel S, Janes SM, Lythgoe MF. Primed infusion with delayed equilibrium of Gd.DTPA for enhanced imaging of small pulmonary metastases. PLoS One 2013; 8:e54903. [PMID: 23382996 PMCID: PMC3561448 DOI: 10.1371/journal.pone.0054903] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Accepted: 12/17/2012] [Indexed: 12/04/2022] Open
Abstract
Objectives To use primed infusions of the magnetic resonance imaging (MRI) contrast agent Gd.DTPA (Magnevist), to achieve an equilibrium between blood and tissue (eqMRI). This may increase tumor Gd concentrations as a novel cancer imaging methodology for the enhancement of small tumor nodules within the low signal-to-noise background of the lung. Methods A primed infusion with a delay before equilibrium (eqMRI) of the Gd(III) chelator Gd.DTPA, via the intraperitoneal route, was used to evaluate gadolinium tumor enhancement as a function of a bolus injection, which is applied routinely in the clinic, compared to gadolinium maintained at equilibrium. A double gated (respiration and cardiac) spin-echo sequence at 9.4T was used to evaluate whole lungs pre contrast and then at 15 (representative of bolus enhancement), 25 and 35 minutes (representative of eqMRI). This was carried out in two lung metastasis models representative of high and low tumor cell seeding. Lungs containing discrete tumor nodes where inflation fixed and taken for haematoxylin and eosin staining as well as CD34 staining for correlation to MRI. Results We demonstrate that sustained Gd enhancement, afforded by Gd equilibrium, increases the detection of pulmonary metastases compared to bolus enhancement and those tumors which enhance at equilibrium are sub-millimetre in size (<0.7 mm2) with a similar morphology to early bronchoalveolar cell carcinomas. Conclusion As Gd-chelates are routinely used in the clinic for detecting tumors by MRI, this methodology is readily transferable to the clinic and advances MRI as a methodology for the detection of small pulmonary tumors.
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Affiliation(s)
- Tammy L Kalber
- UCL Centre of Advanced Biomedical Imaging, Division of Medicine and Institute of Child Health, University College London, London, United Kingdom.
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10
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Schröder L. Xenon for NMR biosensing – Inert but alert. Phys Med 2013; 29:3-16. [DOI: 10.1016/j.ejmp.2011.11.001] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Revised: 10/18/2011] [Accepted: 11/06/2011] [Indexed: 12/24/2022] Open
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11
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Odintsov B, Chun JL, Berry SE. Whole body MRI and fluorescent microscopy for detection of stem cells labeled with superparamagnetic iron oxide (SPIO) nanoparticles and DiI following intramuscular and systemic delivery. Methods Mol Biol 2013; 1052:177-193. [PMID: 23733536 DOI: 10.1007/7651_2013_13] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Methods to monitor transplanted stem cells in vivo are of great importance for potential therapeutic applications. Of particular interest are methods allowing noninvasive detection of stem cells throughout the body. Magnetic resonance imaging (MRI) is a tool that would allow detection of cells in nearly any tissue in the body and is already commonly used in the clinic. MRI tracking of stem cells is therefore feasible and likely to be easily adapted to patients receiving donor cells. Patients with Duchenne muscular dystrophy are good candidates for stem cell therapy, given the naturally regenerative nature of skeletal muscle, which repairs damage by employing endogenous stem cells from the muscle interstitium to regenerate muscle fibers throughout adulthood. We describe methods for labeling stem cells with superparamagnetic iron oxide nanoparticles (SPIO) to enhance MRI contrast, injecting them locally into skeletal and cardiac muscle, or systemically in mouse models for Duchenne muscular dystrophy, and tracking them in muscle tissue of live mice following injection. We focus on the use of whole body MRI to detect stem cells, as this is necessary for conditions such as muscular dystrophy, in which affected tissues are present throughout the body and systemic delivery of stem cells may be necessary. Emphasis is placed on the development of an MRI coil that is field of view (FOV) adjustable and can be used for both whole body imaging to determine stem cell localization as well as subsequent focusing on smaller, local regions where stem cells are present to obtain high-resolution images. We discuss the coil design and its significance for stem cell tracking. We also describe methods for labeling stem cells with a fluorescent dye and for tracking them in postmortem tissue specimens with fluorescent microscopy to correlate, compare, and contrast with results of whole body MRI in preclinical studies.
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12
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Fox MS, Welch I, Hobson D, Santyr GE. A novel intubation technique for minimally invasive longitudinal studies of rat lungs using hyperpolarized 3He magnetic resonance imaging. Lab Anim 2012; 46:311-7. [DOI: 10.1258/la.2012.011139] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Hyperpolarized noble gas (HNG) magnetic resonance imaging (MRI) has been shown to be useful for studying rodent models of lung disease. Image quality can be substantially degraded by signal loss from molecular oxygen entering the airway, requiring invasive surgery to ensure a good seal between the endotracheal (ET) tube and trachea. A modified Foley catheter having an inflatable cuff near the tip provides a novel approach for ensuring image quality for HNG MRI, thereby enabling longitudinal studies and reducing animal numbers. A Foley catheter was modified for rodent intubation and to minimize dead space. Three pairs of age-matched male Sprague Dawley rats 400 (30) g were used. Two pairs were intubated using the Foley and the third with an intravenous catheter. Leak rates were measured from pressure versus time curves within each animal. The pairs were euthanized immediately or six days postrecovery to assess the effects of the procedure on animal health, as reflected by histological examination. The Foley catheter resulted in minimal leak rates (−0.20 (0.03) versus −0.16 (0.05) cmH2O/s), and were shown to be well below upper-limit leak rates of −0.5 and −0.7 cmH2O/s. Tracheal samples from rats in a separate Foley group (not mechanically ventilated) showed superficial damage six days postextubation (grade = 0). 3He imaging performed using the Foley showed good image quality. Though some technical issues remain to be solved, a modified Foley catheter used as an ET tube offers the potential to enable longitudinal studies in rodents and reduce animal numbers.
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Affiliation(s)
- M S Fox
- Physics and Astronomy Department, University of Western Ontario, PAB 138C, London, Ontario N6A 3K7, Canada
- Robarts Research Institute, PO Box 5015, 100 Perth Drive, London, Ontario N6A 5K8, Canada
- University of Western Ontario, 1151 Richmond Street, London, Ontario, N6A 3K7, Canada
| | - I Welch
- University of Western Ontario, 1151 Richmond Street, London, Ontario, N6A 3K7, Canada
| | - D Hobson
- University of Guelph Business Development Office, 150 Research Lane, Suite 102, Guelph, Ontario N1G 4T2, Canada
| | - G E Santyr
- Physics and Astronomy Department, University of Western Ontario, PAB 138C, London, Ontario N6A 3K7, Canada
- Robarts Research Institute, PO Box 5015, 100 Perth Drive, London, Ontario N6A 5K8, Canada
- University of Western Ontario, 1151 Richmond Street, London, Ontario, N6A 3K7, Canada
- Medical Sciences Building, Room M407, University of Western Ontario, London, Ontario N6A 5C1, Canada
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13
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Santyr GE, Couch MJ, Lam WW, Ouriadov A, Drangova M, McCormack DG, Holdsworth DW. Comparison of hyperpolarized (3)He MRI with Xe-enhanced computed tomography imaging for ventilation mapping of rat lung. NMR IN BIOMEDICINE 2011; 24:1073-1080. [PMID: 21274963 DOI: 10.1002/nbm.1659] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2010] [Revised: 11/16/2010] [Accepted: 12/02/2010] [Indexed: 05/30/2023]
Abstract
Lung ventilation was mapped in five healthy Brown Norway rats (210-377 g) using both hyperpolarized (3)He MRI and Xe-enhanced computed tomography (Xe-CT) under similar ventilator conditions. Whole-lung measurements of ventilation r obtained with (3)He MRI were not significantly different from those obtained from Xe-CT (p = 0.1875 by Wilcoxon matched pairs test). The ventilation parameter r is defined as the fraction of refreshed gas per unit volume per breath. Regional ventilation was also measured in four regions of the lung using both methods. A two-tailed paired t-test was performed for each region, yielding p > 0.05 for all but the upper portion of the right lung. The distribution of regional ventilation was evaluated by calculating ventilation gradients in the superior/inferior (S/I) direction. The average S/I gradient obtained using the (3)He MRI method was found to be 0.17 ± 0.04 cm(-1) , whereas the average S/I gradient obtained using the Xe-CT method was found to be 0.016 ± 0.005 cm(-1) . In general, S/I ventilation gradients obtained from both methods were significantly different from each other (p = 0.0019 by two-tailed paired t-test). These regional differences in ventilation measurements may be caused by the manner in which the gas contrast agents distribute physiologically and/or by the imaging modality.
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Affiliation(s)
- Giles E Santyr
- Imaging Research Laboratories, Robarts Research Institute, London, ON, Canada.
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Odintsov B, Chun JL, Mulligan JA, Berry SE. 14.1 T whole body MRI for detection of mesoangioblast stem cells in a murine model of Duchenne muscular dystrophy. Magn Reson Med 2011; 66:1704-14. [PMID: 22086733 DOI: 10.1002/mrm.22942] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2010] [Revised: 02/22/2011] [Accepted: 03/07/2011] [Indexed: 01/16/2023]
Abstract
Noninvasive imaging procedures will be important for stem cell therapy for muscular dystrophy (MD). Mesoangioblasts regenerate muscle in animal models of muscular dystrophy. In this study, superparamagnetic iron oxide nanoparticles were used to visualize mesoangioblasts in vivo with MRI. Mesoangioblasts incorporated superparamagnetic iron oxide without transfection reagents, and cell differentiation was not negatively impacted. A custom-built radiofrequency coil with an adjustable field of view and 14.1 T magnet were used for whole-body MRI of mice. High-resolution images of mesoangioblasts in skeletal and cardiac muscle of Mdx mice were obtained following local delivery. Labeled cells were verified by Prussian blue staining and dystrophin expression, indicating that the wild-type mesoangioblasts survived and differentiated in muscle. Iron-labeled cells were detected with MRI in vivo 6 months following intracardiac injection but were determined to be activated macrophages. Iron-labeled cells were not detected by MRI following systemic delivery but were present in skeletal and cardiac muscle, visualized by Prussian blue staining. Systemically delivered mesoangioblasts were detected in lungs by Prussian blue staining and DiI but not by MRI in our study. MRI may be useful for short-term tracking of mesoangioblasts delivered locally but not for long-term monitoring or detection after systemic delivery.
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Affiliation(s)
- Boris Odintsov
- Biomedical Imaging Center, Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61802, USA
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15
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Namati E, Thiesse J, Sieren JC, Ross A, Hoffman EA, McLennan G. Longitudinal assessment of lung cancer progression in the mouse using in vivo micro-CT imaging. Med Phys 2010; 37:4793-805. [PMID: 20964199 DOI: 10.1118/1.3476454] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Small animal micro-CT imaging is being used increasingly in preclinical biomedical research to provide phenotypic descriptions of genomic models. Most of this imaging is coincident with animal death and is used to show the extent of disease as an end point. Longitudinal imaging overcomes the limitation of single time-point imaging because it enables tracking of the natural history of disease and provides qualitative and, where possible, quantitative assessments of the effects of an intervention. The pulmonary system is affected by many disease conditions, such as lung cancer, chronic obstructive pulmonary disease, asthma, and granulomatous disorders. Noninvasive imaging can accurately assess the lung phenotype within the living animal, evaluating not only global lung measures, but also regional pathology. However, imaging the lung in the living animal is complicated by rapid respiratory motion, which leads to image based artifacts. Furthermore, no standard mouse lung imaging protocols exist for longitudinal assessment, with each group needing to develop their own systematic approach. METHODS In this article, the authors present an outline for performing longitudinal breath-hold gated micro-CT imaging for the assessment of lung nodules in a mouse model of lung cancer. The authors describe modifications to the previously published intermittent isopressure breath-hold technique including a new animal preparation and anesthesia protocol, implementation of a ring artifact reduction, variable scanner geometry, and polynomial beam hardening correction. In addition, the authors describe a multitime-point data set registration and tumor labeling and tracking strategy. RESULTS In vivo micro-CT data sets were acquired at months 2, 3, and 4 posturethane administration in cancer mice (n = 5) and simultaneously in control mice (n = 3). 137 unique lung nodules were identified from the cancer mice while no nodules were detected in the control mice. A total of 411 nodules were segmented and labeled over the three time-points. Lung nodule metrics including RECIST, Ortho, WHO, and 3D volume were determined and extracted. A tumor incidence rate of 30.44 +/- 1.93 SEM for n = 5 was found with identification of nodules as small as 0.11 mm (RECIST) and as large as 1.66 mm (RECIST). In addition, the tumor growth and doubling rate between months 2-3 and 3-4 were calculated. Here, the growth rate was slightly higher in the second period based on the 3D volume data (0.12 +/- 0.13 to 0.13 +/- 0.17 microl) but significantly less based on the linear diameter metrics [RECIST (0.33 +/- 0.19 to 0.17 +/- 0.18 mm); Ortho (0.24 +/- 0.15 to 0.16 +/- 0.15 mm)], indicating the need to understand how each metric is obtained and how to correctly interpret change in tumor size. CONCLUSIONS In conclusion, micro-CT imaging provides a unique platform for in vivo longitudinal assessment of pulmonary lung cancer progression and potentially tracking of therapies at very high resolutions. The ability to evaluate the same subject over time provides for a sensitive assay that can be carried out on a smaller sample size. When integrated with image processing and analysis routines as detailed in this study, the data acquired from micro-CT imaging can now provide a very powerful assessment of pulmonary disease outcomes.
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Affiliation(s)
- Eman Namati
- Department of Internal Medicine, University of Iowa, Iowa City, Iowa 52242, USA; School of Computer Science, Engineering and Mathematics, Flinders University, Adelaide 5042, Australia.
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16
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Al Faraj A, Bessaad A, Cieslar K, Lacroix G, Canet-Soulas E, Crémillieux Y. Long-term follow-up of lung biodistribution and effect of instilled SWCNTs using multiscale imaging techniques. NANOTECHNOLOGY 2010; 21:175103. [PMID: 20368681 DOI: 10.1088/0957-4484/21/17/175103] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Due to their distinctive properties, single-walled carbon nanotubes (SWCNTs) are being more and more extensively used in nanotechnology, with prospects in nanomedicine. It would therefore appear essential to develop and apply appropriate imaging tools for detecting and evaluating their biological impacts with the prospect of medical applications or in the situation of accidental occupational exposure. It has been shown recently that raw SWCNTs with metallic impurities can be noninvasively detected in the lungs by hyperpolarized (3)helium (HP-(3)He) MRI. Moreover raw and purified SWCNTs had no acute biological effect. The purpose of the present longitudinal study was to investigate long-term follow-up by imaging, as well as chronic lung effects. In a 3-month follow-up study, multiscale imaging techniques combining noninvasive HP-(3)He and proton (H) MRI to ex vivo light (histopathological analysis) and transmission electron microscopy (TEM) were used to assess the biodistribution and biological effects of intrapulmonary instilled raw SWCNTs. Specific in vivo detection of carbon nanotubes with MRI relied on their intrinsic metal impurities. MRI also has the ability to evaluate tissue inflammation by the follow-up of local changes in signal intensity. MRI and ex vivo microscopy techniques showed that granulomatous and inflammatory reactions were produced in a time and dose dependent manner by instilled raw SWCNTs.
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Affiliation(s)
- Achraf Al Faraj
- Université Lyon1, CREATIS-LRMN, CNRS 5220, INSERM U630, Lyon, France
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17
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Beltran MA, Paganin DM, Uesugi K, Kitchen MJ. 2D and 3D X-ray phase retrieval of multi-material objects using a single defocus distance. OPTICS EXPRESS 2010; 18:6423-36. [PMID: 20389666 DOI: 10.1364/oe.18.006423] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
A method of tomographic phase retrieval is developed for multi-material objects whose components each has a distinct complex refractive index. The phase-retrieval algorithm, based on the Transport-of-Intensity equation, utilizes propagation-based X-ray phase contrast images acquired at a single defocus distance for each tomographic projection. The method requires a priori knowledge of the complex refractive index for each material present in the sample, together with the total projected thickness of the object at each orientation. The requirement of only a single defocus distance per projection simplifies the experimental setup and imposes no additional dose compared to conventional tomography. The algorithm was implemented using phase contrast data acquired at the SPring-8 Synchrotron facility in Japan. The three-dimensional (3D) complex refractive index distribution of a multi-material test object was quantitatively reconstructed using a single X-ray phase-contrast image per projection. The technique is robust in the presence of noise, compared to conventional absorption based tomography.
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Affiliation(s)
- M A Beltran
- School of Physics, Monash University, VIC 3800, Australia.
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18
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Molecular MRI for sensitive and specific detection of lung metastases. Proc Natl Acad Sci U S A 2010; 107:3693-7. [PMID: 20142483 DOI: 10.1073/pnas.1000386107] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Early and specific detection of metastatic cancer cells in the lung (the most common organ targeted by metastases) could significantly improve cancer treatment outcomes. However, the most widespread lung imaging methods use ionizing radiation and have low sensitivity and/or low specificity for cancer cells. Here we address this problem with an imaging method to detect submillimeter-sized metastases with molecular specificity. Cancer cells are targeted by iron oxide nanoparticles functionalized with cancer-binding ligands, then imaged by high-resolution hyperpolarized (3)He MRI. We demonstrate in vivo detection of pulmonary micrometastates in mice injected with breast adenocarcinoma cells. The method not only holds promise for cancer imaging but more generally suggests a fundamentally unique approach to molecular imaging in the lungs.
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Kitchen MJ, Lewis RA, Morgan MJ, Wallace MJ, Siew ML, Siu KKW, Habib A, Fouras A, Yagi N, Uesugi K, Hooper SB. Dynamic measures of regional lung air volume using phase contrast x-ray imaging. Phys Med Biol 2008; 53:6065-77. [DOI: 10.1088/0031-9155/53/21/012] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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20
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Driehuys B, Nouls J, Badea A, Bucholz E, Ghaghada K, Petiet A, Hedlund LW. Small animal imaging with magnetic resonance microscopy. ILAR J 2008; 49:35-53. [PMID: 18172332 PMCID: PMC2770253 DOI: 10.1093/ilar.49.1.35] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Small animal magnetic resonance microscopy (MRM) has evolved significantly from testing the boundaries of imaging physics to its expanding use today as a tool in noninvasive biomedical investigations. MRM now increasingly provides functional information about living animals, with images of the beating heart, breathing lung, and functioning brain. Unlike clinical MRI, where the focus is on diagnosis, MRM is used to reveal fundamental biology or to noninvasively measure subtle changes in the structure or function of organs during disease progression or in response to experimental therapies. High-resolution anatomical imaging reveals increasingly exquisite detail in healthy animals and subtle architectural aberrations that occur in genetically altered models. Resolution of 100 mum in all dimensions is now routinely attained in living animals, and (10 mum)(3) is feasible in fixed specimens. Such images almost rival conventional histology while allowing the object to be viewed interactively in any plane. In this review we describe the state of the art in MRM for scientists who may be unfamiliar with this modality but who want to apply its capabilities to their research. We include a brief review of MR concepts and methods of animal handling and support, before covering a range of MRM applications-including the heart, lung, and brain-and the emerging field of MR histology. The ability of MRM to provide a detailed functional and anatomical picture in rats and mice, and to track this picture over time, makes it a promising platform with broad applications in biomedical research.
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Affiliation(s)
- Bastiaan Driehuys
- Department of Radiology, Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC 27710, USA.
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21
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Abstract
Pneumonia is a medical and public health priority, and advances against this disease will require improved knowledge of biological mechanisms. Human pneumonia is modeled with experimental infections of animals, most frequently mice. Mouse models are leading to important discoveries relevant to pneumonia, but their limitations must be carefully considered. Several approaches to establishing pneumonia in mice have been developed, and each has specific strengths and weaknesses. Similarly, procedures for characterizing microbial and host responses to infection have unique advantages and disadvantages. Mice are not small humans, and the applicability of results from murine models to human disease depends on understanding the similarities and differences between species. Additional considerations such as mouse strain, microbe strain, and prior mouse-microbe interactions also influence the design and interpretation of experiments. Results from studies of pneumonia in animals, combined with complementary basic and translational studies, are elucidating mechanisms responsible for susceptibility to and pathophysiology of lung infection.
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Affiliation(s)
- Joseph P Mizgerd
- Molecular and Integerative Physiological Sciences Program, Harvard School of Public Health, Department of Environmental Health, 665 Huntington Ave., Building I Rm. 301, Boston, MA 02115, USA.
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Beckmann N, Cannet C, Karmouty-Quintana H, Tigani B, Zurbruegg S, Blé FX, Crémillieux Y, Trifilieff A. Lung MRI for experimental drug research. Eur J Radiol 2007; 64:381-96. [PMID: 17931813 DOI: 10.1016/j.ejrad.2007.08.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2007] [Revised: 07/31/2007] [Accepted: 08/01/2007] [Indexed: 10/22/2022]
Abstract
Current techniques to evaluate the efficacy of potential treatments for airways diseases in preclinical models are generally invasive and terminal. In the past few years, the flexibility of magnetic resonance imaging (MRI) to obtain anatomical and functional information of the lung has been explored with the scope of developing a non-invasive approach for the routine testing of drugs in models of airways diseases in small rodents. With MRI, the disease progression can be followed in the same animal. Thus, a significant reduction in the number of animals used for experimentation is achieved, as well as minimal interference with their well-being and physiological status. In addition, under certain circumstances the duration of the observation period after disease onset can be shortened since the technique is able to detect changes before these are reflected in parameters of inflammation determined using invasive procedures. The objective of this article is to briefly address MRI techniques that are being used in experimental lung research, with special emphasis on applications. Following an introduction on proton techniques and MRI of hyperpolarized gases, the attention is shifted to the MRI analysis of several aspects of lung disease models, including inflammation, ventilation, emphysema, fibrosis and sensory nerve activation. The next subject concerns the use of MRI in pharmacological studies within the context of experimental lung research. A final discussion points towards advantages and limitations of MRI in this area.
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Affiliation(s)
- Nicolau Beckmann
- Discovery Technologies, Novartis Institutes for BioMedical Research, Lichtstr. 35, WSJ-386.2.09, CH-4002 Basel, Switzerland.
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