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Streutker EM, Devamoglu U, Vonk MC, Verdurmen WPR, Le Gac S. Fibrosis-on-Chip: A Guide to Recapitulate the Essential Features of Fibrotic Disease. Adv Healthc Mater 2024; 13:e2303991. [PMID: 38536053 DOI: 10.1002/adhm.202303991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 03/15/2024] [Indexed: 05/05/2024]
Abstract
Fibrosis, which is primarily marked by excessive extracellular matrix (ECM) deposition, is a pathophysiological process associated with many disorders, which ultimately leads to organ dysfunction and poor patient outcomes. Despite the high prevalence of fibrosis, currently there exist few therapeutic options, and importantly, there is a paucity of in vitro models to accurately study fibrosis. This review discusses the multifaceted nature of fibrosis from the viewpoint of developing organ-on-chip (OoC) disease models, focusing on five key features: the ECM component, inflammation, mechanical cues, hypoxia, and vascularization. The potential of OoC technology is explored for better modeling these features in the context of studying fibrotic diseases and the interplay between various key features is emphasized. This paper reviews how organ-specific fibrotic diseases are modeled in OoC platforms, which elements are included in these existing models, and the avenues for novel research directions are highlighted. Finally, this review concludes with a perspective on how to address the current gap with respect to the inclusion of multiple features to yield more sophisticated and relevant models of fibrotic diseases in an OoC format.
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Affiliation(s)
- Emma M Streutker
- Department of Medical BioSciences, Radboud University Medical Center, Geert Grooteplein 28, Nijmegen, 6525 GA, The Netherlands
| | - Utku Devamoglu
- Applied Microfluidics for BioEngineering Research, MESA+ Institute for Nanotechnoloygy and TechMed Centre, Organ-on-Chip Centre, University of Twente, Drienerlolaan 5, Enschede, 7522 NB, The Netherlands
| | - Madelon C Vonk
- Department of Rheumatology, Radboud University Medical Center, Nijmegen, PO Box 9101, Nijmegen, 6500 HB, The Netherlands
| | - Wouter P R Verdurmen
- Department of Medical BioSciences, Radboud University Medical Center, Geert Grooteplein 28, Nijmegen, 6525 GA, The Netherlands
| | - Séverine Le Gac
- Applied Microfluidics for BioEngineering Research, MESA+ Institute for Nanotechnoloygy and TechMed Centre, Organ-on-Chip Centre, University of Twente, Drienerlolaan 5, Enschede, 7522 NB, The Netherlands
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2
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Taskiran NP, Hiura GT, Zhang X, Barr RG, Dashnaw SM, Hoffman EA, Malinsky D, Oelsner EC, Prince MR, Smith BM, Sun Y, Sun Y, Wild JM, Shen W, Hughes EW. Mapping Alveolar Oxygen Partial Pressure in COPD Using Hyperpolarized Helium-3: The Multi-Ethnic Study of Atherosclerosis (MESA) COPD Study. Tomography 2022; 8:2268-2284. [PMID: 36136886 PMCID: PMC9498778 DOI: 10.3390/tomography8050190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 09/05/2022] [Accepted: 09/05/2022] [Indexed: 11/24/2022] Open
Abstract
Chronic obstructive pulmonary disease (COPD) and emphysema are characterized by functional and structural damage which increases the spaces for gaseous diffusion and impairs oxygen exchange. Here we explore the potential for hyperpolarized (HP) 3He MRI to characterize lung structure and function in a large-scale population-based study. Participants (n = 54) from the Multi-Ethnic Study of Atherosclerosis (MESA) COPD Study, a nested case-control study of COPD among participants with 10+ packyears underwent HP 3He MRI measuring pAO2, apparent diffusion coefficient (ADC), and ventilation. HP MRI measures were compared to full-lung CT and pulmonary function testing. High ADC values (>0.4 cm2/s) correlated with emphysema and heterogeneity in pAO2 measurements. Strong correlations were found between the heterogeneity of global pAO2 as summarized by its standard deviation (SD) (p < 0.0002) and non-physiologic pAO2 values (p < 0.0001) with percent emphysema on CT. A regional study revealed a strong association between pAO2 SD and visual emphysema severity (p < 0.003) and an association with the paraseptal emphysema subtype (p < 0.04) after adjustment for demographics and smoking status. HP noble gas pAO2 heterogeneity and the fraction of non-physiological pAO2 results increase in mild to moderate COPD. Measurements of pAO2 are sensitive to regional emphysematous damage detected by CT and may be used to probe pulmonary emphysema subtypes. HP noble gas lung MRI provides non-invasive information about COPD severity and lung function without ionizing radiation.
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Affiliation(s)
- Naz P. Taskiran
- Department of Chemical Engineering, Columbia University, New York, NY 10027, USA
- Correspondence: (N.P.T.); (E.W.H.); Tel.: +1-347-3693052 (N.P.T.); +1-626-4838731 (E.W.H.)
| | - Grant T. Hiura
- Division of General Medicine, Columbia University Irving Medial Center, New York, NY 10032, USA
| | - Xuzhe Zhang
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA
| | - R. Graham Barr
- Division of General Medicine, Columbia University Irving Medial Center, New York, NY 10032, USA
| | - Stephen M. Dashnaw
- Neurological Institute, Radiology, Columbia University, New York, NY 10032, USA
| | - Eric A. Hoffman
- Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Daniel Malinsky
- Mailman School of Public Health, Columbia University, New York, NY 10032, USA
| | - Elizabeth C. Oelsner
- Division of General Medicine, Columbia University Irving Medial Center, New York, NY 10032, USA
| | - Martin R. Prince
- Division of General Medicine, Columbia University Irving Medial Center, New York, NY 10032, USA
- Department of Radiology, Weill Cornell Medicine, New York, NY 10065, USA
| | - Benjamin M. Smith
- Division of General Medicine, Columbia University Irving Medial Center, New York, NY 10032, USA
- Department of Medicine, McGill University, Montreal, QC H3G 2M1, Canada
| | - Yanping Sun
- Division of General Medicine, Columbia University Irving Medial Center, New York, NY 10032, USA
| | - Yifei Sun
- Mailman School of Public Health, Columbia University, New York, NY 10032, USA
| | - Jim M. Wild
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield S10 2TN, UK
| | - Wei Shen
- Division of Pediatric Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Columbia University Irving Medical Center, New York, NY 10032, USA
- Institute of Human Nutrition, College of Physicians & Surgeons, Columbia University Irving Medical Center, New York, NY 10032, USA
- Columbia Magnetic Resonance Research Center (CMRRC), Columbia University, New York, NY 10027, USA
| | - Emlyn W. Hughes
- Department of Physics, Columbia University, New York, NY 10027, USA
- Correspondence: (N.P.T.); (E.W.H.); Tel.: +1-347-3693052 (N.P.T.); +1-626-4838731 (E.W.H.)
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3
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Ohno Y, Hanamatsu S, Obama Y, Ueda T, Ikeda H, Hattori H, Murayama K, Toyama H. Overview of MRI for pulmonary functional imaging. Br J Radiol 2021; 95:20201053. [PMID: 33529053 DOI: 10.1259/bjr.20201053] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Morphological evaluation of the lung is important in the clinical evaluation of pulmonary diseases. However, the disease process, especially in its early phases, may primarily result in changes in pulmonary function without changing the pulmonary structure. In such cases, the traditional imaging approaches to pulmonary morphology may not provide sufficient insight into the underlying pathophysiology. Pulmonary imaging community has therefore tried to assess pulmonary diseases and functions utilizing not only nuclear medicine, but also CT and MR imaging with various technical approaches. In this review, we overview state-of-the art MR methods and the future direction of: (1) ventilation imaging, (2) perfusion imaging and (3) biomechanical evaluation for pulmonary functional imaging.
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Affiliation(s)
- Yoshiharu Ohno
- Department of Radiology, Fujita Health University, School of Medicine, Toyoake, Japan.,Joint Research Laboratory of Advanced Medical Imaging, Fujita Health University School of Medicine, Toyoake, Japan
| | - Satomu Hanamatsu
- Department of Radiology, Fujita Health University, School of Medicine, Toyoake, Japan
| | - Yuki Obama
- Department of Radiology, Fujita Health University, School of Medicine, Toyoake, Japan
| | - Takahiro Ueda
- Department of Radiology, Fujita Health University, School of Medicine, Toyoake, Japan
| | - Hirotaka Ikeda
- Department of Radiology, Fujita Health University, School of Medicine, Toyoake, Japan
| | - Hidekazu Hattori
- Department of Radiology, Fujita Health University, School of Medicine, Toyoake, Japan
| | - Kazuhiro Murayama
- Joint Research Laboratory of Advanced Medical Imaging, Fujita Health University School of Medicine, Toyoake, Japan
| | - Hiroshi Toyama
- Department of Radiology, Fujita Health University, School of Medicine, Toyoake, Japan
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4
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[Assessment of lung impairment in patients with cystic fibrosis : Novel magnetic resonance imaging methods]. Radiologe 2020; 60:823-830. [PMID: 32776240 DOI: 10.1007/s00117-020-00730-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
CLINICAL/METHODOLOGICAL ISSUE The differentiated assessment of respiratory mechanics, gas exchange and pulmonary circulation, as well as structural impairment of the lung are essential for the treatment of patients with cystic fibrosis (CF). Clinical lung function measurements are often not sufficiently specific and are often difficult to perform. STANDARD RADIOLOGICAL METHODS The standard procedures for pulmonary imaging are chest X‑ray and computed tomography (CT) for assessing lung morphology. In more recent studies, an increasing number of centers are using magnetic resonance imaging (MRI) to assess lung structure and function. However, functional imaging is currently limited to specialized centers. METHODOLOGICAL INNOVATIONS In patients with CF, studies showed that MRI with hyperpolarized gases and Fourier decomposition/matrix pencil MRI (FD/MP-MRI) are feasible for assessing pulmonary ventilation. For pulmonary perfusion, dynamic contrast-enhanced MRI (DCE-MRI) or contrast-free methods, e.g., FD-MRI, can be used. PERFORMANCE Functional MRI provides more accurate insight into the pathophysiology of pulmonary function at the regional level. Advantages of MRI over X‑ray are its lack of ionizing radiation, the large number of lung function parameters that can be extracted using different contrast mechanisms, and ability to be used repeatedly over time. ACHIEVEMENTS Early assessment of lung function impairment is needed as the structural changes usually occur later in the course of the disease. However, sufficient experience in clinical application exist only for certain functional lung MRI procedures. PRACTICAL RECOMMENDATIONS Clinical application of the aforementioned techniques, except for DCE-MRI, should be restricted to scientific studies.
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Reiterer M, Branco CM. Endothelial cells and organ function: applications and implications of understanding unique and reciprocal remodelling. FEBS J 2019; 287:1088-1100. [PMID: 31736207 PMCID: PMC7155104 DOI: 10.1111/febs.15143] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 10/21/2019] [Accepted: 11/15/2019] [Indexed: 12/16/2022]
Abstract
The microvasculature is a heterogeneous, dynamic and versatile component of the systemic circulation, with a unique ability to locally self-regulate and to respond to organ demand and environmental stimuli. Endothelial cells from different organs display considerable variation, but it is currently unclear to what extent functional properties of organ-specific endothelial cells are intrinsic, acquired and/or reprogrammable. Vascular function is a fundamental pillar of homeostasis, and dysfunction results in systemic consequences for the organism. Additionally, vascular failure can occur downstream of organ disease or environmental stress, often driving an exacerbation of symptoms and pathologies originally independent of the local circulation. The understanding of the molecular mechanisms underlying endothelial physiology and metabolism holds the promise to inform and improve diagnosis, prognosis and treatment options for a myriad of conditions as unrelated as cancer, neurodegeneration or pulmonary hypertension, and likely everything in between, if we consider that also treatments for such conditions are primarily distributed via the bloodstream. However, studying endothelial function has its challenges: the origin, isolation, culture conditions and preconditioning stimuli make this an extremely variable cell type to study and difficult to source. Animal models exist but are neither trivial to generate, nor necessarily adequately translatable to human disease. In this article, we aim to illustrate the breadth of microvascular functions in different environments, highlighting current and pioneering studies that have advanced our insight into the importance of the integrity of this tissue, as well as the limitations posed by its heterogeneity and plasticity.
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Affiliation(s)
- Moritz Reiterer
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, UK.,Department of Physiology, Development and Neuroscience, University of Cambridge, UK
| | - Cristina M Branco
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, UK
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6
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Relevance of Oxygen Concentration in Stem Cell Culture for Regenerative Medicine. Int J Mol Sci 2019; 20:ijms20051195. [PMID: 30857245 PMCID: PMC6429522 DOI: 10.3390/ijms20051195] [Citation(s) in RCA: 117] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 02/28/2019] [Accepted: 03/04/2019] [Indexed: 01/10/2023] Open
Abstract
The key hallmark of stem cells is their ability to self-renew while keeping a differentiation potential. Intrinsic and extrinsic cell factors may contribute to a decline in these stem cell properties, and this is of the most importance when culturing them. One of these factors is oxygen concentration, which has been closely linked to the maintenance of stemness. The widely used environmental 21% O2 concentration represents a hyperoxic non-physiological condition, which can impair stem cell behaviour by many mechanisms. The goal of this review is to understand these mechanisms underlying the oxygen signalling pathways and their negatively-associated consequences. This may provide a rationale for culturing stem cells under physiological oxygen concentration for stem cell therapy success, in the field of tissue engineering and regenerative medicine.
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7
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Keeley TP, Mann GE. Defining Physiological Normoxia for Improved Translation of Cell Physiology to Animal Models and Humans. Physiol Rev 2019; 99:161-234. [PMID: 30354965 DOI: 10.1152/physrev.00041.2017] [Citation(s) in RCA: 179] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The extensive oxygen gradient between the air we breathe (Po2 ~21 kPa) and its ultimate distribution within mitochondria (as low as ~0.5-1 kPa) is testament to the efforts expended in limiting its inherent toxicity. It has long been recognized that cell culture undertaken under room air conditions falls short of replicating this protection in vitro. Despite this, difficulty in accurately determining the appropriate O2 levels in which to culture cells, coupled with a lack of the technology to replicate and maintain a physiological O2 environment in vitro, has hindered addressing this issue thus far. In this review, we aim to address the current understanding of tissue Po2 distribution in vivo and summarize the attempts made to replicate these conditions in vitro. The state-of-the-art techniques employed to accurately determine O2 levels, as well as the issues associated with reproducing physiological O2 levels in vitro, are also critically reviewed. We aim to provide the framework for researchers to undertake cell culture under O2 levels relevant to specific tissues and organs. We envisage that this review will facilitate a paradigm shift, enabling translation of findings under physiological conditions in vitro to disease pathology and the design of novel therapeutics.
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Affiliation(s)
- Thomas P Keeley
- King's British Heart Foundation Centre of Research Excellence, School of Cardiovascular Medicine and Sciences, Faculty of Life Sciences and Medicine, King's College London , London , United Kingdom
| | - Giovanni E Mann
- King's British Heart Foundation Centre of Research Excellence, School of Cardiovascular Medicine and Sciences, Faculty of Life Sciences and Medicine, King's College London , London , United Kingdom
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8
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Geier ET, Neuhart I, Theilmann RJ, Prisk GK, Sá RC. Spatial persistence of reduced specific ventilation following methacholine challenge in the healthy human lung. J Appl Physiol (1985) 2018; 124:1222-1232. [PMID: 29420156 PMCID: PMC6008074 DOI: 10.1152/japplphysiol.01032.2017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2017] [Revised: 01/16/2018] [Accepted: 02/01/2018] [Indexed: 11/22/2022] Open
Abstract
Specific ventilation imaging was used to identify regions of the healthy lung (6 supine subjects, ages 21-41 yr, 3 men) that experienced a fall in specific ventilation following inhalation of methacholine. This test was repeated 1 wk later and 3 mo later to test for spatial recurrence. Our data showed that 53% confidence interval (CI; 46%, 59%) of volume elements that constricted during one methacholine challenge did so again in another and that this quantity did not vary with time; 46% CI (28%, 64%) recurred 1 wk later, and 56% CI (51%, 61%) recurred 3 mo later. Previous constriction was a strong predictor for future constriction. Volume elements that constricted during one challenge were 7.7 CI (5.2, 10.2) times more likely than nonconstricted elements to constrict in a second challenge, regardless of whether the second episode was 1 wk [7.7 CI (2.9, 12.4)] or 3 mo [7.7 CI (4.6, 10.8)] later. Furthermore, posterior lung elements were more likely to constrict following methacholine than anterior lung elements (volume fraction 0.43 ± 0.22 posterior vs. 0.10 ± 0.03 anterior; P = 0.005), and basal elements that constricted were more likely than their apical counterparts to do so persistently through all three trials (volume fraction 0.14 ± 0.04 basal vs. 0.04 ± 0.04 apical; P = 0.003). Taken together, this evidence suggests a physiological predisposition toward constriction in some lung elements, especially those located in the posterior and basal lung when the subject is supine. NEW & NOTEWORTHY The spatial pattern of bronchoconstriction following methacholine is persistent over time in healthy individuals, in whom chronic inflammation and airway remodeling are assumed to be absent. This suggests that regional lung inflation and airway structure may play dominant roles in determining the spatial pattern of methacholine bronchoconstriction.
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Affiliation(s)
- E. T. Geier
- Department of Medicine, University of California San Diego, San Diego, California
| | - I. Neuhart
- The Ohio State University, Columbus, Ohio
| | - R. J. Theilmann
- Department of Medicine, University of California San Diego, San Diego, California
| | - G. K. Prisk
- Department of Medicine, University of California San Diego, San Diego, California
| | - R. C. Sá
- Department of Medicine, University of California San Diego, San Diego, California
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9
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Ruppert K, Amzajerdian F, Hamedani H, Xin Y, Loza L, Achekzai T, Duncan IF, Profka H, Siddiqui S, Pourfathi M, Cereda MF, Kadlecek S, Rizi RR. Rapid assessment of pulmonary gas transport with hyperpolarized 129Xe MRI using a 3D radial double golden-means acquisition with variable flip angles. Magn Reson Med 2018; 80:2439-2448. [PMID: 29682792 DOI: 10.1002/mrm.27217] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 03/20/2018] [Accepted: 03/24/2018] [Indexed: 12/15/2022]
Abstract
PURPOSE To demonstrate the feasibility of using a 3D radial double golden-means acquisition with variable flip angles to monitor pulmonary gas transport in a single breath hold with hyperpolarized xenon-129 MRI. METHODS Hyperpolarized xenon-129 MRI scans with interleaved gas-phase and dissolved-phase excitations were performed using a 3D radial double golden-means acquisition in mechanically ventilated rabbits. The flip angle was either held fixed at 15 ° or 5 °, or it was varied linearly in ascending or descending order between 5 ° and 15 ° over a sampling interval of 1000 spokes. Dissolved-phase and gas-phase images were reconstructed at high resolution (32 × 32 × 32 matrix size) using all 1000 spokes, or at low resolution (22 × 22 × 22 matrix size) using 400 spokes at a time in a sliding-window fashion. Based on these sliding-window images, relative change maps were obtained using the highest mean flip angle as the reference, and aggregated pixel-based changes were tracked. RESULTS Although the signal intensities in the dissolve-phase maps were mostly constant in the fixed flip-angle acquisitions, they varied significantly as a function of average flip angle in the variable flip-angle acquisitions. The latter trend reflects the underlying changes in observed dissolve-phase magnetization distribution due to pulmonary gas uptake and transport. CONCLUSION 3D radial double golden-means acquisitions with variable flip angles provide a robust means for rapidly assessing lung function during a single breath hold, thereby constituting a particularly valuable tool for imaging uncooperative or pediatric patient populations.
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Affiliation(s)
- Kai Ruppert
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Faraz Amzajerdian
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Hooman Hamedani
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Yi Xin
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Luis Loza
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Tahmina Achekzai
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Ian F Duncan
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Harrilla Profka
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Sarmad Siddiqui
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Mehrdad Pourfathi
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Maurizio F Cereda
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Stephen Kadlecek
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Rahim R Rizi
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
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10
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Kern AL, Vogel-Claussen J. Hyperpolarized gas MRI in pulmonology. Br J Radiol 2018; 91:20170647. [PMID: 29271239 PMCID: PMC5965996 DOI: 10.1259/bjr.20170647] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 12/12/2017] [Accepted: 12/08/2017] [Indexed: 01/20/2023] Open
Abstract
Lung diseases have a high prevalence amongst the world population and their early diagnosis has been pointed out to be key for successful treatment. However, there is still a lack of non-invasive examination methods with sensitivity to early, local deterioration of lung function. Proton-based lung MRI is particularly challenging due to short T2* times and low proton density within the lung tissue. Hyperpolarized gas MRI is aan emerging technology providing a richness of methodologies which overcome the aforementioned problems. Unlike proton-based MRI, lung MRI of hyperpolarized gases may rely on imaging of spins in the lung's gas spaces or inside the lung tissue and thereby add substantial value and diagnostic potential to lung MRI. This review article gives an introduction to the MR physics of hyperpolarized media and presents the current state of hyperpolarized gas MRI of 3Headvasd and 129Xe in pulmonology. Key applications, ranging from static and dynamic ventilation imaging as well as oxygen-pressure mapping to 129Xe dissolved-phase imaging and spectroscopy are presented. Hyperpolarized gas MRI is compared to alternative examination methods based on MRI and future directions of hyperpolarized gas MRI are discussed.
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11
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Abstract
This article reviews the physics and technology of producing large quantities of highly spin-polarized 3He nuclei using spin-exchange (SEOP) and metastability-exchange (MEOP) optical pumping. Both technical developments and deeper understanding of the physical processes involved have led to substantial improvements in the capabilities of both methods. For SEOP, the use of spectrally narrowed lasers and K-Rb mixtures has substantially increased the achievable polarization and polarizing rate. For MEOP nearly lossless compression allows for rapid production of polarized 3He and operation in high magnetic fields has likewise significantly increased the pressure at which this method can be performed, and revealed new phenomena. Both methods have benefitted from development of storage methods that allow for spin-relaxation times of hundreds of hours, and specialized precision methods for polarimetry. SEOP and MEOP are now widely applied for spin-polarized targets, neutron spin filters, magnetic resonance imaging, and precision measurements.
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Affiliation(s)
- T. R. Gentile
- National Institute of Standards and Technology (NIST), Gaithersburg, Maryland 20899, USA
| | - P. J. Nacher
- Laboratoire Kastler Brossel, ENS-PSL Research University, CNRS, UPMC-Sorbonne Universités, Collège de France, Paris, France
| | - B. Saam
- Department of Physics and Astronomy, University of Utah, Salt Lake City, Utah 84112, USA
| | - T. G. Walker
- Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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12
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Adamson EB, Ludwig KD, Mummy DG, Fain SB. Magnetic resonance imaging with hyperpolarized agents: methods and applications. Phys Med Biol 2017; 62:R81-R123. [PMID: 28384123 DOI: 10.1088/1361-6560/aa6be8] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
In the past decade, hyperpolarized (HP) contrast agents have been under active development for MRI applications to address the twin challenges of functional and quantitative imaging. Both HP helium (3He) and xenon (129Xe) gases have reached the stage where they are under study in clinical research. HP 129Xe, in particular, is poised for larger scale clinical research to investigate asthma, chronic obstructive pulmonary disease, and fibrotic lung diseases. With advances in polarizer technology and unique capabilities for imaging of 129Xe gas exchange into lung tissue and blood, HP 129Xe MRI is attracting new attention. In parallel, HP 13C and 15N MRI methods have steadily advanced in a wide range of pre-clinical research applications for imaging metabolism in various cancers and cardiac disease. The HP [1-13C] pyruvate MRI technique, in particular, has undergone phase I trials in prostate cancer and is poised for investigational new drug trials at multiple institutions in cancer and cardiac applications. This review treats the methodology behind both HP gases and HP 13C and 15N liquid state agents. Gas and liquid phase HP agents share similar technologies for achieving non-equilibrium polarization outside the field of the MRI scanner, strategies for image data acquisition, and translational challenges in moving from pre-clinical to clinical research. To cover the wide array of methods and applications, this review is organized by numerical section into (1) a brief introduction, (2) the physical and biological properties of the most common polarized agents with a brief summary of applications and methods of polarization, (3) methods for image acquisition and reconstruction specific to improving data acquisition efficiency for HP MRI, (4) the main physical properties that enable unique measures of physiology or metabolic pathways, followed by a more detailed review of the literature describing the use of HP agents to study: (5) metabolic pathways in cancer and cardiac disease and (6) lung function in both pre-clinical and clinical research studies, concluding with (7) some future directions and challenges, and (8) an overall summary.
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Affiliation(s)
- Erin B Adamson
- Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, United States of America
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13
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Abstract
CLINICAL/METHODICAL ISSUE Separate assessment of respiratory mechanics, gas exchange and pulmonary circulation is essential for the diagnosis and therapy of pulmonary diseases. Due to the global character of the information obtained clinical lung function tests are often not sufficiently specific in the differential diagnosis or have a limited sensitivity in the detection of early pathological changes. STANDARD RADIOLOGICAL METHODS The standard procedures of pulmonary imaging are computed tomography (CT) for depiction of the morphology as well as perfusion/ventilation scintigraphy and single photon emission computed tomography (SPECT) for functional assessment. METHODICAL INNOVATIONS Magnetic resonance imaging (MRI) with hyperpolarized gases, O2-enhanced MRI, MRI with fluorinated gases and Fourier decomposition MRI (FD-MRI) are available for assessment of pulmonary ventilation. For assessment of pulmonary perfusion dynamic contrast-enhanced MRI (DCE-MRI), arterial spin labeling (ASL) and FD-MRI can be used. PERFORMANCE Imaging provides a more precise insight into the pathophysiology of pulmonary function on a regional level. The advantages of MRI are a lack of ionizing radiation, which allows a protective acquisition of dynamic data as well as the high number of available contrasts and therefore accessible lung function parameters. ACHIEVEMENTS Sufficient clinical data exist only for certain applications of DCE-MRI. For the other techniques, only feasibility studies and case series of different sizes are available. The clinical applicability of hyperpolarized gases is limited for technical reasons. PRACTICAL RECOMMENDATIONS The clinical application of the techniques described, except for DCE-MRI, should be restricted to scientific studies.
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Affiliation(s)
- G Sommer
- Klinik für Radiologie und Nuklearmedizin, Universitätsspital Basel, Petersgraben 4, 4031, Basel, Schweiz.
| | - G Bauman
- Klinik für Radiologie und Nuklearmedizin - Radiologische Physik, Universitätsspital Basel, Petersgraben 4, 4031, Basel, Schweiz
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Zhong J, Ruan W, Han Y, Sun X, Ye C, Zhou X. Fast Determination of Flip Angle and T1 in Hyperpolarized Gas MRI During a Single Breath-Hold. Sci Rep 2016; 6:25854. [PMID: 27169670 PMCID: PMC4864326 DOI: 10.1038/srep25854] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 04/25/2016] [Indexed: 01/06/2023] Open
Abstract
MRI of hyperpolarized media, such as (129)Xe and (3)He, shows great potential for clinical applications. The optimal use of the available spin polarization requires accurate flip angle calibrations and T1 measurements. Traditional flip angle calibration methods are time-consuming and suffer from polarization losses during T1 relaxation. In this paper, we propose a method to simultaneously calibrate flip angles and measure T1 in vivo during a breath-hold time of less than 4 seconds. We demonstrate the accuracy, robustness and repeatability of this method and contrast it with traditional methods. By measuring the T1 of hyperpolarized gas, the oxygen pressure in vivo can be calibrated during the same breath hold. The results of the calibration have been applied in variable flip angle (VFA) scheme to obtain a stable steady-state transverse magnetization. Coupled with this method, the ultra-short TE (UTE) and constant VFA (CVFA) schemes are expected to give rise to new applications of hyperpolarized media.
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Affiliation(s)
- Jianping Zhong
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory for Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
- School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Weiwei Ruan
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory for Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Yeqing Han
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory for Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Xianping Sun
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory for Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Chaohui Ye
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory for Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
- School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Xin Zhou
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory for Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
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15
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Baldi S, Hartley R, Brightling C, Gupta S. Asthma. IMAGING 2016. [DOI: 10.1183/2312508x.10002815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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16
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Kruger SJ, Nagle SK, Couch MJ, Ohno Y, Albert M, Fain SB. Functional imaging of the lungs with gas agents. J Magn Reson Imaging 2016; 43:295-315. [PMID: 26218920 PMCID: PMC4733870 DOI: 10.1002/jmri.25002] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 06/26/2015] [Indexed: 12/22/2022] Open
Abstract
This review focuses on the state-of-the-art of the three major classes of gas contrast agents used in magnetic resonance imaging (MRI)-hyperpolarized (HP) gas, molecular oxygen, and fluorinated gas--and their application to clinical pulmonary research. During the past several years there has been accelerated development of pulmonary MRI. This has been driven in part by concerns regarding ionizing radiation using multidetector computed tomography (CT). However, MRI also offers capabilities for fast multispectral and functional imaging using gas agents that are not technically feasible with CT. Recent improvements in gradient performance and radial acquisition methods using ultrashort echo time (UTE) have contributed to advances in these functional pulmonary MRI techniques. The relative strengths and weaknesses of the main functional imaging methods and gas agents are compared and applications to measures of ventilation, diffusion, and gas exchange are presented. Functional lung MRI methods using these gas agents are improving our understanding of a wide range of chronic lung diseases, including chronic obstructive pulmonary disease, asthma, and cystic fibrosis in both adults and children.
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Affiliation(s)
- Stanley J. Kruger
- Department of Medical Physics, University of Wisconsin – Madison, WI, U.S.A
| | - Scott K. Nagle
- Department of Medical Physics, University of Wisconsin – Madison, WI, U.S.A
- Department of Radiology, University of Wisconsin – Madison, WI, U.S.A
- Department of Pediatrics, University of Wisconsin – Madison, WI, U.S.A
| | - Marcus J. Couch
- Thunder Bay Regional Research Institute, Thunder Bay, ON, Canada
- Biotechnology Program, Lakehead University, Thunder Bay, ON, Canada
| | - Yoshiharu Ohno
- Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Mitchell Albert
- Thunder Bay Regional Research Institute, Thunder Bay, ON, Canada
- Department of Chemistry, Lakehead University, Thunder Bay, ON, Canada
| | - Sean B. Fain
- Department of Medical Physics, University of Wisconsin – Madison, WI, U.S.A
- Department of Radiology, University of Wisconsin – Madison, WI, U.S.A
- Department of Biomedical Engineering, University of Wisconsin – Madison, WI, U.S.A
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17
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Jagannathan L, Cuddapah S, Costa M. Oxidative stress under ambient and physiological oxygen tension in tissue culture. ACTA ACUST UNITED AC 2016; 2:64-72. [PMID: 27034917 DOI: 10.1007/s40495-016-0050-5] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Oxygen (O2) levels range from 2-9% in vivo. However, cell culture experiments are performed at atmospheric O2 levels (21%). Oxidative stress due to generation of reactive oxygen species (ROS) in cells cultured at higher than physiological levels is implicated in multitude of deleterious effects including DNA damage, genomic instability and senescence. In addition, oxidative stress activates redox sensitive transcription factors related to inflammatory signaling and apoptotic signaling. Furthermore, several chromatin-modifying enzymes are affected by ROS, potentially impacting epigenetic regulation of gene expression. While primary cells are cultured at lower O2 levels due to their inability to grow at higher O2, the immortalized cells, which display no such apparent growth difficulties, are typically cultured at 21% O2. This review will provide an overview of issues associated with increased oxygen levels in in vitro cell culture and point out the benefits of using lower levels of oxygen tension even for immortalized cells.
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Affiliation(s)
- Lakshmanan Jagannathan
- Department of Environmental Medicine, New York University School of Medicine, Tuxedo, NY 10987
| | - Suresh Cuddapah
- Department of Environmental Medicine, New York University School of Medicine, Tuxedo, NY 10987
| | - Max Costa
- Department of Environmental Medicine, New York University School of Medicine, Tuxedo, NY 10987
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18
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Altes TA, Mugler JP, Ruppert K, Tustison NJ, Gersbach J, Szentpetery S, Meyer CH, de Lange EE, Teague WG. Clinical correlates of lung ventilation defects in asthmatic children. J Allergy Clin Immunol 2015; 137:789-96.e7. [PMID: 26521043 DOI: 10.1016/j.jaci.2015.08.045] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 08/18/2015] [Accepted: 08/21/2015] [Indexed: 12/21/2022]
Abstract
BACKGROUND Lung ventilation defects identified by using hyperpolarized 3-helium gas ((3)He) lung magnetic resonance imaging (MRI) are prevalent in asthmatic patients, but the clinical importance of ventilation defects is poorly understood. OBJECTIVES We sought to correlate the lung defect volume quantified by using (3)He MRI with clinical features in children with mild and severe asthma. METHODS Thirty-one children with asthma (median age, 10 years; age range, 3-17 years) underwent detailed characterization and (3)He lung MRI. Quantification of the (3)He signal defined ventilation defect and hypoventilated, ventilated, and well-ventilated volumes. RESULTS The ventilation defect to total lung volume fraction ranged from 0.1% to 11.6%. Children with ventilation defect percentages in the upper tercile were more likely to have severe asthma than children in the lower terciles (P = .005). The ventilation defect percentage correlated (P < .05 for all) positively with the inhaled corticosteroid dose, total number of controller medications, and total blood eosinophil counts and negatively with the Asthma Control Test score, FEV1 (percent predicted), FEV1/forced vital capacity ratio (percent predicted), and forced expiratory flow rate from 25% to 75% of expired volume (percent predicted). CONCLUSION The lung defect volume percentage measured by using (3)He MRI correlates with several clinical features of asthma, including severity, symptom score, medication requirement, airway physiology, and atopic markers.
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Affiliation(s)
- Talissa A Altes
- Department of Radiology, University of Missouri School of Medicine, Columbia, Mo
| | - John P Mugler
- Division of Medical Imaging Research, Department of Radiology and Medical Imaging, University of Virginia School of Medicine, Charlottesville, Va; Department of Biomedical Engineering, University of Virginia, Charlottesville, Va
| | - Kai Ruppert
- Center for Pulmonary Imaging Research, Cincinnati Children's Hospital, Cincinnati, Ohio
| | - Nicholas J Tustison
- Division of Medical Imaging Research, Department of Radiology and Medical Imaging, University of Virginia School of Medicine, Charlottesville, Va
| | - Joanne Gersbach
- Division of Medical Imaging Research, Department of Radiology and Medical Imaging, University of Virginia School of Medicine, Charlottesville, Va
| | - Sylvia Szentpetery
- Child Health Research Center, Department of Pediatrics, University of Virginia School of Medicine, Charlottesville, Va
| | - Craig H Meyer
- Division of Medical Imaging Research, Department of Radiology and Medical Imaging, University of Virginia School of Medicine, Charlottesville, Va; Department of Biomedical Engineering, University of Virginia, Charlottesville, Va
| | - Eduard E de Lange
- Division of Medical Imaging Research, Department of Radiology and Medical Imaging, University of Virginia School of Medicine, Charlottesville, Va
| | - W Gerald Teague
- Child Health Research Center, Department of Pediatrics, University of Virginia School of Medicine, Charlottesville, Va.
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19
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Clapp J, Hamedani H, Kadlecek S, Xin Y, Shaghaghi H, Siddiqui S, Rossman MD, Rizi RR. Multibreath alveolar oxygen tension imaging. Magn Reson Med 2015; 76:1092-101. [PMID: 26467179 DOI: 10.1002/mrm.26001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Revised: 09/02/2015] [Accepted: 09/04/2015] [Indexed: 12/23/2022]
Abstract
PURPOSE This study tested the ability of a multibreath hyperpolarized HP (3) He MRI protocol to increase the accuracy of regional alveolar oxygen tension (PA O2 ) measurements by lessening the influence of gas-flow artifacts. Conventional single-breath PA O2 measurement has been susceptible to error induced by intervoxel gas flow, particularly when used to study subjects with moderate-to-severe chronic obstructive pulmonary disease (COPD). METHODS Both single-breath and multibreath PA O2 imaging schemes were implemented in seven human subjects (one healthy, three asymptomatic smokers, and three COPD). The number and location of voxels with nonphysiologic PA O2 values generated by intervoxel gas flow were compared between the two protocols. RESULTS The multibreath scheme resulted in a significantly lower total percentage of nonphysiologic PA O2 values (6.0%) than the single-breath scheme (13.7%) (P = 0.006). PA O2 maps showed several patterns of gas-flow artifacts that were present in the single-breath protocol but mitigated by the multibreath approach. Multibreath imaging also allowed for the analysis of slow-filling areas that presented no signal after a single breath. CONCLUSION A multibreath approach enhances the accuracy and completeness of noninvasive PA O2 measurement by significantly lessening the proportion of nonphysiologic values generated by intervoxel gas flow. Magn Reson Med 76:1092-1101, 2016. © 2015 Wiley Periodicals, Inc.
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Affiliation(s)
- Justin Clapp
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Hooman Hamedani
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Stephen Kadlecek
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Yi Xin
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Hoora Shaghaghi
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Sarmad Siddiqui
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Milton D Rossman
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Rahim R Rizi
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
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20
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Marshall H, Parra-Robles J, Deppe MH, Lipson DA, Lawson R, Wild JM. (3)He pO2 mapping is limited by delayed-ventilation and diffusion in chronic obstructive pulmonary disease. Magn Reson Med 2015; 71:1172-8. [PMID: 23661570 DOI: 10.1002/mrm.24779] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
PURPOSE Lung pO2 mapping with (3)He MRI assumes that the sources of signal decay with time during a breath-hold are radiofrequency depolarization and oxygen-dependent T1 relaxation, but the method is sensitive to other sources of spatio-temporal signal change such as diffusion. The purpose of this work was to assess the use of (3)He pO2 mapping in patients with chronic obstructive pulmonary disease. METHODS Ten patients with moderate to severe chronic obstructive pulmonary disease were scanned with a 3D single breath-hold pO2 mapping sequence. RESULTS Images showed signal increasing over time in some lung regions due to delayed ventilation during breath-hold. Regions of physically unrealistic negative pO2 values were seen in all patients, and regional mean pO2 values of -0.3 bar were measured in the two patients most affected by delayed ventilation (where mean time to signal onset was 3-4 s). CONCLUSIONS Movement of gas within the lungs during breath-hold causes regional changes in signal over time that are not related to oxygen concentration, leading to erroneous pO2 measurements using the linear oxygen-dependent signal decay model. These spatio-temporal sources of signal change cannot be reliably separated at present, making pO2 mapping using this methodology unreliable in chronic obstructive pulmonary disease patients with significant bullous emphysema or delayed ventilation.
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Affiliation(s)
- Helen Marshall
- Department of Academic Radiology, University of Sheffield, Sheffield, South Yorkshire, UK
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21
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Hartley R, Baldi S, Brightling C, Gupta S. Novel imaging approaches in adult asthma and their clinical potential. Expert Rev Clin Immunol 2015; 11:1147-62. [PMID: 26289375 DOI: 10.1586/1744666x.2015.1072049] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Currently, imaging in asthma is confined to chest radiography and CT. The emergence of new imaging techniques and tremendous improvement of existing imaging methods, primarily due to technological advancement, has completely changed its research and clinical prospects. In research, imaging in asthma is now being employed to provide quantitative assessment of morphology, function and pathogenic processes at the molecular level. The unique ability of imaging for non-invasive, repeated, quantitative, and in vivo assessment of structure and function in asthma could lead to identification of 'imaging biomarkers' with potential as outcome measures in future clinical trials. Emerging imaging techniques and their utility in the research and clinical setting is discussed in this review.
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Affiliation(s)
- Ruth Hartley
- a 1 Department of Infection, Inflammation and Immunity, Institute for Lung Health, University of Leicester, Leicester, LE3 9QP, UK
| | - Simonetta Baldi
- a 1 Department of Infection, Inflammation and Immunity, Institute for Lung Health, University of Leicester, Leicester, LE3 9QP, UK
| | - Chris Brightling
- a 1 Department of Infection, Inflammation and Immunity, Institute for Lung Health, University of Leicester, Leicester, LE3 9QP, UK
| | - Sumit Gupta
- a 1 Department of Infection, Inflammation and Immunity, Institute for Lung Health, University of Leicester, Leicester, LE3 9QP, UK.,b 2 Radiology Department, Glenfield Hospital, University Hospitals of Leicester NHS Trust, Leicester, LE3 9QP, UK
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22
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Ishii M, Hamedani H, Clapp JT, Kadlecek SJ, Xin Y, Gefter WB, Rossman MD, Rizi RR. Oxygen-weighted Hyperpolarized (3)He MR Imaging: A Short-term Reproducibility Study in Human Subjects. Radiology 2015; 277:247-58. [PMID: 26110668 DOI: 10.1148/radiol.2015142038] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To determine whether hyperpolarized helium 3 magnetic resonance (MR) imaging to measure alveolar partial pressure of oxygen (Pao2) shows sufficient test-retest repeatability and between-cohort differences to be used as a reliable technique for detection of alterations in gas exchange in asymptomatic smokers. MATERIALS AND METHODS The protocol was approved by the local institutional review board and was HIPAA compliant. Informed consent was obtained from all subjects. Two sets of MR images were obtained 10 minutes apart in 25 subjects: 10 nonsmokers (five men, five women; mean ± standard deviation age, 50 years ± 6) and 15 smokers (seven women, eight men; mean age, 50 years ± 8). A mixed-effects model was developed to identify the regional repeatability of Pao2 measurements as an intraclass correlation coefficient. Ten smokers were matched with the 10 nonsmokers on the basis of signal-to-noise ratio (SNR). Three separate models were generated: one for nonsmokers, one for the SNR-matched smokers, and one for the five remaining smokers, who were imaged with a significantly higher SNR. RESULTS Short-term back-to-back regional reproducibility was assessed by using intraclass correlation coefficients, which were 0.67 and 0.65 for SNR case-matched nonsmokers and smokers, respectively. Repeatability was a strong function of SNR; a 50% increase in SNR in the remaining smokers improved the intraclass correlation coefficient to 0.82. Although repeatability was not significantly different between the SNR-matched cohorts (P = .44), the smoker group showed higher spatial and temporal variability in Pao2. CONCLUSION The short-term test-retest repeatability of hyperpolarized gas MR imaging of regional Pao2 was good. Asymptomatic smokers exhibited greater spatial and temporal variability in Pao2 than did the nonsmokers, which suggests that this parameter allows detection of small functional alterations associated with smoking.
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Affiliation(s)
- Masaru Ishii
- From the Department of Otolaryngology-Head and Neck Surgery, The Johns Hopkins University, Baltimore, Md (M.I., R.R.R.); Department of Radiology (H.H., J.T.C., S.J.K., Y.X., W.G.), and Pulmonary, Allergy and Critical Care Division (M.D.R.), University of Pennsylvania, 308 Stemmler Hall, 3450 Hamilton Walk, Philadelphia, PA 19104
| | - Hooman Hamedani
- From the Department of Otolaryngology-Head and Neck Surgery, The Johns Hopkins University, Baltimore, Md (M.I., R.R.R.); Department of Radiology (H.H., J.T.C., S.J.K., Y.X., W.G.), and Pulmonary, Allergy and Critical Care Division (M.D.R.), University of Pennsylvania, 308 Stemmler Hall, 3450 Hamilton Walk, Philadelphia, PA 19104
| | - Justin T Clapp
- From the Department of Otolaryngology-Head and Neck Surgery, The Johns Hopkins University, Baltimore, Md (M.I., R.R.R.); Department of Radiology (H.H., J.T.C., S.J.K., Y.X., W.G.), and Pulmonary, Allergy and Critical Care Division (M.D.R.), University of Pennsylvania, 308 Stemmler Hall, 3450 Hamilton Walk, Philadelphia, PA 19104
| | - Stephen J Kadlecek
- From the Department of Otolaryngology-Head and Neck Surgery, The Johns Hopkins University, Baltimore, Md (M.I., R.R.R.); Department of Radiology (H.H., J.T.C., S.J.K., Y.X., W.G.), and Pulmonary, Allergy and Critical Care Division (M.D.R.), University of Pennsylvania, 308 Stemmler Hall, 3450 Hamilton Walk, Philadelphia, PA 19104
| | - Yi Xin
- From the Department of Otolaryngology-Head and Neck Surgery, The Johns Hopkins University, Baltimore, Md (M.I., R.R.R.); Department of Radiology (H.H., J.T.C., S.J.K., Y.X., W.G.), and Pulmonary, Allergy and Critical Care Division (M.D.R.), University of Pennsylvania, 308 Stemmler Hall, 3450 Hamilton Walk, Philadelphia, PA 19104
| | - Warren B Gefter
- From the Department of Otolaryngology-Head and Neck Surgery, The Johns Hopkins University, Baltimore, Md (M.I., R.R.R.); Department of Radiology (H.H., J.T.C., S.J.K., Y.X., W.G.), and Pulmonary, Allergy and Critical Care Division (M.D.R.), University of Pennsylvania, 308 Stemmler Hall, 3450 Hamilton Walk, Philadelphia, PA 19104
| | - Milton D Rossman
- From the Department of Otolaryngology-Head and Neck Surgery, The Johns Hopkins University, Baltimore, Md (M.I., R.R.R.); Department of Radiology (H.H., J.T.C., S.J.K., Y.X., W.G.), and Pulmonary, Allergy and Critical Care Division (M.D.R.), University of Pennsylvania, 308 Stemmler Hall, 3450 Hamilton Walk, Philadelphia, PA 19104
| | - Rahim R Rizi
- From the Department of Otolaryngology-Head and Neck Surgery, The Johns Hopkins University, Baltimore, Md (M.I., R.R.R.); Department of Radiology (H.H., J.T.C., S.J.K., Y.X., W.G.), and Pulmonary, Allergy and Critical Care Division (M.D.R.), University of Pennsylvania, 308 Stemmler Hall, 3450 Hamilton Walk, Philadelphia, PA 19104
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23
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Ruppert K, Altes TA, Mata JF, Ruset IC, Hersman FW, Mugler JP. Detecting pulmonary capillary blood pulsations using hyperpolarized xenon-129 chemical shift saturation recovery (CSSR) MR spectroscopy. Magn Reson Med 2015; 75:1771-80. [PMID: 26017009 DOI: 10.1002/mrm.25794] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 04/06/2015] [Accepted: 05/05/2015] [Indexed: 01/11/2023]
Abstract
PURPOSE To investigate whether chemical shift saturation recovery (CSSR) MR spectroscopy with hyperpolarized xenon-129 is sensitive to the pulsatile nature of pulmonary blood flow during the cardiac cycle. METHODS A CSSR pulse sequence typically uses radiofrequency (RF) pulses to saturate the magnetization of xenon-129 dissolved in lung tissue followed, after a variable delay time, by an RF excitation and subsequent acquisition of a free-induction decay. Thereby it is possible to monitor the uptake of xenon-129 by lung tissue and extract physiological parameters of pulmonary gas exchange. In the current studies, the delay time was instead held at a constant value, which permitted observation of xenon-129 gas uptake as a function of breath-hold time. CSSR studies were performed in 13 subjects (10 healthy, 2 chronic obstructive pulmonary disease [COPD], 1 second-hand smoke exposure), holding their breath at total lung capacity. RESULTS The areas of the tissue/plasma and the red-blood-cell peaks in healthy subjects varied by an average of 1.7±0.7% and 15.1±3.8%, respectively, during the cardiac cycle. In 2 subjects with COPD these peak pulsations were not detectable during at least part of the measurement period. CONCLUSION CSSR spectroscopy is sufficiently sensitive to detect oscillations in the xenon-129 gas-uptake rate associated with the cardiac cycle.
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Affiliation(s)
- Kai Ruppert
- Center for In-vivo Hyperpolarized Gas MR Imaging, Department of Radiology & Medical Imaging, University of Virginia, Charlottesville, Virginia, USA.,Department of Pulmonary Medicine, Cincinnati Children's Hospital, Cincinnati, Ohio, USA
| | - Talissa A Altes
- Center for In-vivo Hyperpolarized Gas MR Imaging, Department of Radiology & Medical Imaging, University of Virginia, Charlottesville, Virginia, USA
| | - Jaime F Mata
- Center for In-vivo Hyperpolarized Gas MR Imaging, Department of Radiology & Medical Imaging, University of Virginia, Charlottesville, Virginia, USA
| | - Iulian C Ruset
- Xemed, LLC, Durham, New Hampshire, USA.,Department of Physics, University of New Hampshire, Durham, New Hampshire, USA
| | - F William Hersman
- Xemed, LLC, Durham, New Hampshire, USA.,Department of Physics, University of New Hampshire, Durham, New Hampshire, USA
| | - John P Mugler
- Center for In-vivo Hyperpolarized Gas MR Imaging, Department of Radiology & Medical Imaging, University of Virginia, Charlottesville, Virginia, USA
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24
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Neutrophils and inflammatory resolution in the mucosa. Semin Immunol 2015; 27:177-83. [PMID: 25818531 DOI: 10.1016/j.smim.2015.03.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 03/10/2015] [Accepted: 03/11/2015] [Indexed: 12/13/2022]
Abstract
Inflammatory diseases in mucosal organs as diverse as the lung, liver and intestine inevitably require the intimate interactions between neutrophils and epithelia. The physiologic consequences of such interactions often determine endpoint organ function, and for this reason, much recent interest has developed in identifying mechanisms and novel targets to promote the resolution of mucosal inflammation. Physiologically-relevant in vitro and in vivo model systems have aided in discovery of novel pathways to define basic inflammatory mechanisms and approaches to defining the concepts of inflammatory resolution. Here, we will review the recent literature regarding the contribution of neutrophils to inflammatory resolution, with an emphasis on the role of the tissue microenvironment, endogenous pathways for promoting resolution and the molecular determinants of neutrophil-epithelial cell interactions during ongoing inflammation. These recent studies highlight the dynamic nature of pro-resolving pathways and lend insight into the complexity of treating mucosal inflammation.
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25
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Walkup LL, Woods JC. Translational applications of hyperpolarized 3He and 129Xe. NMR IN BIOMEDICINE 2014; 27:1429-1438. [PMID: 24953709 DOI: 10.1002/nbm.3151] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Revised: 04/07/2014] [Accepted: 05/19/2014] [Indexed: 06/03/2023]
Abstract
Clinical magnetic resonance imaging of the lung is technologically challenging, yet over the past two decades hyperpolarized noble gas ((3)He and (129)Xe) imaging has demonstrated the ability to measure multiple pulmonary functional biomarkers. There is a growing need for non-ionizing, non-invasive imaging techniques due to increased concern about cancer risk from ionizing radiation, but the translation of hyperpolarized gas imaging to the pulmonary clinic has been stunted by limited access to the technology. New developments may open doors to greater access and more translation to clinical studies. Here we briefly review a few translational applications of hyperpolarized gas MRI in the contexts of ventilation, diffusion, and dissolved-phase imaging, as well as comparing and contrasting (3)He and (129)Xe gases for these applications. Simple static ventilation MRI reveals regions of the lung not participating in normal ventilation, and these defects have been observed in many pulmonary diseases. Biomarkers related to airspace size and connectivity can be quantified by apparent diffusion coefficient measurements of hyperpolarized gas, and have been shown to be more sensitive to small changes in lung morphology than standard clinical pulmonary functional tests and have been validated by quantitative histology. Parameters related to gas uptake and exchange and lung tissue density can be determined using (129)Xe dissolved-phase MRI. In most cases functional biomarkers can be determined via MRI of either gas, but for some applications one gas may be preferred, such as (3)He for long-range diffusion measurements and (129)Xe for dissolved-phase imaging. Greater access to hyperpolarized gas imaging coupled with newly developing therapeutics makes pulmonary medicine poised for a potential revolution, further adding to the prospects of personalized medicine already evidenced by advancements in molecular biology. Hyperpolarized gas researchers have the opportunity to contribute to this revolution, particularly if greater clinical application of hyperpolarized gas imaging is realized.
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Affiliation(s)
- Laura L Walkup
- Center for Pulmonary Imaging Research, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
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26
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Hamedani H, Shaghaghi H, Kadlecek SJ, Xin Y, Han B, Siddiqui S, Rajaei J, Ishii M, Rossman M, Rizi RR. Vertical gradients in regional alveolar oxygen tension in supine human lung imaged by hyperpolarized 3He MRI. NMR IN BIOMEDICINE 2014; 27:1439-50. [PMID: 25395184 PMCID: PMC5033039 DOI: 10.1002/nbm.3227] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 09/22/2014] [Accepted: 09/22/2014] [Indexed: 06/04/2023]
Abstract
The purpose of this study was to evaluate whether regional alveolar oxygen tension (P(A)O2) vertical gradients imaged with hyperpolarized (3)He can identify smoking-induced pulmonary alterations. These gradients are compared with common clinical measurements including pulmonary function tests (PFTs), the six minute walk test, and the St. George's Respiratory Questionnaire. 8 healthy non-smokers, 12 asymptomatic smokers, and 7 symptomatic subjects with chronic obstructive pulmonary disease (COPD) underwent two sets of back-to-back P(A)O2 imaging acquisitions in the supine position in two opposite directions (top to bottom and bottom to top), followed by clinically standard pulmonary tests. The whole-lung mean, standard deviation (DP(A)O2) and vertical gradients of P(A)O2 along the slices were extracted, and the results were compared with clinically derived metrics. Statistical tests were performed to analyze the differences between cohorts. The anterior-posterior vertical gradients and DP(A)O2 effectively differentiated all three cohorts (p < 0.05). The average vertical gradient P(A)O2 in healthy subjects was -1.03 ± 0.51 Torr/cm toward lower values in the posterior/dependent regions. The directional gradient was absent in smokers (0.36 ± 1.22 Torr/cm) and was in the opposite direction in COPD subjects (2.18 ± 1.54 Torr/cm). The vertical gradients correlated with smoking history (p = 0.004); body mass index (p = 0.037), PFT metrics (forced expiratory volume in 1 s, p = 0.025; residual volume/total lung capacity percent predicted, p = 0.033) and with distance walked in 6 min (p = 0.009). Regional P(A)O2 data indicate that cigarette smoke induces physiological alterations that are not being detected by the most widely used physiological tests.
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Affiliation(s)
- Hooman Hamedani
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
| | - Hoora Shaghaghi
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
| | - Stephen J. Kadlecek
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
| | - Yi Xin
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
| | - Biao Han
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
| | - Sarmad Siddiqui
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
| | - Jennia Rajaei
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
| | - Masaru Ishii
- Departments of Otolaryngology-Head and Neck Surgery, Johns Hopkins University, Baltimore, MD, United States
| | - Milton Rossman
- Department of Pulmonary and Critical Care, Johns Hopkins University of Pennsylvania, Philadelphia, PA, Baltimore, MD, United States
| | - Rahim R. Rizi
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
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Ruppert K. Biomedical imaging with hyperpolarized noble gases. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2014; 77:116701. [PMID: 25360484 DOI: 10.1088/0034-4885/77/11/116701] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Hyperpolarized noble gases (HNGs), polarized to approximately 50% or higher, have led to major advances in magnetic resonance (MR) imaging of porous structures and air-filled cavities in human subjects, particularly the lung. By boosting the available signal to a level about 100 000 times higher than that at thermal equilibrium, air spaces that would otherwise appear as signal voids in an MR image can be revealed for structural and functional assessments. This review discusses how HNG MR imaging differs from conventional proton MR imaging, how MR pulse sequence design is affected and how the properties of gas imaging can be exploited to obtain hitherto inaccessible information in humans and animals. Current and possible future imaging techniques, and their application in the assessment of normal lung function as well as certain lung diseases, are described.
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Hamedani H, Kadlecek SJ, Ishii M, Xin Y, Emami K, Han B, Shaghaghi H, Gopstein D, Cereda M, Gefter WB, Rossman MD, Rizi RR. Alterations of regional alveolar oxygen tension in asymptomatic current smokers: assessment with hyperpolarized (3)He MR imaging. Radiology 2014; 274:585-96. [PMID: 25322340 DOI: 10.1148/radiol.14132809] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To assess the ability of helium 3 ((3)He) magnetic resonance (MR) imaging of regional alveolar partial pressure of oxygen (Pao2) to depict smoking-induced functional alterations and to compare its efficacy to that of current diagnostic techniques. MATERIALS AND METHODS This study was approved by the local institutional review board and was compliant with HIPAA. All subjects provided informed consent. A total of 43 subjects were separated into three groups: nonsmokers, asymptomatic smokers, and symptomatic smokers. All subjects underwent a Pao2 imaging session followed by clinically standard pulmonary function tests (PFTs), the 6-minute walk test, and St George Respiratory Questionnaire (SGRQ). The whole-lung mean and standard deviation of Pao2 were compared with metrics derived from PFTs, the 6-minute walk test, and the SGRQ. A logistic regression model was developed to identify the predictors of alterations to the lungs of asymptomatic smokers. RESULTS The whole-lung standard deviation of Pao2 correlated with PFT metrics (forced expiratory volume in 1 second [FEV1]/forced vital capacity [FVC], Pearson r = -0.69, P < .001; percentage predicted FEV1, Pearson r = -0.67, P < .001; diffusing capacity of lung for carbon monoxide [Dlco], Pearson r = -0.45, P = .003), SGRQ score (Pearson r = 0.67, P < .001), and distance walked in 6 minutes (Pearson r = -0.47, P = .002). The standard deviation of Pao2 was significantly higher in asymptomatic smokers than in nonsmokers (change in the standard deviation of Pao2 = 7.59 mm Hg, P = .041) and lower when compared with symptomatic smokers (change in the standard deviation of Pao2 = 10.72 mm Hg, P = .001). A multivariate prediction model containing FEV1/FVC and the standard deviation of Pao2 (as significant predictors of subclinical changes in smokers) and Dlco (as a confounding variable) was formulated. This model resulted in an area under the receiver operating characteristic curve with a significant increase of 29.2% when compared with a prediction model based solely on nonimaging clinical tests. CONCLUSION The (3)He MR imaging heterogeneity metric (standard deviation of Pao2) enabled the differentiation of all three study cohorts, which indicates that it can depict smoking-related functional alterations in asymptomatic current smokers.
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Affiliation(s)
- Hooman Hamedani
- From the Department of Radiology (H.H., S.J.K., M.I., Y.X., K.E., B.H., H.S., D.G., W.G., R.R.R.), Department of Anesthesiology and Critical Care (M.C.), and Pulmonary, Allergy and Critical Care Division (M.D.R.), University of Pennsylvania, 308 Stemmler Hall, 3450 Hamilton Walk, Philadelphia, PA 19104
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Liu Z, Araki T, Okajima Y, Albert M, Hatabu H. Pulmonary hyperpolarized noble gas MRI: Recent advances and perspectives in clinical application. Eur J Radiol 2014; 83:1282-1291. [DOI: 10.1016/j.ejrad.2014.04.014] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Revised: 02/21/2014] [Accepted: 04/19/2014] [Indexed: 12/01/2022]
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Kadlecek S, Hamedani H, Xu Y, Emami K, Xin Y, Ishii M, Rizi R. Regional alveolar partial pressure of oxygen measurement with parallel accelerated hyperpolarized gas MRI. Acad Radiol 2013; 20:1224-33. [PMID: 24029054 DOI: 10.1016/j.acra.2013.07.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 06/19/2013] [Accepted: 07/03/2013] [Indexed: 11/16/2022]
Abstract
RATIONALE AND OBJECTIVES Alveolar oxygen tension (Pao2) is sensitive to the interplay between local ventilation, perfusion, and alveolar-capillary membrane permeability, and thus reflects physiologic heterogeneity of healthy and diseased lung function. Several hyperpolarized helium ((3)He) magnetic resonance imaging (MRI)-based Pao2 mapping techniques have been reported, and considerable effort has gone toward reducing Pao2 measurement error. We present a new Pao2 imaging scheme, using parallel accelerated MRI, which significantly reduces measurement error. MATERIALS AND METHODS The proposed Pao2 mapping scheme was computer-simulated and was tested on both phantoms and five human subjects. Where possible, correspondence between actual local oxygen concentration and derived values was assessed for both bias (deviation from the true mean) and imaging artifact (deviation from the true spatial distribution). RESULTS Phantom experiments demonstrated a significantly reduced coefficient of variation using the accelerated scheme. Simulation results support this observation and predict that correspondence between the true spatial distribution and the derived map is always superior using the accelerated scheme, although the improvement becomes less significant as the signal-to-noise ratio increases. Paired measurements in the human subjects, comparing accelerated and fully sampled schemes, show a reduced Pao2 distribution width for 41 of 46 slices. CONCLUSION In contrast to proton MRI, acceleration of hyperpolarized imaging has no signal-to-noise penalty; its use in Pao2 measurement is therefore always beneficial. Comparison of multiple schemes shows that the benefit arises from a longer time-base during which oxygen-induced depolarization modifies the signal strength. Demonstration of the accelerated technique in human studies shows the feasibility of the method and suggests that measurement error is reduced here as well, particularly at low signal-to-noise levels.
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Affiliation(s)
- Stephen Kadlecek
- Department of Radiology, University of Pennsylvania, 308C Stemmler Hall, 3450 Hamilton Walk, Philadelphia, PA 19104.
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31
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Mugler JP, Altes TA. Hyperpolarized 129Xe MRI of the human lung. J Magn Reson Imaging 2013; 37:313-31. [PMID: 23355432 DOI: 10.1002/jmri.23844] [Citation(s) in RCA: 240] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2012] [Accepted: 08/29/2012] [Indexed: 11/07/2022] Open
Abstract
By permitting direct visualization of the airspaces of the lung, magnetic resonance imaging (MRI) using hyperpolarized gases provides unique strategies for evaluating pulmonary structure and function. Although the vast majority of research in humans has been performed using hyperpolarized (3)He, recent contraction in the supply of (3)He and consequent increases in price have turned attention to the alternative agent, hyperpolarized (129) Xe. Compared to (3)He, (129)Xe yields reduced signal due to its smaller magnetic moment. Nonetheless, taking advantage of advances in gas-polarization technology, recent studies in humans using techniques for measuring ventilation, diffusion, and partial pressure of oxygen have demonstrated results for hyperpolarized (129)Xe comparable to those previously demonstrated using hyperpolarized (3)He. In addition, xenon has the advantage of readily dissolving in lung tissue and blood following inhalation, which makes hyperpolarized (129)Xe particularly attractive for exploring certain characteristics of lung function, such as gas exchange and uptake, which cannot be accessed using (3)He. Preliminary results from methods for imaging (129) Xe dissolved in the human lung suggest that these approaches will provide new opportunities for quantifying relationships among gas delivery, exchange, and transport, and thus show substantial potential to broaden our understanding of lung disease. Finally, recent changes in the commercial landscape of the hyperpolarized-gas field now make it possible for this innovative technology to move beyond the research laboratory.
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Affiliation(s)
- John P Mugler
- Center for In-vivo Hyperpolarized Gas MR Imaging, Department of Radiology and Medical Imaging, University of Virginia School of Medicine, Charlottesville, Virginia 22908, USA.
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Hamedani H, Kadlecek SJ, Ishii M, Emami K, Kuzma NN, Xin Y, Rossman M, Rizi RR. A variability study of regional alveolar oxygen tension measurement in humans using hyperpolarized (3) He MRI. Magn Reson Med 2013; 70:1557-66. [PMID: 23382040 DOI: 10.1002/mrm.24604] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Revised: 10/28/2012] [Accepted: 11/27/2012] [Indexed: 11/06/2022]
Abstract
PURPOSE A systematic study of the short-term and long-term variability of regional alveolar partial pressure of oxygen tension (pA O2 ) measurements using (3) He magnetic resonance imaging was presented. Additionally, the repeatability of the average evaluated pA O2 was compared with that of the standard pulmonary function tests. METHODS Pulmonary function test and pA O2 imaging were performed on 4 nonsmokers (1 M, 3 F, 56 ± 1.7 years) and 4 smokers (3 M, 1 F, 52 ± 7.5 years) during three visits over the course of 2 weeks. Two measurements were performed per visit. Variability of pA O2 was assessed using a mixed-effect model, with an intraclass correlation coefficient calculated for each group. The coefficient of variation of pA O2 over the 3-day period was also compared with the coefficient of variation of pulmonary function test results. RESULTS Short-term regional variability based on intraclass correlation coefficient was 0.71 for nonsmokers, and 0.63 for smokers, with long-term variability significantly lower at 0.59 and 0.47, respectively. While the coefficient of variation of the average pA O2 was similar to the repeatability of the diffusing capacity of CO, it was significantly higher than that of Forced Vital Capacity (P = 0.02). CONCLUSION Short-term and long-term pA O2 variability differences were used as an indication of true physiological changes in order to measure technical reproducibility. Smokers show higher physiologic variability and less technical reproducibility. The suggested pA O2 -imaging technique showed a reasonable regional repeatability in nonsmokers as well as the ability to detect differences between the two groups with similar reproducibility and superior discriminatory ability when compared with pulmonary function tests.
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Affiliation(s)
- Hooman Hamedani
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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A first principles calculation of the oxygen uptake in the human pulmonary acinus at maximal exercise. Respir Physiol Neurobiol 2012. [PMID: 23201099 DOI: 10.1016/j.resp.2012.10.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
It has recently been shown that the acinus can have a reduced efficiency due to a "screening effect" governed by the ratio of oxygen diffusivity to membrane permeability, the gas flow velocity, as well as the size and configuration of the acinus. We present here a top to bottom calculation of the functioning of a machine acinus at exercise that takes this screening effect into account. It shows that, given the geometry and the breathing dynamics of real acini, respiration can be correlated to a single equivalent parameter that we call the integrative permeability. In particular we find that both V(O(2,max)) and PA(O(2)) depend on this permeability in a non-linear manner. Numerical solutions of dynamic convection-diffusion equations indicate that only a narrow range of permeability values is compatible with the experimental measurements of PA(O(2)) and V(O(2,max)). These permeability values are significantly smaller than those found in the literature. In a second step, we present a new type of evaluation of the diffusive permeability, yielding values compatible with the top to bottom approach, but smaller than the usual morphometric value.
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Bauman G, Eichinger M. Ventilation and perfusion magnetic resonance imaging of the lung. Pol J Radiol 2012; 77:37-46. [PMID: 22802864 PMCID: PMC3389953 DOI: 10.12659/pjr.882579] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Accepted: 01/19/2012] [Indexed: 02/02/2023] Open
Abstract
A close interaction between the respiratory pump, pulmonary parenchyma and blood circulation is essential for a normal lung function. Many pulmonary diseases present, especially in their initial phase, a variable regional impairment of ventilation and perfusion. In the last decades various techniques have been established to measure the lung function. Besides the global pulmonary function tests (PFTs) imaging techniques gained increasing importance to detect local variations in lung function, especially for ventilation and perfusion assessment. Imaging modalities allow for a deeper regional insight into pathophysiological processes and enable improved planning of invasive procedures. In contrast to computed tomography (CT) and the nuclear medicine techniques, magnetic resonance imaging (MRI), as a radiation free imaging modality gained increasing importance since the early 1990 for the assessment of pulmonary function. The major inherent problems of lung tissue, namely the low proton density and the pulmonary and cardiac motion, were overcome in the last years by a constant progress in MR technology. Some MR techniques are still under development, a process which is driven by scientific questions regarding the physiology and pathophysiology of pulmonary diseases, as well as by the need for fast and robust clinically applicable imaging techniques as safe therapy monitoring tools. MRI can be considered a promising ionizing-free alternative to techniques like CT or nuclear medicine techniques for the evaluation of lung function. The goal of this article is to provide an overview on selected MRI techniques for the assessment of pulmonary ventilation and perfusion.
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Affiliation(s)
- Grzegorz Bauman
- German Cancer Research Center, Department of Medical Physics in Radiology, Heidelberg, Germany
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35
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Hamedani H, Kadlecek SJ, Emami K, Kuzma NN, Xu Y, Xin Y, Mongkolwisetwara P, Rajaei J, Barulic A, Wilson Miller G, Rossman M, Ishii M, Rizi RR. A multislice single breath-hold scheme for imaging alveolar oxygen tension in humans. Magn Reson Med 2011; 67:1332-45. [PMID: 22190347 DOI: 10.1002/mrm.23125] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2011] [Revised: 07/06/2011] [Accepted: 07/07/2011] [Indexed: 11/10/2022]
Abstract
Reliable, noninvasive, and high-resolution imaging of alveolar partial pressure of oxygen (p(A)O(2)) is a potentially valuable tool in the early diagnosis of pulmonary diseases. Several techniques have been proposed for regional measurement of p(A)O(2) based on the increased depolarization rate of hyperpolarized (3) He. In this study, we explore one such technique by applying a multislice p(A)O(2) -imaging scheme that uses interleaved-slice ordering to utilize interslice time-delays more efficiently. This approach addresses the low spatial resolution and long breath-hold requirements of earlier techniques, allowing p(A)O(2) measurements to be made over the entire human lung in 10-15 s with a typical resolution of 8.3 × 8.3 × 15.6 mm(3). PO(2) measurements in a glass syringe phantom were in agreement with independent gas analysis within 4.7 ± 4.1% (R = 0.9993). The technique is demonstrated in four human subjects (healthy nonsmoker, healthy former smoker, healthy smoker, and patient with COPD), each imaged six times on 3 different days during a 2-week span. Two independent measurements were performed in each session, consisting of 12 coronal slices. The overall p(A)O(2) mean across all subjects was 95.9 ± 12.2 Torr and correlated well with end-tidal O(2) (R = 0.805, P < 0.0001). The alveolar O(2) uptake rate was consistent with the expected range of 1-2 Torr/s. Repeatable visual features were observed in p(A)O(2) maps over different days, as were characteristic differences among the subjects and gravity-dependent effects.
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Affiliation(s)
- Hooman Hamedani
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
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Fain S, Schiebler ML, McCormack DG, Parraga G. Imaging of lung function using hyperpolarized helium-3 magnetic resonance imaging: Review of current and emerging translational methods and applications. J Magn Reson Imaging 2011; 32:1398-408. [PMID: 21105144 DOI: 10.1002/jmri.22375] [Citation(s) in RCA: 163] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
During the past several years there has been extensive development and application of hyperpolarized helium-3 (HP (3)He) magnetic resonance imaging (MRI) in clinical respiratory indications such as asthma, chronic obstructive pulmonary disease, cystic fibrosis, radiation-induced lung injury, and transplantation. This review focuses on the state-of-the-art of HP (3)He MRI and its application to clinical pulmonary research. This is not an overview of the physics of the method, as this topic has been covered previously. We focus here on the potential of this imaging method and its challenges in demonstrating new types of information that has the potential to influence clinical research and decision making in pulmonary medicine. Particular attention is given to functional imaging approaches related to ventilation and diffusion-weighted imaging with applications in chronic obstructive pulmonary disease, cystic fibrosis, asthma, and radiation-induced lung injury. The strengths and challenges of the application of (3)He MRI in these indications are discussed along with a comparison to established and emerging imaging techniques.
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Affiliation(s)
- Sean Fain
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin, USA
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Abstract
The continued progression of chronic lung disease despite current treatment options has led to the increasing evaluation of molecular imaging tools for diagnosis, treatment planning, drug discovery, and therapy monitoring. Concurrently the development of multimodality positron emission tomography (PET) / computed tomography (CT), single-photon emission computed tomography (SPECT)/CT, and magnetic resonance imaging (MRI)/PET scanners has opened the potential for more sophisticated imaging biomarker probes. Here we review the potential uses of multimodality imaging tools, the established uses of molecular imaging in nononcologic lung pathophysiology and drug discovery, and some of the technical challenges in multimodality molecular imaging of the lung.
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Affiliation(s)
- Delphine L Chen
- Division of Nuclear Medicine Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA
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Deppe MH, Parra-Robles J, Ajraoui S, Wild JM. Combined measurement of pulmonary inert gas washout and regional ventilation heterogeneity by MR of a single dose of hyperpolarized 3
He. Magn Reson Med 2010; 65:1075-83. [DOI: 10.1002/mrm.22709] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2010] [Revised: 09/08/2010] [Accepted: 10/08/2010] [Indexed: 11/11/2022]
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