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Bryden N, McHugh CT, Kelley M, Branca RT. Longitudinal nuclear spin relaxation of 129 Xe in solution and in hollow fiber membranes at low and high magnetic field strengths. Magn Reson Med 2022; 88:2005-2013. [PMID: 35726363 PMCID: PMC9420755 DOI: 10.1002/mrm.29362] [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: 03/31/2022] [Revised: 05/04/2022] [Accepted: 05/26/2022] [Indexed: 11/12/2022]
Abstract
PURPOSE To measure dissolved-phase 129 Xe T1 values at high and low magnetic fields and the field dependence of 129 Xe depolarization by hollow fiber membranes used to infuse hyperpolarized xenon in solution. METHODS Dissolved-phase T1 measurements were made at 11.7T and 2.1 mT by bubbling xenon in solution and by using a variable delay to allow spins to partially relax back to thermal equilibrium before probing their magnetization. At high field, relaxation values were compared to those obtained by using the small flip angle method. For depolarization studies, we probed the magnetization of the polarized gas diffusing through an exchange membrane module placed at different field strengths. RESULTS Total loss of polarization was observed for xenon diffusing through hollow fiber membranes at low field, while significant polarization loss (>20%) was observed at magnetic fields up to 2T. Dissolved-phase 129 Xe T1 values were found consistently shorter at 2.1 mT compared to 11.7T. In addition, both O2 and Xe gas concentrations in solution were found to significantly affect dissolved-phase 129 Xe T1 values. CONCLUSION Dissolved-phase 129 Xe measurements are feasible at low field, but to assess the feasibility of in vivo dissolved-phase imaging and spectroscopy the T1 of xenon in blood will need to be measured. Both O2 and Xe concentrations in solution are found to greatly affect dissolved-phase 129 Xe T1 values and may explain, along with RF miscalibration, the large discrepancy in previously reported results.
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Affiliation(s)
- Nicholas Bryden
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Christian T McHugh
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Michele Kelley
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Rosa T Branca
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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2
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Hopkins SR. Ventilation/Perfusion Relationships and Gas Exchange: Measurement Approaches. Compr Physiol 2020; 10:1155-1205. [PMID: 32941684 DOI: 10.1002/cphy.c180042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Ventilation-perfusion ( V ˙ A / Q ˙ ) matching, the regional matching of the flow of fresh gas to flow of deoxygenated capillary blood, is the most important mechanism affecting the efficiency of pulmonary gas exchange. This article discusses the measurement of V ˙ A / Q ˙ matching with three broad classes of techniques: (i) those based in gas exchange, such as the multiple inert gas elimination technique (MIGET); (ii) those derived from imaging techniques such as single-photon emission computed tomography (SPECT), positron emission tomography (PET), magnetic resonance imaging (MRI), computed tomography (CT), and electrical impedance tomography (EIT); and (iii) fluorescent and radiolabeled microspheres. The focus is on the physiological basis of these techniques that provide quantitative information for research purposes rather than qualitative measurements that are used clinically. The fundamental equations of pulmonary gas exchange are first reviewed to lay the foundation for the gas exchange techniques and some of the imaging applications. The physiological considerations for each of the techniques along with advantages and disadvantages are briefly discussed. © 2020 American Physiological Society. Compr Physiol 10:1155-1205, 2020.
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Affiliation(s)
- Susan R Hopkins
- Departments of Medicine and Radiology, University of California, San Diego, California, USA
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3
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Westcott A, McCormack DG, Parraga G, Ouriadov A. Advanced pulmonary MRI to quantify alveolar and acinar duct abnormalities: Current status and future clinical applications. J Magn Reson Imaging 2019; 50:28-40. [PMID: 30637857 DOI: 10.1002/jmri.26623] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 12/04/2018] [Accepted: 12/05/2018] [Indexed: 12/23/2022] Open
Abstract
There are serious clinical gaps in our understanding of chronic lung disease that require novel, sensitive, and noninvasive in vivo measurements of the lung parenchyma to measure disease pathogenesis and progressive changes over time as well as response to treatment. Until recently, our knowledge and appreciation of the tissue changes that accompany lung disease has depended on ex vivo biopsy and concomitant histological and stereological measurements. These measurements have revealed the underlying pathologies that drive lung disease and have provided important observations about airway occlusion, obliteration of the terminal bronchioles and airspace enlargement, or fibrosis and their roles in disease initiation and progression. ex vivo tissue stereology and histology are the established gold standards and, more recently, micro-computed tomography (CT) measurements of ex vivo tissue samples has also been employed to reveal new mechanistic findings about the progression of obstructive lung disease in patients. While these approaches have provided important understandings using ex vivo analysis of excised samples, recently developed hyperpolarized noble gas MRI methods provide an opportunity to noninvasively measure acinar duct and terminal airway dimensions and geometry in vivo, and, without radiation burden. Therefore, in this review we summarize emerging pulmonary MRI morphometry methods that provide noninvasive in vivo measurements of the lung in patients with bronchopulmonary dysplasia and chronic obstructive pulmonary disease, among others. We discuss new findings, future research directions, as well as clinical opportunities to address current gaps in patient care and for testing of new therapies. Level of Evidence: 5 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2019;50:28-40.
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Affiliation(s)
- Andrew Westcott
- Robarts Research Institute, University of Western Ontario, London, Canada.,Department of Medical Biophysics, University of Western Ontario, London, Canada
| | - David G McCormack
- Division of Respirology, Department of Medicine, University of Western Ontario, London, Canada
| | - Grace Parraga
- Robarts Research Institute, University of Western Ontario, London, Canada.,Department of Medical Biophysics, University of Western Ontario, London, Canada.,Division of Respirology, Department of Medicine, University of Western Ontario, London, Canada
| | - Alexei Ouriadov
- Department of Physics and Astronomy, University of Western Ontario, London, Canada
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4
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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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5
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Menten MJ, Wetscherek A, Fast MF. MRI-guided lung SBRT: Present and future developments. Phys Med 2017; 44:139-149. [PMID: 28242140 DOI: 10.1016/j.ejmp.2017.02.003] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 01/25/2017] [Accepted: 02/07/2017] [Indexed: 12/25/2022] Open
Abstract
Stereotactic body radiotherapy (SBRT) is rapidly becoming an alternative to surgery for the treatment of early-stage non-small cell lung cancer patients. Lung SBRT is administered in a hypo-fractionated, conformal manner, delivering high doses to the target. To avoid normal-tissue toxicity, it is crucial to limit the exposure of nearby healthy organs-at-risk (OAR). Current image-guided radiotherapy strategies for lung SBRT are mostly based on X-ray imaging modalities. Although still in its infancy, magnetic resonance imaging (MRI) guidance for lung SBRT is not exposure-limited and MRI promises to improve crucial soft-tissue contrast. Looking beyond anatomical imaging, functional MRI is expected to inform treatment decisions and adaptations in the future. This review summarises and discusses how MRI could be advantageous to the different links of the radiotherapy treatment chain for lung SBRT: diagnosis and staging, tumour and OAR delineation, treatment planning, and inter- or intrafractional motion management. Special emphasis is placed on a new generation of hybrid MRI treatment devices and their potential for real-time adaptive radiotherapy.
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Affiliation(s)
- Martin J Menten
- Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, UK.
| | - Andreas Wetscherek
- Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, UK
| | - Martin F Fast
- Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, UK.
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6
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Hamedani H, Kadlecek S, Xin Y, Siddiqui S, Gatens H, Naji J, Ishii M, Cereda M, Rossman M, Rizi R. A hybrid multibreath wash-in wash-out lung function quantification scheme in human subjects using hyperpolarized 3 He MRI for simultaneous assessment of specific ventilation, alveolar oxygen tension, oxygen uptake, and air trapping. Magn Reson Med 2017; 78:611-624. [PMID: 27734519 PMCID: PMC5391315 DOI: 10.1002/mrm.26401] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Revised: 08/03/2016] [Accepted: 08/08/2016] [Indexed: 01/06/2023]
Abstract
PURPOSE To present a method for simultaneous acquisition of alveolar oxygen tension (PA O2 ), specific ventilation (SV), and apparent diffusion coefficient (ADC) of hyperpolarized (HP) gas in the human lung, allowing reinterpretation of the PA O2 and SV maps to produce a map of oxygen uptake (R). METHOD An imaging scheme was designed with a series of identical normoxic HP gas wash-in breaths to measure ADC, SV, PA O2 , and R in less than 2 min. Signal dynamics were fit to an iterative recursive model that regionally solved for these parameters. This measurement was successfully performed in 12 subjects classified in three healthy, smoker, and chronic obstructive pulmonary disease (COPD) cohorts. RESULTS The overall whole lung ADC, SV, PA O2 , and R in healthy, smoker, and COPD subjects was 0.20 ± 0.03 cm2 /s, 0.39 ± 0.06,113 ± 2 Torr, and 1.55 ± 0.35 Torr/s, respectively, in healthy subjects; 0.21 ± 0.03 cm2 /s, 0.33 ± 0.06, 115.9 ± 4 Torr, and 0.97 ± 0.2 Torr/s, respectively, in smokers; and 0.25 ± 0.06 cm2 /s, 0.23 ± 0.08, 114.8 ± 6.0Torr, and 0.94 ± 0.12 Torr/s, respectively, in subjects with COPD. Hetrogeneity of SV, PA O2 , and R were indicators of both smoking-related changes and disease, and the severity of the disease correlated with the degree of this heterogeneity. Subjects with symptoms showed reduced oxygen uptake and specific ventilation. CONCLUSION High-resolution, nearly coregistered and quantitative measures of lung function and structure were obtained with less than 1 L of HP gas. This hybrid multibreath technique produced measures of lung function that revealed clear differences among the cohorts and subjects and were confirmed by correlations with global lung measurements. Magn Reson Med 78:611-624, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Hooman Hamedani
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
| | - Stephen Kadlecek
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
| | - Yi Xin
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
| | - Sarmad Siddiqui
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
| | - Heather Gatens
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
| | - Joseph Naji
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
| | - Masaru Ishii
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
- Department of Otolaryngology-Head and Neck Surgery, The Johns Hopkins University, Baltimore, Maryland, USA
| | - Maurizio Cereda
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, United States
| | - Milton Rossman
- Pulmonary, Allergy and Critical Care Division, University of Pennsylvania, Philadelphia, PA, United States
| | - Rahim Rizi
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
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7
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Veldhoen S, Weng AM, Knapp J, Kunz AS, Stäb D, Wirth C, Segerer F, Hebestreit H, Malzahn U, Köstler H, Bley TA. Self-gated Non–Contrast-enhanced Functional Lung MR Imaging for Quantitative Ventilation Assessment in Patients with Cystic Fibrosis. Radiology 2017; 283:242-251. [DOI: 10.1148/radiol.2016160355] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Simon Veldhoen
- From the Department of Diagnostic and Interventional Radiology (S.V., A.M.W., J.K., A.S.K., D.S., C.W., H.K., T.A.B.), Department of Pediatrics (F.S., H.H.), and Clinical Trial Center Würzburg (U.M.), University Hospital Würzburg, Oberdürrbacher Strasse 6, 97080 Würzburg, Germany; and Centre of Advanced Imaging, University of Queensland, Brisbane, Australia (D.S.)
| | - Andreas M. Weng
- From the Department of Diagnostic and Interventional Radiology (S.V., A.M.W., J.K., A.S.K., D.S., C.W., H.K., T.A.B.), Department of Pediatrics (F.S., H.H.), and Clinical Trial Center Würzburg (U.M.), University Hospital Würzburg, Oberdürrbacher Strasse 6, 97080 Würzburg, Germany; and Centre of Advanced Imaging, University of Queensland, Brisbane, Australia (D.S.)
| | - Janine Knapp
- From the Department of Diagnostic and Interventional Radiology (S.V., A.M.W., J.K., A.S.K., D.S., C.W., H.K., T.A.B.), Department of Pediatrics (F.S., H.H.), and Clinical Trial Center Würzburg (U.M.), University Hospital Würzburg, Oberdürrbacher Strasse 6, 97080 Würzburg, Germany; and Centre of Advanced Imaging, University of Queensland, Brisbane, Australia (D.S.)
| | - Andreas S. Kunz
- From the Department of Diagnostic and Interventional Radiology (S.V., A.M.W., J.K., A.S.K., D.S., C.W., H.K., T.A.B.), Department of Pediatrics (F.S., H.H.), and Clinical Trial Center Würzburg (U.M.), University Hospital Würzburg, Oberdürrbacher Strasse 6, 97080 Würzburg, Germany; and Centre of Advanced Imaging, University of Queensland, Brisbane, Australia (D.S.)
| | - Daniel Stäb
- From the Department of Diagnostic and Interventional Radiology (S.V., A.M.W., J.K., A.S.K., D.S., C.W., H.K., T.A.B.), Department of Pediatrics (F.S., H.H.), and Clinical Trial Center Würzburg (U.M.), University Hospital Würzburg, Oberdürrbacher Strasse 6, 97080 Würzburg, Germany; and Centre of Advanced Imaging, University of Queensland, Brisbane, Australia (D.S.)
| | - Clemens Wirth
- From the Department of Diagnostic and Interventional Radiology (S.V., A.M.W., J.K., A.S.K., D.S., C.W., H.K., T.A.B.), Department of Pediatrics (F.S., H.H.), and Clinical Trial Center Würzburg (U.M.), University Hospital Würzburg, Oberdürrbacher Strasse 6, 97080 Würzburg, Germany; and Centre of Advanced Imaging, University of Queensland, Brisbane, Australia (D.S.)
| | - Florian Segerer
- From the Department of Diagnostic and Interventional Radiology (S.V., A.M.W., J.K., A.S.K., D.S., C.W., H.K., T.A.B.), Department of Pediatrics (F.S., H.H.), and Clinical Trial Center Würzburg (U.M.), University Hospital Würzburg, Oberdürrbacher Strasse 6, 97080 Würzburg, Germany; and Centre of Advanced Imaging, University of Queensland, Brisbane, Australia (D.S.)
| | - Helge Hebestreit
- From the Department of Diagnostic and Interventional Radiology (S.V., A.M.W., J.K., A.S.K., D.S., C.W., H.K., T.A.B.), Department of Pediatrics (F.S., H.H.), and Clinical Trial Center Würzburg (U.M.), University Hospital Würzburg, Oberdürrbacher Strasse 6, 97080 Würzburg, Germany; and Centre of Advanced Imaging, University of Queensland, Brisbane, Australia (D.S.)
| | - Uwe Malzahn
- From the Department of Diagnostic and Interventional Radiology (S.V., A.M.W., J.K., A.S.K., D.S., C.W., H.K., T.A.B.), Department of Pediatrics (F.S., H.H.), and Clinical Trial Center Würzburg (U.M.), University Hospital Würzburg, Oberdürrbacher Strasse 6, 97080 Würzburg, Germany; and Centre of Advanced Imaging, University of Queensland, Brisbane, Australia (D.S.)
| | - Herbert Köstler
- From the Department of Diagnostic and Interventional Radiology (S.V., A.M.W., J.K., A.S.K., D.S., C.W., H.K., T.A.B.), Department of Pediatrics (F.S., H.H.), and Clinical Trial Center Würzburg (U.M.), University Hospital Würzburg, Oberdürrbacher Strasse 6, 97080 Würzburg, Germany; and Centre of Advanced Imaging, University of Queensland, Brisbane, Australia (D.S.)
| | - Thorsten A. Bley
- From the Department of Diagnostic and Interventional Radiology (S.V., A.M.W., J.K., A.S.K., D.S., C.W., H.K., T.A.B.), Department of Pediatrics (F.S., H.H.), and Clinical Trial Center Würzburg (U.M.), University Hospital Würzburg, Oberdürrbacher Strasse 6, 97080 Würzburg, Germany; and Centre of Advanced Imaging, University of Queensland, Brisbane, Australia (D.S.)
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8
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Zhang Z, Guan Y, Li H, Zhao X, Han Y, Xia Y, Sun X, Liu S, Ye C, Zhou X. Quantitative comparison of lung physiological parameters in single and multiple breathhold with hyperpolarized xenon magnetic resonance. Biomed Phys Eng Express 2016. [DOI: 10.1088/2057-1976/2/5/055013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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9
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Comment A. Dissolution DNP for in vivo preclinical studies. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 264:39-48. [PMID: 26920829 DOI: 10.1016/j.jmr.2015.12.027] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 12/29/2015] [Accepted: 12/30/2015] [Indexed: 06/05/2023]
Abstract
The tremendous polarization enhancement afforded by dissolution dynamic nuclear polarization (DNP) can be taken advantage of to perform preclinical in vivo molecular and metabolic imaging. Following the injection of molecules that are hyperpolarized via dissolution DNP, real-time measurements of their biodistribution and metabolic conversion can be recorded. This technology therefore provides a unique and invaluable tool for probing cellular metabolism in vivo in animal models in a noninvasive manner. It gives the opportunity to follow and evaluate disease progression and treatment response without requiring ex vivo destructive tissue assays. Although its considerable potential has now been widely recognized, hyperpolarized magnetic resonance by dissolution DNP remains a challenging method to implement for routine in vivo preclinical measurements. The aim of this article is to provide an overview of the current state-of-the-art technology for preclinical applications and the challenges that need to be addressed to promote it and allow its wider dissemination in the near future.
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Affiliation(s)
- Arnaud Comment
- General Electric Healthcare, Pollards Wood, Nightingales Lane, Chalfont St Giles, Buckinghamshire HP8 4SP, United Kingdom; Institute of Physics of Biological Systems, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
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10
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Flors L, Altes T, Mugler J, de Lange E, Miller G, Mata J, Ruset I, Hersman F. New insights into lung diseases using hyperpolarized gas MRI. RADIOLOGIA 2015. [DOI: 10.1016/j.rxeng.2014.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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11
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New insights into lung diseases using hyperpolarized gas MRI. RADIOLOGIA 2015; 57:303-13. [PMID: 25747807 DOI: 10.1016/j.rx.2014.12.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 12/23/2014] [Accepted: 12/28/2014] [Indexed: 11/23/2022]
Abstract
Hyperpolarized (HP) gases are a new class of contrast agents that permit to obtain high temporal and spatial resolution magnetic resonance images (MRI) of the lung airspaces. HP gas MRI has become important research tool not only for morphological and functional evaluation of normal pulmonary physiology but also for regional quantification of pathologic changes occurring in several lung diseases. The purpose of this work is to provide an introduction to MRI using HP noble gases, describing both the basic principles of the technique and the new information about lung disease provided by clinical studies with this method. The applications of the technique in normal subjects, smoking related lung disease, asthma, and cystic fibrosis are reviewed.
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12
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Detection of brown adipose tissue and thermogenic activity in mice by hyperpolarized xenon MRI. Proc Natl Acad Sci U S A 2014; 111:18001-6. [PMID: 25453088 DOI: 10.1073/pnas.1403697111] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The study of brown adipose tissue (BAT) in human weight regulation has been constrained by the lack of a noninvasive tool for measuring this tissue and its function in vivo. Existing imaging modalities are nonspecific and intrinsically insensitive to the less active, lipid-rich BAT of obese subjects, the target population for BAT studies. We demonstrate noninvasive imaging of BAT in mice by hyperpolarized xenon gas MRI. We detect a greater than 15-fold increase in xenon uptake by BAT during stimulation of BAT thermogenesis, which enables us to acquire background-free maps of the tissue in both lean and obese mouse phenotypes. We also demonstrate in vivo MR thermometry of BAT by hyperpolarized xenon gas. Finally, we use the linear temperature dependence of the chemical shift of xenon dissolved in adipose tissue to directly measure BAT temperature and to track thermogenic activity in vivo.
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13
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Zheng Y, Cates GD, Tobias WA, Mugler JP, Miller GW. Very-low-field MRI of laser polarized xenon-129. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2014; 249:108-117. [PMID: 25462954 DOI: 10.1016/j.jmr.2014.09.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 09/29/2014] [Accepted: 09/29/2014] [Indexed: 06/04/2023]
Abstract
We describe a homebuilt MRI system for imaging laser-polarized xenon-129 at a very low holding field of 2.2mT. A unique feature of this system was the use of Maxwell coils oriented at so-called "magic angles" to generate the transverse magnetic field gradients, which provided a simple alternative to Golay coils. We used this system to image a laser-polarized xenon-129 phantom with both a conventional gradient-echo and a fully phase-encoded pulse sequence. In other contexts, a fully phase-encoded acquisition, also known as single-point or constant-time imaging, has been used to enable distortion-free imaging of short-T2∗ species. Here we used this technique to overcome imperfections associated with our homebuilt MRI system while also taking full advantage of the long T2∗ available at very low field. Our results demonstrate that xenon-129 image quality can be dramatically improved at low field by combining a fully phase-encoded k-space acquisition with auxiliary measurements of system imperfections including B0 field drift and gradient infidelity.
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Affiliation(s)
- Yuan Zheng
- Department of Physics, University of Virginia, Charlottesville, VA 22904, USA
| | - Gordon D Cates
- Department of Physics, University of Virginia, Charlottesville, VA 22904, USA; Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA 22908, USA
| | - William A Tobias
- Department of Physics, University of Virginia, Charlottesville, VA 22904, USA
| | - John P Mugler
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA 22908, USA
| | - G Wilson Miller
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA 22908, USA.
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14
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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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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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Taratula O, Bai Y, D'Antonio EL, Dmochowski IJ. Enantiopure Cryptophane- 129Xe Nuclear Magnetic Resonance Biosensors Targeting Carbonic Anhydrase. Supramol Chem 2014; 27:65-71. [PMID: 25506191 DOI: 10.1080/10610278.2014.906601] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The (+) and (-) enantiomers for a cryptophane-7-bond-linker-benzenesulfonamide biosensor (C7B) were synthesized and their chirality confirmed by electronic circular dichroism (ECD) spectroscopy. Biosensor binding to carbonic anhydrase II (CAII) was characterized for both enantiomers by hyperpolarized (hp) 129Xe NMR spectroscopy. Our previous study of the racemic (+/-) C7B biosensor-CAII complex [Chambers, et al., J. Am. Chem. Soc. 2009, 131, 563-569], identified two "bound" 129Xe@C7B peaks by hp 129Xe NMR (at 71 and 67 ppm, relative to "free" biosensor at 64 ppm), which led to the initial hypothesis that (+) and (-) enantiomers produce diastereomeric peaks when coordinated to Zn2+ at the chiral CAII active site. Unexpectedly, the single enantiomers complexed with CAII also identified two "bound" 129Xe@C7B peaks: (+) 72, 68 ppm and (-) 68, 67 ppm. These results are consistent with X-ray crystallographic evidence for benzenesulfonamide inhibitors occupying a second site near the CAII surface. As illustrated by our studies of this model protein-ligand interaction, hp 129Xe NMR spectroscopy can be useful for identifying supramolecular assemblies in solution.
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Affiliation(s)
- Olena Taratula
- Department of Chemistry, University of Pennsylvania, 231 South 34 St., Philadelphia, PA 19104
| | - Yubin Bai
- Department of Chemistry, University of Pennsylvania, 231 South 34 St., Philadelphia, PA 19104
| | - Edward L D'Antonio
- Department of Chemistry, University of Pennsylvania, 231 South 34 St., Philadelphia, PA 19104
| | - Ivan J Dmochowski
- Department of Chemistry, University of Pennsylvania, 231 South 34 St., Philadelphia, PA 19104
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Tetsumoto S, Takeda Y, Imai H, Kimura A, Jin Y, Nakanishi K, Maeda Y, Kuhara H, Tsujino K, Iwasaki T, Shigeta H, Kondo Y, Ito M, Minami T, Hirata H, Takahashi R, Kohmo S, Nagatomo I, Inoue K, Kida H, Kijima T, Tachibana I, Maeda N, Funahashi T, Shimomura I, Fujiwara H, Kumanogoh A. Validation of noninvasive morphological and diffusion imaging in mouse emphysema by micro-computed tomography and hyperpolarized (129)Xe magnetic resonance imaging. Am J Respir Cell Mol Biol 2014; 49:592-600. [PMID: 23668642 DOI: 10.1165/rcmb.2012-0350oc] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Animal disease models are pivotal in investigating the pathogenesis of emphysema and developing novel drugs, but the modalities to evaluate murine emphysema models have been of limited validity and sensitivity. In this study, we evaluated hyperpolarized (129)Xe magnetic resonance imaging (MRI) and micro-computed tomography (micro-CT) compared with traditional methods, such as plethysmography and histology. Elastase-treated mice and adiponectin knockout mice were used as murine emphysema models to evaluate these modalities. Three weeks after elastase administration, significant and heterogeneous emphysema was evaluated according to the mean linear intercept and plethysmography parameters. Notably, the distribution of low-density areas, as examined by micro-CT, correlated with the mean linear intercept and plethysmography parameters in whole lungs. These correlations were also observed in regional areas. Furthermore, we introduced hyperpolarized (129)Xe MRI, which can evaluate gas exchange between the alveoli and blood during spontaneous breathing. Parameters of gas exchange (fD) and alveolar size (Vs/Va) were significantly decreased in elastase-treated mice, and moderately correlated with the plethysmography parameters. Of importance, we could detect a decrease of the fD value in low-density areas with micro-CT, suggesting that gas exchange decreased in emphysematous lesions. Likewise, these parameters (fD and Vs/Va) were also decreased in adiponectin knockout mice, which exhibit emphysema with a homogeneous distribution. We demonstrated the feasibility of (129)Xe MRI and micro-CT in combination with traditional modalities. These noninvasive modalities provide complementary data that can be used for repeated estimations of regional gas exchange and lung morphology.
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Affiliation(s)
- Satoshi Tetsumoto
- 1 Department of Respiratory Medicine, Allergy, and Rheumatic Diseases, Graduate School of Medicine
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Bai Y, Wang Y, Goulian M, Driks A, Dmochowski IJ. Bacterial spore detection and analysis using hyperpolarized 129Xe chemical exchange saturation transfer (Hyper-CEST) NMR. Chem Sci 2014; 5:3197-3203. [PMID: 25089181 DOI: 10.1039/c4sc01190b] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Previously, we reported hyperpolarized 129Xe chemical exchange saturation transfer (Hyper-CEST) NMR techniques for the ultrasensitive (i.e., 1 picomolar) detection of xenon host molecules known as cryptophane. Here, we demonstrate a more general role for Hyper-CEST NMR as a spectroscopic method for probing nanoporous structures, without the requirement for cryptophane or engineered xenon-binding sites. Hyper-CEST 129Xe NMR spectroscopy was employed to detect Bacillus anthracis and Bacillus subtilis spores in solution, and interrogate the layers that comprise their structures. 129Xe-spore samples were selectively irradiated with radiofrequency pulses; the depolarized 129Xe returned to aqueous solution and depleted the 129Xe-water signal, providing measurable contrast. Removal of the outermost spore layers in B. anthracis and B. subtilis (the exosporium and coat, respectively) enhanced 129Xe exchange with the spore interior. Notably, the spores were invisible to hyperpolarized 129Xe NMR direct detection methods, highlighting the lack of high-affinity xenon-binding sites, and the potential for extending Hyper-CEST NMR structural analysis to other biological and synthetic nanoporous structures.
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Affiliation(s)
- Yubin Bai
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Yanfei Wang
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Mark Goulian
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Adam Driks
- Department of Microbiology and Immunology, Loyola University Chicago, Maywood, Illinois 60153, USA
| | - Ivan J Dmochowski
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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Klippel S, Döpfert J, Jayapaul J, Kunth M, Rossella F, Schnurr M, Witte C, Freund C, Schröder L. Cell Tracking with Caged Xenon: Using Cryptophanes as MRI Reporters upon Cellular Internalization. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201307290] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Klippel S, Döpfert J, Jayapaul J, Kunth M, Rossella F, Schnurr M, Witte C, Freund C, Schröder L. Cell tracking with caged xenon: using cryptophanes as MRI reporters upon cellular internalization. Angew Chem Int Ed Engl 2013; 53:493-6. [PMID: 24307424 DOI: 10.1002/anie.201307290] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Indexed: 11/09/2022]
Abstract
Caged xenon has great potential in overcoming sensitivity limitations for solution-state NMR detection of dilute molecules. However, no application of such a system as a magnetic resonance imaging (MRI) contrast agent has yet been performed with live cells. We demonstrate MRI localization of cells labeled with caged xenon in a packed-bed bioreactor working under perfusion with hyperpolarized-xenon-saturated medium. Xenon hosts enable NMR/MRI experiments with switchable contrast and selectivity for cell-associated versus unbound cages. We present MR images with 10(3) -fold sensitivity enhancement for cell-internalized, dual-mode (fluorescence/MRI) xenon hosts at low micromolar concentrations. Our results illustrate the capability of functionalized xenon to act as a highly sensitive cell tracer for MRI detection even without signal averaging. The method will bridge the challenging gap for translation to in vivo studies for the optimization of targeted biosensors and their multiplexing applications.
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Affiliation(s)
- Stefan Klippel
- ERC Project BiosensorImaging, Leibniz-Institut für Molekulare Pharmakologie (FMP), 13125 Berlin (Germany) https://www.fmp-berlin.de/schroeder; Protein Biochemistry Group, Freie Universität Berlin, 14195 Berlin (Germany)
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Freeman MS, Cleveland ZI, Qi Y, Driehuys B. Enabling hyperpolarized (129) Xe MR spectroscopy and imaging of pulmonary gas transfer to the red blood cells in transgenic mice expressing human hemoglobin. Magn Reson Med 2013; 70:1192-9. [PMID: 24006177 DOI: 10.1002/mrm.24915] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 07/05/2013] [Accepted: 07/17/2013] [Indexed: 01/06/2023]
Abstract
PURPOSE Hyperpolarized (HP) (129) Xe gas in the alveoli can be detected separately from (129) Xe dissolved in pulmonary barrier tissues (blood plasma and parenchyma) and red blood cells (RBCs) of humans, allowing this isotope to probe impaired gas uptake. Unfortunately, mice, which are favored as lung disease models, do not display a unique RBC resonance, thus limiting the preclinical utility of (129) Xe MR. Here we overcome this limitation using a commercially available strain of transgenic mice that exclusively expresses human hemoglobin. METHODS Dynamic HP (129) Xe MR spectroscopy, and three-dimensional radial MRI of gaseous and dissolved (129) Xe were performed in both wild-type (C57BL/6) and transgenic mice. RESULTS Unlike wild-type animals, transgenic mice displayed two dissolved (129) Xe NMR peaks at 198 and 217 ppm, corresponding to (129) Xe dissolved in barrier tissues and RBCs, respectively. Moreover, signal from these resonances could be imaged separately, using a 1-point variant of the Dixon technique. CONCLUSION It is now possible to examine the dynamics and spatial distribution of pulmonary gas uptake by the RBCs of mice using HP (129) Xe MR spectroscopy and imaging. When combined with ventilation imaging, this ability will enable translational "mouse-to-human" studies of impaired gas exchange in a variety of pulmonary diseases.
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Affiliation(s)
- Matthew S Freeman
- Center for In Vivo Microscopy, Duke University Medical Center, Durham, North Carolina, USA; Medical Physics Graduate Program, Duke University, Durham, North Carolina, USA
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22
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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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Lilburn DM, Pavlovskaya GE, Meersmann T. Perspectives of hyperpolarized noble gas MRI beyond 3He. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2013; 229:173-86. [PMID: 23290627 PMCID: PMC3611600 DOI: 10.1016/j.jmr.2012.11.014] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 11/12/2012] [Accepted: 11/15/2012] [Indexed: 05/29/2023]
Abstract
Nuclear Magnetic Resonance (NMR) studies with hyperpolarized (hp) noble gases are at an exciting interface between physics, chemistry, materials science and biomedical sciences. This paper intends to provide a brief overview and outlook of magnetic resonance imaging (MRI) with hp noble gases other than hp (3)He. A particular focus are the many intriguing experiments with (129)Xe, some of which have already matured to useful MRI protocols, while others display high potential for future MRI applications. Quite naturally for MRI applications the major usage so far has been for biomedical research but perspectives for engineering and materials science studies are also provided. In addition, the prospects for surface sensitive contrast with hp (83)Kr MRI is discussed.
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Affiliation(s)
| | | | - Thomas Meersmann
- University of Nottingham, School of Clinical Sciences, Sir Peter Mansfield Magnetic Resonance Centre, Nottingham NG7 2RD, United Kingdom
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Six JS, Hughes-Riley T, Stupic KF, Pavlovskaya GE, Meersmann T. Pathway to cryogen free production of hyperpolarized Krypton-83 and Xenon-129. PLoS One 2012; 7:e49927. [PMID: 23209620 PMCID: PMC3507956 DOI: 10.1371/journal.pone.0049927] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Accepted: 10/16/2012] [Indexed: 11/24/2022] Open
Abstract
Hyperpolarized (hp) 129Xe and hp 83Kr for magnetic resonance imaging (MRI) are typically obtained through spin-exchange optical pumping (SEOP) in gas mixtures with dilute concentrations of the respective noble gas. The usage of dilute noble gases mixtures requires cryogenic gas separation after SEOP, a step that makes clinical and preclinical applications of hp 129Xe MRI cumbersome. For hp 83Kr MRI, cryogenic concentration is not practical due to depolarization that is caused by quadrupolar relaxation in the condensed phase. In this work, the concept of stopped flow SEOP with concentrated noble gas mixtures at low pressures was explored using a laser with 23.3 W of output power and 0.25 nm linewidth. For 129Xe SEOP without cryogenic separation, the highest obtained MR signal intensity from the hp xenon-nitrogen gas mixture was equivalent to that arising from 15.5±1.9% spin polarized 129Xe in pure xenon gas. The production rate of the hp gas mixture, measured at 298 K, was 1.8 cm3/min. For hp 83Kr, the equivalent of 4.4±0.5% spin polarization in pure krypton at a production rate of 2 cm3/min was produced. The general dependency of spin polarization upon gas pressure obtained in stopped flow SEOP is reported for various noble gas concentrations. Aspects of SEOP specific to the two noble gas isotopes are discussed and compared with current theoretical opinions. A non-linear pressure broadening of the Rb D1 transition was observed and taken into account for the qualitative description of the SEOP process.
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Affiliation(s)
- Joseph S. Six
- University of Nottingham, School of Clinical Sciences, Sir Peter Mansfield Magnetic Resonance Centre, Nottingham, United Kingdom
| | - Theodore Hughes-Riley
- University of Nottingham, School of Clinical Sciences, Sir Peter Mansfield Magnetic Resonance Centre, Nottingham, United Kingdom
| | - Karl F. Stupic
- University of Nottingham, School of Clinical Sciences, Sir Peter Mansfield Magnetic Resonance Centre, Nottingham, United Kingdom
| | - Galina E. Pavlovskaya
- University of Nottingham, School of Clinical Sciences, Sir Peter Mansfield Magnetic Resonance Centre, Nottingham, United Kingdom
| | - Thomas Meersmann
- University of Nottingham, School of Clinical Sciences, Sir Peter Mansfield Magnetic Resonance Centre, Nottingham, United Kingdom
- * E-mail:
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Bai Y, Hill PA, Dmochowski IJ. Utilizing a water-soluble cryptophane with fast xenon exchange rates for picomolar sensitivity NMR measurements. Anal Chem 2012; 84:9935-41. [PMID: 23106513 DOI: 10.1021/ac302347y] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Hyperpolarized (129)Xe chemical exchange saturation transfer ((129)Xe Hyper-CEST) NMR is a powerful technique for the ultrasensitive, indirect detection of Xe host molecules (e.g., cryptophane-A). Irradiation at the appropriate Xe-cryptophane resonant radio frequency results in relaxation of the bound hyperpolarized (129)Xe and rapid accumulation of depolarized (129)Xe in bulk solution. The cryptophane effectively "catalyzes" this process by providing a unique molecular environment for spin depolarization to occur, while allowing xenon exchange with the bulk solution during the hyperpolarized lifetime (T(1) ≈ 1 min). Following this scheme, a triacetic acid cryptophane-A derivative (TAAC) was indirectly detected at 1.4 picomolar concentration at 320 K in aqueous solution, which is the record for a single-unit xenon host. To investigate this sensitivity enhancement, the xenon binding kinetics of TAAC in water was studied by NMR exchange lifetime measurement. At 297 K, k(on) ≈ 1.5 × 10(6) M(-1) s(-1) and k(off) = 45 s(-1), which represent the fastest Xe association and dissociation rates measured for a high-affinity, water-soluble xenon host molecule near rt. NMR line width measurements provided similar exchange rates at rt, which we assign to solvent-Xe exchange in TAAC. At 320 K, k(off) was estimated to be 1.1 × 10(3) s(-1). In Hyper-CEST NMR experiments, the rate of (129)Xe depolarization achieved by 14 pM TAAC in the presence of radio frequency (RF) pulses was calculated to be 0.17 μM·s(-1). On a per cryptophane basis, this equates to 1.2 × 10(4)(129)Xe atoms s(-1) (or 4.6 × 10(4) Xe atoms s(-1), all Xe isotopes), which is more than an order of magnitude faster than k(off), the directly measurable Xe-TAAC exchange rate. This compels us to consider multiple Xe exchange processes for cryptophane-mediated bulk (129)Xe depolarization, which provide at least 10(7)-fold sensitivity enhancements over directly detected hyperpolarized (129)Xe NMR signals.
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Affiliation(s)
- Yubin Bai
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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Acosta RH, Blümler P, Münnemann K, Spiess HW. Mixture and dissolution of laser polarized noble gases: spectroscopic and imaging applications. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2012; 66:40-69. [PMID: 22980033 DOI: 10.1016/j.pnmrs.2012.03.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Accepted: 03/20/2012] [Indexed: 06/01/2023]
Affiliation(s)
- Rodolfo H Acosta
- FAMAF, Universidad Nacional de Córdoba, IFEG - CONICET, Córdoba, Argentina
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Abstract
Several methods allow regional gas exchange to be inferred from imaging of regional ventilation and perfusion (V/Q) ratios. Each method measures slightly different aspects of gas exchange and has inherent advantages and drawbacks that are reviewed. Single photon emission computed tomography can provide regional measure of ventilation and perfusion from which regional V/Q ratios can be derived. PET methods using inhaled or intravenously administered nitrogen-13 provide imaging of both regional blood flow, shunt, and ventilation. Electric impedance tomography has recently been refined to allow simultaneous measurements of both regional ventilation and blood flow. MRI methods utilizing hyperpolarized helium-3 or xenon-129 are currently being refined and have been used to estimate local PaO(2) in both humans and animals. Microsphere methods are included in this review as they provide measurements of regional ventilation and perfusion in animals. One of their advantages is their greater spatial resolution than most imaging methods and the ability to use them as gold standards against which new imaging methods can be tested. In general, the reviewed methods differ in characteristics such as spatial resolution, possibility of repeated measurements, radiation exposure, availability, expensiveness, and their current stage of development.
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Affiliation(s)
- Johan Petersson
- Department of Anesthesiology and Intensive Care, Karolinska University Hospital Solna, Stockholm, Sweden.
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Badea CT, Guo X, Clark D, Johnston SM, Marshall CD, Piantadosi CA. Dual-energy micro-CT of the rodent lung. Am J Physiol Lung Cell Mol Physiol 2012; 302:L1088-97. [PMID: 22427526 DOI: 10.1152/ajplung.00359.2011] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The purpose of this work is to investigate the use of dual-energy micro-computed tomography (CT) for the estimation of vascular, tissue, and air fractions in rodent lungs using a postreconstruction three material decomposition method. Using simulations, we have estimated the accuracy limits of the decomposition for realistic micro-CT noise levels. Next, we performed experiments involving ex vivo lung imaging in which intact rat lungs were carefully removed from the thorax, injected with an iodine-based contrast agent, and then inflated with different volumes of air (n = 2). Finally, we performed in vivo imaging studies in C57BL/6 mice (n = 5) using fast prospective respiratory gating in end inspiration and end expiration for three different levels of positive end expiratory pressure (PEEP). Before imaging, mice were injected with a liposomal blood pool contrast agent. The three-dimensional air, tissue, and blood fraction maps were computed and analyzed. The results indicate that separation and volume estimation of the three material components of the lungs are possible. The mean accuracy values for air, blood, and tissue were 93, 93, and 90%, respectively. The absolute accuracy in determining all fraction materials was 91.6%. The coefficient of variation was small (2.5%) indicating good repeatability. The minimum difference that we could detect in material fractions was 15%. As expected, an increase in PEEP levels for the living mouse resulted in statistically significant increases in air fractions at end expiration but no significant changes at end inspiration. Our method has applicability in preclinical pulmonary studies where changes in lung structure and gas volume as a result of lung injury, environmental exposures, or drug bioactivity would have important physiological implications.
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Affiliation(s)
- C T Badea
- Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA.
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Bauman G, Scholz A, Rivoire J, Terekhov M, Friedrich J, de Oliveira A, Semmler W, Schreiber LM, Puderbach M. Lung ventilation- and perfusion-weighted Fourier decomposition magnetic resonance imaging: in vivo validation with hyperpolarized 3He and dynamic contrast-enhanced MRI. Magn Reson Med 2012; 69:229-37. [PMID: 22392633 DOI: 10.1002/mrm.24236] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2011] [Revised: 01/14/2012] [Accepted: 02/13/2012] [Indexed: 12/22/2022]
Abstract
The purpose of this work was to validate ventilation-weighted (VW) and perfusion-weighted (QW) Fourier decomposition (FD) magnetic resonance imaging (MRI) with hyperpolarized (3)He MRI and dynamic contrast-enhanced perfusion (DCE) MRI in a controlled animal experiment. Three healthy pigs were studied on 1.5-T MR scanner. For FD MRI, the VW and QW images were obtained by postprocessing of time-resolved lung image sets. DCE acquisitions were performed immediately after contrast agent injection. (3)He MRI data were acquired following the administration of hyperpolarized helium and nitrogen mixture. After baseline MR scans, pulmonary embolism was artificially produced. FD MRI and DCE MRI perfusion measurements were repeated. Subsequently, atelectasis and air trapping were induced, which followed with FD MRI and (3)He MRI ventilation measurements. Distributions of signal intensities in healthy and pathologic lung tissue were compared by statistical analysis. Images acquired using FD, (3)He, and DCE MRI in all animals before the interventional procedure showed homogeneous ventilation and perfusion. Functional defects were detected by all MRI techniques at identical anatomical locations. Signal intensity in VW and QW images was significantly lower in pathological than in healthy lung parenchyma. The study has shown usefulness of FD MRI as an alternative, noninvasive, and easily implementable technique for the assessment of acute changes in lung function.
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Affiliation(s)
- Grzegorz Bauman
- Department of Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Germany.
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30
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Cleveland ZI, Möller HE, Hedlund LW, Nouls JC, Freeman MS, Qi Y, Driehuys B. In vivo MR imaging of pulmonary perfusion and gas exchange in rats via continuous extracorporeal infusion of hyperpolarized 129Xe. PLoS One 2012; 7:e31306. [PMID: 22363613 PMCID: PMC3283644 DOI: 10.1371/journal.pone.0031306] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Accepted: 01/06/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Hyperpolarized (HP) (129)Xe magnetic resonance imaging (MRI) permits high resolution, regional visualization of pulmonary ventilation. Additionally, its reasonably high solubility (>10%) and large chemical shift range (>200 ppm) in tissues allow HP (129)Xe to serve as a regional probe of pulmonary perfusion and gas transport, when introduced directly into the vasculature. In earlier work, vascular delivery was accomplished in rats by first dissolving HP (129)Xe in a biologically compatible carrier solution, injecting the solution into the vasculature, and then detecting HP (129)Xe as it emerged into the alveolar airspaces. Although easily implemented, this approach was constrained by the tolerable injection volume and the duration of the HP (129)Xe signal. METHODS AND PRINCIPAL FINDINGS Here, we overcome the volume and temporal constraints imposed by injection, by using hydrophobic, microporous, gas-exchange membranes to directly and continuously infuse (129)Xe into the arterial blood of live rats with an extracorporeal (EC) circuit. The resulting gas-phase (129)Xe signal is sufficient to generate diffusive gas exchange- and pulmonary perfusion-dependent, 3D MR images with a nominal resolution of 2×2×2 mm(3). We also show that the (129)Xe signal dynamics during EC infusion are well described by an analytical model that incorporates both mass transport into the blood and longitudinal relaxation. CONCLUSIONS Extracorporeal infusion of HP (129)Xe enables rapid, 3D MR imaging of rat lungs and, when combined with ventilation imaging, will permit spatially resolved studies of the ventilation-perfusion ratio in small animals. Moreover, EC infusion should allow (129)Xe to be delivered elsewhere in the body and make possible functional and molecular imaging approaches that are currently not feasible using inhaled HP (129)Xe.
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Affiliation(s)
- Zackary I. Cleveland
- Department of Radiology, Center for In Vivo Microscopy, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Harald E. Möller
- Department of Radiology, Center for In Vivo Microscopy, Duke University Medical Center, Durham, North Carolina, United States of America
- Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Laurence W. Hedlund
- Department of Radiology, Center for In Vivo Microscopy, Duke University Medical Center, Durham, North Carolina, United States of America
| | - John C. Nouls
- Department of Radiology, Center for In Vivo Microscopy, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Matthew S. Freeman
- Department of Radiology, Center for In Vivo Microscopy, Duke University Medical Center, Durham, North Carolina, United States of America
- Graduate Program in Medical Physics, Duke University, Durham, North Carolina, United States of America
| | - Yi Qi
- Department of Radiology, Center for In Vivo Microscopy, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Bastiaan Driehuys
- Department of Radiology, Center for In Vivo Microscopy, Duke University Medical Center, Durham, North Carolina, United States of America
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Ghosh RK, Kadlecek SJ, Ardenkjaer-Larsen JH, Pullinger BM, Pileio G, Levitt MH, Kuzma NN, Rizi RR. Measurements of the persistent singlet state of N2O in blood and other solvents--potential as a magnetic tracer. Magn Reson Med 2012; 66:1177-80. [PMID: 21928358 DOI: 10.1002/mrm.23119] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The development of hyperpolarized tracers has been limited by short nuclear polarization lifetimes. The dominant relaxation mechanism for many hyperpolarized agents in solution arises from intramolecular nuclear dipole-dipole coupling modulated by molecular motion. It has been previously demonstrated that nuclear spin relaxation due to this mechanism can be removed by storing the nuclear polarization in long-lived, singlet-like states. In the case of N(2)O, storing the polarization of the nitrogen nuclei has been shown to substantially increase the polarization lifetime. The feasibility of utilizing N(2)O as a tracer is investigated by measuring the singlet-state lifetime of the N(2)O when dissolved in a variety of solvents including whole blood. Comparison of the singlet lifetime to longitudinal relaxation and between protonated and deuterated solvents is consistent with the dominance of spin-rotation relaxation, except in the case of blood.
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Affiliation(s)
- R K Ghosh
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6056, USA.
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Möller HE, Cleveland ZI, Driehuys B. Relaxation of hyperpolarized 129Xe in a deflating polymer bag. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2011; 212:109-15. [PMID: 21752680 PMCID: PMC3163736 DOI: 10.1016/j.jmr.2011.06.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Revised: 06/17/2011] [Accepted: 06/19/2011] [Indexed: 05/09/2023]
Abstract
In magnetic resonance imaging with hyperpolarized (HP) noble gases, data is often acquired during prolonged gas delivery from a storage reservoir. However, little is known about the extent to which relaxation within the reservoir will limit the useful acquisition time. For quantitative characterization, 129Xe relaxation was studied in a bag made of polyvinyl fluoride (Tedlar). Particular emphasis was on wall relaxation, as this mechanism is expected to dominate. The HP 129Xe magnetization dynamics in the deflating bag were accurately described by a model assuming dissolution of Xe in the polymer matrix and dipolar relaxation with neighboring nuclear spins. In particular, the wall relaxation rate changed linearly with the surface-to-volume ratio and exhibited a relaxivity of κ=0.392±0.008 cm/h, which is in reasonable agreement with κ=0.331±0.051 cm/h measured in a static Tedlar bag. Estimates for the bulk gas-phase 129Xe relaxation yielded T1bulk=2.55±0.22 h, which is dominated by intrinsic Xe-Xe relaxation, with small additional contributions from magnetic field inhomogeneities and oxygen-induced relaxation. Calculations based on these findings indicate that relaxation may limit HP 129Xe experiments when slow gas delivery rates are employed as, for example, in mouse imaging or vascular infusion experiments.
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Affiliation(s)
- Harald E. Möller
- Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstr. 1a, 04103 Leipzig, Germany
- Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA
- Corresponding author: Prof. Dr. Harald E. Möller, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstr. 1a, 04103 Leipzig, Germany, Fax: +49 341 9940 2448
| | - Zackary I. Cleveland
- Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Bastiaan Driehuys
- Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA
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Stupic KF, Elkins ND, Pavlovskaya GE, Repine JE, Meersmann T. Effects of pulmonary inhalation on hyperpolarized krypton-83 magnetic resonance T1 relaxation. Phys Med Biol 2011; 56:3731-48. [PMID: 21628780 DOI: 10.1088/0031-9155/56/13/001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The (83)Kr magnetic resonance (MR) relaxation time T(1) of krypton gas in contact with model surfaces was previously found to be highly sensitive to surface composition, surface-to-volume ratio, and surface temperature. The work presented here explored aspects of pulmonary (83)Kr T(1) relaxation measurements in excised lungs from healthy rats using hyperpolarized (hp) (83)Kr with approximately 4.4% spin polarization. MR spectroscopy without spatial resolution was applied to the ex vivo lungs that actively inhale hp (83)Kr through a custom designed ventilation system. Various inhalation schemes were devised to study the influence of anatomical dead space upon the measured (83)Kr T(1) relaxation times. The longitudinal (83)Kr relaxation times in the distal airways and the respiratory zones were independent of the lung inhalation volume, with T(1) = 1.3 s and T(1) = 1.0 s, depending only on the applied inhalation scheme. The obtained data were highly reproducible between different specimens. Further, the (83)Kr T(1) relaxation times in excised lungs were unaffected by the presence of up to 40% oxygen in the hp gas mixture. The results support the possible importance of (83)Kr as a biomarker for evaluating lung function.
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Affiliation(s)
- K F Stupic
- Sir Peter Mansfield Magnetic Resonance Centre, School of Clinical Sciences, University of Nottingham, Nottingham, NG7 2RD, UK
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34
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Ma ZL, Sorte EG, Saam B. Collisional 3He and 129Xe frequency shifts in Rb-noble-gas mixtures. PHYSICAL REVIEW LETTERS 2011; 106:193005. [PMID: 21668151 DOI: 10.1103/physrevlett.106.193005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Indexed: 05/30/2023]
Abstract
The Fermi-contact interaction that characterizes collisional spin exchange of a noble gas with an alkali-metal vapor also gives rise to NMR and EPR frequency shifts of the noble-gas nucleus and the alkali-metal atom, respectively. We have measured the enhancement factor κ0 that characterizes these shifts for Rb-129Xe to be 493±31, making use of the previously measured value of κ0 for Rb-3He. This result allows accurate 129Xe polarimetry with no need to reference a thermal-equilibrium NMR signal.
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Affiliation(s)
- Z L Ma
- Department of Physics and Astronomy, University of Utah, 115 South 1400 East, Salt Lake City, Utah 84112-0830, USA
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35
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van Echteld CJA, Beckmann N. A View on Imaging in Drug Research and Development for Respiratory Diseases. J Pharmacol Exp Ther 2011; 337:335-349. [DOI: 10.1124/jpet.110.172635] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023] Open
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36
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Luna A, Sánchez-Gonzalez J, Caro P. Diffusion-weighted imaging of the chest. Magn Reson Imaging Clin N Am 2011; 19:69-94. [PMID: 21129636 DOI: 10.1016/j.mric.2010.09.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Diffusion-weighted imaging (DWI) is feasible in the chest with currently available MR imaging scanners, although it is technically demanding. Although there is scarce clinical experience, the use of DWI has shown promising results in the characterization of pulmonary nodules, in lung cancer characterization and staging, and in the evaluation of mediastinal and pleural pathology. Ongoing research opens a door to noninvasive evaluation of heart fibers by means of diffusion-tensor imaging. Another area under investigation is the use of DWI of hyperpolarized gases as an early biomarker of pulmonary disease.
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Affiliation(s)
- Antonio Luna
- MR Unit, SERCOSA, Health Time Group, Clinica las Nieves, Carmelo Torres 2, 23007 Jaén, Spain.
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37
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Arthurs OJ, Gallagher FA. Functional and molecular imaging with MRI: potential applications in paediatric radiology. Pediatr Radiol 2011; 41:185-98. [PMID: 20972674 DOI: 10.1007/s00247-010-1842-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2010] [Revised: 07/29/2010] [Accepted: 08/25/2010] [Indexed: 01/17/2023]
Abstract
MRI is a very versatile tool for noninvasive imaging and it is particularly attractive as an imaging technique in paediatric patients given the absence of ionizing radiation. Recent advances in the field of MRI have enabled tissue function to be probed noninvasively, and increasingly MRI is being used to assess cellular and molecular processes. For example, dynamic contrast-enhanced MRI has been used to assess tissue vascularity, diffusion-weighted imaging can quantify molecular movements of water in tissue compartments and MR spectroscopy provides a quantitative assessment of metabolite levels. A number of targeted contrast agents have been developed that bind specifically to receptors on the vascular endothelium or cell surface and there are several MR methods for labelling cells and tracking cellular movements. Hyperpolarization techniques have the capability of massively increasing the sensitivity of MRI and these have been used to image tissue pH, successful response to drug treatment as well as imaging the microstructure of the lungs. Although there are many challenges to be overcome before these techniques can be translated into routine paediatric imaging, they could potentially be used to aid diagnosis, predict disease outcome, target biopsies and determine treatment response noninvasively.
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Affiliation(s)
- Owen J Arthurs
- Department of Radiology, Addenbrooke's Hospital, Cambridge University Teaching Hospitals NHS Foundation Trust, University of Cambridge, Box 218, Level 5, Hills Road, Cambridge, CB2 0QQ, UK
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Abstract
Hyperpolarized noble gases ((3)He and (129)Xe) can provide NMR signal enhancements of 10,000 to 100,000 times that of thermally polarized gases and have shown great potential for applications in lung magnetic resonance imaging (MRI) by greatly enhancing the sensitivity and contrast. These gases obtain a highly polarized state by employing a spin exchange optical pumping technique. In this chapter, the underlying physics of spin exchange optical pumping for production of hyperpolarized noble gases is explained and the basic components and procedures for building a polarizer are described. The storage and delivery strategies of hyperpolarized gases for in vivo imaging are discussed. Many of the problems that are likely to be encountered in practical experiments and the corresponding detailed approaches to overcome them are also discussed.
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Affiliation(s)
- Xin Zhou
- Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, 430071 Wuhan, Hubei Province, China.
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Zhang LJ, Wang ZJ, Lu L, Zhu K, Chai X, Zhao YE, Peng J, Lu GM. Dual energy CT ventilation imaging after aerosol inhalation of iodinated contrast medium in rabbits. Eur J Radiol 2010; 78:266-71. [PMID: 21109377 DOI: 10.1016/j.ejrad.2010.10.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Revised: 10/11/2010] [Accepted: 10/20/2010] [Indexed: 11/30/2022]
Abstract
PURPOSE To assess the feasibility of dual energy CT (DECT) after aerosol inhalation of iodinated contrast medium for the evaluation of ventilation function in rabbits with airway obstruction. MATERIALS AND METHODS The study was approved by our institutional animal experimental committee and performed according to animal care guidelines. Airway obstruction was created by injecting gelatin sponge into the right bronchus of 6 New Zealand rabbits. One additional rabbit served as control without airway obstruction. All 7 rabbits then underwent inhalation of aerosol iodinated contrast medium for 5 min, followed by DECT of the lungs from which ventilation CT images were created. CT number and overlay value (calculated iodine enhancement on the ventilation images in hounsfield unit) of the obstructed and non-obstructed lung lobes were measured at 80-kVp, 140-kVp, and weighted average 120-kVp. Immediately after DECT scan, the rabbits were sacrificed, the lungs were removed and detailed pathological examination of the locations and parenchymal changes of the obstructed lung lobes were performed and correlated with DECT ventilation imaging findings. RESULTS Data from one rabbit with airway obstruction were excluded because of post-procedure pneumatothorax. Seventeen normal lung lobes without airway obstruction proven by histopathology had nearly homogeneous ventilation, while 13 abnormal lung lobes had ventilation defects on DECT ventilation images. CT numbers and overlay values of the normal (CT number, -737.77 ± 71.46 HU, -768.84 ± 73.86 HU, -731.86 ± 65.92 HU for 140-kVp, 80-kVp, and weighted average 120-kVp; overlay value, 46.58 ± 19.49 HU) and abnormal lung lobes (CT number, -183.58 ± 173.37 HU, -124.93 ± 242.23 HU, -166.07 ± 191.57 HU for 140-kVp, 80-kVp, and weighted average 120-kVp; overlay value, 0.00 ± 0.00 HU) were significantly different at 80-kVp, 140-kVp, and weighted average 120-kVp (P < 0.001 for all). Diffuse hemorrhage, inflammatory cell infiltration, and exudation were observed at histopathology in the obstructed lung lobes. CONCLUSIONS It is feasible to study regional lung ventilation function using DECT after aerosol inhalation of iodinated contrast medium in rabbit. The safety of inhalation of iodine contrast medium is unknown, and has to be investigated further before use of this new method in humans.
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Affiliation(s)
- Long-Jiang Zhang
- Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, 305 Zhongshan East Road, Xuanwu District, Nanjing, Jiangsu 210002, China
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Comment A, Jannin S, Hyacinthe JN, Miéville P, Sarkar R, Ahuja P, Vasos PR, Montet X, Lazeyras F, Vallée JP, Hautle P, Konter JA, van den Brandt B, Ansermet JP, Gruetter R, Bodenhausen G. Hyperpolarizing gases via dynamic nuclear polarization and sublimation. PHYSICAL REVIEW LETTERS 2010; 105:018104. [PMID: 20867484 DOI: 10.1103/physrevlett.105.018104] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2010] [Indexed: 05/29/2023]
Abstract
A high throughput method was designed to produce hyperpolarized gases by combining low-temperature dynamic nuclear polarization with a sublimation procedure. It is illustrated by applications to 129Xe nuclear magnetic resonance in xenon gas, leading to a signal enhancement of 3 to 4 orders of magnitude compared to the room-temperature thermal equilibrium signal at 7.05 T.
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Affiliation(s)
- A Comment
- Laboratory for Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
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Taratula O, Dmochowski IJ. Functionalized 129Xe contrast agents for magnetic resonance imaging. Curr Opin Chem Biol 2009; 14:97-104. [PMID: 19914122 DOI: 10.1016/j.cbpa.2009.10.009] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2009] [Revised: 10/02/2009] [Accepted: 10/08/2009] [Indexed: 10/20/2022]
Abstract
The concept of 'xenon biosensor' for magnetic resonance imaging (MRI) was first proposed by a Berkeley team in 2001, with evidence that hyperpolarized 129Xe bound to a biotin-labeled cryptophane can detect streptavidin at much lower concentrations (nM-microM) than is typical for contrast-enhanced MRI experiments. 129Xe biosensors have undergone many recent developments to address challenges in molecular imaging. For example, cryptophanes that exhibit 10-fold higher xenon affinity with distinct 129Xe magnetic resonance spectra have been synthesized. Also relevant are dendrimeric cryptophane assemblies and inorganic zeolites that localize many 129Xe atoms to rare targets. Finally, this article considers biosensors that produce measurable changes in 129Xe chemical shift based upon the activity of oligonucleotides, proteins, or enzymes, and includes the first cell studies.
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Affiliation(s)
- Olena Taratula
- Department of Chemistry, University of Pennsylvania, 231 South 34th St., Philadelphia, PA 19104-6323, USA
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Cleveland ZI, Möller HE, Hedlund LW, Driehuys B. Continuously infusing hyperpolarized 129Xe into flowing aqueous solutions using hydrophobic gas exchange membranes. J Phys Chem B 2009; 113:12489-99. [PMID: 19702286 PMCID: PMC2747043 DOI: 10.1021/jp9049582] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hyperpolarized (HP) (129)Xe yields high signal intensities in nuclear magnetic resonance (NMR) and, through its large chemical shift range of approximately 300 ppm, provides detailed information about the local chemical environment. To exploit these properties in aqueous solutions and living tissues requires the development of methods for efficiently dissolving HP (129)Xe over an extended time period. To this end, we have used commercially available gas exchange modules to continuously infuse concentrated HP (129)Xe into flowing liquids, including rat whole blood, for periods as long as one hour and have demonstrated the feasibility of dissolved-phase MR imaging with submillimeter resolution within minutes. These modules, which exchange gases using hydrophobic microporous polymer membranes, are compatible with a variety of liquids and are suitable for infusing HP (129)Xe into the bloodstream in vivo. Additionally, we have developed a detailed mathematical model of the infused HP (129)Xe signal dynamics that should be useful in designing improved infusion systems that yield even higher dissolved HP (129)Xe signal intensities.
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Loring SH, Butler JP, Patz S. Science to practice: how do we interpret the transfer of hyperpolarized 129Xe from blood into alveolar gas? Radiology 2009; 252:319-21. [PMID: 19703872 DOI: 10.1148/radiol.2522090555] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Stephen H Loring
- Department of Anesthesia and Critical Care, Beth Israel Deaconess Hospital, Harvard Medical School, 330 Brookline Ave, Dana 717, Boston, MA 02215, USA.
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