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Chen J, Pal P, Ahrens ET. Enhanced detection of paramagnetic fluorine-19 magnetic resonance imaging agents using zero echo time sequence and compressed sensing. NMR IN BIOMEDICINE 2022; 35:e4725. [PMID: 35262991 PMCID: PMC10655826 DOI: 10.1002/nbm.4725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 02/25/2022] [Accepted: 03/04/2022] [Indexed: 06/14/2023]
Abstract
Fluorine-19 (19 F) magnetic resonance imaging (MRI) is an emerging technique offering specific detection of labeled cells in vivo. Lengthy acquisition times and modest signal-to-noise ratio (SNR) makes three-dimensional spin-density-weighted 19 F imaging challenging. Recent advances in tracer paramagnetic metallo-perfluorocarbon (MPFC) nanoemulsion probes have shown multifold SNR improvements due to an accelerated 19 F T1 relaxation rate and a commensurate gain in imaging speed and averages. However, 19 F T2 -reduction and increased linewidth limit the amount of metal additive in MPFC probes, thus constraining the ultimate SNR. To overcome these barriers, we describe a compressed sampling (CS) scheme, implemented using a "zero" echo time (ZTE) sequence, with data reconstructed via a sparsity-promoting algorithm. Our CS-ZTE scheme acquires k-space data using an undersampled spherical radial pattern and signal averaging. Image reconstruction employs off-the-shelf sparse solvers to solve a joint total variation and l 1 -norm regularized least square problem. To evaluate CS-ZTE, we performed simulations and acquired 19 F MRI data at 11.7 T in phantoms and mice receiving MPFC-labeled dendritic cells. For MPFC-labeled cells in vivo, we show SNR gains of ~6.3 × with 8-fold undersampling. We show that this enhancement is due to three mechanisms including undersampling and commensurate increase in signal averaging in a fixed scan time, denoising attributes from the CS algorithm, and paramagnetic reduction of T1 . Importantly, 19 F image intensity analyses yield accurate estimates of absolute quantification of 19 F spins. Overall, the CS-ZTE method using MPFC probes achieves ultrafast imaging, a substantial boost in detection sensitivity, accurate 19 F spin quantification, and minimal image artifacts.
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Affiliation(s)
- Jiawen Chen
- Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, California, USA
| | - Piya Pal
- Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, California, USA
| | - Eric T. Ahrens
- Department of Radiology, University of California San Diego, La Jolla, California, USA
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2
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Inhaled Gas Magnetic Resonance Imaging: Advances, Applications, Limitations, and New Frontiers. Mol Imaging 2021. [DOI: 10.1016/b978-0-12-816386-3.00013-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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3
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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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4
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Neal MA, Pippard BJ, Simpson AJ, Thelwall PE. Dynamic susceptibility contrast 19 F-MRI of inhaled perfluoropropane: a novel approach to combined pulmonary ventilation and perfusion imaging. Magn Reson Med 2019; 83:452-461. [PMID: 31468589 PMCID: PMC6899496 DOI: 10.1002/mrm.27933] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 07/12/2019] [Accepted: 07/16/2019] [Indexed: 12/19/2022]
Abstract
PURPOSE To assess alveolar perfusion by applying dynamic susceptibility contrast MRI to 19 F-MRI of inhaled perfluoropropane (PFP). We hypothesized that passage of gadolinium-based contrast agent (GBCA) through the pulmonary microvasculature would reduce magnetic susceptibility differences between water and gas components of the lung, elevating the T 2 ∗ of PFP. METHODS Lung-representative phantoms were constructed of aqueous PFP-filled foams to characterize the impact of aqueous/gas phase magnetic susceptibility differences on PFP T 2 ∗ . Aqueous phase magnetic susceptibility was modulated by addition of different concentrations of GBCA. In vivo studies were performed to measure the impact of intravenously administered GBCA on the T 2 ∗ of inhaled PFP in mice (7.0 Tesla) and in healthy volunteers (3.0 Tesla). RESULTS Perfluoropropane T 2 ∗ was sensitive to modulation of magnetic susceptibility difference between gas and water components of the lung, both in phantom models and in vivo. Negation of aqueous/gas phase magnetic susceptibility difference was achieved in lung-representative phantoms and in mice, resulting in a ~2 to 3× elevation in PFP T 2 ∗ (3.7 to 8.5 ms and 0.7 to 2.6 ms, respectively). Human studies demonstrated a transient elevation of inhaled PFP T 2 ∗ (1.50 to 1.64 ms) during passage of GBCA bolus through the lung circulation, demonstrating sensitivity to lung perfusion. CONCLUSION We demonstrate indirect detection of a GBCA in the pulmonary microvasculature via changes to the T 2 ∗ of gas phase PFP within directly adjacent alveoli. This approach holds potential for assessing alveolar perfusion by dynamic susceptibility contrast 19 F-MRI of inhaled PFP, with concurrent assessment of lung ventilation properties, relevant to lung physiology and disease.
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Affiliation(s)
- Mary A Neal
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom.,Newcastle Magnetic Resonance Centre, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Benjamin J Pippard
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom.,Newcastle Magnetic Resonance Centre, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - A John Simpson
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom.,Respiratory Medicine, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, United Kingdom
| | - Peter E Thelwall
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom.,Newcastle Magnetic Resonance Centre, Newcastle University, Newcastle upon Tyne, United Kingdom
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5
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Neal MA, Pippard BJ, Hollingsworth KG, Maunder A, Dutta P, Simpson AJ, Blamire AM, Wild JM, Thelwall PE. Optimized and accelerated 19 F-MRI of inhaled perfluoropropane to assess regional pulmonary ventilation. Magn Reson Med 2019; 82:1301-1311. [PMID: 31099437 PMCID: PMC6767591 DOI: 10.1002/mrm.27805] [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: 11/08/2018] [Revised: 03/12/2019] [Accepted: 04/15/2019] [Indexed: 12/14/2022]
Abstract
PURPOSE To accelerate 19 F-MR imaging of inhaled perfluoropropane using compressed sensing methods, and to optimize critical scan acquisition parameters for assessment of lung ventilation properties. METHODS Simulations were performed to determine optimal acquisition parameters for maximal perfluoropropane signal-to-noise ratio (SNR) in human lungs for a spoiled gradient echo sequence. Optimized parameters were subsequently employed for 19 F-MRI of inhaled perfluoropropane in a cohort of 11 healthy participants using a 3.0 T scanner. The impact of 1.8×, 2.4×, and 3.0× undersampling ratios on 19 F-MRI acquisitions was evaluated, using both retrospective and prospective compressed sensing methods. RESULTS 3D spoiled gradient echo 19 F-MR ventilation images were acquired at 1-cm isotropic resolution within a single breath hold. Mean SNR was 11.7 ± 4.1 for scans acquired within a single breath hold (duration = 18 s). Acquisition of 19 F-MRI scans at shorter scan durations (4.5 s) was also demonstrated as feasible. Application of both retrospective (n = 8) and prospective (n = 3) compressed sensing methods demonstrated that 1.8× acceleration had negligible impact on qualitative image appearance, with no statistically significant change in measured lung ventilated volume. Acceleration factors of 2.4× and 3.0× resulted in increasing differences between fully sampled and undersampled datasets. CONCLUSION This study demonstrates methods for determining optimal acquisition parameters for 19 F-MRI of inhaled perfluoropropane and shows significant reduction in scan acquisition times (and thus participant breath hold duration) by use of compressed sensing.
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Affiliation(s)
- Mary A Neal
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom.,Newcastle Magnetic Resonance Centre, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Benjamin J Pippard
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom.,Newcastle Magnetic Resonance Centre, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Kieren G Hollingsworth
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom.,Newcastle Magnetic Resonance Centre, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Adam Maunder
- POLARIS, Academic Unit of Radiology, University of Sheffield, Royal Hallamshire Hospital, Sheffield, United Kingdom
| | - Prosenjit Dutta
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - A John Simpson
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom.,Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, United Kingdom
| | - Andrew M Blamire
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom.,Newcastle Magnetic Resonance Centre, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - James M Wild
- POLARIS, Academic Unit of Radiology, University of Sheffield, Royal Hallamshire Hospital, Sheffield, United Kingdom
| | - Peter E Thelwall
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom.,Newcastle Magnetic Resonance Centre, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, United Kingdom
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6
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Couch MJ, Ball IK, Li T, Fox MS, Biman B, Albert MS. 19 F MRI of the Lungs Using Inert Fluorinated Gases: Challenges and New Developments. J Magn Reson Imaging 2018; 49:343-354. [PMID: 30248212 DOI: 10.1002/jmri.26292] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 07/23/2018] [Accepted: 07/26/2018] [Indexed: 12/27/2022] Open
Abstract
Fluorine-19 (19 F) MRI using inhaled inert fluorinated gases is an emerging technique that can provide functional images of the lungs. Inert fluorinated gases are nontoxic, abundant, relatively inexpensive, and the technique can be performed on any MRI scanner with broadband multinuclear imaging capabilities. Pulmonary 19 F MRI has been performed in animals, healthy human volunteers, and in patients with lung disease. In this review, the technical requirements of 19 F MRI are discussed, along with various imaging approaches used to optimize the image quality. Lung imaging is typically performed in humans using a gas mixture containing 79% perfluoropropane (PFP) or sulphur hexafluoride (SF6 ) and 21% oxygen. In lung diseases, such as asthma, chronic obstructive pulmonary disease (COPD), and cystic fibrosis (CF), ventilation defects are apparent in regions that the inhaled gas cannot access. 19 F lung images are typically acquired in a single breath-hold, or in a time-resolved, multiple breath fashion. The former provides measurements of the ventilation defect percent (VDP), while the latter provides measurements of gas replacement (ie, fractional ventilation). Finally, preliminary comparisons with other functional lung imaging techniques are discussed, such as Fourier decomposition MRI and hyperpolarized gas MRI. Overall, functional 19 F lung MRI is expected to complement existing proton-based structural imaging techniques, and the combination of structural and functional lung MRI will provide useful outcome measures in the future management of pulmonary diseases in the clinic. Level of Evidence: 3 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;49:343-354.
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Affiliation(s)
- Marcus J Couch
- Translational Medicine Program, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Iain K Ball
- Philips Electronics Australia, North Ryde, Sydney, Australia
| | - Tao Li
- Department of Chemistry, Lakehead University, Thunder Bay, Ontario, Canada
| | - Matthew S Fox
- Imaging Program, Lawson Health Research Institute, London, Ontario, Canada.,Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada
| | - Birubi Biman
- Thunder Bay Regional Health Sciences Centre, Thunder Bay, Ontario, Canada.,Northern Ontario School of Medicine, Thunder Bay, Ontario, Canada.,Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Mitchell S Albert
- Department of Chemistry, Lakehead University, Thunder Bay, Ontario, Canada.,Northern Ontario School of Medicine, Thunder Bay, Ontario, Canada.,Thunder Bay Regional Health Research Institute, Thunder Bay, Ontario, Canada
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7
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Gómez-Vallejo V, Lekuona A, Baz Z, Szczupak B, Cossío U, Llop J. Ion beam induced 18F-radiofluorination: straightforward synthesis of gaseous radiotracers for the assessment of regional lung ventilation using positron emission tomography. Chem Commun (Camb) 2018; 52:11931-11934. [PMID: 27711291 DOI: 10.1039/c6cc06249k] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A simple, straightforward and efficient method for the synthesis of [18F]CF4 and [18F]SF6 based on an ion beam-induced isotopic exchange reaction is presented. Positron emission tomography ventilation studies in rodents using [18F]CF4 showed a uniform distribution of the radiofluorinated gas within the lungs and rapid elimination after discontinuation of the administration.
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Affiliation(s)
- V Gómez-Vallejo
- Molecular Imaging Unit, CIC biomaGUNE, Paseo Miramón 182, 20009 San Sebastián, Guipúzcoa, Spain.
| | - A Lekuona
- Molecular Imaging Unit, CIC biomaGUNE, Paseo Miramón 182, 20009 San Sebastián, Guipúzcoa, Spain.
| | - Z Baz
- Molecular Imaging Unit, CIC biomaGUNE, Paseo Miramón 182, 20009 San Sebastián, Guipúzcoa, Spain.
| | - B Szczupak
- Molecular Imaging Unit, CIC biomaGUNE, Paseo Miramón 182, 20009 San Sebastián, Guipúzcoa, Spain.
| | - U Cossío
- Molecular Imaging Unit, CIC biomaGUNE, Paseo Miramón 182, 20009 San Sebastián, Guipúzcoa, Spain.
| | - J Llop
- Molecular Imaging Unit, CIC biomaGUNE, Paseo Miramón 182, 20009 San Sebastián, Guipúzcoa, Spain.
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8
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Wielpütz MO, Kauczor HU. Imaging cystic fibrosis lung disease with MRI. IMAGING 2016. [DOI: 10.1183/2312508x.10002415] [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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9
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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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10
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Couch MJ, Ball IK, Li T, Fox MS, Ouriadov AV, Biman B, Albert MS. Inert fluorinated gas MRI: a new pulmonary imaging modality. NMR IN BIOMEDICINE 2014; 27:1525-1534. [PMID: 25066661 DOI: 10.1002/nbm.3165] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 06/06/2014] [Accepted: 06/12/2014] [Indexed: 06/03/2023]
Abstract
Fluorine-19 ((19)F) MRI of the lungs using inhaled inert fluorinated gases can potentially provide high quality images of the lungs that are similar in quality to those from hyperpolarized (HP) noble gas MRI. Inert fluorinated gases have the advantages of being nontoxic, abundant, and inexpensive compared with HP gases. Due to the high gyromagnetic ratio of (19)F, there is sufficient thermally polarized signal for imaging, and averaging within a single breath-hold is possible due to short longitudinal relaxation times. Therefore, the gases do not need to be hyperpolarized prior to their use in MRI. This eliminates the need for an expensive polarizer and expensive isotopes. Inert fluorinated gas MRI of the lungs has been previously demonstrated in animals, and more recently in healthy volunteers and patients with lung diseases. The ongoing improvements in image quality demonstrate the potential of (19)F MRI for visualizing the distribution of ventilation in human lungs and detecting functional biomarkers. In this brief review, the development of inert fluorinated gas MRI, current progress, and future prospects are discussed. The current state of HP noble gas MRI is also briefly discussed in order to provide context to the development of this new imaging modality. Overall, this may be a viable clinical imaging modality that can provide useful information for the diagnosis and management of chronic respiratory diseases.
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Affiliation(s)
- Marcus J Couch
- Lakehead University, Thunder Bay, Ontario, Canada; Thunder Bay Regional Research Institute, Thunder Bay, Ontario, Canada
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11
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Halaweish AF, Moon RE, Foster WM, Soher BJ, McAdams HP, MacFall JR, Ainslie MD, MacIntyre NR, Charles HC. Perfluoropropane gas as a magnetic resonance lung imaging contrast agent in humans. Chest 2014; 144:1300-1310. [PMID: 23722696 DOI: 10.1378/chest.12-2597] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
BACKGROUND Fluorine-enhanced MRI is a relatively inexpensive and straightforward technique that facilitates regional assessments of pulmonary ventilation. In this report, we assess its suitability through the use of perfluoropropane (PFP) in a cohort of human subjects with normal lungs and subjects with lung disease. METHODS Twenty-eight subjects between the ages of 18 and 71 years were recruited for imaging and were classified based on spirometry findings and medical history. Imaging was carried out on a Siemens TIM Trio 3T MRI scanner using two-dimensional, gradient echo, fast low-angle shot and three-dimensional gradient echo, volumetric, interpolated, breath-hold examination sequences for proton localizers and PFP functional scans, respectively. Respiratory waveforms and physiologic signals of interest were monitored throughout the imaging sessions. A region-growing algorithm was applied to the proton localizers to define the lung field of view for analysis of the PFP scans. RESULTS All subjects tolerated the gas mixture well with no adverse side effects. Images of healthy lungs demonstrated a homogeneous distribution of the gas with sufficient signal-to-noise ratios, while lung images from asthmatic and emphysematous lungs demonstrated increased heterogeneity and ventilation defects. CONCLUSIONS Fluorine-enhanced MRI using a normoxic PFP gas mixture is a well-tolerated, radiation-free technique for regionally assessing pulmonary ventilation. The inherent physical characteristics and applicability of the gaseous agent within a magnetic resonance setting facilitated a clear differentiation between normal and diseased lungs.
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Affiliation(s)
- Ahmed F Halaweish
- Department of Radiology, Durham NC; Department of Radiology, Duke Image Analysis Laboratory, Duke University School of Medicine, Durham NC
| | - Richard E Moon
- Department of Medicine, Division of Pulmonary Medicine, Durham NC; Department of Anesthesiology, GVTU Division, Durham NC
| | - W Michael Foster
- Department of Medicine, Division of Pulmonary Medicine, Durham NC
| | | | - H Page McAdams
- Department of Radiology, Division of Chest Radiology, Durham NC
| | | | - Maureen D Ainslie
- Department of Radiology, Durham NC; Department of Radiology, Duke Image Analysis Laboratory, Duke University School of Medicine, Durham NC
| | - Neil R MacIntyre
- Department of Medicine, Division of Pulmonary Medicine, Durham NC
| | - H Cecil Charles
- Department of Radiology, Durham NC; Department of Radiology, Duke Image Analysis Laboratory, Duke University School of Medicine, Durham NC.
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12
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Couch MJ, Ball IK, Li T, Fox MS, Littlefield SL, Biman B, Albert MS. Pulmonary Ultrashort Echo Time19F MR Imaging with Inhaled Fluorinated Gas Mixtures in Healthy Volunteers: Feasibility. Radiology 2013; 269:903-9. [DOI: 10.1148/radiol.13130609] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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13
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Terekhov M, Scholz A, Schreiber LM. Measurement of anesthetic uptake kinetics in the brain using (19)F MRI and cross-correlation analysis after pulsed application. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2013; 27:107-11. [PMID: 23760558 DOI: 10.1007/s10334-013-0380-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 04/25/2013] [Accepted: 05/02/2013] [Indexed: 11/29/2022]
Abstract
OBJECT We present a pilot study based on (19)F-MRI to measure fast and slow wash-in and wash-out kinetics of volatile anesthetics in pig brain. METHOD The periodic administration of anesthetics in pulsed mode is used to enhance the sensitivity of the anesthetic concentration detection by (19)F-MRI signal. Temporal correlation analysis allows mapping the kinetics time constants. RESULTS The clear correlation response to anesthetics concentration changes was found in the brain region in comparison with fatty tissues. CONCLUSION The methodology may yield important pharmacological findings on regional effect of the anesthetics in brain and be a step towards human studies.
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Affiliation(s)
- Maxim Terekhov
- Department of Radiology, Section of Medical Physics, Johannes Gutenberg University Medical Center Mainz, Langenbeckstrasse 1, 55131, Mainz, Germany,
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14
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Biederer J, Beer M, Hirsch W, Wild J, Fabel M, Puderbach M, Van Beek EJR. MRI of the lung (2/3). Why … when … how? Insights Imaging 2012; 3:355-71. [PMID: 22695944 PMCID: PMC3481084 DOI: 10.1007/s13244-011-0146-8] [Citation(s) in RCA: 145] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Revised: 11/20/2011] [Accepted: 12/19/2011] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Among the modalities for lung imaging, proton magnetic resonance imaging (MRI) has been the latest to be introduced into clinical practice. Its value to replace X-ray and computed tomography (CT) when radiation exposure or iodinated contrast material is contra-indicated is well acknowledged: i.e. for paediatric patients and pregnant women or for scientific use. One of the reasons why MRI of the lung is still rarely used, except in a few centres, is the lack of consistent protocols customised to clinical needs. METHODS This article makes non-vendor-specific protocol suggestions for general use with state-of-the-art MRI scanners, based on the available literature and a consensus discussion within a panel of experts experienced in lung MRI. RESULTS Various sequences have been successfully tested within scientific or clinical environments. MRI of the lung with appropriate combinations of these sequences comprises morphological and functional imaging aspects in a single examination. It serves in difficult clinical problems encountered in daily routine, such as assessment of the mediastinum and chest wall, and even might challenge molecular imaging techniques in the near future. CONCLUSION This article helps new users to implement appropriate protocols on their own MRI platforms. Main Messages • MRI of the lung can be readily performed on state-of-the-art 1.5-T MRI scanners. • Protocol suggestions based on the available literature facilitate its use for routine • MRI offers solutions for complicated thoracic masses with atelectasis and chest wall invasion. • MRI is an option for paediatrics and science when CT is contra-indicated.
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Affiliation(s)
- J Biederer
- University Hospital Schleswig-Holstein, Campus Kiel, Department of Diagnostic Radiology, Arnold-Heller-Straße 3, Haus 23, 24105, Kiel, Germany,
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15
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Ruiz-Cabello J, Barnett BP, Bottomley PA, Bulte JW. Fluorine (19F) MRS and MRI in biomedicine. NMR IN BIOMEDICINE 2011; 24:114-29. [PMID: 20842758 PMCID: PMC3051284 DOI: 10.1002/nbm.1570] [Citation(s) in RCA: 366] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2009] [Revised: 04/23/2010] [Accepted: 04/26/2010] [Indexed: 05/04/2023]
Abstract
Shortly after the introduction of (1)H MRI, fluorinated molecules were tested as MR-detectable tracers or contrast agents. Many fluorinated compounds, which are nontoxic and chemically inert, are now being used in a broad range of biomedical applications, including anesthetics, chemotherapeutic agents, and molecules with high oxygen solubility for respiration and blood substitution. These compounds can be monitored by fluorine ((19)F) MRI and/or MRS, providing a noninvasive means to interrogate associated functions in biological systems. As a result of the lack of endogenous fluorine in living organisms, (19)F MRI of 'hotspots' of targeted fluorinated contrast agents has recently opened up new research avenues in molecular and cellular imaging. This includes the specific targeting and imaging of cellular surface epitopes, as well as MRI cell tracking of endogenous macrophages, injected immune cells and stem cell transplants.
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Affiliation(s)
- Jesús Ruiz-Cabello
- Russell H. Morgan Department of Radiology, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Vascular Biology Program and Cellular Imaging Section, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, USA
- NMR Group, Institute of Functional Studies, Complutense University and CIBERES, Madrid, Spain
| | - Brad P. Barnett
- Russell H. Morgan Department of Radiology, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Vascular Biology Program and Cellular Imaging Section, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, USA
| | - Paul A. Bottomley
- Russell H. Morgan Department of Radiology, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jeff W.M. Bulte
- Russell H. Morgan Department of Radiology, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Vascular Biology Program and Cellular Imaging Section, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, USA
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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Magnetic Resonance Imaging and Computational Fluid Dynamics of High Frequency Oscillatory Ventilation (HFOV). ACTA ACUST UNITED AC 2011. [DOI: 10.1007/978-3-642-20326-8_7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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17
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Fusaro L, Locci E, Lai A, Luhmer M. Highlighting cavities in proteins by NMR using sulfur hexafluoride as a spy molecule. J Phys Chem B 2010; 114:3398-403. [PMID: 20163136 DOI: 10.1021/jp100098u] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Cavities in proteins can be studied experimentally by using some detectable atoms, such as xenon, or molecules which act as reporter, such as a spy. The interest of sulfur hexafluoride (SF(6)) for probing hydrophobic cavities by solution-state NMR is investigated. The wheat nonspecific lipid transfer protein (LTP) was selected as a model system for this purpose. The binding of SF(6) is straightforwardly detected by the (19)F chemical shift, line width, or longitudinal relaxation time measurements, which can be carried out at low SF(6) concentration without interference from resonances of the protein. Most interestingly, the binding of SF(6) gives rise to selective intermolecular (1)H{(19)F} heteronuclear Overhauser effects (HOEs). Molecular dynamics simulation and NMR spectrum modeling show that the experimental HOESY spectra are consistent with (1)H{(19)F} HOEs arising from SF(6) in the cavity of LTP. SF(6) is found to be an advantageous alternative to hyperpolarized (129)Xe and small organic compounds for probing cavities in proteins by solution-state NMR.
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Affiliation(s)
- Luca Fusaro
- Dipartimento di Scienze Chimiche, Università di Cagliari, Cittadella Universitaria di Monserrato, 09042 Monserrato (CA), Italy
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Pinjari RV, Gejji SP. On the Binding of SF6 to Cucurbit[6]uril Host: Density Functional Investigations. J Phys Chem A 2010; 114:2338-43. [PMID: 20070110 DOI: 10.1021/jp9090602] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Rahul V. Pinjari
- Department of Chemistry, University of Pune, Ganeshkhind, Pune 411007, India
| | - Shridhar P. Gejji
- Department of Chemistry, University of Pune, Ganeshkhind, Pune 411007, India
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