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Elbehairy AF, Marshall H, Naish JH, Wild JM, Parraga G, Horsley A, Vestbo J. Advances in COPD imaging using CT and MRI: linkage with lung physiology and clinical outcomes. Eur Respir J 2024; 63:2301010. [PMID: 38548292 DOI: 10.1183/13993003.01010-2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 03/16/2024] [Indexed: 05/04/2024]
Abstract
Recent years have witnessed major advances in lung imaging in patients with COPD. These include significant refinements in images obtained by computed tomography (CT) scans together with the introduction of new techniques and software that aim for obtaining the best image whilst using the lowest possible radiation dose. Magnetic resonance imaging (MRI) has also emerged as a useful radiation-free tool in assessing structural and more importantly functional derangements in patients with well-established COPD and smokers without COPD, even before the existence of overt changes in resting physiological lung function tests. Together, CT and MRI now allow objective quantification and assessment of structural changes within the airways, lung parenchyma and pulmonary vessels. Furthermore, CT and MRI can now provide objective assessments of regional lung ventilation and perfusion, and multinuclear MRI provides further insight into gas exchange; this can help in structured decisions regarding treatment plans. These advances in chest imaging techniques have brought new insights into our understanding of disease pathophysiology and characterising different disease phenotypes. The present review discusses, in detail, the advances in lung imaging in patients with COPD and how structural and functional imaging are linked with common resting physiological tests and important clinical outcomes.
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Affiliation(s)
- Amany F Elbehairy
- Department of Chest Diseases, Faculty of Medicine, Alexandria University, Alexandria, Egypt
- Division of Infection, Immunity and Respiratory Medicine, The University of Manchester and Manchester University NHS Foundation Trust, Manchester Academic Health Sciences Centre, Manchester, UK
| | - Helen Marshall
- POLARIS, Imaging, Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Josephine H Naish
- MCMR, Manchester University NHS Foundation Trust, Manchester, UK
- Bioxydyn Limited, Manchester, UK
| | - Jim M Wild
- POLARIS, Imaging, Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK
- Insigneo Institute for in silico Medicine, Sheffield, UK
| | - Grace Parraga
- Robarts Research Institute, Western University, London, ON, Canada
- Department of Medical Biophysics, Western University, London, ON, Canada
- Division of Respirology, Western University, London, ON, Canada
| | - Alexander Horsley
- Division of Infection, Immunity and Respiratory Medicine, The University of Manchester and Manchester University NHS Foundation Trust, Manchester Academic Health Sciences Centre, Manchester, UK
| | - Jørgen Vestbo
- Division of Infection, Immunity and Respiratory Medicine, The University of Manchester and Manchester University NHS Foundation Trust, Manchester Academic Health Sciences Centre, Manchester, UK
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Babaeipour R, Ouriadov A, Fox MS. Deep Learning Approaches for Quantifying Ventilation Defects in Hyperpolarized Gas Magnetic Resonance Imaging of the Lung: A Review. Bioengineering (Basel) 2023; 10:1349. [PMID: 38135940 PMCID: PMC10740978 DOI: 10.3390/bioengineering10121349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 11/06/2023] [Accepted: 11/21/2023] [Indexed: 12/24/2023] Open
Abstract
This paper provides an in-depth overview of Deep Neural Networks and their application in the segmentation and analysis of lung Magnetic Resonance Imaging (MRI) scans, specifically focusing on hyperpolarized gas MRI and the quantification of lung ventilation defects. An in-depth understanding of Deep Neural Networks is presented, laying the groundwork for the exploration of their use in hyperpolarized gas MRI and the quantification of lung ventilation defects. Five distinct studies are examined, each leveraging unique deep learning architectures and data augmentation techniques to optimize model performance. These studies encompass a range of approaches, including the use of 3D Convolutional Neural Networks, cascaded U-Net models, Generative Adversarial Networks, and nnU-net for hyperpolarized gas MRI segmentation. The findings highlight the potential of deep learning methods in the segmentation and analysis of lung MRI scans, emphasizing the need for consensus on lung ventilation segmentation methods.
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Affiliation(s)
- Ramtin Babaeipour
- School of Biomedical Engineering, Faculty of Engineering, The University of Western Ontario, London, ON N6A 3K7, Canada;
| | - Alexei Ouriadov
- School of Biomedical Engineering, Faculty of Engineering, The University of Western Ontario, London, ON N6A 3K7, Canada;
- Department of Physics and Astronomy, The University of Western Ontario, London, ON N6A 3K7, Canada;
- Lawson Health Research Institute, London, ON N6C 2R5, Canada
| | - Matthew S. Fox
- Department of Physics and Astronomy, The University of Western Ontario, London, ON N6A 3K7, Canada;
- Lawson Health Research Institute, London, ON N6C 2R5, Canada
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Foo CT, Langton D, Thompson BR, Thien F. Functional lung imaging using novel and emerging MRI techniques. Front Med (Lausanne) 2023; 10:1060940. [PMID: 37181360 PMCID: PMC10166823 DOI: 10.3389/fmed.2023.1060940] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 04/03/2023] [Indexed: 05/16/2023] Open
Abstract
Respiratory diseases are leading causes of death and disability in the world. While early diagnosis is key, this has proven difficult due to the lack of sensitive and non-invasive tools. Computed tomography is regarded as the gold standard for structural lung imaging but lacks functional information and involves significant radiation exposure. Lung magnetic resonance imaging (MRI) has historically been challenging due to its short T2 and low proton density. Hyperpolarised gas MRI is an emerging technique that is able to overcome these difficulties, permitting the functional and microstructural evaluation of the lung. Other novel imaging techniques such as fluorinated gas MRI, oxygen-enhanced MRI, Fourier decomposition MRI and phase-resolved functional lung imaging can also be used to interrogate lung function though they are currently at varying stages of development. This article provides a clinically focused review of these contrast and non-contrast MR imaging techniques and their current applications in lung disease.
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Affiliation(s)
- Chuan T. Foo
- Department of Respiratory Medicine, Eastern Health, Melbourne, VIC, Australia
- Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, VIC, Australia
| | - David Langton
- Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, VIC, Australia
- Department of Thoracic Medicine, Peninsula Health, Frankston, VIC, Australia
| | - Bruce R. Thompson
- Melbourne School of Health Science, Melbourne University, Melbourne, VIC, Australia
| | - Francis Thien
- Department of Respiratory Medicine, Eastern Health, Melbourne, VIC, Australia
- Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, VIC, Australia
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Hsia CCW, Bates JHT, Driehuys B, Fain SB, Goldin JG, Hoffman EA, Hogg JC, Levin DL, Lynch DA, Ochs M, Parraga G, Prisk GK, Smith BM, Tawhai M, Vidal Melo MF, Woods JC, Hopkins SR. Quantitative Imaging Metrics for the Assessment of Pulmonary Pathophysiology: An Official American Thoracic Society and Fleischner Society Joint Workshop Report. Ann Am Thorac Soc 2023; 20:161-195. [PMID: 36723475 PMCID: PMC9989862 DOI: 10.1513/annalsats.202211-915st] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Multiple thoracic imaging modalities have been developed to link structure to function in the diagnosis and monitoring of lung disease. Volumetric computed tomography (CT) renders three-dimensional maps of lung structures and may be combined with positron emission tomography (PET) to obtain dynamic physiological data. Magnetic resonance imaging (MRI) using ultrashort-echo time (UTE) sequences has improved signal detection from lung parenchyma; contrast agents are used to deduce airway function, ventilation-perfusion-diffusion, and mechanics. Proton MRI can measure regional ventilation-perfusion ratio. Quantitative imaging (QI)-derived endpoints have been developed to identify structure-function phenotypes, including air-blood-tissue volume partition, bronchovascular remodeling, emphysema, fibrosis, and textural patterns indicating architectural alteration. Coregistered landmarks on paired images obtained at different lung volumes are used to infer airway caliber, air trapping, gas and blood transport, compliance, and deformation. This document summarizes fundamental "good practice" stereological principles in QI study design and analysis; evaluates technical capabilities and limitations of common imaging modalities; and assesses major QI endpoints regarding underlying assumptions and limitations, ability to detect and stratify heterogeneous, overlapping pathophysiology, and monitor disease progression and therapeutic response, correlated with and complementary to, functional indices. The goal is to promote unbiased quantification and interpretation of in vivo imaging data, compare metrics obtained using different QI modalities to ensure accurate and reproducible metric derivation, and avoid misrepresentation of inferred physiological processes. The role of imaging-based computational modeling in advancing these goals is emphasized. Fundamental principles outlined herein are critical for all forms of QI irrespective of acquisition modality or disease entity.
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Taskiran NP, Hiura GT, Zhang X, Barr RG, Dashnaw SM, Hoffman EA, Malinsky D, Oelsner EC, Prince MR, Smith BM, Sun Y, Sun Y, Wild JM, Shen W, Hughes EW. Mapping Alveolar Oxygen Partial Pressure in COPD Using Hyperpolarized Helium-3: The Multi-Ethnic Study of Atherosclerosis (MESA) COPD Study. Tomography 2022; 8:2268-2284. [PMID: 36136886 PMCID: PMC9498778 DOI: 10.3390/tomography8050190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 09/05/2022] [Accepted: 09/05/2022] [Indexed: 11/24/2022] Open
Abstract
Chronic obstructive pulmonary disease (COPD) and emphysema are characterized by functional and structural damage which increases the spaces for gaseous diffusion and impairs oxygen exchange. Here we explore the potential for hyperpolarized (HP) 3He MRI to characterize lung structure and function in a large-scale population-based study. Participants (n = 54) from the Multi-Ethnic Study of Atherosclerosis (MESA) COPD Study, a nested case-control study of COPD among participants with 10+ packyears underwent HP 3He MRI measuring pAO2, apparent diffusion coefficient (ADC), and ventilation. HP MRI measures were compared to full-lung CT and pulmonary function testing. High ADC values (>0.4 cm2/s) correlated with emphysema and heterogeneity in pAO2 measurements. Strong correlations were found between the heterogeneity of global pAO2 as summarized by its standard deviation (SD) (p < 0.0002) and non-physiologic pAO2 values (p < 0.0001) with percent emphysema on CT. A regional study revealed a strong association between pAO2 SD and visual emphysema severity (p < 0.003) and an association with the paraseptal emphysema subtype (p < 0.04) after adjustment for demographics and smoking status. HP noble gas pAO2 heterogeneity and the fraction of non-physiological pAO2 results increase in mild to moderate COPD. Measurements of pAO2 are sensitive to regional emphysematous damage detected by CT and may be used to probe pulmonary emphysema subtypes. HP noble gas lung MRI provides non-invasive information about COPD severity and lung function without ionizing radiation.
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Affiliation(s)
- Naz P. Taskiran
- Department of Chemical Engineering, Columbia University, New York, NY 10027, USA
- Correspondence: (N.P.T.); (E.W.H.); Tel.: +1-347-3693052 (N.P.T.); +1-626-4838731 (E.W.H.)
| | - Grant T. Hiura
- Division of General Medicine, Columbia University Irving Medial Center, New York, NY 10032, USA
| | - Xuzhe Zhang
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA
| | - R. Graham Barr
- Division of General Medicine, Columbia University Irving Medial Center, New York, NY 10032, USA
| | - Stephen M. Dashnaw
- Neurological Institute, Radiology, Columbia University, New York, NY 10032, USA
| | - Eric A. Hoffman
- Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Daniel Malinsky
- Mailman School of Public Health, Columbia University, New York, NY 10032, USA
| | - Elizabeth C. Oelsner
- Division of General Medicine, Columbia University Irving Medial Center, New York, NY 10032, USA
| | - Martin R. Prince
- Division of General Medicine, Columbia University Irving Medial Center, New York, NY 10032, USA
- Department of Radiology, Weill Cornell Medicine, New York, NY 10065, USA
| | - Benjamin M. Smith
- Division of General Medicine, Columbia University Irving Medial Center, New York, NY 10032, USA
- Department of Medicine, McGill University, Montreal, QC H3G 2M1, Canada
| | - Yanping Sun
- Division of General Medicine, Columbia University Irving Medial Center, New York, NY 10032, USA
| | - Yifei Sun
- Mailman School of Public Health, Columbia University, New York, NY 10032, USA
| | - Jim M. Wild
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield S10 2TN, UK
| | - Wei Shen
- Division of Pediatric Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Columbia University Irving Medical Center, New York, NY 10032, USA
- Institute of Human Nutrition, College of Physicians & Surgeons, Columbia University Irving Medical Center, New York, NY 10032, USA
- Columbia Magnetic Resonance Research Center (CMRRC), Columbia University, New York, NY 10027, USA
| | - Emlyn W. Hughes
- Department of Physics, Columbia University, New York, NY 10027, USA
- Correspondence: (N.P.T.); (E.W.H.); Tel.: +1-347-3693052 (N.P.T.); +1-626-4838731 (E.W.H.)
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Wei Y, Yang C, Jiang H, Li Q, Che F, Wan S, Yao S, Gao F, Zhang T, Wang J, Song B. Multi-nuclear magnetic resonance spectroscopy: state of the art and future directions. Insights Imaging 2022; 13:135. [PMID: 35976510 PMCID: PMC9382599 DOI: 10.1186/s13244-022-01262-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 07/04/2022] [Indexed: 12/16/2022] Open
Abstract
With the development of heteronuclear fluorine, sodium, phosphorus, and other probes and imaging technologies as well as the optimization of magnetic resonance imaging (MRI) equipment and sequences, multi-nuclear magnetic resonance (multi-NMR) has enabled localize molecular activities in vivo that are central to a variety of diseases, including cardiovascular disease, neurodegenerative pathologies, metabolic diseases, kidney, and tumor, to shift from the traditional morphological imaging to the molecular imaging, precision diagnosis, and treatment mode. However, due to the low natural abundance and low gyromagnetic ratios, the clinical application of multi-NMR has been hampered. Several techniques have been developed to amplify the NMR sensitivity such as the dynamic nuclear polarization, spin-exchange optical pumping, and brute-force polarization. Meanwhile, a wide range of nuclei can be hyperpolarized, such as 2H, 3He, 13C, 15 N, 31P, and 129Xe. The signal can be increased and allows real-time observation of biological perfusion, metabolite transport, and metabolic reactions in vivo, overcoming the disadvantages of conventional magnetic resonance of low sensitivity. HP-NMR imaging of different nuclear substrates provides a unique opportunity and invention to map the metabolic changes in various organs without invasive procedures. This review aims to focus on the recent applications of multi-NMR technology not only in a range of preliminary animal experiments but also in various disease spectrum in human. Furthermore, we will discuss the future challenges and opportunities of this multi-NMR from a clinical perspective, in the hope of truly bridging the gap between cutting-edge molecular biology and clinical applications.
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Affiliation(s)
- Yi Wei
- Department of Radiology, West China Hospital, Sichuan University, No. 37, Guoxue Alley, Chengdu, 610041, People's Republic of China
| | - Caiwei Yang
- Department of Radiology, West China Hospital, Sichuan University, No. 37, Guoxue Alley, Chengdu, 610041, People's Republic of China
| | - Hanyu Jiang
- Department of Radiology, West China Hospital, Sichuan University, No. 37, Guoxue Alley, Chengdu, 610041, People's Republic of China
| | - Qian Li
- Department of Radiology, West China Hospital, Sichuan University, No. 37, Guoxue Alley, Chengdu, 610041, People's Republic of China
| | - Feng Che
- Department of Radiology, West China Hospital, Sichuan University, No. 37, Guoxue Alley, Chengdu, 610041, People's Republic of China
| | - Shang Wan
- Department of Radiology, West China Hospital, Sichuan University, No. 37, Guoxue Alley, Chengdu, 610041, People's Republic of China
| | - Shan Yao
- Department of Radiology, West China Hospital, Sichuan University, No. 37, Guoxue Alley, Chengdu, 610041, People's Republic of China
| | - Feifei Gao
- Department of Radiology, West China Hospital, Sichuan University, No. 37, Guoxue Alley, Chengdu, 610041, People's Republic of China
| | - Tong Zhang
- Department of Radiology, West China Hospital, Sichuan University, No. 37, Guoxue Alley, Chengdu, 610041, People's Republic of China
| | - Jiazheng Wang
- Clinical & Technical Support, Philips Healthcare, Beijing, China
| | - Bin Song
- Department of Radiology, West China Hospital, Sichuan University, No. 37, Guoxue Alley, Chengdu, 610041, People's Republic of China. .,Department of Radiology, Sanya People's Hospital, Sanya, China.
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Yaremko BP, Capaldi DP, Sheikh K, Palma DA, Warner A, Dar AR, Yu E, Rodrigues GB, Louie AV, Landis M, Sanatani M, Vincent MD, Younus J, Kuruvilla S, Chen JZ, Erickson A, Gaede S, Parraga G, Hoover DA. Functional Lung Avoidance for Individualized Radiotherapy (FLAIR): Results of a Double-Blind, Randomized Controlled Trial. Int J Radiat Oncol Biol Phys 2022; 113:1072-1084. [DOI: 10.1016/j.ijrobp.2022.04.047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 04/29/2022] [Accepted: 04/30/2022] [Indexed: 10/18/2022]
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Roach DJ, Willmering MM, Plummer JW, Walkup LL, Zhang Y, Hossain MM, Cleveland ZI, Woods JC. Hyperpolarized 129Xenon MRI Ventilation Defect Quantification via Thresholding and Linear Binning in Multiple Pulmonary Diseases. Acad Radiol 2022; 29 Suppl 2:S145-S155. [PMID: 34393064 PMCID: PMC8837732 DOI: 10.1016/j.acra.2021.06.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 06/21/2021] [Accepted: 06/26/2021] [Indexed: 02/03/2023]
Abstract
RATIONALE There is no agreed upon method for quantifying ventilation defect percentage (VDP) with high sensitivity and specificity from hyperpolarized (HP) gas ventilation MR images in multiple pulmonary diseases for both pediatrics and adults, yet identifying such methods will be necessary for future multi-site trials. Most HP gas MRI ventilation research focuses on a specific pulmonary disease and utilizes one quantification scheme for determining VDP. Here we sought to determine the potential of different methods for quantifying VDP from HP 129Xe images in multiple pulmonary diseases through comparison of the most utilized quantification schemes: linear binning and thresholding. MATERIALS AND METHODS HP 129Xe MRI was performed in a total of 176 subjects (125 pediatrics and 51 adults, age 20.98±16.48 years) who were either healthy controls (n = 23) or clinically diagnosed with cystic fibrosis (CF) (n = 37), lymphangioleiomyomatosis (LAM) (n = 29), asthma (n = 22), systemic juvenile idiopathic arthritis (sJIA) (n = 11), interstitial lung disease (ILD) (n = 7), or were bone marrow transplant (BMT) recipients (n = 47). HP 129Xe ventilation images were acquired during a ≤16 second breath-hold using a 2D multi-slice gradient echo sequence on a 3T Philips scanner (TR/TE 8.0/4.0ms, FA 10-12°, FOV 300 × 300mm, voxel size≈3 × 3 × 15mm). Images were analyzed using 5 different methods to quantify VDPs: linear binning (histogram normalization with binning into 6 clusters) following either linear or a variant of a nonparametric nonuniform intensity normalization algorithm (N4ITK) bias-field correction, thresholding ≤60% of the mean signal intensity with linear bias-field correction, and thresholding ≤60% and ≤75% of the mean signal intensity following N4ITK bias-field correction. Spirometry was successfully obtained in 84% of subjects. RESULTS All quantification schemes were able to label visually identifiable ventilation defects in similar regions within all subjects. The VDPs of control subjects were significantly lower (p<0.05) compared to BMT, CF, LAM, and ILD subjects for most of the quantification methods. No one quantification scheme was better able to differentiate individual disease groups from the control group. Advanced statistical modeling of the VDP quantification schemes revealed that in comparing controls to the combined disease group, N4ITK bias-field corrected 60% thresholding had the highest predictive efficacy, sensitivity, and specificity at the VDP cut-point of 2.3%. However, compared to the thresholding quantification schemes, linear binning was able to capture and label subtle low-ventilation regions in subjects with milder obstruction, such as subjects with asthma. CONCLUSION The difference in VDP between healthy controls and patients varied between the different disease states for all quantification methods. Although N4ITK bias-field corrected 60% thresholding was superior in separating the combined diseased group from controls, linear binning is able to better label low-ventilation regions unlike the current, 60% thresholding scheme. For future clinical trials, a consensus will need to be reached on which VDP scheme to utilize, as there are subtle advantages for each for specific disease.
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Affiliation(s)
- David J Roach
- Center for Pulmonary Imaging Research, Division of Pulmonary Medicine and Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Matthew M Willmering
- Center for Pulmonary Imaging Research, Division of Pulmonary Medicine and Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Joseph W Plummer
- Center for Pulmonary Imaging Research, Division of Pulmonary Medicine and Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Laura L Walkup
- Center for Pulmonary Imaging Research, Division of Pulmonary Medicine and Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio; Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Yin Zhang
- Department of Biostatistics and Epidemiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Md Monir Hossain
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio; Department of Biostatistics and Epidemiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Zackary I Cleveland
- Center for Pulmonary Imaging Research, Division of Pulmonary Medicine and Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio; Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Jason C Woods
- Center for Pulmonary Imaging Research, Division of Pulmonary Medicine and Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio; Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.
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Ding Y, Yang L, Zhou Q, Bi J, Li Y, Pi G, Wei W, Hu D, Rao Q, Li H, Zhao L, Liu A, Du D, Wang X, Zhou X, Han G, Qing K. A pilot study of function-based radiation therapy planning for lung cancer using hyperpolarized xenon-129 ventilation MRI. J Appl Clin Med Phys 2022; 23:e13502. [PMID: 35045204 PMCID: PMC8906214 DOI: 10.1002/acm2.13502] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 11/01/2021] [Accepted: 11/29/2021] [Indexed: 11/05/2022] Open
Abstract
PURPOSE Radiation-induced lung injury (RILI) is a common side effect in patients with non-small cell lung cancer (NSCLC) treated with radiotherapy. Minimizing irradiation into highly functional areas of the lung may reduce the occurrence of RILI. The aim of this study is to evaluate the feasibility and utility of hyperpolarized xenon-129 magnetic resonance imaging (MRI), an imaging tool for evaluation of the pulmonary function, to guide radiotherapy planning. METHODS Ten locally advanced NSCLC patients were recruited. Each patient underwent a simulation computed tomography (CT) scan and hyperpolarized xenon-129 MRI, then received 64 Gyin 32 fractions for radiotherapy. Clinical contours were drawn on CT. Lung regions with good ventilation were contoured based on the MRI. Two intensity-modulated radiation therapy plans were made for each patient: an anatomic plan (Plan-A) based on CT alone and a function-based plan (Plan-F) based on CT and MRI results. Compared to Plan-A, Plan-F was generated with two additional steps: (1) beam angles were carefully chosen to minimize direct radiation entering well-ventilated areas, and (2) additional optimization criteria were applied to well-ventilated areas to minimize dose exposure. V20Gy , V10Gy , V5Gy , and the mean dose in the lung were compared between the two plans. RESULTS Plan-A and Plan-F were both clinically acceptable and met similar target coverage and organ-at-risk constraints (p > 0.05) except for the ventilated lungs. Compared with Plan-A, V5Gy (Plan-A: 30.7 ± 11.0%, Plan-F: 27.2 ± 9.3%), V10Gy (Plan-A: 22.0 ± 8.6%, Plan-F: 19.3 ± 7.0%), and V20Gy (Plan-A: 12.5 ± 5.6%, Plan-F: 11.0 ± 4.1%) for well-ventilated lung areas were significantly reduced in Plan-F (p < 0.05). CONCLUSION In this pilot study, function-based radiotherapy planning using hyperpolarized xenon-129 MRI is demonstrated to be feasible in 10 patients with NSCLC with the potential to reduce radiation exposure in well-ventilated areas of the lung defined by hyperpolarized xenon-129 MRI.
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Affiliation(s)
- Yi Ding
- Department of Radiation Oncology, Hubei Cancer Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Lu Yang
- Department of Radiation Oncology, Renmin Hospital, Wuhan University, Wuhan, China
| | - Qian Zhou
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Wuhan National Laboratory for Optoelectronics, Chinese Academy of Sciences, Wuhan, China
| | - Jianping Bi
- Department of Radiation Oncology, Hubei Cancer Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ying Li
- Department of Radiation Oncology, Hubei Cancer Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Guoliang Pi
- Department of Radiation Oncology, Hubei Cancer Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Wei Wei
- Department of Radiation Oncology, Hubei Cancer Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Desheng Hu
- Department of Radiation Oncology, Hubei Cancer Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qiuchen Rao
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Wuhan National Laboratory for Optoelectronics, Chinese Academy of Sciences, Wuhan, China
| | - Haidong Li
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Wuhan National Laboratory for Optoelectronics, Chinese Academy of Sciences, Wuhan, China
| | - Li Zhao
- Department of Biomedical Engineering, Zhejiang University, Hangzhou, China
| | - An Liu
- Department of Radiation Oncology, City of Hope National Medical Center, Duarte, California, USA
| | - Dongsu Du
- Department of Radiation Oncology, City of Hope National Medical Center, Duarte, California, USA
| | - Xiao Wang
- Department of Radiation Oncology, Cancer Institute of New Jersey, Rutgers University, New Brunswick, New Jersey, USA
| | - Xin Zhou
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Wuhan National Laboratory for Optoelectronics, Chinese Academy of Sciences, Wuhan, China
| | - Guang Han
- Department of Radiation Oncology, Hubei Cancer Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Kun Qing
- Department of Radiation Oncology, City of Hope National Medical Center, Duarte, California, USA
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Meng XF, Lin QY, Yin H, Li ZQ. Hyperpolarized 3 helium MRI measured apparent diffusion coefficient and its correlations with pulmonary functions tests in patients with chronic obstructive pulmonary disease: A meta-analysis. Clin Respir J 2021; 15:1185-1193. [PMID: 34288505 DOI: 10.1111/crj.13425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 07/01/2021] [Accepted: 07/15/2021] [Indexed: 01/11/2023]
Abstract
BACKGROUND This study evaluates role of hyperpolarized 3 helium (3 He) MRI measured apparent diffusion coefficient (ADC) in examining pulmonary function of chronic obstructive pulmonary disease (COPD) patients. METHODS After literature search in electronic databases, studies were selected by following precise eligibility criteria. Meta-analyses were performed to estimate mean difference in ADC between COPD patients and healthy individuals and to seek correlations between lung ADC and pulmonary function. Metaregression analyses were performed to seek relationships between ADC and age, gender, BMI, cigarette pack-years, and pulmonary function tests. RESULTS Twenty-five studies (622 COPD patients and 469 healthy controls) were included. Lung ADC was 0.402 (95% confidence interval [CI]: 0.374, 0.429) in COPD patients and 0.228 (95% CI: 0.205, 0.252) in healthy individuals (mean difference 0.160 [95% CI: 0.127, 0.193]; p < 0.001). In metaregression, age (coefficient: 0.006; p = 0.004), pack-years (coefficient: 0.005; p = 0.018), forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) ratio (coefficient: -1.815; p = 0.007), percent predicted diffusion capacity of carbon monoxide (DLCO) (coefficient: -0.004; p = 0.008), and percent predicted inspiratory capacity (coefficient: -0.004; p = 0.012) were significantly associated with ADC in COPD patients. In meta-analysis of correlation coefficients, ADC was significantly correlated with FEV1 (r = -0.62; p < 0.00001), FEV1/FVC (r = -0.80; p < 0.00001), DLCO (r = -0.85; p < 0.00001), functional residual capacity (r = 0.71; p < 0.00001), reserve volume (r = 0.53; p = 0.0001), and emphysema index (r = 0.89; p < 0.00001). CONCLUSION Hyperpolarized 3 He MRI measured ADC was higher in COPD patients than in healthy individuals and was inversely associated with FEV1, FEV1/FVC, DLCO, and inspiratory capacity.
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Affiliation(s)
- Xian-Feng Meng
- Department of Medical Imaging, Heilongjiang Provincial Hospital, Harbin, Heilongjiang, China
| | - Qing-Yan Lin
- Department of Respiratory and Critical Care Medicine, Heilongjiang Provincial Hospital, Harbin, Heilongjiang, China
| | - Honglei Yin
- Department of Respiratory and Critical Care Medicine, Heilongjiang Provincial Hospital, Harbin, Heilongjiang, China
| | - Zeng-Qi Li
- Department of Stomatology, Heilongjiang Provincial Hospital, Harbin, Heilongjiang, China
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11
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Brooke JP, Hall IP. Novel Thoracic MRI Approaches for the Assessment of Pulmonary Physiology and Inflammation. Adv Exp Med Biol 2021; 1304:123-145. [PMID: 34019267 DOI: 10.1007/978-3-030-68748-9_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Excessive pulmonary inflammation can lead to damage of lung tissue, airway remodelling and established structural lung disease. Novel therapeutics that specifically target inflammatory pathways are becoming increasingly common in clinical practice, but there is yet to be a similar stepwise change in pulmonary diagnostic tools. A variety of thoracic magnetic resonance imaging (MRI) tools are currently in development, which may soon fulfil this emerging clinical need for highly sensitive assessments of lung structure and function. Given conventional MRI techniques are poorly suited to lung imaging, alternate strategies have been developed, including the use of inhaled contrast agents, intravenous contrast and specialized lung MR sequences. In this chapter, we discuss technical challenges of performing MRI of the lungs and how they may be overcome. Key thoracic MRI modalities are reviewed, namely, hyperpolarized noble gas MRI, oxygen-enhanced MRI (OE-MRI), ultrashort echo time (UTE) MRI and dynamic contrast-enhanced (DCE) MRI. Finally, we consider potential clinical applications of these techniques including phenotyping of lung disease, evaluation of novel pulmonary therapeutic efficacy and longitudinal assessment of specific patient groups.
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Affiliation(s)
- Jonathan P Brooke
- Department of Respiratory Medicine, University of Nottingham, Queens Medical Centre, Nottingham, UK.
| | - Ian P Hall
- Department of Respiratory Medicine, University of Nottingham, Queens Medical Centre, Nottingham, UK.
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12
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Pippard BJ, Neal MA, Maunder AM, Hollingsworth KG, Biancardi A, Lawson RA, Fisher H, Matthews JNS, Simpson AJ, Wild JM, Thelwall PE. Reproducibility of 19 F-MR ventilation imaging in healthy volunteers. Magn Reson Med 2021; 85:3343-3352. [PMID: 33507591 PMCID: PMC7986730 DOI: 10.1002/mrm.28660] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 12/07/2020] [Accepted: 12/07/2020] [Indexed: 01/23/2023]
Abstract
Purpose To assess the reproducibility of percentage ventilated lung volume (%VV) measurements in healthy volunteers acquired by fluorine (19F)‐MRI of inhaled perfluoropropane, implemented at two research sites. Methods In this prospective, ethically approved study, 40 healthy participants were recruited (May 2018‐June 2019) to one of two research sites. Participants underwent a single MRI scan session on a 3T scanner, involving periodic inhalation of a 79% perfluoropropane/21% oxygen gas mixture. Each gas inhalation session lasted about 30 seconds, consisting of three deep breaths of gas followed by a breath‐hold. Four 19F‐MR ventilation images were acquired per participant, each separated by approximately 6 minutes. The value of %VV was determined by registering separately acquired 1H images to ventilation images before semi‐automated image segmentation, performed independently by two observers. Reproducibility of %VV measurements was assessed by components of variance, intraclass correlation coefficients, coefficients of variation (CoV), and the Dice similarity coefficient. Results The MRI scans were well tolerated throughout, with no adverse events. There was a high degree of consistency in %VV measurements for each participant (CoVobserver1 = 0.43%; CoVobserver2 = 0.63%), with overall precision of %VV measurements determined to be within ± 1.7% (95% confidence interval). Interobserver agreement in %VV measurements revealed a high mean Dice similarity coefficient (SD) of 0.97 (0.02), with only minor discrepancies between observers. Conclusion We demonstrate good reproducibility of %VV measurements in a group of healthy participants using 19F‐MRI of inhaled perfluoropropane. Our methods have been successfully implemented across two different study sites, supporting the feasibility of performing larger multicenter clinical studies.
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Affiliation(s)
- Benjamin J. Pippard
- Newcastle Magnetic Resonance CentreNewcastle UniversityNewcastle upon TyneUnited Kingdom
- Translational and Clinical Research InstituteNewcastle UniversityNewcastle upon TyneUnited Kingdom
| | - Mary A. Neal
- Newcastle Magnetic Resonance CentreNewcastle UniversityNewcastle upon TyneUnited Kingdom
- Translational and Clinical Research InstituteNewcastle UniversityNewcastle upon TyneUnited Kingdom
| | - Adam M. Maunder
- POLARIS, Department of IICDUniversity of SheffieldRoyal Hallamshire HospitalSheffieldUnited Kingdom
| | - Kieren G. Hollingsworth
- Newcastle Magnetic Resonance CentreNewcastle UniversityNewcastle upon TyneUnited Kingdom
- Translational and Clinical Research InstituteNewcastle UniversityNewcastle upon TyneUnited Kingdom
| | - Alberto Biancardi
- POLARIS, Department of IICDUniversity of SheffieldRoyal Hallamshire HospitalSheffieldUnited Kingdom
| | - Rod A. Lawson
- Respiratory MedicineSheffield Teaching Hospitals National Health Service Foundation TrustSheffieldUnited Kingdom
| | - Holly Fisher
- Population Health Sciences InstituteNewcastle UniversityNewcastle upon TyneUnited Kingdom
| | - John N. S. Matthews
- Population Health Sciences InstituteNewcastle UniversityNewcastle upon TyneUnited Kingdom
- School of Mathematics, Statistics and PhysicsNewcastle UniversityNewcastle upon TyneUnited Kingdom
| | - A. John Simpson
- Translational and Clinical Research InstituteNewcastle UniversityNewcastle upon TyneUnited Kingdom
- Respiratory MedicineNewcastle upon Tyne Hospitals National Health Service Foundation TrustNewcastle upon TyneUnited Kingdom
| | - Jim M. Wild
- POLARIS, Department of IICDUniversity of SheffieldRoyal Hallamshire HospitalSheffieldUnited Kingdom
| | - Peter E. Thelwall
- Newcastle Magnetic Resonance CentreNewcastle UniversityNewcastle upon TyneUnited Kingdom
- Translational and Clinical Research InstituteNewcastle UniversityNewcastle upon TyneUnited Kingdom
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13
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Serajeddini H, Eddy RL, Licskai C, McCormack DG, Parraga G. FEV 1 and MRI ventilation defect reversibility in asthma and COPD. Eur Respir J 2020; 55:13993003.01947-2019. [PMID: 31806718 DOI: 10.1183/13993003.01947-2019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 11/22/2019] [Indexed: 12/15/2022]
Affiliation(s)
- Hana Serajeddini
- Robarts Research Institute, Western University, London, ON, Canada.,Division of Respirology, Dept of Medicine, Western University, London, ON, Canada.,Contributed equally as first authors
| | - Rachel L Eddy
- Robarts Research Institute, Western University, London, ON, Canada.,Dept of Medical Biophysics, Western University, London, ON, Canada.,Contributed equally as first authors
| | - Christopher Licskai
- Division of Respirology, Dept of Medicine, Western University, London, ON, Canada
| | - David G McCormack
- Division of Respirology, Dept of Medicine, Western University, London, ON, Canada
| | - Grace Parraga
- Robarts Research Institute, Western University, London, ON, Canada .,Division of Respirology, Dept of Medicine, Western University, London, ON, Canada.,Dept of Medical Biophysics, Western University, London, ON, Canada
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14
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Thiboutot J, Yuan W, Park HC, Lerner AD, Mitzner W, Yarmus LB, Li X, Brown RH. Current Advances in COPD Imaging. Acad Radiol 2019; 26:335-43. [PMID: 30093217 DOI: 10.1016/j.acra.2018.05.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 05/29/2018] [Accepted: 05/29/2018] [Indexed: 02/01/2023]
Abstract
OBJECTIVE To review the recent advances in available technologies for imaging COPD and present the novel optical coherence tomography (OCT) airway imaging technology. MATERIALS AND METHODS This is an unstructured review of published evidence of available pulmonary imaging technologies along with a demonstration of state-of-the-art OCT imaging technology of in vivo human and animal airways. RESULTS Advanced imaging techniques such as Magnetic Resonance (MR) imaging using hyperoloarized noble gases, micro-Computed Tomography (micro-CT), and OCT aim to further our understanding of COPD. Lung densitometry can aid in identifying an exacerbation prone phenotype which may have implications for targeting specific therapies to these individuals. MR ventilation scans have the ability to provide a functional and regional distribution of airflow obstruction offering insight into the airway and parenchymal changes induced by COPD. Micro-CT gives a near microscopic view of the terminal bronchioles and alveoli permitting study of the microarchitecture of the lung ex vivo. Optical coherence tomography can visualize the microstructure of the airway walls (epithelium, smooth muscle, blood vessels, cartilage) permitting real time in vivo as well as longitudinal evaluation of airway changes in patients with COPD. CONCLUSION Advanced imaging techniques play a vital role in expanding our current understanding of COPD.
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15
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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16
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Stewart NJ, Chan H, Hughes PJ, Horn FC, Norquay G, Rao M, Yates DP, Ireland RH, Hatton MQ, Tahir BA, Ford P, Swift AJ, Lawson R, Marshall H, Collier GJ, Wild JM. Comparison of 3 He and 129 Xe MRI for evaluation of lung microstructure and ventilation at 1.5T. J Magn Reson Imaging 2018; 48:632-642. [PMID: 29504181 PMCID: PMC6175321 DOI: 10.1002/jmri.25992] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 02/07/2018] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND To support translational lung MRI research with hyperpolarized 129 Xe gas, comprehensive evaluation of derived quantitative lung function measures against established measures from 3 He MRI is required. Few comparative studies have been performed to date, only at 3T, and multisession repeatability of 129 Xe functional metrics have not been reported. PURPOSE/HYPOTHESIS To compare hyperpolarized 129 Xe and 3 He MRI-derived quantitative metrics of lung ventilation and microstructure, and their repeatability, at 1.5T. STUDY TYPE Retrospective. POPULATION Fourteen healthy nonsmokers (HN), five exsmokers (ES), five patients with chronic obstructive pulmonary disease (COPD), and 16 patients with nonsmall-cell lung cancer (NSCLC). FIELD STRENGTH/SEQUENCE 1.5T. NSCLC, COPD patients and selected HN subjects underwent 3D balanced steady-state free-precession lung ventilation MRI using both 3 He and 129 Xe. Selected HN, all ES, and COPD patients underwent 2D multislice spoiled gradient-echo diffusion-weighted lung MRI using both hyperpolarized gas nuclei. ASSESSMENT Ventilated volume percentages (VV%) and mean apparent diffusion coefficients (ADC) were derived from imaging. COPD patients performed the whole MR protocol in four separate scan sessions to assess repeatability. Same-day pulmonary function tests were performed. STATISTICAL TESTS Intermetric correlations: Spearman's coefficient. Intergroup/internuclei differences: analysis of variance / Wilcoxon's signed rank. Repeatability: coefficient of variation (CV), intraclass correlation (ICC) coefficient. RESULTS A significant positive correlation between 3 He and 129 Xe VV% was observed (r = 0.860, P < 0.001). VV% was larger for 3 He than 129 Xe (P = 0.001); average bias, 8.79%. A strong correlation between mean 3 He and 129 Xe ADC was obtained (r = 0.922, P < 0.001). MR parameters exhibited good correlations with pulmonary function tests. In COPD patients, mean CV of 3 He and 129 Xe VV% was 4.08% and 13.01%, respectively, with ICC coefficients of 0.541 (P = 0.061) and 0.458 (P = 0.095). Mean 3 He and 129 Xe ADC values were highly repeatable (mean CV: 2.98%, 2.77%, respectively; ICC: 0.995, P < 0.001; 0.936, P < 0.001). DATA CONCLUSION: 129 Xe lung MRI provides near-equivalent information to 3 He for quantitative lung ventilation and microstructural MRI at 1.5T. LEVEL OF EVIDENCE 3 Technical Efficacy Stage 2 J. Magn. Reson. Imaging 2018.
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Affiliation(s)
- Neil J. Stewart
- Academic Unit of RadiologyUniversity of SheffieldSheffieldUK
| | - Ho‐Fung Chan
- Academic Unit of RadiologyUniversity of SheffieldSheffieldUK
| | | | - Felix C. Horn
- Academic Unit of RadiologyUniversity of SheffieldSheffieldUK
| | - Graham Norquay
- Academic Unit of RadiologyUniversity of SheffieldSheffieldUK
| | - Madhwesha Rao
- Academic Unit of RadiologyUniversity of SheffieldSheffieldUK
| | - Denise P. Yates
- Novartis Institutes for Biomedical ResearchCambridgeMassachusettsUSA
| | - Rob H. Ireland
- Academic Unit of Clinical OncologyUniversity of SheffieldSheffieldUK
| | - Matthew Q. Hatton
- Academic Unit of Clinical OncologyUniversity of SheffieldSheffieldUK
- Sheffield Teaching Hospitals NHS Foundation TrustSheffieldUK
| | - Bilal A. Tahir
- Academic Unit of RadiologyUniversity of SheffieldSheffieldUK
- Academic Unit of Clinical OncologyUniversity of SheffieldSheffieldUK
| | - Paul Ford
- Academic Unit of RadiologyUniversity of SheffieldSheffieldUK
| | - Andrew J. Swift
- Academic Unit of RadiologyUniversity of SheffieldSheffieldUK
| | - Rod Lawson
- Sheffield Teaching Hospitals NHS Foundation TrustSheffieldUK
| | - Helen Marshall
- Academic Unit of RadiologyUniversity of SheffieldSheffieldUK
| | | | - Jim M. Wild
- Academic Unit of RadiologyUniversity of SheffieldSheffieldUK
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17
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Ebner L, He M, Virgincar RS, Heacock T, Kaushik SS, Freemann MS, McAdams HP, Kraft M, Driehuys B. Hyperpolarized 129Xenon Magnetic Resonance Imaging to Quantify Regional Ventilation Differences in Mild to Moderate Asthma: A Prospective Comparison Between Semiautomated Ventilation Defect Percentage Calculation and Pulmonary Function Tests. Invest Radiol 2017; 52:120-7. [PMID: 27662575 DOI: 10.1097/RLI.0000000000000322] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVES The aim of this study was to investigate ventilation in mild to moderate asthmatic patients and age-matched controls using hyperpolarized (HP) Xenon magnetic resonance imaging (MRI) and correlate findings with pulmonary function tests (PFTs). MATERIALS AND METHODS This single-center, Health Insurance Portability and Accountability Act-compliant prospective study was approved by our institutional review board. Thirty subjects (10 young asthmatic patients, 26 ± 6 years; 3 males, 7 females; 10 older asthmatic patients, 64 ± 6 years; 3 males, 7 females; 10 healthy controls) were enrolled. After repeated PFTs 1 week apart, the subjects underwent 2 MRI scans within 10 minutes, inhaling 1-L volumes containing 0.5 to 1 L of Xe. Xe ventilation signal was quantified by linear binning, from which the ventilation defect percentage (VDP) was derived. Differences in VDP among subgroups and variability with age were evaluated using 1-tailed t tests. Correlation of VDP with PFTs was tested using Pearson correlation coefficient. Reproducibility of VDP was assessed using Bland-Altman plots, linear regression (R), intraclass correlation coefficient, and concordance correlation coefficient. RESULTS Ventilation defect percentage was significantly higher in young asthmatic patients versus young healthy subjects (8.4% ± 3.2% vs 5.6% ± 1.7%, P = 0.031), but not in older asthmatic patients versus age-matched controls (16.8% ± 10.3% vs 11.6% ± 6.6%, P = 0.13). Ventilation defect percentage was found to increase significantly with age (healthy, P = 0.05; asthmatic patients, P = 0.033). Ventilation defect percentage was highly reproducible (R = 0.976; intraclass correlation coefficient, 0.977; concordance correlation coefficient, 0.976) and significantly correlated with FEV1% (r = -0.42, P = 0.025), FEF25%-75% (r = -0.45, P = 0.019), FEV1/FVC (r = -0.71, P < 0.0001), FeNO (r = 0.69, P < 0.0001), and RV/TLC (r = 0.51, P = 0.0067). Bland-Altman analysis showed a bias for VDP of -0.88 ± 1.52 (FEV1%, -0.33 ± 7.18). CONCLUSIONS Xenon MRI is able to depict airway obstructions in mild to moderate asthma and significantly correlates with PFTs.
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Lessard E, Young HM, Bhalla A, Pike D, Sheikh K, McCormack DG, Ouriadov A, Parraga G. Pulmonary 3He Magnetic Resonance Imaging Biomarkers of Regional Airspace Enlargement in Alpha-1 Antitrypsin Deficiency. Acad Radiol 2017. [PMID: 28645458 DOI: 10.1016/j.acra.2017.05.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
RATIONALE AND OBJECTIVES Thoracic x-ray computed tomography (CT) and hyperpolarized 3He magnetic resonance imaging (MRI) provide quantitative measurements of airspace enlargement in patients with emphysema. For patients with panlobular emphysema due to alpha-1 antitrypsin deficiency (AATD), sensitive biomarkers of disease progression and response to therapy have been difficult to develop and exploit, especially those biomarkers that correlate with outcomes like quality of life. Here, our objective was to generate and compare CT and diffusion-weighted inhaled-gas MRI measurements of emphysema including apparent diffusion coefficient (ADC) and MRI-derived mean linear intercept (Lm) in patients with AATD, chronic obstructive pulmonary disease (COPD) ex-smokers, and elderly never-smokers. MATERIALS AND METHODS We enrolled patients with AATD (n = 8; 57 ± 7 years), ex-smokers with COPD (n = 8; 77 ± 6 years), and a control group of never-smokers (n = 5; 64 ± 2 years) who underwent thoracic CT, MRI, spirometry, plethysmography, the St. George's Respiratory Questionnaire, and the 6-minute walk test during a single 2-hour visit. MRI-derived ADC, Lm, surface-to-volume ratio, and ventilation defect percent were generated for the apical, basal, and whole lung as was CT lung area ≤-950 Hounsfield units (RA950), low attenuating clusters, and airway count. RESULTS In patients with AATD, there was a significantly different MRI-derived ADC (P = .03), Lm (P < .0001), and surface-to-volume ratio (P < .0001), but not diffusing capacity of carbon monoxide, residual volume or total lung capacity, or CT RA950 (P > .05) compared to COPD ex-smokers with a significantly different St. George's Respiratory Questionnaire. CONCLUSIONS In this proof-of-concept demonstration, we evaluated CT and MRI lung emphysema measurements and observed significantly worse MRI biomarkers of emphysema in patients with AATD compared to patients with COPD, although CT RA950 and diffusing capacity of carbon monoxide were not significantly different, underscoring the sensitivity of MRI measurements of AATD emphysema.
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Affiliation(s)
- Eric Lessard
- Robarts Research Institute, 1151 Richmond Street North, London, ON, Canada N6A 5B7; Department of Medical Biophysics, The University of Western Ontario, 1151 Richmond St North, London, ON, Canada N6A 5C1
| | - Heather M Young
- Robarts Research Institute, 1151 Richmond Street North, London, ON, Canada N6A 5B7; Department of Medical Biophysics, The University of Western Ontario, 1151 Richmond St North, London, ON, Canada N6A 5C1
| | - Anurag Bhalla
- Robarts Research Institute, 1151 Richmond Street North, London, ON, Canada N6A 5B7
| | - Damien Pike
- Robarts Research Institute, 1151 Richmond Street North, London, ON, Canada N6A 5B7; Department of Medical Biophysics, The University of Western Ontario, 1151 Richmond St North, London, ON, Canada N6A 5C1
| | - Khadija Sheikh
- Robarts Research Institute, 1151 Richmond Street North, London, ON, Canada N6A 5B7; Department of Medical Biophysics, The University of Western Ontario, 1151 Richmond St North, London, ON, Canada N6A 5C1
| | - David G McCormack
- Division of Respirology, Department of Medicine, The University of Western Ontario, London, Ontario, Canada
| | - Alexei Ouriadov
- Robarts Research Institute, 1151 Richmond Street North, London, ON, Canada N6A 5B7; Department of Medical Biophysics, The University of Western Ontario, 1151 Richmond St North, London, ON, Canada N6A 5C1
| | - Grace Parraga
- Robarts Research Institute, 1151 Richmond Street North, London, ON, Canada N6A 5B7; Department of Medical Biophysics, The University of Western Ontario, 1151 Richmond St North, London, ON, Canada N6A 5C1.
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Abstract
In the past decade, hyperpolarized (HP) contrast agents have been under active development for MRI applications to address the twin challenges of functional and quantitative imaging. Both HP helium (3He) and xenon (129Xe) gases have reached the stage where they are under study in clinical research. HP 129Xe, in particular, is poised for larger scale clinical research to investigate asthma, chronic obstructive pulmonary disease, and fibrotic lung diseases. With advances in polarizer technology and unique capabilities for imaging of 129Xe gas exchange into lung tissue and blood, HP 129Xe MRI is attracting new attention. In parallel, HP 13C and 15N MRI methods have steadily advanced in a wide range of pre-clinical research applications for imaging metabolism in various cancers and cardiac disease. The HP [1-13C] pyruvate MRI technique, in particular, has undergone phase I trials in prostate cancer and is poised for investigational new drug trials at multiple institutions in cancer and cardiac applications. This review treats the methodology behind both HP gases and HP 13C and 15N liquid state agents. Gas and liquid phase HP agents share similar technologies for achieving non-equilibrium polarization outside the field of the MRI scanner, strategies for image data acquisition, and translational challenges in moving from pre-clinical to clinical research. To cover the wide array of methods and applications, this review is organized by numerical section into (1) a brief introduction, (2) the physical and biological properties of the most common polarized agents with a brief summary of applications and methods of polarization, (3) methods for image acquisition and reconstruction specific to improving data acquisition efficiency for HP MRI, (4) the main physical properties that enable unique measures of physiology or metabolic pathways, followed by a more detailed review of the literature describing the use of HP agents to study: (5) metabolic pathways in cancer and cardiac disease and (6) lung function in both pre-clinical and clinical research studies, concluding with (7) some future directions and challenges, and (8) an overall summary.
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Affiliation(s)
- Erin B Adamson
- Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, United States of America
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20
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Yablonskiy DA, Sukstanskii AL, Quirk JD. Diffusion lung imaging with hyperpolarized gas MRI. NMR Biomed 2017; 30:10.1002/nbm.3448. [PMID: 26676342 PMCID: PMC4911335 DOI: 10.1002/nbm.3448] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 10/20/2015] [Accepted: 10/22/2015] [Indexed: 05/28/2023]
Abstract
Lung imaging using conventional 1 H MRI presents great challenges because of the low density of lung tissue, lung motion and very fast lung tissue transverse relaxation (typical T2 * is about 1-2 ms). MRI with hyperpolarized gases (3 He and 129 Xe) provides a valuable alternative because of the very strong signal originating from inhaled gas residing in the lung airspaces and relatively slow gas T2 * relaxation (typical T2 * is about 20-30 ms). However, in vivo human experiments should be performed very rapidly - usually during a single breath-hold. In this review, we describe the recent developments in diffusion lung MRI with hyperpolarized gases. We show that a combination of the results of modeling of gas diffusion in lung airspaces and diffusion measurements with variable diffusion-sensitizing gradients allows the extraction of quantitative information on the lung microstructure at the alveolar level. From an MRI scan of less than 15 s, this approach, called in vivo lung morphometry, allows the provision of quantitative values and spatial distributions of the same physiological parameters as measured by means of 'standard' invasive stereology (mean linear intercept, surface-to-volume ratio, density of alveoli, etc.). In addition, the approach makes it possible to evaluate some advanced Weibel parameters characterizing lung microstructure: average radii of alveolar sacs and ducts, as well as the depth of their alveolar sleeves. Such measurements, providing in vivo information on the integrity of pulmonary acinar airways and their changes in different diseases, are of great importance and interest to a broad range of physiologists and clinicians. We also discuss a new type of experiment based on the in vivo lung morphometry technique combined with quantitative computed tomography measurements, as well as with gradient echo MRI measurements of hyperpolarized gas transverse relaxation in the lung airspaces. Such experiments provide additional information on the blood vessel volume fraction, specific gas volume and length of the acinar airways, and allow the evaluation of lung parenchymal and non-parenchymal tissue. Copyright © 2015 John Wiley & Sons, Ltd.
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Affiliation(s)
| | | | - James D Quirk
- Department of Radiology, Washington University, St. Louis, MO, USA
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Davis C, Sheikh K, Pike D, Svenningsen S, McCormack DG, O'Donnell D, Neder JA, Parraga G. Ventilation Heterogeneity in Never-smokers and COPD:: Comparison of Pulmonary Functional Magnetic Resonance Imaging with the Poorly Communicating Fraction Derived From Plethysmography. Acad Radiol 2016; 23:398-405. [PMID: 26774739 DOI: 10.1016/j.acra.2015.10.022] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 09/22/2015] [Accepted: 10/04/2015] [Indexed: 11/29/2022]
Abstract
RATIONALE AND OBJECTIVES Pulmonary functional magnetic resonance imaging provides a way to quantify ventilation and its heterogeneity-a hallmark finding in chronic obstructive pulmonary disease (COPD). Unfortunately, the etiology and physiological meaning of ventilation defects and their relationship to pulmonary function and symptoms in COPD are not well understood. Another biomarker of ventilation heterogeneity is provided by the "poorly communicating fraction" (PCF), and is calculated as the ratio of total lung capacity to alveolar volume made using whole-body plethysmography. Our objective was to compare ventilation heterogeneity using hyperpolarized (3)He magnetic resonance imaging (MRI) and PCF measurements in elderly never-smokers and in ex-smokers with COPD. MATERIALS AND METHODS One hundred forty-six participants (71 ± 8 years, range = 48-87 years) provided written informed consent including 45 elderly never-smokers (71 ± 6 years, range = 61-84 years) and 101 ex-smokers with COPD (71 ± 8 years, range = 48-87 years). During a single 2-hour visit, spirometry, plethysmography, and hyperpolarized (3)He MRI were acquired. The MRI-derived ventilation defect percent (VDP) and plethysmography measurements were acquired and PCF values were calculated. Linear regression, Pearson correlations, and Bland-Altman analysis were used to evaluate the relationships for PCF and MRI VDP. RESULTS PCF (P < 0.001) and VDP (P < 0.001) were significantly increased with increasing COPD severity. There was a significant relationship for VDP and PCF (r = 0.68, P < 0.001) in all subjects and COPD subjects alone (r = 0.61, P < 0.001). Bland-Altman analysis showed that PCF and VDP were significantly different (mean bias = 9.7, upper limit = 32, lower limit = -13, P < 0.001), and in severe-grade COPD, PCF overestimates of VDP were significantly greater. CONCLUSIONS In elderly never-smokers and in ex-smokers with COPD, PCF and VDP are moderately correlated estimates of COPD ventilation heterogeneity that may be reflecting similar pathophysiology.
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Affiliation(s)
- Christopher Davis
- Imaging Research Laboratories, Robarts Research Institute, 1151 Richmond Street North, London, N6A 5B7, Canada
| | - Khadija Sheikh
- Imaging Research Laboratories, Robarts Research Institute, 1151 Richmond Street North, London, N6A 5B7, Canada; Department of Medical Biophysics, The University of Western Ontario, 1151 Richmond St North, London, N6A 5B7, Canada
| | - Damien Pike
- Imaging Research Laboratories, Robarts Research Institute, 1151 Richmond Street North, London, N6A 5B7, Canada; Department of Medical Biophysics, The University of Western Ontario, 1151 Richmond St North, London, N6A 5B7, Canada
| | - Sarah Svenningsen
- Imaging Research Laboratories, Robarts Research Institute, 1151 Richmond Street North, London, N6A 5B7, Canada; Department of Medical Biophysics, The University of Western Ontario, 1151 Richmond St North, London, N6A 5B7, Canada
| | - David G McCormack
- Division of Respirology, Department of Medicine, The University of Western Ontario, London, Canada
| | - Denis O'Donnell
- Division of Respirology, Department of Medicine, Queens University, 99 University Ave, Kingston, K7L 3N6, Canada
| | - J Alberto Neder
- Division of Respirology, Department of Medicine, Queens University, 99 University Ave, Kingston, K7L 3N6, Canada
| | - Grace Parraga
- Imaging Research Laboratories, Robarts Research Institute, 1151 Richmond Street North, London, N6A 5B7, Canada; Department of Medical Biophysics, The University of Western Ontario, 1151 Richmond St North, London, N6A 5B7, Canada.
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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: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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Pike D, Kirby M, Eddy RL, Guo F, Capaldi DPI, Ouriadov A, McCormack DG, Parraga G. Regional Heterogeneity of Chronic Obstructive Pulmonary Disease Phenotypes: Pulmonary (3)He Magnetic Resonance Imaging and Computed Tomography. COPD 2016; 13:601-9. [PMID: 26788765 DOI: 10.3109/15412555.2015.1123682] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Pulmonary ventilation may be visualized and measured using hyperpolarized (3)He magnetic resonance imaging (MRI) while emphysema and its distribution can be quantified using thoracic computed tomography (CT). Our objective was to phenotype ex-smokers with COPD based on the apical-to-basal distribution of ventilation abnormalities and emphysema to better understand how these phenotypes change regionally as COPD progresses. We evaluated 100 COPD ex-smokers who provided written informed consent and underwent spirometry, CT and (3)He MRI. (3)He MRI ventilation imaging was used to quantify the ventilation defect percent (VDP) for whole-lung and individual lung lobes. Regional VDP was used to generate the apical-lung (AL)-to-basal-lung (BL) difference (ΔVDP); a positive ΔVDP indicated AL-predominant and negative ΔVDP indicated BL-predominant ventilation defects. Emphysema was quantified using the relative-area-of-the-lung ≤-950HU (RA950) of the CT density histogram for whole-lung and individual lung lobes. The AL-to-BL RA950 difference (ΔRA950) was generated with a positive ΔRA950 indicating AL-predominant emphysema and a negative ΔRA950 indicating BL-predominant emphysema. Seventy-two ex-smokers reported BL-predominant MRI ventilation defects and 71 reported AL-predominant CT emphysema. BL-predominant ventilation defects (AL/BL: GOLD I = 18%/82%, GOLD II = 24%/76%) and AL-predominant emphysema (AL/BL: GOLD I = 84%/16%, GOLD II = 72%/28%) were the major phenotypes in mild-moderate COPD. In severe COPD there was a more uniform distribution for ventilation defects (AL/BL: GOLD III = 40%/60%, GOLD IV = 43%/57%) and emphysema (AL/BL: GOLD III = 64%/36%, GOLD IV = 43%/57%). Basal-lung ventilation defects predominated in mild-moderate GOLD grades, and a more homogeneous distribution of ventilation defects was observed in more advanced grade COPD; these differences suggest that over time, regional ventilation abnormalities become more homogenously distributed during disease progression.
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Affiliation(s)
- Damien Pike
- a Robarts Research Institute, The University of Western Ontario , London , Canada.,b Department of Medical Biophysics , The University of Western Ontario , London , Canada
| | - Miranda Kirby
- c James Hogg Research Centre, St. Paul's Hospital, University of British Columbia , Vancouver , Canada
| | - Rachel L Eddy
- a Robarts Research Institute, The University of Western Ontario , London , Canada.,b Department of Medical Biophysics , The University of Western Ontario , London , Canada
| | - Fumin Guo
- a Robarts Research Institute, The University of Western Ontario , London , Canada.,d Graduate Program in Biomedical Engineering, The University of Western Ontario , London , Canada
| | - Dante P I Capaldi
- a Robarts Research Institute, The University of Western Ontario , London , Canada.,b Department of Medical Biophysics , The University of Western Ontario , London , Canada
| | - Alexei Ouriadov
- a Robarts Research Institute, The University of Western Ontario , London , Canada
| | - David G McCormack
- e Division of Respirology, Department of Medicine , The University of Western Ontario , London , Canada
| | - Grace Parraga
- a Robarts Research Institute, The University of Western Ontario , London , Canada.,b Department of Medical Biophysics , The University of Western Ontario , London , Canada.,d Graduate Program in Biomedical Engineering, The University of Western Ontario , London , Canada
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Yablonskiy DA, Sukstanskii AL, Quirk JD, Woods JC, Conradi MS. Probing lung microstructure with hyperpolarized noble gas diffusion MRI: theoretical models and experimental results. Magn Reson Med 2016; 71:486-505. [PMID: 23554008 DOI: 10.1002/mrm.24729] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The introduction of hyperpolarized gases ((3)He and (129)Xe) has opened the door to applications for which gaseous agents are uniquely suited-lung MRI. One of the pulmonary applications, diffusion MRI, relies on measuring Brownian motion of inhaled hyperpolarized gas atoms diffusing in lung airspaces. In this article we provide an overview of the theoretical ideas behind hyperpolarized gas diffusion MRI and the results obtained over the decade-long research. We describe a simple technique based on measuring gas apparent diffusion coefficient (ADC) and an advanced technique, in vivo lung morphometry, that quantifies lung microstructure both in terms of Weibel parameters (acinar airways radii and alveolar depth) and standard metrics (mean linear intercept, surface-to-volume ratio, and alveolar density) that are widely used by lung researchers but were previously available only from invasive lung biopsy. This technique has the ability to provide unique three-dimensional tomographic information on lung microstructure from a less than 15 s MRI scan with results that are in good agreement with direct histological measurements. These safe and sensitive diffusion measurements improve our understanding of lung structure and functioning in health and disease, providing a platform for monitoring the efficacy of therapeutic interventions in clinical trials.
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Paulin GA, Ouriadov A, Lessard E, Sheikh K, McCormack DG, Parraga G. Noninvasive quantification of alveolar morphometry in elderly never- and ex-smokers. Physiol Rep 2015; 3:3/10/e12583. [PMID: 26462748 PMCID: PMC4632953 DOI: 10.14814/phy2.12583] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Diffusion-weighted magnetic resonance imaging (MRI) provides a way to generate in vivo lung images with contrast sensitive to the molecular displacement of inhaled gas at subcellular length scales. Here, we aimed to evaluate hyperpolarized 3He MRI estimates of the alveolar dimensions in 38 healthy elderly never-smokers (73 ± 6 years, 15 males) and 21 elderly ex-smokers (70 ± 10 years, 14 males) with (n = 8, 77 ± 6 years) and without emphysema (n = 13, 65 ± 10 years). The ex-smoker and never-smoker subgroups were significantly different for FEV1/FVC (P = 0.0001) and DLCO (P = 0.009); while ex-smokers with emphysema reported significantly diminished FEV1/FVC (P = 0.02) and a trend toward lower DLCO (P = 0.05) than ex-smokers without emphysema. MRI apparent diffusion coefficients (ADC) and CT measurements of emphysema (relative area–CT density histogram, RA950) were significantly different (P = 0.001 and P = 0.007) for never-smoker and ex-smoker subgroups. In never-smokers, the MRI estimate of mean linear intercept (260 ± 27 μm) was significantly elevated as compared to the results previously reported in younger never-smokers (210 ± 30 μm), and trended smaller than in the age-matched ex-smokers (320 ± 72 μm, P = 0.06) evaluated here. Never-smokers also reported significantly smaller internal (220 ± 24 μm, P = 0.01) acinar radius but greater alveolar sheath thickness (120 ± 4 μm, P < 0.0001) than ex-smokers. Never-smokers were also significantly different than ex-smokers without emphysema for alveolar sheath thickness but not ADC, while ex-smokers with emphysema reported significantly different ADC but not alveolar sheath thickness compared to ex-smokers without CT evidence of emphysema. Differences in alveolar measurements in never- and ex-smokers demonstrate the sensitivity of MRI measurements to the different effects of smoking and aging on acinar morphometry.
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Affiliation(s)
- Gregory A Paulin
- Imaging Research Laboratories, Robarts Research Institute The University of Western Ontario, London, Ontario, Canada Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada
| | - Alexei Ouriadov
- Imaging Research Laboratories, Robarts Research Institute The University of Western Ontario, London, Ontario, Canada
| | - Eric Lessard
- Imaging Research Laboratories, Robarts Research Institute The University of Western Ontario, London, Ontario, Canada Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada
| | - Khadija Sheikh
- Imaging Research Laboratories, Robarts Research Institute The University of Western Ontario, London, Ontario, Canada Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada
| | - David G McCormack
- Division of Respirology, Department of Medicine, The University of Western Ontario, London, Ontario, Canada
| | - Grace Parraga
- Imaging Research Laboratories, Robarts Research Institute The University of Western Ontario, London, Ontario, Canada Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada
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26
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Ouriadov A, Fox M, Hegarty E, Parraga G, Wong E, Santyr GE. Early stage radiation-induced lung injury detected using hyperpolarized (129) Xe Morphometry: Proof-of-concept demonstration in a rat model. Magn Reson Med 2015; 75:2421-31. [PMID: 26154889 DOI: 10.1002/mrm.25825] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 05/27/2015] [Accepted: 06/08/2015] [Indexed: 11/08/2022]
Abstract
PURPOSE Radiation-induced lung injury (RILI) is still the major dose-limiting toxicity related to lung cancer radiation therapy, and it is difficult to predict and detect patients who are at early risk of severe pneumonitis and fibrosis. The goal of this proof-of-concept preclinical demonstration was to investigate the potential of hyperpolarized (129) Xe diffusion-weighted MRI to detect the lung morphological changes associated with early stage RILI. METHODS Hyperpolarized (129) Xe MRI was performed using eight different diffusion sensitizations (0.0-115 s/cm(2) ) in a small group of control rats (n = 4) and rats 2 wk after radiation exposure (n = 5). The diffusion-weighted images were used to obtain morphological estimates of the pulmonary parenchyma including external radius (R), internal radius (r), alveolar sleeve depth (h), and mean airspace chord length (Lm ). The histological mean linear intercept (MLI) were obtained for five control and five irradiated animals. RESULTS Mean R, r, and Lm were both significantly different (P < 0.02) in the irradiated rats (74 ± 17 µm, 43 ± 12 µm, and 54 ± 17 µm, respectively) compared with the control rats (100 ± 12 µm, 67 ± 10 µm, and 79 ± 12 µm, respectively). Changes in measured Lm values were consistent with changes in MLI values observed by histology. CONCLUSIONS Hyperpolarized (129) Xe MRI provides a way to detect and measure regional microanatomical changes in lung parenchyma in a preclinical model of RILI. Magn Reson Med 75:2421-2431, 2016. © 2015 Wiley Periodicals, Inc.
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Affiliation(s)
- Alexei Ouriadov
- Imaging Research Laboratories, Robarts Research Institute, Western University, London, Ontario, Canada
| | - Matthew Fox
- Imaging Research Laboratories, Robarts Research Institute, Western University, London, Ontario, Canada.,Department of Medical Biophysics, Western University, London, Ontario, Canada
| | - Elaine Hegarty
- Imaging Research Laboratories, Robarts Research Institute, Western University, London, Ontario, Canada
| | - Grace Parraga
- Imaging Research Laboratories, Robarts Research Institute, Western University, London, Ontario, Canada.,Department of Medical Biophysics, Western University, London, Ontario, Canada
| | - Eugene Wong
- Department of Medical Biophysics, Western University, London, Ontario, Canada.,Department of Physics and Astronomy, Western University, London, Ontario, Canada
| | - Giles E Santyr
- Imaging Research Laboratories, Robarts Research Institute, Western University, London, Ontario, Canada.,Department of Medical Biophysics, Western University, London, Ontario, Canada.,Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada
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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. Radiología (English Edition) 2015. [DOI: 10.1016/j.rxeng.2014.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Flors L, Altes TA, Mugler JP 3rd, de Lange EE, Miller GW, Mata JF, Ruset IC, Hersman FW. 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] [What about the content of this article? (0)] [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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Quirk JD, Chang YV, Yablonskiy DA. In vivo lung morphometry with hyperpolarized (3) He diffusion MRI: reproducibility and the role of diffusion-sensitizing gradient direction. Magn Reson Med 2015; 73:1252-7. [PMID: 24752926 PMCID: PMC4205219 DOI: 10.1002/mrm.25241] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 03/13/2014] [Accepted: 03/14/2014] [Indexed: 12/25/2022]
Abstract
PURPOSE Lung morphometry with hyperpolarized gas diffusion MRI is a highly sensitive technique for the noninvasive measurement of acinar microstructural parameters traditionally only accessible by histology. The goal of this work is to establish the reproducibility of these measurements in healthy volunteers and their dependence on the direction of the applied diffusion-sensitizing gradient. METHODS Hyperpolarized helium-3 ((3) He) lung morphometry MRI was performed on a total of five healthy subjects. Two subjects received duplicate imaging on the same day and three subjects received duplicate imaging after a 4-month or 27-month delay to assess reproducibility. Four subjects repeated the measurement during the same session with different diffusion-sensitizing gradient directions to determine the effect on the parameter estimates. RESULTS The (3) He lung morphometry measurements were reproducible over the short term and long term (e.g., % coefficient of variation [CV] of mean chord length, Lm = 2.1% and 2.9%, respectively) and across different diffusion gradient directions (Lm % CV = 2.6%). Results also show independence of field inhomogeneity effects at 1.5T. CONCLUSION (3) He lung morphometry is a reproducible technique for measuring acinar microstructure and is effectively independent of the choice of diffusion gradient direction. This provides confidence for the use of this technique to compare populations and treatment efficacy.
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Affiliation(s)
- James D Quirk
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA
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Horn FC, Tahir BA, Stewart NJ, Collier GJ, Norquay G, Leung G, Ireland RH, Parra-Robles J, Marshall H, Wild JM. Lung ventilation volumetry with same-breath acquisition of hyperpolarized gas and proton MRI. NMR Biomed 2014; 27:1461-1467. [PMID: 25208220 DOI: 10.1002/nbm.3187] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 07/19/2014] [Accepted: 07/21/2014] [Indexed: 06/03/2023]
Abstract
The purpose of this work was to assess the reproducibility of percentage of ventilated lung volume (PV) measured from hyperpolarized (HP) (3)He and (1)H anatomical images acquired in the same breath-hold when compared with PV measured from (3)He and (1)H images from separate breath-holds. Volumetric (3)He ventilation and (1)H anatomical images of the same resolution were acquired during the same breath-hold. To assess reproducibility, this procedure was performed twice with a short gap between acquisitions. In addition, (1)H images were also acquired in a separate breath for comparison. PV ((3)He ventilated volume divided by (1)H total lung volume) was calculated using the single-breath-hold images (PV(single)) and the separate-breath-hold images (PV(separate)). Short-term reproducibility of PV measurement was assessed for both single- and separate-breath acquisitions. Dice similarity coefficients (DSCs) were calculated to quantify spatial overlap between (3)He and (1)H segmentations for the single- and separate-breath-hold acquisitions. The efficacy of using the separate-breath method combined with image registration was also assessed. The mean magnitude difference between the two sets of PV values (±standard deviation) was 1.49 ± 1.32% for PV(single) and 4.19 ± 4.10% for PV(separate), with a significant difference (p < 0.01). The mean magnitude difference between the two PV values for the registered separate-breath technique (PV(sep-registered)) was 2.27 ± 2.23%. Bland-Altman analysis showed that PV measured with single-breath acquisitions was more repeatable than PV measured with separate-breath acquisitions, regardless of image registration. DSC values were significantly greater (p < 0.01) for single-breath acquisition than for separate-breath acquisition. Acquisition of HP gas ventilation and (1)H anatomical images in a single breath-hold provides a more reproducible means of percentage lung ventilation volume measurement than the previously used separate-breath-hold scan approach, and reduces errors.
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Affiliation(s)
- F C Horn
- Academic Radiology, Department of Cardiovascular Sciences, University of Sheffield, UK
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Abstract
The small airways are defined as those less than 2 mm in diameter. They are a major site of pathology in many lung diseases, not least chronic obstructive pulmonary disease (COPD) and asthma. The small airways are frequently involved early in the course of these diseases, with significant pathology demonstrable often before the onset of symptoms or changes in spirometry and imaging. Despite their importance, they have proven relatively difficult to study. This is in part due to their relative inaccessibility to biopsy and their small size which makes their imaging difficult. Traditional lung function tests may only become abnormal once there is a significant burden of disease within them. This has led to the term 'the quiet zone' of the lung. In recent years, more specialised tests have been developed which may detect these changes earlier, perhaps offering the possibility of earlier diagnosis and intervention. These tests are now moving from the realms of clinical research laboratories into routine clinical practice and are increasingly useful in the diagnosis and monitoring of respiratory diseases. This article gives an overview of small airways physiology and some of the routine and more advanced tests of airway function.
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Affiliation(s)
- William McNulty
- National Heart and lung Institute, Imperial College London and Royal Brompton Hospital, London, UK
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Kirby M, Pike D, McCormack DG, Sin DD, Lam S, Coxson HO, Parraga G. Longitudinal Computed Tomography and Magnetic Resonance Imaging of COPD: Thoracic Imaging Network of Canada (TINCan) Study Objectives. Chronic Obstr Pulm Dis 2014; 1:200-211. [PMID: 28848822 PMCID: PMC5556865 DOI: 10.15326/jcopdf.1.2.2014.0136] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/09/2014] [Indexed: 11/21/2022]
Abstract
Although the human and societal burden and cost of COPD is staggering, there are few clinical tools that provide earlier diagnoses or a means to regionally monitor disease in a way that might lead to improved therapies and outcomes. In acknowledgement of the current gaps in COPD therapy, the objective of the Thoracic Imaging Network of Canada (TINCan) is to improve COPD patient phenotyping through imaging, to provide methods and imaging-based intermediate endpoints for the development of new treatments, and to evaluate disease progression and patient-based outcomes in COPD patients and those at risk of COPD. Here we summarize and outline the TINCan study protocol and describe our objectives. TINCan is a prospective study that aims to identify and quantify novel COPD phenotypes from thoracic computed tomography (CT) and thoracic hyperpolarized noble gas magnetic resonance imaging (MRI) in 200 ex-smokers, 50 years of age or greater, including asymptomatic ex-smokers with normal pulmonary function and Global initiative for chronic Obstructive Lung Disease (GOLD) Unclassified (U) , and GOLD stages I-IV patients. Baseline and 2-year follow-up measurements will be acquired using spirometry, plethysmography, diffusing capacity of the lung for carbon monoxide (DLCO), St. George's Respiratory Questionnaire (SGRQ), 6-minute walk test (6MWT), thoracic CT and hyperpolarized helium-3 (3He) and xenon 129 (129Xe) MRI. TINCan provides a unique opportunity to quantify and compare novel lung structure-function measurements and investigate their relationship with well-established clinical measurements and outcomes. Such intermediate endpoints of COPD may be used to stratify patients for personalized treatments and to develop new treatments to improve outcomes, a long-standing clinical goal.
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Affiliation(s)
- Miranda Kirby
- Department of Radiology, University of British Columbia, Vancouver, Canada
- University of British Columbia, James Hogg Research Center and The Institute of Heart and Lung Health, St. Paul's Hospital, Vancouver, Canada
| | - Damien Pike
- Imaging Research Laboratories, 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
| | - Don D. Sin
- University of British Columbia, James Hogg Research Center and The Institute of Heart and Lung Health, St. Paul's Hospital, Vancouver, Canada
- Department of Medicine, University of British Columbia, Vancouver, Canada
| | - Stephen Lam
- Department of Integrative Oncology, British Columbia Cancer Agency Research Centre, Vancouver, Canada
| | - Harvey O. Coxson
- Department of Radiology, University of British Columbia, Vancouver, Canada
- University of British Columbia, James Hogg Research Center and The Institute of Heart and Lung Health, St. Paul's Hospital, Vancouver, Canada
- Co-lead principal investigators
| | - Grace Parraga
- Imaging Research Laboratories, Robarts Research Institute, University of Western Ontario, London, Canada
- Department of Medical Biophysics, University of Western Ontario, London, Canada
- Co-lead principal investigators
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Kirby M, Ouriadov A, Svenningsen S, Owrangi A, Wheatley A, Etemad‐Rezai R, Santyr GE, McCormack DG, Parraga G. Hyperpolarized 3He and 129Xe magnetic resonance imaging apparent diffusion coefficients: physiological relevance in older never- and ex-smokers. Physiol Rep 2014; 2:e12068. [PMID: 25347853 PMCID: PMC4187551 DOI: 10.14814/phy2.12068] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 05/30/2014] [Accepted: 06/04/2014] [Indexed: 11/24/2022] Open
Abstract
Noble gas pulmonary magnetic resonance imaging (MRI) is transitioning away from (3)He to (129)Xe gas, but the physiological/clinical relevance of (129)Xe apparent diffusion coefficient (ADC) parenchyma measurements is not well understood. Therefore, our objective was to generate (129)Xe MRI ADC for comparison with (3)He ADC and with well-established measurements of alveolar structure and function in older never-smokers and ex-smokers with chronic obstructive pulmonary disease (COPD). In four never-smokers and 10 COPD ex-smokers, (3)He (b = 1.6 sec/cm(2)) and (129)Xe (b = 12, 20, and 30 sec/cm(2)) ADC, computed tomography (CT) density-threshold measurements, and the diffusing capacity for carbon monoxide (DLCO) were measured. To understand regional differences, the anterior-posterior (APG) and superior-inferior (∆SI) ADC differences were evaluated. Compared to never-smokers, COPD ex-smokers showed greater (3)He ADC (P = 0.006), (129)Xe ADCb12 (P = 0.006), and ADCb20 (P = 0.006), but not for ADCb30 (P > 0.05). Never-smokers and COPD ex-smokers had significantly different APG for (3)He ADC (P = 0.02), (129)Xe ADCb12 (P = 0.006), and ADCb20 (P = 0.01), but not for ADCb30 (P > 0.05). ∆SI for never- and ex-smokers was significantly different for (3)He ADC (P = 0.046), but not for (129)Xe ADC (P > 0.05). There were strong correlations for DLCO with (3)He ADC and (129)Xe ADCb12 (both r = -0.95, P < 0.05); in a multivariate model (129)Xe ADCb12 was the only significant predictor of DLCO (P = 0.049). For COPD ex-smokers, CT relative area <-950 HU (RA950) correlated with (3)He ADC (r = 0.90, P = 0.008) and (129)Xe ADCb12 (r = 0.85, P = 0.03). In conclusion, while (129)Xe ADCb30 may be appropriate for evaluating subclinical or mild emphysema, in this small group of never-smokers and ex-smokers with moderate-to-severe emphysema, (129)Xe ADCb12 provided a physiologically appropriate estimate of gas exchange abnormalities and alveolar microstructure.
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Affiliation(s)
- Miranda Kirby
- Imaging Research Laboratories, Robarts Research Institute, The University of Western Ontario, London, Ontario, Canada
- Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada
| | - Alexei Ouriadov
- Imaging Research Laboratories, Robarts Research Institute, The University of Western Ontario, London, Ontario, Canada
| | - Sarah Svenningsen
- Imaging Research Laboratories, Robarts Research Institute, The University of Western Ontario, London, Ontario, Canada
- Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada
| | - Amir Owrangi
- Imaging Research Laboratories, Robarts Research Institute, The University of Western Ontario, London, Ontario, Canada
- Graduate Program in Biomedical Engineering, The University of Western Ontario, London, Ontario, Canada
| | - Andrew Wheatley
- Imaging Research Laboratories, Robarts Research Institute, The University of Western Ontario, London, Ontario, Canada
| | - Roya Etemad‐Rezai
- Department of Medical Imaging, The University of Western Ontario, London, Ontario, Canada
| | - Giles E. Santyr
- Imaging Research Laboratories, Robarts Research Institute, The University of Western Ontario, London, Ontario, Canada
- Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada
| | - David G. McCormack
- Division of Respirology, Department of Medicine, The University of Western Ontario, London, Ontario, Canada
| | - Grace Parraga
- Imaging Research Laboratories, Robarts Research Institute, The University of Western Ontario, London, Ontario, Canada
- Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada
- Graduate Program in Biomedical Engineering, The University of Western Ontario, London, Ontario, Canada
- Department of Medical Imaging, The University of Western Ontario, London, Ontario, Canada
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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] [What about the content of this article? (0)] [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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Leary D, Winkler T, Braune A, Maksym GN. Effects of airway tree asymmetry on the emergence and spatial persistence of ventilation defects. J Appl Physiol (1985) 2014; 117:353-62. [PMID: 24947031 DOI: 10.1152/japplphysiol.00881.2013] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Asymmetry and heterogeneity in the branching of the human bronchial tree are well documented, but their effects on bronchoconstriction and ventilation distribution in asthma are unclear. In a series of seminal studies, Venegas et al. have shown that bronchoconstriction may lead to self-organized patterns of patchy ventilation in a computational model that could explain areas of poor ventilation [ventilation defects (VDefs)] observed in positron emission tomography images during induced bronchoconstriction. To investigate effects of anatomic asymmetry on the emergence of VDefs we used the symmetric tree computational model that Venegas and Winkler developed using different trees, including an anatomic human airway tree provided by M. Tawhai (University of Auckland), a symmetric tree, and three trees with intermediate asymmetry (Venegas JG, Winkler T, Musch G, Vidal Melo MF, Layfield D, Tgavalekos N, Fischman AJ, Callahan RJ, Bellani G, Harris RS. Nature 434: 777-782, 2005 and Winkler T, Venegas JG. J Appl Physiol 103: 655-663, 2007). Ventilation patterns, lung resistance (RL), lung elastance (EL), and the entropy of the ventilation distribution were compared at different levels of airway smooth muscle activation. We found VDefs emerging in both symmetric and asymmetric trees, but VDef locations were largely persistent in asymmetric trees, and bronchoconstriction reached steady state sooner than in a symmetric tree. Interestingly, bronchoconstriction in the asymmetric tree resulted in lower RL (∼%50) and greater EL (∼%25). We found that VDefs were universally caused by airway instability, but asymmetry in airway branching led to local triggers for the self-organized patchiness in ventilation and resulted in persistent locations of VDefs. These findings help to explain the emergence and the persistence in location of VDefs found in imaging studies.
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Affiliation(s)
- D Leary
- Dalhousie University, Halifax, Nova Scotia, Canada; and
| | - T Winkler
- Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - A Braune
- Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - G N Maksym
- Dalhousie University, Halifax, Nova Scotia, Canada; and
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Pike D, Lindenmaier TJ, Sin DD, Parraga G. Imaging evidence of the relationship between atherosclerosis and chronic obstructive pulmonary disease. ACTA ACUST UNITED AC 2014. [DOI: 10.2217/iim.13.70] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Owrangi AM, Wang JX, Wheatley A, McCormack DG, Parraga G. Quantitative 1H and hyperpolarized 3He magnetic resonance imaging: Comparison in chronic obstructive pulmonary disease and healthy never-smokers. Eur J Radiol 2014; 83:64-72. [DOI: 10.1016/j.ejrad.2012.02.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Accepted: 02/27/2012] [Indexed: 10/28/2022]
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Kirby M, Parraga G. Pulmonary functional imaging using hyperpolarized noble gas MRI: six years of start-up experience at a single site. Acad Radiol 2013; 20:1344-56. [PMID: 24119346 DOI: 10.1016/j.acra.2013.02.020] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2012] [Revised: 01/31/2013] [Accepted: 02/01/2013] [Indexed: 12/01/2022]
Abstract
RATIONALE AND OBJECTIVES In this review, we summarize our experience evaluating pulmonary function in 330 different subjects using hyperpolarized noble gas magnetic resonance imaging (MRI) after enrollment and screening of >1100 subjects with and without respiratory disease during the period February 1, 2006, through November 1, 2012. MATERIALS AND METHODS We discuss the feasibility of hyperpolarized gas MRI research in a small nonhospital research unit and provide an overview of our experience since we initiated patient-based studies. We also discuss the importance of infrastructure support, collaboration, research trainees, and a large and willing patient population that helped to advance the research and technological deliverables. A summary of patient safety and tolerability, key feasibility, and research milestones is provided, as well as a roadmap for future studies. RESULTS Hyperpolarized (3)He and (129)Xe gas MRI is feasible at smaller centers without significant human resources for large and small longitudinal studies by virtue of its excellent patient safety and tolerability, the speed with which images can be acquired and quantitatively analyzed and the high spatial-temporal dynamics of the method that allows for acute and chronic therapy studies. CONCLUSIONS The hyperpolarized noble gas MRI community's highly collaborative efforts and motivation to further the development and application of this tool has resulted in a moment-of-opportunity to translate the method clinically to provide an improved understanding of pulmonary disease. There are, as well, new and unprecedented opportunities for the evaluation of disease progression and to help develop the new treatments and interventions critically required for chronic pulmonary disease.
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Affiliation(s)
- Miranda Kirby
- Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, Canada, N6A 5K8; Department of Medical Biophysics, London, Canada
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Abstract
A better understanding of the anatomic structure and physiological function of the lung is fundamental to understanding the pathogenesis of pulmonary disease and how to design and deliver better treatments and measure response to intervention. Magnetic resonance imaging (MRI) with the hyperpolarised noble gases helium-3 ((3)He) and xenon-129 ((129)Xe) provides both structural and functional pulmonary measurements, and because it does not require the use of x-rays or other ionising radiation, offers the potential for intensive serial and longitudinal studies in paediatric patients. These facts are particularly important in the evaluation of chronic lung diseases such as asthma and cystic fibrosis- both of which can be considered paediatric respiratory diseases with unmet therapy needs. This review discusses MRI-based imaging methods with a focus on hyperpolarised gas MRI. We also discuss the strengths and limitations as well as the future work required for clinical translation towards paediatric respiratory disease.
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Affiliation(s)
- Miranda Kirby
- Imaging Research Laboratories, Robarts Research Institute, London, Canada.
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Owrangi AM, Entwistle B, Lu A, Chiu J, Hussain N, Etemad-Rezai R, Parraga G. Semi-automated scoring of pulmonary emphysema from X-ray CT: trainee reproducibility and accuracy. Eur J Radiol 2013; 82:e734-41. [PMID: 23957938 DOI: 10.1016/j.ejrad.2013.07.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Revised: 05/14/2013] [Accepted: 07/16/2013] [Indexed: 01/21/2023]
Abstract
OBJECTIVE We developed a semi-automated tool to quantify emphysema from thoracic X-ray multi-detector (64-slice) computed tomography (CT) for training purposes and multi-reader studies. MATERIALS AND METHODS Thoracic X-ray CT was acquired in 93 ex-smokers, who were evaluated by six trainees with little or no expertise (trainees) and a single experienced thoracic radiologist (expert). A graphic user interface (GUI) was developed for emphysema quantification based on the percentile of lung where a score of 0=no abnormalities, 1=1-25%, 2=26-50%, 3=51-75% and 4=76-100% for each lung side/slice. Trainees blinded to subject characteristics scored randomized images twice; accuracy was determined by comparison to expert scores, density histogram 15th percentile (HU 15), relative area at -950 HU (RA(950)), low attenuation clusters at -950 HU (LAC(950)), -856 HU (LAC(856)) and the diffusing capacity for carbon monoxide (DL(CO%pred)). Intra- and inter-observer reproducibility was evaluated using coefficients-of-variation (COV), intra-class (ICC) and Pearson correlations. RESULTS Trainee-expert correlations were significant (r=0.85-0.97, p<0.0001) and a significant trainee bias (0.15 ± 0.22) was observed. Emphysema score was correlated with RA(950) (r=0.88, p<0.0001), HU 15 (r=-0.77, p<0.0001), LAC(950) (r=0.76, p<0.0001), LAC(856) (r=0.74, p=0.0001) and DLCO%pred (r=-0.71, p<0.0001). Intra-observer reproducibility (COV=4-27%; ICC=0.75-0.94) was moderate to high for trainees; intra- and inter-observer COV were negatively and non-linearly correlated with emphysema score. CONCLUSION We developed a GUI for rapid and interactive emphysema scoring that allows for comparison of multiple readers with clinical and radiological standards.
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Affiliation(s)
- Amir M Owrangi
- Imaging Research Laboratories, Robarts Research Institute, London, Canada; Graduate Program in Biomedical Engineering.
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Owrangi AM, Etemad-Rezai R, McCormack DG, Cunningham IA, Parraga G. Computed tomography density histogram analysis to evaluate pulmonary emphysema in ex-smokers. Acad Radiol 2013; 20:537-45. [PMID: 23570935 DOI: 10.1016/j.acra.2012.11.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Revised: 11/12/2012] [Accepted: 11/13/2012] [Indexed: 11/18/2022]
Abstract
RATIONALE AND OBJECTIVES High-resolution computed tomography (CT) measurements of emphysema typically use Hounsfield unit (HU) density histogram thresholds or observer scores based on regions of low x-ray attenuation. Our objective was to develop an automated measurement of emphysema using principal component analysis (PCA) of the CT density histogram. MATERIALS AND METHODS Ninety-seven ex-smokers, including 53 subjects with chronic obstructive pulmonary disease (COPD) and 44 asymptomatic subjects (AEs), provided written informed consent to imaging as well as plethysmography and spirometry. We applied PCA to the CT density histogram to generate whole lung and regional density histogram principal components including the first and second components and the sum of both principal components (density histogram principal component score [DHPCS]). Significant relationships for DHPCS with single HU thresholds, pulmonary function measurements, an expert's emphysema score, and hyperpolarized (3)He magnetic resonance imaging apparent diffusion coefficients (ADCs) were determined using linear regression and Pearson coefficients. Receiver operator characteristics analysis was performed using forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) as the independent diagnostic. RESULTS There was a significant difference (P < .0001) between AE and COPD subjects for DHPCS; FEV1/FVC; diffusing capacity of lung for carbon monoxide%predicted; attenuation values below -950, -910, and -856 HU; and (3)He ADCs. There were significant correlations for DHPCS with FEV1/FVC (r = -0.85, P < .0001); diffusing capacity of lung for carbon monoxide%predicted (r = -0.67, P < .0001); attenuation values below -950/-910/-856 HU (r = 0.93/0.96/0.76, P < .0001); and (3)He ADCs (r = 0.85, P < .0001). Receiver operator characteristics analysis showed a 91% classification rate for DHPCS. CONCLUSIONS We generated an automated emphysema score using PCA of the CT density histogram with a 91% COPD classification rate that showed strong and significant correlations with pulmonary function tests, single HU thresholds, and (3)He magnetic resonance imaging ADCs.
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Affiliation(s)
- Amir M Owrangi
- Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, Canada N6A 5K8
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Virgincar RS, Cleveland ZI, Kaushik SS, Freeman MS, Nouls J, Cofer GP, Martinez-Jimenez S, He M, Kraft M, Wolber J, McAdams HP, Driehuys B. Quantitative analysis of hyperpolarized 129Xe ventilation imaging in healthy volunteers and subjects with chronic obstructive pulmonary disease. NMR Biomed 2013; 26:424-35. [PMID: 23065808 PMCID: PMC3624045 DOI: 10.1002/nbm.2880] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Revised: 09/11/2012] [Accepted: 09/12/2012] [Indexed: 05/12/2023]
Abstract
In this study, hyperpolarized (129) Xe MR ventilation and (1) H anatomical images were obtained from three subject groups: young healthy volunteers (HVs), subjects with chronic obstructive pulmonary disease (COPD) and age-matched controls (AMCs). Ventilation images were quantified by two methods: an expert reader-based ventilation defect score percentage (VDS%) and a semi-automated segmentation-based ventilation defect percentage (VDP). Reader-based values were assigned by two experienced radiologists and resolved by consensus. In the semi-automated analysis, (1) H anatomical images and (129) Xe ventilation images were both segmented following registration to obtain the thoracic cavity volume and ventilated volume, respectively, which were then expressed as a ratio to obtain the VDP. Ventilation images were also characterized by generating signal intensity histograms from voxels within the thoracic cavity volume, and heterogeneity was analyzed using the coefficient of variation (CV). The reader-based VDS% correlated strongly with the semi-automatically generated VDP (r = 0.97, p < 0.0001) and with CV (r = 0.82, p < 0.0001). Both (129) Xe ventilation defect scoring metrics readily separated the three groups from one another and correlated significantly with the forced expiratory volume in 1 s (FEV1 ) (VDS%: r = -0.78, p = 0.0002; VDP: r = -0.79, p = 0.0003; CV: r = -0.66, p = 0.0059) and other pulmonary function tests. In the healthy subject groups (HVs and AMCs), the prevalence of ventilation defects also increased with age (VDS%: r = 0.61, p = 0.0002; VDP: r = 0.63, p = 0.0002). Moreover, ventilation histograms and their associated CVs distinguished between subjects with COPD with similar ventilation defect scores, but visibly different ventilation patterns.
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Affiliation(s)
- Rohan S. Virgincar
- Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, USA
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
- Department of Radiology, Duke University Medical Center, Durham, NC, USA
| | - Zackary I. Cleveland
- Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, USA
- Department of Radiology, Duke University Medical Center, Durham, NC, USA
| | - S. Sivaram Kaushik
- Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, USA
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Matthew S. Freeman
- Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, USA
- Medical Physics Graduate Program, Duke University, Durham, NC, USA
| | - John Nouls
- Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, USA
- Department of Radiology, Duke University Medical Center, Durham, NC, USA
| | - Gary P. Cofer
- Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, USA
- Department of Radiology, Duke University Medical Center, Durham, NC, USA
| | | | - Mu He
- Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, USA
- Department of Electrical and Computer Engineering, Duke University, Durham, NC, USA
| | - Monica Kraft
- Department of Pulmonary and Critical Care Medicine, Duke University Medical Center, Durham, NC, USA
| | - Jan Wolber
- GE Healthcare, The Grove Center, White Lion Rd, Amersham, UK
- Academic Radiology, University of Sheffield, Royal Hallamshire Hospital, Sheffield, UK
| | - H. Page McAdams
- Department of Radiology, Duke University Medical Center, Durham, NC, USA
| | - Bastiaan Driehuys
- Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, USA
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
- Department of Radiology, Duke University Medical Center, Durham, NC, USA
- Medical Physics Graduate Program, Duke University, Durham, NC, USA
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Cereda M, Emami K, Xin Y, Kadlecek S, Kuzma NN, Mongkolwisetwara P, Profka H, Pickup S, Ishii M, Kavanagh BP, Deutschman CS, Rizi RR. Imaging the interaction of atelectasis and overdistension in surfactant-depleted lungs. Crit Care Med 2013; 41:527-35. [PMID: 23263577 PMCID: PMC3557664 DOI: 10.1097/ccm.0b013e31826ab1f2] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
OBJECTIVE Atelectasis and surfactant depletion may contribute to greater distension-and thereby injury-of aerated lung regions; recruitment of atelectatic lung may protect these regions by attenuating such overdistension. However, the effects of atelectasis (and recruitment) on aerated airspaces remain elusive. We tested the hypothesis that during mechanical ventilation, surfactant depletion increases the dimensions of aerated airspaces and that lung recruitment reverses these changes. DESIGN Prospective imaging study in an animal model. SETTING Research imaging facility. SUBJECTS Twenty-seven healthy Sprague Dawley rats. INTERVENTIONS Surfactant depletion was obtained by saline lavage in anesthetized, ventilated rats. Alveolar recruitment was accomplished using positive end-expiratory pressure and exogenous surfactant administration. MEASUREMENTS AND MAIN RESULTS Airspace dimensions were estimated by measuring the apparent diffusion coefficient of He, using diffusion-weighted hyperpolarized gas magnetic resonance imaging. Atelectasis was demonstrated using computerized tomography and by measuring oxygenation. Saline lavage increased atelectasis (increase in nonaerated tissue from 1.2% to 13.8% of imaged area, p < 0.001), and produced a concomitant increase in mean apparent diffusion coefficient (~33%, p < 0.001) vs. baseline; the heterogeneity of the computerized tomography signal and the variance of apparent diffusion coefficient were also increased. Application of positive end-expiratory pressure and surfactant reduced the mean apparent diffusion coefficient (~23%, p < 0.001), and its variance, in parallel to alveolar recruitment (i.e., less computerized tomography densities and heterogeneity, increased oxygenation). CONCLUSIONS Overdistension of aerated lung occurs during atelectasis is detectable using clinically relevant magnetic resonance imaging technology, and could be a key factor in the generation of lung injury during mechanical ventilation. Lung recruitment by higher positive end-expiratory pressure and surfactant administration reduces airspace distension.
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Affiliation(s)
- Maurizio Cereda
- Department of Anesthesiology and Critical Care and Stavropoulos Sepsis Research Program, University of Pennsylvania, Philadelphia, PA, USA.
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Ouriadov A, Farag A, Kirby M, McCormack DG, Parraga G, Santyr GE. Lung morphometry using hyperpolarized 129
Xe apparent diffusion coefficient anisotropy in chronic obstructive pulmonary disease. Magn Reson Med 2013; 70:1699-706. [DOI: 10.1002/mrm.24595] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Revised: 11/19/2012] [Accepted: 11/20/2012] [Indexed: 12/27/2022]
Affiliation(s)
- Alexei Ouriadov
- Ph.D., Imaging Research Laboratories; Robarts Research Institute; Western University, London Ontario Canada
| | - Adam Farag
- Ph.D., Imaging Research Laboratories; Robarts Research Institute; Western University, London Ontario Canada
| | - Miranda Kirby
- Ph.D., Imaging Research Laboratories; Robarts Research Institute; Western University, London Ontario Canada
- Department of Medical Biophysics; Western University; London Ontario Canada
| | | | - Grace Parraga
- Ph.D., Imaging Research Laboratories; Robarts Research Institute; Western University, London Ontario Canada
- Department of Medical Biophysics; Western University; London Ontario Canada
- Department of Medical Imaging; Western University; London Ontario Canada
| | - Giles E. Santyr
- Ph.D., Imaging Research Laboratories; Robarts Research Institute; Western University, London Ontario Canada
- Department of Medical Biophysics; Western University; London Ontario Canada
- Department of Medical Imaging; Western University; London Ontario Canada
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Mathew L, Kirby M, Farquhar D, Licskai C, Santyr G, Etemad-Rezai R, Parraga G, McCormack DG. Hyperpolarized 3He functional magnetic resonance imaging of bronchoscopic airway bypass in chronic obstructive pulmonary disease. Can Respir J 2012; 19:41-3. [PMID: 22332133 DOI: 10.1155/2012/675743] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A 73-year-old exsmoker with Global initiative for chronic Obstructive Lung Disease stage III chronic obstructive pulmonary disease underwent airway bypass (AB) as part of the Exhale Airway Stents for Emphysema (EASE) trial, and was the only EASE subject to undergo hyperpolarized 3He magnetic resonance imaging for evaluation of lung function pre- and post-AB. 3He magnetic resonance imaging was acquired twice previously (32 and eight months pre-AB) and twice post-AB (six and 12 months post-AB). Six months post-AB, his increase in forced vital capacity was <12% predicted, and he was classified as an AB nonresponder. However, post-AB, he also demonstrated improvements in quality of life scores, 6 min walk distance and improvements in 3He gas distribution in the regions of stent placement. Given the complex relationship between well-established pulmonary function and quality of life measurements, the present case provides evidence of the value-added information functional imaging may provide in chronic obstructive pulmonary disease interventional studies.
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Yamamoto T, Kabus S, von Berg J, Lorenz C, Chung MP, Hong JC, Loo BW, Keall PJ. Reproducibility of four-dimensional computed tomography-based lung ventilation imaging. Acad Radiol 2012; 19:1554-65. [PMID: 22975070 PMCID: PMC5357435 DOI: 10.1016/j.acra.2012.07.006] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Revised: 07/11/2012] [Accepted: 07/20/2012] [Indexed: 12/13/2022]
Abstract
RATIONALE AND OBJECTIVES A novel ventilation imaging method based on four-dimensional (4D) computed tomography (CT) has been applied to the field of radiation oncology. Understanding its reproducibility is a prerequisite for clinical applications. The purpose of this study was to quantify the reproducibility of 4D CT ventilation imaging over different days and the same session. MATERIALS AND METHODS Two ventilation images were created from repeat 4D CT scans acquired over the average time frames of 15 days for 6 lung cancer patients and 5 minutes for another 6 patients. The reproducibility was quantified using the voxel-based Spearman rank correlation coefficients for all lung voxels and Dice similarity coefficients (DSC) for the spatial overlap of segmented high-, moderate-, and low-functional lung volumes. Furthermore, the relationship between the variation in abdominal motion range as a measure of the depth of breathing and variation in ventilation was evaluated using linear regression. RESULTS The voxel-based correlation between the two ventilation images was moderate on average (0.50 ± 0.15). The DSCs were also moderate for the high- (0.60 ± 0.08), moderate- (0.46 ± 0.06), and low-functional lung (0.58 ± 0.09). No patients demonstrated strong correlations. The relationship between the motion range variation and ventilation variation was found to be moderate and significant. CONCLUSIONS We investigated the reproducibility of 4D CT ventilation imaging over the time frames of 15 days and 5 minutes and found that it was only moderately reproducible. Respiratory variation during 4D CT scans was found to deteriorate the reproducibility. Improvement of 4D CT imaging is necessary to increase the reproducibility of 4D CT ventilation imaging.
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Affiliation(s)
- Tokihiro Yamamoto
- Department of Radiation Oncology, Stanford University School of Medicine, 875 Blake Wilbur Dr., Stanford, CA 94305-5847, USA
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Mathew L, Wheatley A, Castillo R, Castillo E, Rodrigues G, Guerrero T, Parraga G. Hyperpolarized (3)He magnetic resonance imaging: comparison with four-dimensional x-ray computed tomography imaging in lung cancer. Acad Radiol 2012; 19:1546-53. [PMID: 22999648 DOI: 10.1016/j.acra.2012.08.007] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 08/14/2012] [Accepted: 08/21/2012] [Indexed: 10/27/2022]
Abstract
RATIONALE AND OBJECTIVES Pulmonary functional imaging using four-dimensional x-ray computed tomographic (4DCT) imaging and hyperpolarized (3)He magnetic resonance imaging (MRI) provides regional lung function estimates in patients with lung cancer in whom pulmonary function measurements are typically dominated by tumor burden. The aim of this study was to evaluate the quantitative spatial relationship between 4DCT and hyperpolarized (3)He MRI ventilation maps. MATERIALS AND METHODS Eleven patients with lung cancer provided written informed consent to 4DCT imaging and MRI performed within 11 ± 14 days. Hyperpolarized (3)He MRI was acquired in breath-hold after inhalation from functional residual capacity of 1 L hyperpolarized (3)He, whereas 4DCT imaging was acquired over a single tidal breath of room air. For hyperpolarized (3)He MRI, the percentage ventilated volume was generated using semiautomated segmentation; for 4DCT imaging, pulmonary function maps were generated using the correspondence between identical tissue elements at inspiratory and expiratory phases to generate percentage ventilated volume. RESULTS After accounting for differences in image acquisition lung volumes ((3)He MRI: 1.9 ± 0.5 L ipsilateral, 2.3 ± 0.7 L contralateral; 4DCT imaging: 1.2 ± 0.3 L ipsilateral, 1.3 ± 0.4 L contralateral), there was no significant difference in percentage ventilated volume between hyperpolarized (3)He MRI (72 ± 11% ipsilateral, 79 ± 12% contralateral) and 4DCT imaging (74 ± 3% ipsilateral, 75 ± 4% contralateral). Spatial correspondence between 4DCT and (3)He MRI ventilation was evaluated using the Dice similarity coefficient index (ipsilateral, 86 ± 12%; contralateral, 88 ± 12%). CONCLUSIONS Despite rather large differences in image acquisition breathing maneuvers, good spatial and significant quantitative agreement was observed for ventilation maps on hyperpolarized (3)He MRI and 4DCT imaging, suggesting that pulmonary regions with good lung function are similar between modalities in this small group of patients with lung cancer.
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Niles DJ, Kruger SJ, Dardzinski BJ, Harman A, Jarjour NN, Ruddy M, Nagle SK, François CJ, Fain SB. Exercise-induced bronchoconstriction: reproducibility of hyperpolarized 3He MR imaging. Radiology 2012; 266:618-25. [PMID: 23169798 DOI: 10.1148/radiol.12111973] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To quantitatively evaluate interday, interreader, and intersite agreement of readers of hyperpolarized helium 3 (HPHe) MR images in patients with exercise-induced bronchoconstriction. MATERIALS AND METHODS This HIPAA-compliant, institutional review board approved study included 13 patients with exercise-induced bronchoconstriction. On two separate days, HPHe MR imaging of the lungs was performed at baseline, immediately after a 10-minute exercise challenge (postchallenge), and 45 minutes after exercise (recovery). Patients were imaged at two sites, six at site A and seven at site B. Images were analyzed independently by multiple readers at each site. Lung volume, ventilation defect volume, ventilated volume, and the number of defects were measured quantitatively, and the location of defects was evaluated qualitatively at site A. Interday and interreader agreement were evaluated by using the intraclass correlation coefficient (ICC), and intersite agreement was evaluated by using a modified Bland-Altman analysis. RESULTS The ICC between days for ventilation defect volume, ventilated volume, and number of defects was at least 0.74 at both sites. The ICC for lung volume was greater at site B (0.83-0.86) than at site A (0.60-0.65). Defects seen in the same location in the lung on both days included 19.7% of those seen on baseline images and 29.2% and 18.6% of defects on postchallenge and recovery images, respectively. Interreader ICC for each measurement was at least 0.82 for each site. Analysis of intersite agreement showed biases of 612 mL for lung volume, -60.7 mL for ventilation defect volume, 2.91% for ventilated volume, and -6.56 for number of defects. CONCLUSION The reported measures of reproducibility of HPHe MR imaging may help in the design and interpretation of single- and multicenter studies of patients with exercise-induced bronchoconstriction.
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Affiliation(s)
- David J Niles
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin, 1111 Highland Ave, Room 1005, Madison, WI 53705-2275, USA
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Kirby M, Kanhere N, Etemad-Rezai R, McCormack DG, Parraga G. Hyperpolarized helium-3 magnetic resonance imaging of chronic obstructive pulmonary disease exacerbation. J Magn Reson Imaging 2012; 37:1223-7. [DOI: 10.1002/jmri.23896] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Accepted: 09/17/2012] [Indexed: 11/06/2022] Open
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Kirby M, Svenningsen S, Owrangi A, Wheatley A, Farag A, Ouriadov A, Santyr GE, Etemad-Rezai R, Coxson HO, McCormack DG, Parraga G. Hyperpolarized3He and129Xe MR Imaging in Healthy Volunteers and Patients with Chronic Obstructive Pulmonary Disease. Radiology 2012; 265:600-10. [DOI: 10.1148/radiol.12120485] [Citation(s) in RCA: 170] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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