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Ohno Y, Ozawa Y, Nagata H, Bando S, Cong S, Takahashi T, Oshima Y, Hamabuchi N, Matsuyama T, Ueda T, Yoshikawa T, Takenaka D, Toyama H. Area-Detector Computed Tomography for Pulmonary Functional Imaging. Diagnostics (Basel) 2023; 13:2518. [PMID: 37568881 PMCID: PMC10416899 DOI: 10.3390/diagnostics13152518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 07/22/2023] [Accepted: 07/25/2023] [Indexed: 08/13/2023] Open
Abstract
An area-detector CT (ADCT) has a 320-detector row and can obtain isotropic volume data without helical scanning within an area of nearly 160 mm. The actual-perfusion CT data within this area can, thus, be obtained by means of continuous dynamic scanning for the qualitative or quantitative evaluation of regional perfusion within nodules, lymph nodes, or tumors. Moreover, this system can obtain CT data with not only helical but also step-and-shoot or wide-volume scanning for body CT imaging. ADCT also has the potential to use dual-energy CT and subtraction CT to enable contrast-enhanced visualization by means of not only iodine but also xenon or krypton for functional evaluations. Therefore, systems using ADCT may be able to function as a pulmonary functional imaging tool. This review is intended to help the reader understand, with study results published during the last a few decades, the basic or clinical evidence about (1) newly applied reconstruction methods for radiation dose reduction for functional ADCT, (2) morphology-based pulmonary functional imaging, (3) pulmonary perfusion evaluation, (4) ventilation assessment, and (5) biomechanical evaluation.
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Affiliation(s)
- Yoshiharu Ohno
- Department of Diagnostic Radiology, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan
- Joint Research Laboratory of Advanced Medical Imaging, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan;
| | - Yoshiyuki Ozawa
- Department of Radiology, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan; (Y.O.)
| | - Hiroyuki Nagata
- Joint Research Laboratory of Advanced Medical Imaging, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan;
| | - Shuji Bando
- Department of Radiology, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan; (Y.O.)
| | - Shang Cong
- Department of Radiology, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan; (Y.O.)
| | - Tomoki Takahashi
- Department of Radiology, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan; (Y.O.)
| | - Yuka Oshima
- Department of Radiology, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan; (Y.O.)
| | - Nayu Hamabuchi
- Department of Radiology, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan; (Y.O.)
| | - Takahiro Matsuyama
- Department of Radiology, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan; (Y.O.)
| | - Takahiro Ueda
- Department of Radiology, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan; (Y.O.)
| | - Takeshi Yoshikawa
- Department of Diagnostic Radiology, Hyogo Cancer Center, Akashi 673-0021, Hyogo, Japan
| | - Daisuke Takenaka
- Department of Diagnostic Radiology, Hyogo Cancer Center, Akashi 673-0021, Hyogo, Japan
| | - Hiroshi Toyama
- Department of Radiology, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan; (Y.O.)
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Jung JW, Oh JS, Bae B, Ahn YH, Kim LW, Choi J, Kim HY, Kang HR, Lee CH. Ultra-high-resolution computed tomography shows changes in the lungs related with airway hyperresponsiveness in a murine asthma model. Sci Rep 2021; 11:17584. [PMID: 34475448 PMCID: PMC8413288 DOI: 10.1038/s41598-021-96853-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 08/09/2021] [Indexed: 11/12/2022] Open
Abstract
In vivo presentation of airway hyper-responsiveness (AHR) at the different time points of the allergic reaction is not clearly understood. The purpose of this study was to investigate how AHR manifests in the airway and the lung parenchyma in vivo following exposure to different stimuli and in the early and late phases of asthma after allergen exposure. Ovalbumin (OVA)-induced allergic asthma model was established using 6-week female BALB/c mice. Enhanced pause was measured with a non-invasive method to assess AHR. The dynamic changes of the airway and lung parenchyma were evaluated with ultra-high-resolution computed tomography (128 multi-detector, 1024 × 1024 matrix) for 10 h. While the methacholine challenge showed no grossly visible changes in the proximal airway and lung parenchyma despite provoking AHR, the OVA challenge induced significant immediate changes manifesting as peribronchial ground glass opacities, consolidations, air-trapping, and paradoxical proximal airway dilatations. After resolution of immediate response, multiple episodes of AHRs occurred with paradoxical proximal airway dilatation and peripheral air-trapping in late phase over a prolonged time period in vivo. Understanding of airflow limitation based on the structural changes of asthmatic airway would be helpful to make an appropriate drug delivery strategy for the treatment of asthma.
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Affiliation(s)
- Jae-Woo Jung
- Institute of Allergy and Clinical Immunology, Seoul National University Medical Research Center, Seoul, Korea.,Department of Internal Medicine, Chung-Ang University College of Medicine, Seoul, Korea
| | - Jung Suk Oh
- Department of Radiology, Catholic University, Seoul St. Mary's Hospital, Seoul, Korea
| | - Boram Bae
- Institute of Allergy and Clinical Immunology, Seoul National University Medical Research Center, Seoul, Korea
| | - Yoon Hae Ahn
- Department of Internal Medicine, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Korea
| | - Lucy Wooyeon Kim
- Institute of Allergy and Clinical Immunology, Seoul National University Medical Research Center, Seoul, Korea
| | - Jiwoong Choi
- Department of Internal Medicine, University of Kansas School of Medicine, Kansas City, KS, USA.,Department of Bioengineering, University of Kansas, Lawrence, KS, USA
| | - Hye-Young Kim
- Institute of Allergy and Clinical Immunology, Seoul National University Medical Research Center, Seoul, Korea.,Laboratory of Mucosal Immunology, Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, Korea
| | - Hye-Ryun Kang
- Institute of Allergy and Clinical Immunology, Seoul National University Medical Research Center, Seoul, Korea. .,Department of Internal Medicine, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Korea.
| | - Chang Hyun Lee
- Department of Radiology and Institute of Radiation, Seoul National University College of Medicine, Seoul National University Hospital, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Korea.
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Park J, Kim S, Lim JK, Jin KN, Yang MS, Chae KJ, Jin GY, Kim TB, Kim HK, Lee KE, Lee CH, Choi S. Quantitative CT Image-Based Structural and Functional Changes during Asthma Acute Exacerbations. J Appl Physiol (1985) 2021; 131:1056-1066. [PMID: 34382839 DOI: 10.1152/japplphysiol.00743.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Asthma acute exacerbations (AE) have been investigated using quantitative computed tomography (QCT)-based imaging metrics, but QCT has not yet been used to investigate a comprehensive set of imaging metrics during AE. This study aims to explore imaging features, captured both at segmental and parenchymal scales, during asthma AE, compared to stable asthma (SA). Two sets of the QCT images at total lung capacity (TLC) and functional residual capacity (FRC) were captured for 14 subjects during asthma AE and in SA phase, respectively. We calculated airway wall thickness (WT), hydraulic diameter (Dh), and airway circularity (Cr) of the 36 segmental airways, percentage of functional small airway disease (fSAD%), percentage of emphysema, tissue fraction (βtiss), and coefficient of variation of βtiss (CV of βtiss). We performed Spearman correlation tests for changes in QCT metrics and pulmonary function tests, measured in AE and SA. During asthma AE, structural metrics, i.e., WT, Dh, and Cr, were not changed significantly. In functional metrics, CV of βtiss at FRC indicating the heterogeneity of lung tissue distribution was significantly increased, while the mean of βtiss at FRC did not change during AE. An increase of fSAD% during AE was most correlated with a decrease of forced expiratory volume in 1 second and forced vital capacity, especially in the lower lobes. This study demonstrates that the heterogeneous feature of βtiss measured at lower lobes is more noticeable during asthma AE, compared with other traditional imaging metrics. This metric could be utilized to identify unique features during asthma AE.
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Affiliation(s)
- Joonwoo Park
- School of Mechanical Engineering, Kyungpook National University, Daegu, Korea (South), Republic of
| | - Sujeong Kim
- Department of Internal Medicine, School of Medicine, Kyungpook National University, Daegu, Korea (South), Republic of
| | - Jae-Kwang Lim
- Department of Radiology, School of Medicine, Kyungpook National University, Daegu, Korea (South), Republic of
| | - Kwang Nam Jin
- Department of Radiology, Seoul Metropolitan Government, Seoul, Korea (South), Republic of
| | - Min Suk Yang
- Department of Internal Medicine, Seoul Metropolitan Government, Seoul, Korea (South), Republic of
| | - Kum Ju Chae
- Department of Radiology, Chonbuk National University, Jeonju, Korea (South), Republic of
| | - Gong Yong Jin
- Department of Radiology, Chonbuk National University, Jeonju, Korea (South), Republic of
| | - Tae-Bum Kim
- Department of Allergy and Clinical Immunology, Asan Medical Center, Seoul, Korea (South), Republic of
| | - Hee-Kyoo Kim
- Department of Internal Medicine, Kosin University, Busan, Korea (South), Republic of
| | - Kyeong Eun Lee
- Department of Statistics, Kyungpook National University, Daegu, Korea (South), Republic of
| | - Chang Hyun Lee
- Department of Radiology, Seoul National University Hospital, Seoul, Korea (South), Republic of
| | - Sanghun Choi
- School of Mechanical Engineering, Kyungpook National University, Daegu, Korea (South), Republic of
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Polak AG, Obojski A, Mroczka J. Quantitative Assessment of the Airway Response to Bronchial Tests Based on a Spirometric Curve Shift. IEEE Trans Biomed Eng 2021; 68:739-746. [PMID: 32746039 DOI: 10.1109/tbme.2020.3004907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVE Although spirometry is the most common pulmonary function test, there is no method to quantitatively infer about airway resistance or other properties from the flow-volume curves. Recently, an identifiable inverse model for forced expiration was proposed, as well as the idea to deduce changes in airway resistances and compliances from spirometric curve evolution. The aim of this work was to combine the above advances in a method for assessing the airway response to bronchial tests from a spirometric curve shift. METHODS The approach is based on the differential measurement of the degree, site of maximal effect and width of changes, further recalculated into relative changes in the distribution of airway resistances (δRg) and compliances (δCg) along the bronchial tree. To this end, appropriate models were identified using the pre- and post-test spirometry data. The accuracy was validated using sets of data simulated by the anatomy and physiology based models. Finally, the method was used to analyze the bronchodilation tests of three asthmatic subjects. RESULTS The expected errors in assessing the degree, site and width of changes in the zone of conducting airways were 6.3%, 2.4 generations and 22%, respectively, and for δRg and δCg were 5-10% and 13-16%, respectively. The analyses of clinical data indicated a significant reduction in resistances and an increase in compliances of airway generations 8-12, consistent with clinical knowledge. CONCLUSION An unprecedented method to plausibly transforming the spirometry data into the site and degree of changes in airway properties has been proposed. SIGNIFICANCE The method can be used to deduce about the effects of bronchial tests, as well as to monitor changes in the airways between visits or to investigate how inhaled pharmaceuticals affect the bronchi.
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Yang MS, Choi S, Choi Y, Jin KN. Association Between Airway Parameters and Abdominal Fat Measured via Computed Tomography in Asthmatic Patients. ALLERGY, ASTHMA & IMMUNOLOGY RESEARCH 2018; 10:503-515. [PMID: 30088370 PMCID: PMC6082818 DOI: 10.4168/aair.2018.10.5.503] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 05/10/2018] [Accepted: 05/17/2018] [Indexed: 11/20/2022]
Abstract
Purpose We aimed to investigate whether airway parameters, assessed via computed tomography (CT), are associated with abdominal fat areas and to compare the clinical characteristics of asthmatic patients with and without elevated visceral to subcutaneous fat area ratio (EV). Methods Asthmatic patients (aged ≥40 years) were prospectively recruited. Chest (airway) and fat areas were assessed via CT. Airway parameters, including bronchial wall thickness (WT), lumen diameter (LD), lumen area (LA), wall area (WA), total area (TA), as well as WA/TA percentage (wall area %) were measured at the apical segmental bronchus in the right upper lobe. Visceral (VFA), subcutaneous (SFA) and total (TFA) fat areas (cm2) were also measured. The correlations between abdominal fat areas and airway parameters were assessed. EV was defined as VFA/SFA ≥ 0.4. Results Fifty asthmatic patients were included (mean age 62.9 years; 52% female); 38% had severe asthma. Significant correlations were found between VFA and both LD and LA (r = −0.35, P = 0.01; r = −0.34, P = 0.02, respectively), and SFA and both WA and TA (r = 0.38, P = 0.007; r = 0.34, P = 0.02, respectively). Exacerbations, requiring corticosteroid therapy or ER visitation, were significantly more frequent in subjects without EV (83% vs. 34%, P = 0.05). Conclusions Abdominal fat is associated with asthma, according to the location of fat accumulation. In asthmatic subjects, visceral fat seems to be attributable to the bronchial luminal narrowing, while subcutaneous fat may be related to thickening of bronchial wall.
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Affiliation(s)
- Min Suk Yang
- Department of Internal Medicine, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul, Korea
| | - Sanghun Choi
- Department of Mechanical Engineering, Kyungpook National University, Daegu, Korea
| | - Yera Choi
- Department of Radiology, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul, Korea
| | - Kwang Nam Jin
- Department of Radiology, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul, Korea.
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White Paper of the Society of Computed Body Tomography and Magnetic Resonance on Dual-Energy CT, Part 3. J Comput Assist Tomogr 2017; 41:1-7. [DOI: 10.1097/rct.0000000000000538] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Hwang HJ, Hoffman EA, Lee CH, Goo JM, Levin DL, Kauczor HU, Seo JB. The role of dual-energy computed tomography in the assessment of pulmonary function. Eur J Radiol 2016; 86:320-334. [PMID: 27865580 DOI: 10.1016/j.ejrad.2016.11.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 11/02/2016] [Accepted: 11/04/2016] [Indexed: 01/05/2023]
Abstract
The assessment of pulmonary function, including ventilation and perfusion status, is important in addition to the evaluation of structural changes of the lung parenchyma in various pulmonary diseases. The dual-energy computed tomography (DECT) technique can provide the pulmonary functional information and high resolution anatomic information simultaneously. The application of DECT for the evaluation of pulmonary function has been investigated in various pulmonary diseases, such as pulmonary embolism, asthma and chronic obstructive lung disease and so on. In this review article, we will present principles and technical aspects of DECT, along with clinical applications for the assessment pulmonary function in various lung diseases.
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Affiliation(s)
- Hye Jeon Hwang
- Department of Radiology, Hallym University College of Medicine, Hallym University Sacred Heart Hospital, 22, Gwanpyeong-ro 170beon-gil, Dongan-gu, Anyang-si, Gyeonggi-do 431-796, Republic of Korea
| | - Eric A Hoffman
- Departments of Radiology, Medicine, and Biomedical Engineering, University of Iowa, 200 Hawkins Dr, CC 701 GH, Iowa City, IA 52241, United States
| | - Chang Hyun Lee
- Department of Radiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul 110-799, Republic of Korea
| | - Jin Mo Goo
- Department of Radiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul 110-799, Republic of Korea
| | - David L Levin
- Department of Radiology, Mayo Clinic College of Medicine, 200 First Street, SW, Rochester, MN 55905, United States
| | - Hans-Ulrich Kauczor
- Diagnostic and Interventional Radiology, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany; Translational Lung Research Center Heidelberg (TLRC), Member of the German Center for Lung Research (DZL), Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Joon Beom Seo
- Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Pungnap 2-dong, Songpa-ku, Seoul, 05505, Republic of Korea.
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Park EA, Goo JM, Park SJ, Lee CH, Park CM. Collateral Ventilation Quantification Using Xenon-Enhanced Dynamic Dual-Energy CT: Differences between Canine and Swine Models of Bronchial Occlusion. Korean J Radiol 2015; 16:648-56. [PMID: 25995696 PMCID: PMC4435996 DOI: 10.3348/kjr.2015.16.3.648] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 02/17/2015] [Indexed: 11/20/2022] Open
Abstract
Objective The aim of this study was to evaluate whether the difference in the degree of collateral ventilation between canine and swine models of bronchial obstruction could be detected by using xenon-enhanced dynamic dual-energy CT. Materials and Methods Eight mongrel dogs and six pigs underwent dynamic dual-energy scanning of 64-slice dual-source CT at 12-second interval for 2-minute wash-in period (60% xenon) and at 24-second interval for 3-minute wash-out period with segmental bronchus occluded. Ventilation parameters of magnitude (A value), maximal slope, velocity (K value), and time-to-peak (TTP) enhancement were calculated from dynamic xenon maps using exponential function of Kety model. Results A larger difference in A value between parenchyma was observed in pigs than in dogs (absolute difference, -33.0 ± 5.0 Hounsfield units [HU] vs. -2.8 ± 7.1 HU, p = 0.001; normalized percentage difference, -79.8 ± 1.8% vs. -5.4 ± 16.4%, p = 0.0007). Mean maximal slopes in both periods in the occluded parenchyma only decreased in pigs (all p < 0.05). K values of both periods were not different (p = 0.892) in dogs. However, a significant (p = 0.027) difference was found in pigs in the wash-in period. TTP was delayed in the occluded parenchyma in pigs (p = 0.013) but not in dogs (p = 0.892). Conclusion Xenon-ventilation CT allows the quantification of collateral ventilation and detection of differences between canine and swine models of bronchial obstruction.
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Affiliation(s)
- Eun-Ah Park
- Department of Radiology, Seoul National University College of Medicine and Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 110-744, Korea
| | - Jin Mo Goo
- Department of Radiology, Seoul National University College of Medicine and Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 110-744, Korea. ; Cancer Research Institute, Seoul National University College of Medicine, Seoul 110-744, Korea
| | - Sang Joon Park
- Department of Radiology, Seoul National University College of Medicine and Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 110-744, Korea. ; Cancer Research Institute, Seoul National University College of Medicine, Seoul 110-744, Korea
| | - Chang Hyun Lee
- Department of Radiology, Seoul National University College of Medicine and Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 110-744, Korea
| | - Chang Min Park
- Department of Radiology, Seoul National University College of Medicine and Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 110-744, Korea. ; Cancer Research Institute, Seoul National University College of Medicine, Seoul 110-744, Korea
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Gosens R, Grainge C. Bronchoconstriction and airway biology: potential impact and therapeutic opportunities. Chest 2015; 147:798-803. [PMID: 25732446 DOI: 10.1378/chest.14-1142] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Recent work has demonstrated that mechanical forces occurring in the airway as a consequence of bronchoconstriction are sufficient to not only induce symptoms but also influence airway biology. Animal and human in vitro and in vivo work demonstrates that the airways are structurally and functionally altered by mechanical stress induced by bronchoconstriction. Compression of the airway epithelium and mechanosensing by the airway smooth muscle trigger the activation and release of growth factors, causing cell proliferation, extracellular matrix protein accumulation, and goblet cell differentiation. These effects of bronchoconstriction are of major importance to asthma pathophysiology and appear sufficient to induce remodeling independent of the inflammatory response. We review these findings in detail and discuss previous studies in light of this new evidence regarding the influence of mechanical forces in the airways. Furthermore, we highlight potential impacts of therapies influencing mechanical forces on airway structure and function in asthma.
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Affiliation(s)
- Reinoud Gosens
- Groningen Research Institute for Asthma and COPD, Department of Molecular Pharmacology, University of Groningen, Groningen, The Netherlands.
| | - Chris Grainge
- Hunter Medical Research Institute, University of Newcastle, Newcastle, NSW, Australia
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Park HW, Jung JW, Kim KM, Kim TW, Lee SH, Lee CH, Goo JM, Min KU, Cho SH. Xenon ventilation computed tomography and the management of asthma in the elderly. Respirology 2014; 19:389-95. [PMID: 24512222 DOI: 10.1111/resp.12242] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Revised: 12/19/2012] [Accepted: 11/12/2013] [Indexed: 11/27/2022]
Abstract
BACKGROUND AND OBJECTIVE Xenon ventilation computed tomography (CT) has shown potential in assessing the regional ventilation status in subjects with asthma. The purpose of this study was to evaluate the usefulness of xenon ventilation CT in the management of asthma in the elderly. METHODS Treatment-naïve asthmatics aged 65 years or older were recruited. Before initiation of medication, spirometry with bronchodilator (BD) reversibility, questionnaires to assess the severity of symptoms including a visual analogue scale (VAS), tests to evaluate cognitive function and mood, and xenon ventilation CT were performed. Xenon gas trapping (XT) on xenon ventilation CT represents an area where inhaled xenon gas was not expired and was trapped. Symptoms and lung functions were measured again after the 12-week treatment. RESULTS A total of 30 elderly asthmatics were enrolled. The severity of dyspnoea measured by the VAS showed a significant correlation with the total number of areas of XT on the xenon ventilation CT taken in the pre-BD wash-out phase (r = -0.723, P < 0.001). The total number of areas of XT significantly decreased after BD inhalation, and differences in the total number of areas of XT (between the pre- and post-BD wash-out phases) at baseline showed significant correlations with the per cent increases in forced expiratory volume in 1 s after subsequent anti-asthma treatment (r = -0.775, P < 0.001). CONCLUSIONS Xenon ventilation CT may be an objective and promising tool in the measurement of dyspnoea and prediction of the treatment response in elderly asthmatics.
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Affiliation(s)
- Heung-Woo Park
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea; Institute of Allergy and Clinical Immunology, Seoul National University Medical Research Center, Seoul, Korea
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Xenon-Enhanced Dual-Energy CT Lung Ventilation Imaging: Techniques and Clinical Applications. AJR Am J Roentgenol 2014; 202:309-17. [PMID: 24450670 DOI: 10.2214/ajr.13.11191] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Thien F. Measuring and imaging small airways dysfunction in asthma. Asia Pac Allergy 2013; 3:224-30. [PMID: 24260727 PMCID: PMC3826607 DOI: 10.5415/apallergy.2013.3.4.224] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 10/04/2013] [Indexed: 11/26/2022] Open
Abstract
Asthma is a chronic inflammatory disorder of the airways causing typical symptoms, and the diagnosis is supported by evidence of airflow obstruction which is variable, reversible or inducible. However, standard assessment of lung function with spirometry does not measure dysfunction in small airways which are < 2 mm in diameter towards the periphery of the lung. These airways make only a small contribution to airway resistance under normal circumstances. Nevertheless, there is mounting evidence that pathology and dysfunction in these small airways are implicated in the pathogenesis and natural history of asthma. Using forced oscillation and the multibreath nitrogen washout techniques, uneven ventilation (ventilation heterogeneity) due to small airways dysfunction has been shown to be an important marker of asthma disease activity, even in the absence of abnormalities in standard spirometric measurements. Recent advances in imaging research, particularly with hyperpolarised gas magnetic resonance imaging, have also given insights into the significance and dynamic nature of ventilation heterogeneity in asthma. The challenge is to integrate these new physiological and imaging insights to further our understanding of asthma and facilitate potential new treatments.
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Affiliation(s)
- Francis Thien
- Department of Respiratory Medicine, Eastern Health and Monash University, Box Hill Hospital, Box Hill, VIC 3128, Australia
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New insight into the assessment of asthma using xenon ventilation computed tomography. Ann Allergy Asthma Immunol 2013; 111:90-95.e2. [PMID: 23886225 DOI: 10.1016/j.anai.2013.04.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 04/11/2013] [Accepted: 04/27/2013] [Indexed: 11/24/2022]
Abstract
BACKGROUND Image analyses include computed tomography (CT), magnetic resonance imaging, and xenon ventilation CT, which is new modality to evaluate pulmonary functional imaging. OBJECTIVE To examine the usefulness of dual-energy xenon ventilation CT in asthmatic patients. METHODS A total of 43 patients 18 years or older who were nonsmokers were included in the study. Xenon CT images in wash-in and wash-out phases were obtained at baseline and after inhalation of methacholine and salbutamol. The degrees of ventilation defects and xenon trappings were evaluated through visual analysis. RESULTS Ventilation defects and xenon trapping were significantly increased and decreased after methacholine challenge and salbutamol inhalation, respectively (P < .005). The ventilation abnormalities were not significantly related to the percentage of forced expiratory volume in 1 second (FEV1) or the ratio of FEV1 to forced vital capacity. Xenon trappings after salbutamol inhalation were negatively related to the scores of the asthma control test, wheezing, or night symptoms, with statistical significance (P < .05), whereas, FEV1 showed no significant correlation with symptom scores. Baseline FEV1 was significantly lower and dyspnea and wheezing were more severe in the non-full reversal group than in the full reversal group after salbutamol inhalation in xenon CT (P < .05). The degree of ventilation defects were positively correlated with FEV1 improvement after 3 months of treatment (P = .02). CONCLUSION The results of this study suggest that xenon ventilation CT can be used as a new method to assess ventilation abnormalities in asthma, and these ventilation abnormalities can be used as novel parameters that reflect the status of asthma control and symptom severity.
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