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Bauer C, Eberlein M, Beichel RR. Airway tree reconstruction in expiration chest CT scans facilitated by information transfer from corresponding inspiration scans. Med Phys 2016; 43:1312-23. [PMID: 26936716 DOI: 10.1118/1.4941692] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Analysis and comparison of airways imaged in pairs of inspiration and expiration lung CT scans provides important information for quantitative assessment of lung diseases like chronic obstructive pulmonary disease. However, airway tree reconstruction in expiration CT scans is a challenging problem. Typically, only a low number of airway branches are found in expiration scans, compared to inspiration scans. To detect more airways in expiration CT scans, the authors introduce a novel airway reconstruction approach and assess its performance. METHODS The method requires a pair of inspiration and expiration CT scans and utilizes information from the inspiration scan to facilitate reconstructing the airway tree in the expiration lung CT scan. First, an initial airway tree (high confidence) and airway candidates (limited confidence) are reconstructed in the expiration scan by utilizing a 3D graph-based reconstruction method. Then, the 3D airway tree is reconstructed in the inspiration scan. Second, correspondences between expiration and inspiration tree structures are identified by utilizing a novel hierarchical tree matching algorithm that utilizes a local CT image-based similarity criterion. Third, the tree information from the inspiration airway tree is used to select expiration candidates, resulting in the final expiration tree structure. The approach was evaluated on a diverse set of 40 scan pairs and compared to the baseline method, which utilizes only the expiration CT scan. RESULTS The proposed method produced a significant (p < 0.05) increase in airway tree length by 13.35 cm, on average, which represents an 11.21% increase relative to the baseline result using only the expiration CT scan. A detailed analysis of all additionally identified airways resulted in a true and false positive rate of 94.8% and 5.2%, respectively. The true positive rate was found to be significantly higher than the false positive rate (p < 0.05). CONCLUSIONS The proposed method allowed increasing the number of found airways in expiration scans significantly. In addition, the algorithm establishes correspondence between inspiration and expiration airway trees, which can facilitate label transfer between airway trees and quantitative assessment of change in airways. The approach can be adapted to facilitate airway reconstruction in several longitudinal lung CT scans by means of mutual information transfer.
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Affiliation(s)
- Christian Bauer
- Department of Electrical and Computer Engineering, The University of Iowa, Iowa City, Iowa 52242 and The Iowa Institute for Biomedical Imaging, The University of Iowa, Iowa City, Iowa 52242
| | - Michael Eberlein
- Department of Internal Medicine, The University of Iowa Carver College of Medicine, Iowa City, Iowa 52242
| | - Reinhard R Beichel
- Department of Electrical and Computer Engineering, The University of Iowa, Iowa City, Iowa 52242; The Iowa Institute for Biomedical Imaging, The University of Iowa, Iowa City, Iowa 52242; and Department of Internal Medicine, The University of Iowa Carver College of Medicine, Iowa City, Iowa 52242
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Kloth C, Thaiss WM, Ditt H, Hetzel J, Schülen E, Nikolaou K, Horger M. Segmental bronchi collapsibility: computed tomography-based quantification in patients with chronic obstructive pulmonary disease and correlation with emphysema phenotype, corresponding lung volume changes and clinical parameters. J Thorac Dis 2016; 8:3521-3529. [PMID: 28149545 DOI: 10.21037/jtd.2016.12.20] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Global pulmonary function tests lack region specific differentiation that might influence therapy in severe chronic obstructive pulmonary disease (COPD) patients. Therefore, the aim of this work was to assess the degree of expiratory 3rd generation bronchial lumen collapsibility in patients with severe COPD using chest-computed tomography (CT), to evaluate emphysema-phenotype, lobar volumes and correlate results with pulmonary function tests. METHODS Thin-slice chest-CTs acquired at end-inspiration & end-expiration in 42 COPD GOLD IV patients (19 females, median-age: 65.9 y) from November 2011 to July 2014 were re-evaluated. The cross-sectional area of all segmental bronchi was measured 5 mm below the bronchial origin in both examinations. Lung lobes were semi-automatically segmented, volumes calculated at end-inspiratory and end-expiratory phase and visually defined emphysema-phenotypes defined. Results of CT densitometry were compared with lung functional tests including forced expiratory volume at 1 s (FEV1), total lung capacity (TLC), vital capacity (VC), residual volume (RV), diffusion capacity parameters and the maximal expiratory flow rates (MEFs). RESULTS Mean expiratory bronchial collapse was 31%, stronger in lobes with homogenous (38.5%) vs. heterogeneous emphysema-phenotype (27.8%, P=0.014). The mean lobar expiratory volume reduction was comparable in both emphysema-phenotypes (volume reduction 18.6%±8.3% in homogenous vs. 17.6%±16.5% in heterogeneous phenotype). The degree of bronchial lumen collapsibility, did not correlate with expiratory volume reduction. MEF25 correlated weakly with 3rd generation airway collapsibility (r=0.339, P=0.03). All patients showed a concentric expiratory reduction of bronchial cross-sectional area. CONCLUSIONS Changes in collapsibility of 3rd generation bronchi in COPD grade IV patients is significantly lower than that in the trachea and the main bronchi. Collapsibility did not correlate with the reduction in lung volume but was significantly higher in lobes with homogeneous vs. heterogeneous emphysema phenotype. Changes in the 3rd generation bronchial calibres between inspiration and expiration are not predictive for the degree of small airway collapsibility and related airflow limitation.
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Affiliation(s)
- Christopher Kloth
- Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, 72076 Tübingen, Germany
| | - Wolfgang Maximilian Thaiss
- Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, 72076 Tübingen, Germany
| | - Hendrik Ditt
- Siemens AG Healthcare, Imaging & Therapy Systems Computed Tomography & Radiation Oncology, HC IM CR R&D PA CA DC, 91301 Forchheim, Germany
| | - Jürgen Hetzel
- Department of Internal Medicine II, Eberhard-Karls-University, 72076 Tübingen, German
| | - Eva Schülen
- Department of Internal Medicine II, Eberhard-Karls-University, 72076 Tübingen, German
| | - Konstantin Nikolaou
- Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, 72076 Tübingen, Germany
| | - Marius Horger
- Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, 72076 Tübingen, Germany
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Early origins of chronic obstructive lung diseases across the life course. Eur J Epidemiol 2014; 29:871-85. [PMID: 25537319 DOI: 10.1007/s10654-014-9981-5] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 12/06/2014] [Indexed: 12/12/2022]
Abstract
Chronic obstructive lung diseases, like asthma and chronic obstructive pulmonary disease, have high prevalences and are a major public health concern. Chronic obstructive lung diseases have at least part of their origins in early life. Exposure to an adverse environment during critical periods in early life might lead to permanent developmental adaptations which results in impaired lung growth with smaller airways and lower lung volume, altered immunological responses and related inflammation, and subsequently to increased risks of chronic obstructive lung diseases throughout the life course. Various pathways leading from early life factors to respiratory health outcomes in later life have been studied, including fetal and early infant growth patterns, preterm birth, maternal obesity, diet and smoking, children's diet, allergen exposure and respiratory tract infections, and genetic susceptibility. Data on potential adverse factors in the embryonic and preconception period and respiratory health outcomes are scarce. Also, the underlying mechanisms how specific adverse exposures in the fetal and early postnatal period lead to chronic obstructive lung diseases in later life are not yet fully understood. Current studies suggest that interactions between early environmental exposures and genetic factors such as changes in DNA-methylation and RNA expression patterns may explain the early development of chronic obstructive lung diseases. New well-designed epidemiological studies are needed to identify specific critical periods and to elucidate the mechanisms underlying the development of chronic obstructive lung disease throughout the life course.
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Effect of lung volume on airway luminal area assessed by computed tomography in chronic obstructive pulmonary disease. PLoS One 2014; 9:e90040. [PMID: 24587205 PMCID: PMC3938549 DOI: 10.1371/journal.pone.0090040] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Accepted: 01/31/2014] [Indexed: 11/19/2022] Open
Abstract
Background Although airway luminal area (Ai) is affected by lung volume (LV), how is not precisely understood. We hypothesized that the effect of LV on Ai would differ by airway generation, lung lobe, and chronic obstructive pulmonary disease (COPD) severity. Methods Sixty-seven subjects (15 at risk, 18, 20, and 14 for COPD stages 1, 2, and 3) underwent pulmonary function tests and computed tomography scans at full inspiration and expiration (at functional residual capacity). LV and eight selected identical airways were measured in the right lung. Ai was measured at the mid-portion of the 3rd, the segmental bronchus, to 6th generation of the airways, leading to 32 measurements per subject. Results The ratio of expiratory to inspiratory LV (LV E/I ratio) and Ai (Ai E/I ratio) was defined for evaluation of changes. The LV E/I ratio increased as COPD severity progressed. As the LV E/I ratio was smaller, the Ai E/I ratio was smaller at any generation among the subjects. Overall, the Ai E/I ratios were significantly smaller at the 5th (61.5%) and 6th generations (63.4%) and than at the 3rd generation (73.6%, p<0.001 for each), and also significantly lower in the lower lobe than in the upper or middle lobe (p<0.001 for each). And, the Ai E/I ratio decreased as COPD severity progressed only when the ratio was corrected by the LV E/I ratio (at risk v.s.stage3 p<0.001, stage1 v.s.stage3 p<0.05). Conclusions From full inspiration to expiration, the airway luminal area shrinks more at the distal airways compared with the proximal airways and in the lower lobe compared with the other lobes. Generally, the airways shrink more as COPD severity progresses, but this phenomenon becomes apparent only when lung volume change from inspiration to expiration is taken into account.
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Abstract
Previous studies have suggested that asthma, like other common diseases, has at least part of its origin early in life. Low birth weight has been shown to be associated with increased risks of asthma, chronic obstructive airway disease, and impaired lung function in adults, and increased risks of respiratory symptoms in early childhood. The developmental plasticity hypothesis suggests that the associations between low birth weight and diseases in later life are explained by adaptation mechanisms in fetal life and infancy in response to various adverse exposures. Various pathways leading from adverse fetal and infant exposures to growth adaptations and respiratory health outcomes have been studied, including fetal and early infant growth patterns, maternal smoking and diet, children's diet, respiratory tract infections and acetaminophen use, and genetic susceptibility. Still, the specific adverse exposures in fetal and early postnatal life leading to respiratory disease in adult life are not yet fully understood. Current studies suggest that both environmental and genetic factors in various periods of life, and their epigenetic mechanisms may underlie the complex associations of low birth weight with respiratory disease in later life. New well-designed epidemiological studies are needed to identify the specific underlying mechanisms. This review is focused on specific adverse fetal and infant growth patterns and exposures, genetic susceptibility, possible respiratory adaptations and perspectives for new studies.
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Affiliation(s)
- Liesbeth Duijts
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands.
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Influence of inspiration level on bronchial lumen measurements with computed tomography. Respir Med 2011; 106:677-86. [PMID: 22154247 DOI: 10.1016/j.rmed.2011.11.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Revised: 11/14/2011] [Accepted: 11/16/2011] [Indexed: 11/21/2022]
Abstract
BACKGROUND Bronchial dimensions measured in CT images generally do not take inspiration level into consideration. However, some studies showed that the bronchial membrane is distensible with airway inflation. Therefore, re-examination of the elasticity of bronchi is needed. PURPOSE To assess the influence of respiration on bronchial lumen area (defined as distensibility) in different segmental bronchi and to explore the correlations between distensibility and both lung function and emphysema severity. MATERIAL AND METHODS In 44 subjects with COPD related to alpha-1-antitrypsin deficiency (AATD), bronchial lumen area was measured in CT images, acquired at different inspiration levels. Measurements were done at matched locations in one apical and two basal segmental airways (RB1, RB10 and LB10). Airway distensibility was calculated as lumen area difference divided by lung volume difference. RESULTS Bronchial lumen area in the lower lobes (RB10 and LB10) correlated positively with FEV(1)%predicted (p=0.027 for RB10; and p=0.037 for LB10, respectively). Lumen area is influenced by respiration (p=0.006, p=0.045, and, p=0.005 for RB1, RB10 and LB10, respectively). Airway distensibility was different between upper and lower bronchi (p<0.001), but it was not correlated with lung function. CONCLUSION Lumen area of third generation bronchi is dependent on inspiration level and this distensibility is different between bronchi in the upper and lower lobes. Therefore, changes in lumen area over time should be studied whilst accounting for the lung volume changes, in order to estimate the progression of bronchial disease while excluding the effects of hyperinflation.
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Wang K, Liu CT, Wu YH, Feng YL, Bai HL, Ma ES, Wen FQ. Effects of formoterol-budesonide on airway remodeling in patients with moderate asthma. Acta Pharmacol Sin 2011; 32:126-32. [PMID: 21170080 DOI: 10.1038/aps.2010.170] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
AIM To evaluate the effect of inhaled formoterol-budesonide on airway remodeling in adult patients with moderate asthma. METHODS Thirty asthmatic patients and thirty control subjects were enrolled. Asthmatic subjects used inhaled Symbicort 4.5/160 μg twice daily for one year. The effect of formoterol-budesonide on airway remodeling was assessed with comparing high-resolution computer tomography (HRCT) images of asthmatic patients and controls, as well as expression levels of cytokines and growth factors, inflammatory cell count in induced sputum, and airway hyper-responsiveness. RESULTS The differences in age and gender between the two groups were not significant. However, differences in FVC %pred, FEV(1) %pred, and PC(20) between the two groups were significant. After treatment with formoterol-budesonide, the asthma patients' symptoms were relieved, and their lung function was improved. The WT and WA% of HRCT images in patients with asthma was increased, whereas treatment with formoterol-budesonide caused these values to decrease. The expression of MMP-9, TIMP-1, and TGF-β(1) in induced sputum samples increased in patients with asthma and decreased dramatically after treatment with formoterol-budesonide. The WT and WA% are correlated with the expression levels of cytokines and growth factors, inflammatory cell count in induced sputum, and airway hyper-responsiveness, while these same values are correlated negatively with FEV(1)/FVC and FEV(1)%. CONCLUSION Formoterol-budesonide might interfere in chronic inflammation and airway remodeling in asthmatic patients. HRCT can be used to effectively evaluate airway remodeling in asthmatic patients.
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Hasan N, Landsberg DM, Acevedo RA, Sah BP. AIRWAY PRESSURE RELEASE VENTILATION (APRV) IN THE MANAGEMENT OF STATUS ASTHMATICUS. Chest 2009. [DOI: 10.1378/chest.136.4_meetingabstracts.25s-e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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Current world literature. Curr Opin Allergy Clin Immunol 2009; 9:79-85. [PMID: 19106700 DOI: 10.1097/aci.0b013e328323adb4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Simpson JL, Milne DG, Gibson PG. Neutrophilic asthma has different radiographic features to COPD and smokers. Respir Med 2009; 103:881-7. [PMID: 19168339 DOI: 10.1016/j.rmed.2008.12.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2008] [Revised: 12/11/2008] [Accepted: 12/18/2008] [Indexed: 10/21/2022]
Abstract
BACKGROUND Neutrophilic asthma and COPD are obstructive airway diseases common in older age and have a characteristic airway inflammation with neutrophilic bronchitis. The structural differences between neutrophilic asthma and COPD have not been investigated. The aim of this study was to examine the airway and parenchymal abnormalities using high resolution computed tomographic (HRCT) scanning in participants with neutrophilic asthma, COPD and smoking controls. METHODS Participants (neutrophilic asthma (n=10), COPD (n=17) and smoking controls (n=8)) underwent clinical assessment and sputum induction. HRCT of the chest was performed and independently scored by a radiologist blinded to the subject group using a modified Bhalla scoring system. RESULTS Participants were of a similar age and those with COPD had a similar degree of airflow obstruction to those with neutrophilic asthma. The pattern of radiographic abnormalities differed between groups. Abnormal bronchial wall thickening was significantly more common in neutrophilic asthma, compared to COPD or smoking controls. Emphysema was greatest in the COPD group, and not recorded as a feature of neutrophilic asthma. FEV(1)% predicted was negatively associated with bronchial wall thickening and consolidation while KCO% predicted was negatively associated with the total emphysema score. Bronchiectasis was minimal in all groups. CONCLUSION The pattern of radiographic lung abnormality in neutrophilic asthma differs significantly from COPD, and resembles asthma. Neutrophilic asthma is a distinct inflammatory subtype of asthma with a different pathogenesis to COPD.
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Affiliation(s)
- Jodie L Simpson
- Centre for Asthma and Respiratory Diseases, University of Newcastle, Newcastle, Australia.
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