Quantitative CT Image-Based Structural and Functional Changes during Asthma Acute Exacerbations

2021 ◽  
Author(s):  
Joonwoo Park ◽  
Sujeong Kim ◽  
Jae-Kwang Lim ◽  
Kwang Nam Jin ◽  
Min Suk Yang ◽  
...  
Keyword(s):  
Pulmonary Function Tests ◽  
Quantitative Computed Tomography ◽  
Airway Disease ◽  
Forced Expiratory Volume ◽  
Imaging Features ◽  
Quantitative Ct ◽  
Functional Changes ◽  
Small Airway Disease ◽  
Acute Exacerbations ◽  
Residual Capacity

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.

Measurement of total lung aerosol deposition as an index of lung abnormality

1988 ◽  
Vol 64 (4) ◽  
pp. 1527-1536 ◽  
Author(s):  
C. S. Kim ◽  
G. A. Lewars ◽  
M. A. Sackner
Keyword(s):  
Pulmonary Function Tests ◽  
Aerosol Deposition ◽  
Airway Disease ◽  
Forced Expiratory Volume ◽  
Chronic Obstructive ◽  
Small Airway Disease ◽  
Patient Screening ◽  
Chart Recorder ◽  
Strong Linear Correlation ◽  
Relationship Of

Total aerosol deposition in the lung was measured in 100 subjects with various lung conditions. The subjects consisted of 40 normals (N), 15 asymptomatic smokers (S), 10 smokers with small airway disease (SAD), 20 with chronic simple bronchitis (SB), and 15 with chronic obstructive bronchitis (COPD), and a relationship of total aerosol deposition to degree of lung abnormality was investigated. The subjects were categorized by medical history and a battery of pulmonary function tests, including spirometry, body plethysmography, and single and multiple N2 washout measurements. Subjects repeatedly breathed a monodisperse test aerosol (1.0 micron diam) from a collapsible rebreathing bag (0.5 liter volume) at a rate of 30 breaths/min, while inhaled and exhaled aerosol concentrations were continuously monitored by a laser aerosol photometer in situ and recorded on a strip-chart recorder. The number of rebreathing breaths resulting in 90% aerosol loss from the bag (N90) was determined, and percent predicted N90 values were then determined from the results of computer simulation and used as a deposition index. The percent predicted N90 values were 99.7 +/- 14, 86.5 +/- 15, 66.9 +/- 17, 51 +/- 12, and 30.9 +/- 9, respectively, for N, S, SAD, SB, and COPD. All of these values were significantly different from each other (P less than 0.05). There was no difference between male and female but percent predicted N90 values were slightly higher in young than in old normals. Percent predicted N90 values showed a strong linear correlation with spirometric measurements of forced expiratory volume in 1 s and maximum midexpiratory flow rate. However, many of the SAD and SB with normal spirometry showed abnormal N90. These results suggest that total lung aerosol deposition is a sensitive index of lung abnormality and may be of potential use for nonspecific general patient screening.

scholarly journals Quantitative CT parameters correlate with lung function in chronic obstructive pulmonary disease: a systematic review and meta-analysis

2019 ◽  
Author(s):  
Yan Wang ◽  
Shan Lin ◽  
Jian-Ting Li ◽  
Jing Wu ◽  
Dong Han ◽  
...  
Keyword(s):  
Lung Function ◽  
Pulmonary Disease ◽  
Meta Analysis ◽  
Pulmonary Function Tests ◽  
Quantitative Computed Tomography ◽  
Airflow Obstruction ◽  
Forced Expiratory Volume ◽  
Airway Wall ◽  
Quantitative Ct ◽  
Ct Measurements

Abstract Background The aim of the study was to analyze the correlation between quantitative computed tomography (CT) parameters and airflow obstruction in patients with chronic obstruction pulmonary disease (COPD). Methods PubMed, Embase, Cochrane and Web of Knowledge were searched by two investigators from inception to 2018, using a combination of pertinent items to discover articles that investigated the relationship between CT measurements and lung function parameters in patients with COPD. Five reviewers independently evaluated the quality, extracted data and evaluated bias. The correlation coefficient was calculated and heterogeneity was explored. The following CT measurements were extracted: percentage of lung attenuation area < -950 Hounsfield Units (HU), mean lung density, percentage of airway wall area, air trapping index, airway wall thickness. Two airflow obstruction parameters were extracted: forced expiratory volume in the first second as a percentage of prediction (FEV1% pred) and FEV1 divided by forced expiratory volume lung capacity. Results A total of 117 studies (19,942 participants) were identified, 36 of which (4,762 participants) were suitable for meta-analysis. Results from our analysis demonstrated that there was a significant correlation between quantitative CT parameters and lung function. The absolute pooled correlation coefficients ranged from 0.44 (95% CI, 0.36 to 0.53) to 0.71(95% CI,0.65 to 0.77) for inspiratory CT and 0.59 (95% CI, 0.53 to 0.65) to 0.66 (95% CI,0.61 to 0.72) for expiratory CT. Conclusions Results from this analysis demonstrated that quantitative CT parameters are significantly correlated with lung function in patients with COPD. With recent advances in chest CT, we can evaluate morphological features in the lungs that cannot be obtained by other clinical indices, such as pulmonary function tests. Therefore, CT can provide a quantitative method to advance the development and testing of new interventions and therapies for patients with COPD .

scholarly journals A 3D-CNN model with CT-based parametric response mapping for classifying COPD subjects

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Thao Thi Ho ◽  
Taewoo Kim ◽  
Woo Jin Kim ◽  
Chang Hyun Lee ◽  
Kum Ju Chae ◽  
...  
Keyword(s):  
Neural Network ◽  
Pulmonary Function Tests ◽  
Airway Disease ◽  
Chronic Obstructive ◽  
Respiratory Disorder ◽  
Obstructive Pulmonary Disease ◽  
Response Mapping ◽  
Small Airway Disease ◽  
3D Cnn ◽  
Parametric Response

AbstractChronic obstructive pulmonary disease (COPD) is a respiratory disorder involving abnormalities of lung parenchymal morphology with different severities. COPD is assessed by pulmonary-function tests and computed tomography-based approaches. We introduce a new classification method for COPD grouping based on deep learning and a parametric-response mapping (PRM) method. We extracted parenchymal functional variables of functional small airway disease percentage (fSAD%) and emphysema percentage (Emph%) with an image registration technique, being provided as input parameters of 3D convolutional neural network (CNN). The integrated 3D-CNN and PRM (3D-cPRM) achieved a classification accuracy of 89.3% and a sensitivity of 88.3% in five-fold cross-validation. The prediction accuracy of the proposed 3D-cPRM exceeded those of the 2D model and traditional 3D CNNs with the same neural network, and was comparable to that of 2D pretrained PRM models. We then applied a gradient-weighted class activation mapping (Grad-CAM) that highlights the key features in the CNN learning process. Most of the class-discriminative regions appeared in the upper and middle lobes of the lung, consistent with the regions of elevated fSAD% and Emph% in COPD subjects. The 3D-cPRM successfully represented the parenchymal abnormalities in COPD and matched the CT-based diagnosis of COPD.

Physical Signs in Childhood Asthma

PEDIATRICS ◽  
1976 ◽  
Vol 58 (4) ◽  
pp. 537-541
Author(s):  
J. O. O. Commey ◽  
Henry Levison
Keyword(s):  
Pulmonary Function ◽  
Airway Obstruction ◽  
Pulmonary Function Tests ◽  
Severe Disease ◽  
Airway Disease ◽  
Chronic Obstructive ◽  
Scalene Muscle ◽  
Lung Capacity ◽  
Residual Capacity ◽  
Severe Airway Obstruction

In 62 children with bronchial asthma, the presence of subjective dyspnea and wheeze, and some physical signs commonly associated with chronic obstructive airway disease in older patients, were compared with results of routine pulmonary function tests. Overall, airway resistance and the relationships of residual volume and functional residual capacity to total lung capacity were increased and other measurements of pulmonary function were moderately decreased. The time-honored subjective dyspnea, wheeze, rhonchi, and prolonged expiration were least useful as indices of severity of disease. Most of the patients, particularly those in whom laboratory testing revealed marked impairment, had notable rhonchi, prolonged expiration, scalene muscle and sternocleidomastoid contraction, and supraclavicular indrawing. Only sternocleidomastoid contraction and supraclavicular indrawing clearly correlated with the severity of airway obstruction. A call is made for a search for these useful signs, whose presence may be the only clue to moderately severe disease; however, their absence does not guarantee absence of severe airway obstruction.

scholarly journals Does the nitrogen single-breath washout test contribute to detecting pulmonary involvement in rheumatoid arthritis? A pilot study

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Elizabeth Jauhar Cardoso Bessa ◽  
Felipe de Miranda Carbonieri Ribeiro ◽  
Geraldo da Rocha Castelar Pinheiro ◽  
Agnaldo José Lopes
Keyword(s):  
Rheumatoid Arthritis ◽  
Pulmonary Function Tests ◽  
Airway Disease ◽  
Pulmonary Involvement ◽  
Phase Iii ◽  
Ventilation Distribution ◽  
Lung Capacity ◽  
Single Breath ◽  
Small Airway Disease ◽  
Phase Iii Slope

Abstract Objective There has been growing interest in studying small airway disease through measures of ventilation distribution, thanks to the resurgence of the nitrogen single-breath washout (N2SBW) test. Therefore, this study evaluated the contribution of the N2SBW test to the detection of pulmonary involvement in patients with rheumatoid arthritis (RA). Results Twenty-one patients with RA underwent clinical evaluation, pulmonary function tests (PFTs), including the N2SBW test, and computed tomography (CT). The main tomographic findings were air trapping and bronchiectasis (57.1% and 23.8% of cases, respectively). According to the phase III slope of the N2SBW (phase III slope), 11 and 10 patients had values < 120% predicted and > 120% predicted, respectively. Five patients with limited involvement on CT had a phase III slope > 120%. The residual volume/total lung capacity ratio was significantly different between patients with phase III slopes < 120% and > 120% (P = 0.024). Additionally, rheumatoid factor positivity was higher in patients with a phase III slope > 120% (P = 0.021). In patients with RA and airway disease on CT, the N2SBW test detects inhomogeneity in the ventilation distribution in approximately half of the cases, even in those with normal conventional PFT results.

Resistance and Collapse in Bronchial Airways

1970 ◽  
Vol 38 (6) ◽  
pp. 767-782 ◽  
Author(s):  
P. Howard ◽  
I. W. Webster
Keyword(s):  
Air Flow ◽  
Forced Expiratory Volume ◽  
The Body ◽  
Alveolar Pressure ◽  
Functional Changes ◽  
Chest Disease ◽  
Acute Exacerbations ◽  
Forced Expiratory Flow ◽  
Obstructive Airways Disease ◽  
Airways Resistance

1. The Forced Expiratory Volume (FEV) was measured in normal persons and patients with obstructive airways disease at mouth pressures from 0 mmHg to levels high enough to prevent air flow altogether by using a Starling resistor at the mouth. 2. Evidence was obtained in support of the idea that, during forced expiratory flow, airways might function with the properties of a Starling resistor. This is considered to divide the airway into upstream and downstream segments at the site of airway collapse. The technique was simple, capable of being performed on outpatients and provided a means of studying the collapsibility of airways, airways resistance and alveolar pressure. 3. The FEV in normal persons and patients with disease was determined by the properties of the upstream segment. Since this segment contains only a proportion of the total airways resistance it was not surprising to find imprecise correlations between the FEV and airways resistance measured by the body plethysmograph. 4. Preliminary observations of patients during acute exacerbations of chest disease suggest that functional changes can occur throughout the length of the airway (i.e. in both upstream and downstream segments). 5. In the longer term during the natural history of obstructive airways disease, airways resistance and the more ready collapse of airways may develop independently. 6. Impaired alveolar pressure may contribute towards the reduction in air flow during acute exacerbations of chest disease.

Breathing Patterns and Regional Ventilation Distribution in Tetraplegic Patients and in Normal Subjects

1972 ◽  
Vol 42 (2) ◽  
pp. 117-128 ◽  
Author(s):  
B. Bake ◽  
A. R. Fugl-Meyer ◽  
G. Grimby
Keyword(s):  
Tidal Volume ◽  
Cervical Spinal Cord ◽  
Regional Distribution ◽  
Normal Subjects ◽  
Airway Disease ◽  
Breathing Patterns ◽  
Rib Cage ◽  
Small Airway Disease ◽  
Residual Capacity ◽  
Traumatic Transection

1. The regional distribution of ventilation was studied with 133Xe techniques in the sitting position in six patients with complete traumatic transection of the cervical spinal cord, 3–40 months after the lesion, and in four normal subjects. The relative contributions of the rib cage and abdomen to ventilation were determined from chest-wall motions. 2. Total lung capacity (TLC) was decreased and residual volume increased in the patients. After correction for the decreased TLC, the distribution of the regional functional residual capacity in the tetraplegic patients was similar to that of the normal subjects. In the patients, where the abdomen contributed to about half of the tidal volume, decreased ventilation of basal regions was demonstrated from measurements of regional tidal volumes (Vtr) and regional 133Xe wash-in curves. 3. The distribution of ventilation in normal persons, however, was not changed by varying the relative contributions of the rib cage and abdomen to the tidal volume, as shown from Vtr and regional 133Xe wash-out measurements. 4. The results in the tetraplegic patients are interpreted as evidence of ‘small airway disease’, presumably from infection of the air way and impairment of the cough.

Validation of Forced Expiratory Volume at 6 Seconds of Exhalation (FEV 6 ) in the Detection of Small Airway Disease

CHEST Journal ◽  
2015 ◽  
Vol 148 (4) ◽  
pp. 894A
Author(s):  
Edgardo Tiglao ◽  
Teresita DeGuia ◽  
Maria Encarnita Limpin ◽  
Aileen Guzman-Banzon
Keyword(s):  
Airway Disease ◽  
Forced Expiratory Volume ◽  
Small Airway ◽  
Small Airway Disease

scholarly journals Phenotypic Clusters On Computed Tomography Reflects Asthma Heterogeneity And Severity

2021 ◽  
Author(s):  
Sujeong Kim ◽  
Sanghun Choi ◽  
Taewoo Kim ◽  
Kwang Nam Jin ◽  
Sang-Heon Cho ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Severe Asthma ◽  
Visual Analysis ◽  
Quantitative Computed Tomography ◽  
Airway Disease ◽  
Small Airways ◽  
Functional Changes ◽  
Severe Allergic Asthma ◽  
Emphysematous Lung ◽  
Severity Of The Disease

Abstract Background: Asthma comprises heterogeneous inflammatory airway disorders whose classification has not been established. Quantitative computed tomography (QCT) methods can differentiate lung disease using accurate assessment of location, extent, and severity of the disease. This study aimed to identify heterogeneous asthmatic groups by QCT metrics of airway and parenchymal structure, which is associated with radiologists’ visual analysis and bronchodilator responses in a prospective design.Methods: Using the input from QCT-based metrics, including hydraulic diameter (Dh), luminal wall thickness (WT), functional small airway disease (fSAD), and emphysematous lung (Emph), a cluster analysis was performed and compared with grouping based on site of airway involvement and remodeling evaluated by radiologists.Results: 61 asthmatics were grouped into four clusters with different clinical severities. From C1 to C4, more severe lung function deterioration, higher fixed obstruction rate, and more frequent asthma exacerbation in 5-year follow-up were observed. C1 presented non-severe asthma with increased WT, Dh of proximal airways, and fSAD. C2 was mixed with non-severe and severe asthma, which had reserved bronchodilator responses of proximal airways. C3 and C4 presented severe asthmatics that exhibited reduced Dh of proximal airway and its bronchodilator responsiveness; C3 was severe allergic asthma without fSAD, while C4 was ex-smokers with significantly high fSAD% and Emph%. These clusters were correlated with the grouping by radiologists and their clinical outcomes.Conclusions: Four QCT imaging-based clusters with distinct structural and functional changes in proximal and small airways can stratify heterogeneous asthmatics and may serve as complementary tools for predicting future asthma outcomes.

scholarly journals The Diagnostic Value of Forced Expiratory Time

2011 ◽  
Vol 1 (1) ◽  
pp. 39-42
Author(s):  
Siraj O. Wali
Keyword(s):  
Tertiary Care ◽  
Airway Disease ◽  
Diagnostic Value ◽  
Forced Expiratory Volume ◽  
Small Airway ◽  
Airflow Limitation ◽  
Forced Expiration ◽  
Care Hospital ◽  
Expiratory Time ◽  
Small Airway Disease

Objective: Airway obstruction can be clinically quantified at the bedside by measuring the time taken for forced expiration. The aim of this study was to examine the accuracy of the forced expiratory time in detecting airflow limitation, and small airway disease when compared with simple spirometry as a gold standard test. Method: Simple spirometry and forced expiratory time were performed on 201 subjects (age range; 12-81 years), referred to a pulmonary function laboratory at a tertiary care hospital. The diagnostic accuracy of forced expiratory time and its correlation with spirometric parameters were tested. Forced expiratory time > 6 seconds was regarded as abnormal, and the ratio of forced expiratory volume in the first second to forced vital capacity of < 70% was considered indicative of an airflow limitation. Results: Forced expiratory time was found to correlate weakly with spirometric parameters. Forced expiratory time at a cut-off value of => 6 seconds had a sensitivity of 61% and a specificity of 79% in predicting obstructive airway disease when compared with simple spirometry. On the other hand, the sensitivity and the specificity of forced expiratory time in predicting small airway disease were 47% and 86%, respectively. Conclusion: Forced expiratory time does not correlate well with all parameters of a simple spirometry. Its sensitivity and specificity for detecting airflow limitation and small airway disease were not high enough to be used as a diagnostic test. However, it may be effective enough to be utilized to confirm the diagnosis of small airway disease.

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