Wall Area Percentage Research Articles

Diagnostic value of CT in patients with stable chronic obstructive pulmonary disease at high altitude: Observational study.

This research aims to explore the diagnostic value of computed tomography (CT) indicators in patients with stable chronic obstructive pulmonary disease (COPD) in a plateau of China, and to find out the correlation between CT indexes and lung function and symptoms. This study screened out 53 stable COPD patients and 53 healthy people through inclusion and exclusion criteria in Hongyuan county, Aba Prefecture, Sichuan Province, between July 2020 and December 2020, and then collected their baseline data, conducted lung function tests and chest CT scans, and collected COPD Assessment Test (CAT), modified Medical Research Council Dyspnea Scale (mMRC) scores. The CT indexes of the 2 groups were compared, binary logistic regression was used to analyze the influence of COPD, the receiver operating characteristic (ROC) curve was used to evaluate the diagnostic value of the CT indexes for COPD. The Spearman test was used to understand the correlation analysis between the CT indexes and lung function, symptom score, and the number of acute exacerbations. Multiple linear regression was used to analyze the influencing factors of lung function. The percentage of low-attenuation areas less than -950 Hounsfield units (%LAA-950; t = -4.387,P = 0), percentage of wall area (WA%; t = -4.501, P = 0), and thickness-diameter ratio (TDR; t = -4.779, P = 0) in the COPD group were higher than those in the normal group. ROC shows that: %LAA-950 (P = .047) and TDR (P = .034) were independent influence in COPD in the plateau. %LAA-950 combined with TDR (AUC = 0.757, P < .001) had the value of diagnosis of COPD in the plateau. All 3 indexes are negatively correlated with lung function, and positively correlated with the symptoms and the number of acute exacerbations. Multiple linear regression analysis showed that the main factors for decrease of ratio of measurement to prediction of forced expiratory volume to the first second (FEV1%) included %LAA-950 (OR = -0.449, P < .001) and WA% (OR = -0.516, P < .001). CT indexes have a certain diagnostic value in patients with stable COPD at high altitude.

Lower skeletal muscle density and airway structure on computed tomography in asthma

BackgroundLower skeletal muscle density may reflect muscle adiposity and metabolic dysregulation that potentially impair disease control and lung function independent of high body mass index (BMI) in patients with asthma. ObjectiveTo investigate whether the lower density of pectoralis muscles (PMs) and erector spinae muscles (ESMs) on chest computed tomography was associated with airway structural changes in patients with asthma. MethodsConsecutive patients with asthma and healthy controls undergoing chest computed tomography were retrospectively analyzed. The ESM and PM density, areas of subcutaneous adipose tissue near the PM and epicardial adipose tissue, wall area percent of the airways, and airway fractal dimension (AFD) were quantified on computed tomography. ResultsThe study included 179 patients with asthma (52% women) and 88 controls (47% women). All the controls were 60 years old or younger. The PM and ESM density in female patients with asthma who were 60 years old or younger were significantly lower than those in controls after adjustment for BMI. In female patients with asthma at all ages, lower PM and ESM density (but not subcutaneous or epicardial adipose tissue area) was associated with greater wall area percent of the airways and lower AFD after adjusting for age, height, BMI, smoking status, blood eosinophil count, and oral corticosteroid use. The only association between ESM density and AFD was found in male patients with asthma. ConclusionLower skeletal muscle density may be associated with airway wall thickening and less complexity of the airway luminal tree in female patients with asthma.

Low-Dose CT-derived Bronchial Parameters in Individuals with Healthy Lungs.

Background CT-derived bronchial parameters have been linked to chronic obstructive pulmonary disease and asthma severity, but little is known about these parameters in healthy individuals. Purpose To investigate the distribution of bronchial parameters at low-dose CT in individuals with healthy lungs from a Dutch general population. Materials and Methods In this prospective study, low-dose chest CT performed between May 2017 and October 2022 were obtained from participants who had completed the second-round assessment of the prospective, longitudinal Imaging in Lifelines study. Participants were aged at least 45 years, and those with abnormal spirometry, self-reported respiratory disease, or signs of lung disease at CT were excluded. Airway lumens and walls were segmented automatically. The square root of the bronchial wall area of a hypothetical airway with an internal perimeter of 10 mm (Pi10), luminal area (LA), wall thickness (WT), and wall area percentage were calculated. Associations between sex, age, height, weight, smoking status, and bronchial parameters were assessed using univariable and multivariable analyses. Results The study sample was composed of 8869 participants with healthy lungs (mean age, 60.9 years ± 10.4 [SD]; 4841 [54.6%] female participants), including 3672 (41.4%) never-smokers and 1197 (13.5%) individuals who currently smoke. Bronchial parameters for male participants were higher than those for female participants (Pi10, slope [β] range = 3.49-3.66 mm; LA, β range = 25.40-29.76 mm2; WT, β range = 0.98-1.03 mm; all P < .001). Increasing age correlated with higher Pi10, LA, and WT (r2 range = 0.06-0.09, 0.02-0.01, and 0.02-0.07, respectively; all P < .001). Never-smoking individuals had the lowest Pi10 followed by formerly smoking and currently smoking individuals (3.62 mm ± 0.13, 3.68 mm ± 0.14, and 3.70 mm ± 0.14, respectively; all P < .001). In multivariable regression models, age, sex, height, weight, and smoking history explained up to 46% of the variation in bronchial parameters. Conclusion In healthy individuals, bronchial parameters differed by sex, height, weight, and smoking history; male sex and increasing age were associated with wider lumens and thicker walls. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Emrich and Varga-Szemes in this issue.

Associations of fractional exhaled nitric oxide with airway dimension and mucus plugs on ultra-high-resolution computed tomography in former smokers and nonsmokers with asthma

BackgroundAssociations of fractional exhaled nitric oxide (FeNO) with airway wall remodeling and mucus plugs remain to be explored in smokers and nonsmokers with asthma. Ultra-high-resolution computed tomography (U-HRCT), which allows accurate structural quantification of airways >1 mm in diameter, was used in this study to examine whether higher FeNO was associated with thicker walls of the 3rd to 6th generation airways and mucus plugging in patients with asthma. MethodsThe retrospective analyses included consecutive former smokers and nonsmokers with asthma who underwent U-HRCT in a hospital. The ratio of wall area to summed lumen and wall area was calculated as the wall area percent (WA%). Mucus plugging was visually scored. ResultsNinety-seven patients with asthma (including 59 former smokers) were classified into low (<20 ppb), middle (20–35 ppb), and high (>35 ppb) FeNO groups (n = 24, 26, and 47). In analysis including all patients and subanalysis including nonsmokers or former smokers, WA% in the 6th generation airways was consistently higher in the high FeNO group than in the low FeNO group, whereas WA% in the 3rd to 5th generation airways was not. In multivariable models, WA% in the 6th generation airways and the rate of mucus plugging were higher in the high FeNO group than in the low FeNO group after adjusting for age, sex, body mass index, smoking status, lung volume, and allergic rhinitis presence. ConclusionsHigher FeNO may reflect the inflammation and remodeling of relatively peripheral airways in asthma in both former smokers and nonsmokers.

Long-term efficacy of house dust mite sublingual immunotherapy on clinical and pulmonary function in patients with asthma and allergic rhinitis

BackgroundA previous study reported that house dust mite (HDM) sublingual immunotherapy (SLIT) for 48 weeks was effective as add on treatment for allergic asthma; however, data regarding its long-term efficacy is scarce. ObjectiveThis open-label extension study aimed to evaluate the effect of HDM SLIT on asthma control, pulmonary function, airway inflammation and remodeling throughout the 5-year treatment period. MethodsA total of 140 patients with asthma and allergic rhinitis sensitized to HDM were randomized to receive either drugs alone or drugs plus SLIT for 5 years. Asthma Control Questionnaire (ACQ)-5, Asthma Quality of Life Questionnaire (AQLQ), Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ), spirometry, quantitative computed tomography, and type 2 biomarkers were assessed. ResultsAn improvement in the ACQ-5, AQLQ, and RQLQ scores was observed in the SLIT group compared with the control group. HDM SLIT increased lung function and reduced the percentage of airway wall area (WA/Ao). The levels of fractional exhaled nitric oxide (FeNO), blood eosinophil, serum specific IgE (s-IgE) for HDM, and total IgE decreased and were sustained during the 5 years. The change in type 2 biomarkers correlated with change in AQLQ score. Based on receiver operating characteristic (ROC) analysis for predicting responders, the area under the ROC curve in FEV1% predicted, WA/Ao, FeNO, and s-IgE was high. Multivariate regression analysis showed that the strongest predictor of responders was FeNO. ConclusionsHDM SLIT continued to provide sustained efficacy, improve lung function, and prevent progression of airway inflammation and remodeling in asthma through to year 5.

Differences in the Quantitative HRCT Characteristics of Patients with Asthma, COPD and Asthma-COPD Overlap and Their Relationships with Pulmonary Function.

We compared pulmonary function indices and quantitative CT parameters of airway remodeling, air trapping, and emphysema in asthmatic patients and patients with COPD and asthma-COPD overlap (ACO) and explored their relationships with airflow limitation. Patients with asthma (n=48), COPD (n=52), and ACO (n=30) and controls (n=54) who completed pulmonary function tests and HRCT scans were retrospectively enrolled in our study. Quantitative CT analysis software was used to assess emphysema (LAA%), airway wall dimensions (wall area (WA), luminal area (LA), and wall area percentage (WA%)), and air trapping ((relative volume change of -860 HU to -950 HU (RVC-860 to-950) and the expiration-to-inspiration ratio of the mean lung density (MLDE/I))). Differences in pulmonary function and HRCT parameters were compared among the groups. Spearman correlation analysis and regression analysis were utilized to explore structure‒function relationships. The LAA% in COPD and ACO patients was significantly greater than that in asthmatic patients and controls. The WA% and WA in COPD and ACO patients were greater than those in controls, whereas the WA% and LA between asthmatic patients and controls reached statistical significance. The RVC-860 to -950 levels decreased in the following order: ACO, COPD, and asthma. RVC-860 to -950 independently predicted FEV1% in asthmatic patients; LAA% and MLDE/I in COPD patients; and LAA%, WA% and RVC-860 to -950 in ACO patients. Comparable emphysema was observed in patients with COPD and ACO but not in asthmatic patients. All patients exhibited proximal airway remodeling. The bronchi were thickened outward in COPD and ACO patients but are thickened inward in asthmatic patients. Furthermore, air trapping in ACO patients was the most severe among all the groups. Indirect lung densitometry measurements might be more predictive of the degree of airflow limitation than direct airway measurements in obstructive airway diseases.

Influence of different working lengths on the shaping ability of Reciproc Blue in the apical third and apical foramen

Aim: This study aimed to assess the shaping ability of Reciproc Blue in the apical third and apical foramen of moderately curved canals at different working lengths (WLs), by micro-computed tomography. Methods: Thirty-six mesial roots (mesiobuccal and mesiolingual canals) were included, each with 2 separate root canals and independent apical foramina, according to type IV of Vertucci’s classification of first and second mandibular molars. The canals were instrumented at three different WLs: G-1, 1mm short of the major apical foramen; G0, at the major apical foramen; G+1, 1mm beyond the major apical foramen. The groups were assessed for changes in root canal volume and untouched wall area in the apical third. Groups G0 and G+1 were also compared for percentage of untouched walls at the apical foramen. One-way ANOVA (post hoc Tukey test) and Student’s t-test adopted a 5% level of significance. Results: Root canal volumes (mm3) in the apical third were 22.86±10.46, 44.48±24.91, and 55.71±21.32 in G-1, G0 and G+1, respectively. G-1 volume following instrumentation increased significantly less than that of G0 or G+1 (P&gt;.05); G0 did not differ from G+1. The percentage of untouched wall area in the apical third did not differ among the three groups (P&gt;.05). G0 and G+1 did not differ regarding untouched walls in the major apical foramem walls. Conclusion: Extending the WL from 1mm short of the apical foramen to a point at and beyond the WL increases the apical third volume without increasing the prepared area. Untouched surface areas of the apical foramen were not modified by instrumentation at or beyond the foramen.

Quantitative assessment of airway wall thickness in COPD patients with interstitial lung abnormalities.

Whether the airway is involved in the pathogenesis of interstitial lung abnormalities (ILA) is not well understood. Also the impact of ILA on lung function in COPD patients remains controversial. We aimed to assess the quantitative CT measurements of airway wall thickness (AWT) and lung function according to ILA status in COPD patients. 157 COPD patients discharged from our hospital from August 1, 2019 through August 31, 2022 who underwent chest CT imagings and pulmonary function tests were retrospectively enrolled. Linear regression analysis and multiple models were used to analyze associations between quantitative assessment of airway wall changes and the presence of ILA. In 157 COPD patients, 23 patients (14.6%) had equivocal ILA, 42 patients (26.8%) had definite ILA. The definite ILA group had the highest measurements of Pi10 (square root of theoretical airway wall area with a lumen perimeter of 10 mm), segmental AWT and segmental WA% (percentage of wall area), whereas the no ILA group had the lowest measurements of Pi10, segmental AWT and segmental WA%. In the adjusted analyses (adjusted by age, sex, body mass index, smoking intensity, COPD GOLD stage, lung function, slice thickness and scanner type), compared to COPD patients without ILA, the measurements of Pi10, segmental AWT and segmental WA% were higher in definite ILA group with differences of 0.225 mm (p = 0.012), 0.152 mm (p < 0.001), 4.8% (p < 0.001) respectively. COPD patients with definite ILA tended to have higher FEV1% predicted, FVC% predicted and lower MMEF75/25% predicted, but there were no statistically differences among the three groups. Our study demonstrates the higher AWT measures in COPD patients with ILA compared to the patients without ILA. These findings suggest that the airway may be involved in the pathogenesis of ILA.

Correlation between pulmonary quantitative CT measurement indicators and respiratory symptoms in patients with chronic obstructive pulmonary disease in stable stage

Objective: To explore the correlation between pulmonary quantitative CT measurement indicators and respiratory symptoms in patients with stable chronic obstructive pulmonary disease (COPD). Methods: A total of 186 patients with COPD in stable stage who visited in the outpatient department of Beijing Hospital from March 2021 to February 2022 were prospectively included. Demographic data, respiratory symptoms and lung function were collected. The original DICOM data of high-resolution CT (HRCT) were processed using the FACT medical imaging information system and the pulmonary emphysema index pixel index-950 (PI-950) and the airway wall thickness (4-6 T) and the percentage of airway area (4-6 WA%) of the 4-6 generation bronchi which represent the segmental and subsegmental bronchi were measured automatically. According to the modified British medical research council dyspnea scale (mMRC, 0-1 point for low score group, 2-4 points for high score group), chronic obstructive pulmonary disease assessment test (CAT, score<10 points for low score group,≥10 points for high score group), cough, expectoration and wheezing (asymptomatic group and symptomatic group), they were divided into two groups as dependent variables. The relationship between imaging parameters and the above symptoms was evaluated using a logistic regression model. Results: The study ultimately included 186 patients who met the inclusion criteria, including 162 males and 24 females, aged (68.9±9.3) years old. There were 83 patients in the high mMRC group, 120 patients in the high CAT group, 146 patients in the cough group, 154 patients in the expectoration group, and 65 patients in the wheezing group. The age and emphysema parameter PI-950 in the high score group of mMRC were higher than those in the low score group, while the percentage of the forced expiratory volume in 1 second (FEV1) predicted value (FEV1 pred) after medication, the percentage of carbon monoxide diffusion volume (DLCO) predicted value (DLCO pred), and the percentage of the maximum midexpiratory flow (MMEF) predicted value (MMEF pred) after medication were lower than those in the low score group (all P<0.05). The age of the high CAT group was higher than that of the low score group, while FEV1 pred and MMEF pred after medication were lower than those of the low score group (all P<0.05). The proportion of males, patients with smoking history, and smoking index in the cough group were higher than those in the non cough group, while the 4 WA% was lower than that in the non cough group (all P<0.05). The proportion of males, patients with smoking history, smoking index, and PI-950 in the expectoration group were higher than those in the non expectoration group, while FEV1 pred after medication and 4 WA% were lower than those in the non expectoration group (all P<0.05). The 5 WA% and 6 WA% of the wheezing group were higher than those of the non wheezing group, while MMEF pred after medication was lower than that of the non wheezing group (all P<0.05). Multivariate logistic regression analysis showed that after adjusting for demographic characteristics, smoking, combined diseases, lung function and other confounding factors, for every 10% increase in PI-950, the likelihood of developing more severe dyspnea for the patients (high score group according to mMRC) increased by 67.3% (OR=1.673, 95%CI: 1.052-2.658); Every 10% increase in 6WA% increased the likelihood of wheezing by 3.189 times (OR=4.189, 95%CI: 1.070-16.395). No correlation was found between various imaging indicators and cough, expectoration, and CAT scores (P>0.05). Conclusion: Quantitative CT measurement indicators in stable COPD patients can explain the presence and severity of respiratory symptoms, the pulmonary emphysema indicator is associated with dyspnea, and the percentage of proximal airway wall area is associated with wheezing.

Reduced Total Airway Count and Airway Wall Tapering after Three-Years in Ex-Smokers

Computed tomography (CT) total-airway-count (TAC) and airway wall-thickness differ across chronic obstructive pulmonary disease (COPD) severities, but longitudinal insights are lacking. The aim of this study was to evaluate longitudinal CT airway measurements over three-years in ex-smokers. In this prospective convenience sample study, ex-smokers with (n = 50; 13 female; age = 70 ± 9 years; pack-years = 43 ± 26) and without (n = 40; 17 female; age = 69 ± 10 years; pack-years = 31 ± 17) COPD completed CT, 3He magnetic resonance imaging (MRI), and pulmonary function tests at baseline and three-year follow-up. CT TAC, airway wall-area (WA), lumen-area (LA), and wall-area percent (WA%) were generated. Emphysema was quantified as the relative-area-of-the-lung with attenuation < –950 Hounsfield-units (RA950). MRI ventilation-defect-percent (VDP) was also quantified. Differences over time were evaluated using paired-samples t tests. Multivariable prediction models using the backwards approach were generated. After three-years, forced-expiratory-volume in 1-second (FEV1) was not different in ex-smokers with (p = 0.4) and without (p = 0.5) COPD, whereas RA950 was (p < 0.001, p = 0.02, respectively). In ex-smokers without COPD, there was no change in TAC (p = 0.2); however, LA (p = 0.009) and WA% (p = 0.01) were significantly different. In ex-smokers with COPD, TAC (p < 0.001), WA (p = 0.04), LA (p < 0.001), and WA% (p < 0.001) were significantly different. In all ex-smokers, TAC was related to VDP (baseline: ρ = –0.30, p = 0.005; follow-up: ρ = –0.33, p = 0.002). In significant multivariable models, baseline airway wall-thickness was predictive of TAC worsening. After three-years, in the absence of FEV1 worsening, TAC diminished only in ex-smokers with COPD and airway walls were thinner in all ex-smokers. These longitudinal findings suggest that the evaluation of CT airway remodeling may be a useful clinical tool for predicting disease progression and managing COPD. Clinical trial registration: www.clinicaltrials.gov NCT02279329

Comparison of the effects of itraconazole and prednisolone on fibroblast growth factor-2 gene expression and clinical manifestations in patients with persistent severe asthma.

Considering the possible role of fungal sensitization in the treatment of resistant asthma, which may lead to the remodeling of bronchial structure, we theorized that itraconazole could result in better control of asthma. In this regard, this study aimed to compare the effects of itraconazole and prednisolone (routinely prescribed) on clinical, structural, and biomarker findings of the remodeling of asthma. This double-blind controlled randomized clinical trial was performed on 70 adult patients suffering from severe persistent asthma. The intervention group received 200 mg of itraconazole per day, and the control group received 10 mg of prednisolone per day, for 32 weeks, in addition to the classic treatment of asthma. The subjects were randomly divided into two groups, and assigned by sealed envelope. Blinding was performed by repacking the drug in a similar container. Primary outcomes were asthma control test score, fibroblast growth factor 2, and wall area percentage on RB1 bronchus measured by computed tomography. The outcomes were compared in subjects classified as allergic, eosinophilic, T2 low asthma, and four types of inflammatory cell classification in sputum. Seventy subjects finished the 32-week trial (35 subjects in each group). Baseline data did not show significant differences between groups. A comparison of asthma variants showed significantly more severe cough and dyspnea in the allergic variant and higher spirometry results in T2-low asthma. Sputum cytology revealed a mixed pattern as the most frequent type (47%). After the trial, two groups improved in many parameters; however, FGF-2 improved more significantly by itraconazole (4.66±16.92 decreased to 1.14±2.98), and FEV1/FVC was significantly higher in the itraconazole group, compared to the control group. These results did not change in terms of asthma variants and sputum classification. Itraconazole was superior to prednisolone in the treatment of many clinical and spirometry aspects in severe persistent asthma.

Reproducibility of a combined artificial intelligence and optimal-surface graph-cut method to automate bronchial parameter extraction

ObjectivesComputed tomography (CT)–based bronchial parameters correlate with disease status. Segmentation and measurement of the bronchial lumen and walls usually require significant manpower. We evaluate the reproducibility of a deep learning and optimal-surface graph-cut method to automatically segment the airway lumen and wall, and calculate bronchial parameters.MethodsA deep-learning airway segmentation model was newly trained on 24 Imaging in Lifelines (ImaLife) low-dose chest CT scans. This model was combined with an optimal-surface graph-cut for airway wall segmentation. These tools were used to calculate bronchial parameters in CT scans of 188 ImaLife participants with two scans an average of 3 months apart. Bronchial parameters were compared for reproducibility assessment, assuming no change between scans.ResultsOf 376 CT scans, 374 (99%) were successfully measured. Segmented airway trees contained a mean of 10 generations and 250 branches. The coefficient of determination (R2) for the luminal area (LA) ranged from 0.93 at the trachea to 0.68 at the 6th generation, decreasing to 0.51 at the 8th generation. Corresponding values for Wall Area Percentage (WAP) were 0.86, 0.67, and 0.42, respectively. Bland–Altman analysis of LA and WAP per generation demonstrated mean differences close to 0; limits of agreement (LoA) were narrow for WAP and Pi10 (± 3.7% of mean) and wider for LA (± 16.4–22.8% for 2–6th generations). From the 7th generation onwards, there was a sharp decrease in reproducibility and a widening LoA.ConclusionThe outlined approach for automatic bronchial parameter measurement on low-dose chest CT scans is a reliable way to assess the airway tree down to the 6th generation.Statement on clinical relevanceThis reliable and fully automatic pipeline for bronchial parameter measurement on low-dose CT scans has potential applications in screening for early disease and clinical tasks such as virtual bronchoscopy or surgical planning, while also enabling the exploration of bronchial parameters in large datasets.Key Points• Deep learning combined with optimal-surface graph-cut provides accurate airway lumen and wall segmentations on low-dose CT scans.• Analysis of repeat scans showed that the automated tools had moderate-to-good reproducibility of bronchial measurements down to the 6thgeneration airway.• Automated measurement of bronchial parameters enables the assessment of large datasets with less man-hours.

Deep Learning-Based Segmentation of Airway Morphology from Endobronchial Optical Coherence Tomography

Background: Manual measurement of endobronchial optical coherence tomography (EB-OCT) images means a heavy workload in the clinical practice, which can also introduce bias if the subjective opinions of doctors are involved. Objective: We aim to develop a convolutional neural network (CNN)-based EB-OCT image analysis algorithm to automatically identify and measure EB-OCT parameters of airway morphology. Methods: The ResUNet, MultiResUNet, and Siamese network were used for analyzing airway inner area (Ai), airway wall area (Aw), airway wall area percentage (Aw%), and airway bifurcate segmentation obtained from EB-OCT imaging, respectively. The accuracy of the automatic segmentations was verified by comparing with manual measurements. Results: Thirty-three patients who were diagnosed with asthma (n = 13), chronic obstructive pulmonary disease (COPD, n = 13), and normal airway (n = 7) were enrolled. EB-OCT was performed in RB9 segment (lateral basal segment of the right lower lobe), and a total of 17,820 OCT images were collected for CNN training, validation, and testing. After training, the Ai, Aw, and airway bifurcate were readily identified in both normal airway and airways of asthma and COPD. The ResUNet and the MultiResUNet resulted in a mean dice similarity coefficient of 0.97 and 0.95 for Ai and Aw segmentation. The accuracy Siamese network in identifying airway bifurcate was 96.6%. Bland-Altman analysis indicated there was a negligible bias between manual and CNN measurements for Ai (bias = −0.02 to 0.01, 95% CI = −0.12 to 0.14) and Aw% (bias = −0.06 to 0.12, 95% CI = −1.98 to 2.14). Conclusion: EB-OCT imaging in conjunction with ResUNet, MultiResUNet, and Siamese network could automatically measure normal and diseased airway structure with an accurate performance.

Quantitative CT Metrics for the Prediction of Therapeutic Effect in Asthma.

Background: Few studies have explored the correlation between asthma medication and features on HRCT images. We aim to analyse the differences and temporal changes of lung function and airway resistance in asthma with diverse HRCT phenotypes in a short period after inhalation of budesonide/formoterol. Method: This observational study recruited 55 adult patients with varying severities of asthma. We performed detailed airway metrics measurements of chest CT scans, such as airway wall thickness (WT), wall area percentage (WA%), wall thickness percentage (T/OR), and airways with an inner perimeter of 10 mm (Pi10). The effect of lung structural features on asthma medication response was explored according to the WA% and T/OR twelve hours post-drug administration. Using multivariable regression models, we then assessed the influence of WA% on lung function. Results: WA% (p < 0.001) and T/OR (p < 0.001) significantly increased in asthma than in healthy control subjects. Compared to mild asthma, airway walls were further thickened (WA%, p = 0.023; T/OR: p = 0.029) and associated with lumen narrowing (Pi10, p = 0.055) in moderate to severe asthma. WA% and T/OR correlated well with lung function (FEV1, FVC, MMEF, and PEF) and airway resistance (R5, R20, Rp, and Fres). Regression analysis showed that MEF25 decreased with increasing age and WA% (R2 = 0.58, p < 0.001). Patients with thickened airway walls experienced a maximal increase in FVC, FEV1, and PEF at 2 h (p < 0.001) and a maximal decrease of R5, Z5, and Rp at 2 h (p < 0.001) in those with a thickened airway pattern. Conclusions: Asthma patients with different bronchial wall thicknesses exhibited variable lung function changes. Specifically, patients with thick airway wall patterns were more sensitive to inhaled budesonide in the short term.

Quantitative CT parameters correlate with lung function in chronic obstructive pulmonary disease: A systematic review and meta-analysis.

This study aimed to analyze the correlation between quantitative computed tomography (CT) parameters and airflow obstruction in patients with COPD. PubMed, Embase, Cochrane and Web of Knowledge were searched by two investigators from inception to July 2022, 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 extracted data, and evaluated it for quality and 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, and 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. A total of 141 studies (25,214 participants) were identified, which 64 (6,341 participants) were suitable for our 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 0.26 (95% CI, 0.18 to 0.33) to 0.70 (95% CI, 0.65 to 0.75) for inspiratory CT and 0.56 (95% CI, 0.51 to 0.60) to 0.74 (95% CI, 0.68 to 0.80) for expiratory CT. 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.

Quantitative Airway Assessment of Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia (DIPNECH) on CT as a Novel Biomarker.

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) occurs due to abnormal proliferation of pulmonary neuroendocrine cells. We hypothesized that performing a quantitative analysis of airway features on chest CT may reveal differences to matched controls, which could ultimately help provide an imaging biomarker. A retrospective quantitative analysis of chest CTs in patients with DIPNECH and age matched controls was carried out using semi-automated post-processing software. Paired segmental airway and artery diameters were measured for each bronchopulmonary segment, and the airway:artery (AA) ratio, airway wall thickness:artery ratio (AWTA ratio) and wall area percentage (WAP) calculated. Nodule number, size, shape and location was recorded. Correlation between CT measurements and pulmonary function testing was performed. 16 DIPNECH and 16 control subjects were analysed (all female, mean age 61.7 +/- 11.8 years), a combined total of 425 bronchopulmonary segments. The mean AwtA ratio, AA ratio and WAP for the DIPNECH group was 0.57, 1.18 and 68.8%, respectively, compared with 0.38, 1.03 and 58.3% in controls (p &lt; 0.001, &lt;0.001, 0.03, respectively). DIPNECH patients had more nodules than controls (22.4 +/- 32.6 vs. 3.6 +/- 3.6, p = 0.03). AA ratio correlated with FVC (R2 = 0.47, p = 0.02). A multivariable model incorporating nodule number, AA ratio and AWTA-ratio demonstrated good performance for discriminating DIPNECH and controls (AUC 0.971; 95% CI: 0.925-1.0). Quantitative CT airway analysis in patients with DIPNECH demonstrates increased airway wall thickness and airway:artery ratio compared to controls. Quantitative CT measurement of airway wall thickening offers a potential imaging biomarker for treatment response.

Airway involvement in inflammatory bowel disease: Inflammatory bowel disease patients have bronchial wall thickening.

Recent epidemiological studies have revealed a high co-occurrence of asthma or COPD and IBD. Herein, we examined the impact of IBD on the bronchial wall structure using three-dimensional computed tomography (3D-CT). Subjects who were diagnosed with IBD and had undergone chest CT were recruited from consecutive medical records. Screening chest CT scan data during the same period were used as normal controls. Airway dimensions were measured by validated software. Overall, 136 IBD and 99 control subjects were recruited. The bronchial walls of patients with IBD were significantly thicker than those of control subjects. Multiple linear regression analysis showed that Crohn's disease and ulcerative colitis were independent determinants of wall area percentage after adjusting for age, sex, and smoking status. Airway walls in patients with IBD were thicker than those in normal control subjects. Airway involvement in IBD may be more frequent than recognized.

Efficacy of a house dust mite sublingual immunotherapy tablet as add-on dupilumab in asthma with rhinitis

BackgroundHDM SLIT is one of the disease-modifying treatment for allergic asthma, and has demonstrated efficacy in clinical trials. Dupilumab, blocks IL-4 and IL-13 signaling, key drivers of type 2 inflammation, and is approved for patients with uncontrolled, moderate-to-severe asthma. The aim of this study was to evaluate outcomes after HDM SLIT initiation in asthma with rhinitis not optimally controlled with dupilumab in a real-world setting. MethodsAt baseline and 48 weeks after treatment, asthma control questionnaire (ACQ)-5, asthma quality of life questionnaire (AQLQ) and rhinoconjunctivitis quality of life questionnaire (RQLQ) were assessed. Spirometry, type 2 inflammatory biomarkers and quantitative computed tomographic parameters of airway remodeling were also collected. ResultsOf 47 patients received HDM SLIT and 41 completed the study. Combined HDM SLIT and dupilumab improved ACQ-5 (p < 0.05), AQLQ (p < 0.05), RQLQ (p < 0.05), and increased lung function and reduced FeNO (p < 0.05) and airway percentage wall area, and wall thickness (each, p < 0.05). The change in ACQ-5 and AQLQ score correlated with both changes in FeNO and FEV1 percent predicted. Multiple regression analysis showed that the change in FEV1 percent predicted was independent factor for improvement of AQLQ (r2 = 0.510, p = 0.012). Based on ROC analysis for predicting SLIT responders, the baseline area under the curves in serum HDM specific-IgE, total IgE and FEV1 percent predicted were high (>0.8). ConclusionsThese results support the benefits of adding HDM SLIT to pharmacotherapy plus dupilumab in uncontrolled asthma with rhinitis.

Further evidence for association of YKL-40 with severe asthma airway remodeling

BackgroundThe chitinase-like protein YKL-40 is associated with airflow limitation on spirometry and airway remodeling in patients with asthma. It remains unclear whether YKL-40 is associated with morphologic changes in the airways and parenchyma or with future progression of airflow limitation in severe asthma. ObjectiveTo evaluate the association of circulating YKL-40 levels with morphologic changes in the airways and parenchyma and with longitudinal progression of airflow limitation. MethodsThe patients were participants in the Hokkaido Severe Asthma Cohort Study (n = 127), including smokers. This study consisted of 2 parts. In analysis 1, we analyzed associations between circulating YKL-40 levels and several asthma-related indices, including computed tomography–derived indices of proximal wall area percentage, the complexity of the airways (airway fractal dimension), and the parenchyma (exponent D) cross-sectionally (n = 97). In analysis 2, we evaluated the impact of circulating YKL-40 levels on forced expiratory volume in 1 second (FEV1) decline longitudinally for a 5-year follow-up (n = 103). ResultsCirculating YKL-40 levels were significantly associated with proximal wall area percentage and airway fractal dimension (r = 0.25, P = .01; r = −0.22, P = .04, respectively), but not with exponent D. The mean annual change in FEV1 was −33.7 (± 23.3) mL/y, and the circulating YKL-40 level was a significant independent factor associated with annual FEV1 decline (β = −0.24, P = .02), even after controlling for exponent D (β = −0.26, P = .01). ConclusionThese results provide further evidence for the association of YKL-40 with the pathogenesis of airway remodeling in severe asthma.

Pulmonary MRI and Cluster Analysis Help Identify Novel Asthma Phenotypes.

Outside eosinophilia, current clinical asthma phenotypes do not show strong relationships with disease pathogenesis or treatment responses. While chest x-ray computed tomography (CT) phenotypes have previously been explored, functional MRI measurements provide complementary phenotypic information. To derive novel data-driven asthma phenotypic clusters using functional MRI airway biomarkers that better describe airway pathologies in patients. Retrospective. A total of 45 patients with asthma who underwent post-bronchodilator 129 Xe MRI, volume-matched CT, spirometry and plethysmography within a 90-minute visit. Three-dimensional gradient-recalled echo 129 Xe ventilation sequence at 3T. We measured MRI ventilation defect percent (VDP), CT airway wall-area percent (WA%), wall-thickness (WT, WT* [*normalized for age/sex/height]), lumen-area (LA), lumen-diameter (D, D*) and total airway count (TAC). Univariate relationships were utilized to select variables for k-means cluster analysis and phenotypic subgroup generation. Spirometry and plethysmography measurements were compared across imaging-based clusters. Spearman correlation (ρ), one-way analysis of variance (ANOVA) or Kruskal-Wallis tests with post hoc Bonferroni correction for multiple comparisons, significance level 0.05. Based on limited common variance (Kaiser-Meyer-Olkin-measure=0.44), four unique clusters were generated using MRI VDP, TAC, WT* and D* (52 ± 14 years, 27 female). Imaging measurements were significantly different across clusters as was the forced expiratory volume in 1-second (FEV1 %pred ), residual volume/total lung capacity and airways resistance. Asthma-control (P=0.9), quality-of-life scores (P=0.7) and the proportions of severe-asthma (P=0.4) were not significantly different. Cluster1 (n=15/8 female) reflected mildly abnormal CT airway measurements and FEV1 with moderately abnormal VDP. Cluster2 (n=12/12 female) reflected moderately abnormal TAC, WT and FEV1 . In Cluster3 and Cluster4 (n=14/6 female, n=4/1 female, respectively), there was severely reduced TAC, D and FEV1 , but Cluster4 also had significantly worse, severely abnormal VDP (7 ± 5% vs. 41 ± 12%). We generated four proof-of-concept MRI-derived clusters of asthma with distinct structure-function pathologies. Cluster analysis of asthma using 129 Xe MRI in combination with CT biomarkers is feasible and may challenge currently used paradigms for asthma phenotyping and treatment decisions. 3 TECHNICAL EFFICACY: Stage.