Percentage Of Low Attenuation Area Research Articles

Sublobar resection or lobectomy and postoperative respiratory complications in emphysematous lungs.

Pulmonary resection in patients with severe emphysema may impact postoperative respiratory complications. Low-attenuation areas evaluated using three-dimensional computed tomography to assess emphysematous changes are strongly associated with postoperative respiratory complications. Herein, we investigated the relationship between low-attenuation area, the surgical procedure and resected lung volume, which has not been explored in previous studies. We retrospectively evaluated patients with primary or metastatic lung cancer who underwent surgical resection. The low-attenuation area percentage (low-attenuation area/total lung area × 100) and resected lung volume were calculated using three-dimensional computed tomography software, and the relationship with postoperative respiratory complications was analysed. Postoperative respiratory complications occurred in 66 patients (17%) in the total cohort (n = 383). We set the median value of 1.1% as the cut-off value for low-attenuation area percentage to predict postoperative respiratory complications, which occurred in 24% and 10% of patients with low-attenuation area >1.1% and <1.1%, respectively (P < 0.001). Postoperative respiratory complications occurred in approximately one-third of the patients with low-attenuation area >1.1%, whose resected lung volume was ≥15.8% or ≥5 resected subsegments. Multivariable analysis revealed that sublobar resection was associated with a significantly lower risk of postoperative respiratory complications in patients with low-attenuation area >1.1% (odds ratio 0.4, 95% confidence interval 0.183-0.875). Emphysema is a risk factor for postoperative respiratory complications, and lobectomy is an independent predictive risk factor. Preserving more lung parenchyma may yield better short-term prognoses in patients with emphysematous lungs.

A systematic assessment and optimization of photon-counting CT for lung density quantifications.

Photon-counting computed tomography (PCCT) has recently emerged into clinical use; however, its optimum imaging protocols and added benefits remains unknown in terms of providing more accurate lung density quantification compared to energy-integrating computed tomography (EICT) scanners. To systematically assess the performance of a clinical PCCT scanner for lung density quantifications and compare it against EICT. This cross-sectional study involved a retrospective analysis of subjects scanned (August-December 2021) using a clinical PCCT system. The influence of altering reconstruction parameters was studied (reconstruction kernel, pixel size, slice thickness). A virtual CT dataset of anthropomorphic virtual subjects was acquired to demonstrate the correspondence of findings to clinical dataset, and to perform systematic imaging experiments, not possible using human subjects. The virtual subjects were imaged using a validated, scanner-specific CT simulator of a PCCT and two EICT (defined as EICT A and B) scanners. The images were evaluated using mean absolute error (MAE) of lung and emphysema density against their corresponding ground truth. Clinical and virtual PCCT datasets showed similar trends, with sharper kernels and smaller voxel sizes increasing percentage of low-attenuation areas below -950 HU (LAA-950) by up to 15.7±6.9% and 11.8±5.5%, respectively. Under the conditions studied, higher doses, thinner slices, smaller pixel sizes, iterative reconstructions, and quantitative kernels with medium sharpness resulted in lower lung MAE values. While using these settings for PCCT, changes in the dose level (13 to 1.3 mGy), slice thickness (0.4 to 1.5mm), pixel size (0.49 to 0.98mm), reconstruction technique (70keV-VMI to wFBP), and kernel (Qr48 to Qr60) increased lung MAE by 15.3±2.0, 1.4±0.6, 2.2±0.3, 4.2±0.8, and 9.1±1.6 HU, respectively. At the optimum settings identified per scanner, PCCT images exhibited lower lung and emphysema MAE than those of EICT scanners (by 2.6±1.0 and 9.6±3.4 HU, compared to EICT A, and by 4.8±0.8 and 7.4±2.3 HU, compared to EICT B). The accuracy of lung density measurements was correlated with subjects' mean lung density (p<0.05), measured by PCCT at optimum setting under the conditions studied. Photon-counting CT demonstrated superior performance in density quantifications, with its influences of imaging parameters in line with energy-integrating CT scanners. The technology offers improvement in lung quantifications, thus demonstrating potential toward more objective assessment of respiratory conditions.

Quantitative emphysema on computed tomography imaging of chest is a risk factor for prognosis of esophagectomy: A retrospective cohort study.

The low attenuation area percentage (LAA%) is gaining popularity. LAA% is an index of quantitative emphysema on computed tomography (CT) imaging of the chest. This study aims to retrospectively investigate whether preoperative LAA% is associated with postoperative prognosis in patients with esophageal cancer who were scheduled for esophagectomy. From January 2016 to March 2020, 105 patients with esophageal cancer underwent esophagectomy via right thoracotomy and neoadjuvant chemotherapy. A Synapse Vincent volume analyzer (Fujifilm Medical, Tokyo, Japan) was used for measurement. The software automatically quantified LAA% using a threshold of less than - 950 Hounsfield units on CT images of lung regions. Cox proportional hazard analyses were performed in univariable and multivariable forms. Estimates of the receiver operating curve are used to determine the cutoff value for death of LAA%, and the binary value is then inserted into Cox proportional hazard analyses. The preoperative LAA% cutoff value was ≥ 6.3%. Patients with a preoperative LAA% ≥6.3% had a significantly worse prognosis than those with a preoperative LAA% of < 6.3%. LAA% ≥6.3% (hazard ratio: 6.76; 95% confidence interval: 2.56-17.90, P < .001) was the most influential preoperative factor for overall survival after esophagectomy in multivariate Cox proportional hazard analyses. LAA% is one of the preoperative risk factors for survival after esophagectomy and an indicator of lung condition using routinely performed preoperative CT images. We quantified the extent of preoperative emphysema in patients with esophageal cancer, who were scheduled for surgery, and for the first time, reported LAA% as one of the preoperative risk factors for survival after esophagectomy.

Percentage of low attenuation area on computed tomography detects chronic lung allograft dysfunction, especially bronchiolitis obliterans syndrome, after bilateral lung transplantation.

The percentage of low attenuation area (%LAA) on computed tomography (CT) is useful for evaluating lung emphysema, and higher %LAA was observed in patients with chronic lung allograft dysfunction (CLAD). This study investigated the relationship between the %LAA and the development of CLAD after bilateral lung transplantation (LT). We conducted a single-center retrospective study of 75 recipients who underwent bilateral LT; the recipients were divided into a CLAD group (n=30) and a non-CLAD group (n=45). The %LAA was calculated using CT and compared between the two groups from 4 years before to 4 years after the diagnosis of CLAD. The relationships between the %LAA and the percent baseline values of the pulmonary function test parameters were also calculated. The %LAA was significantly higher in the CLAD group than in the non-CLAD group from 2 years before to 2 years after the diagnosis of CLAD (P<.05). In particular, patients with bronchiolitis obliterans syndrome (BOS) exhibited significant differences even from 4 years before to 4 years after diagnosis (P<.05). Significant negative correlations between the %LAA and the percent baseline values of the forced expiratory volume in 1 s (r=-.36, P=.0031), the forced vital capacity (r=-.27, P=.027), and the total lung capacity (r=-.40, P<.001) were seen at the time of CLAD diagnosis. The %LAA on CT was associated with the development of CLAD and appears to have the potential to predict CLAD, especially BOS, after bilateral LT.

Automated Coronary Artery Calcium and Quantitative Emphysema in Lung Cancer Screening: Association With Mortality, Lung Cancer Incidence, and Airflow Obstruction.

To assess automated coronary artery calcium (CAC) and quantitative emphysema (percentage of low attenuation areas [%LAA]) for predicting mortality and lung cancer (LC) incidence in LC screening. To explore correlations between %LAA, CAC, and forced expiratory value in 1 second (FEV 1 ) and the discriminative ability of %LAA for airflow obstruction. Baseline low-dose computed tomography scans of the BioMILD trial were analyzed using an artificial intelligence software. Univariate and multivariate analyses were performed to estimate the predictive value of %LAA and CAC. Harrell C -statistic and time-dependent area under the curve (AUC) were reported for 3 nested models (Model survey : age, sex, pack-years; Model survey-LDCT : Model survey plus %LAA plus CAC; Model final : Model survey-LDCT plus selected confounders). The correlations between %LAA, CAC, and FEV 1 and the discriminative ability of %LAA for airflow obstruction were tested using the Pearson correlation coefficient and AUC-receiver operating characteristic curve, respectively. A total of 4098 volunteers were enrolled. %LAA and CAC independently predicted 6-year all-cause (Model final hazard ratio [HR], 1.14 per %LAA interquartile range [IQR] increase [95% CI, 1.05-1.23], 2.13 for CAC ≥400 [95% CI, 1.36-3.28]), noncancer (Model final HR, 1.25 per %LAA IQR increase [95% CI, 1.11-1.37], 3.22 for CAC ≥400 [95%CI, 1.62-6.39]), and cardiovascular (Model final HR, 1.25 per %LAA IQR increase [95% CI, 1.00-1.46], 4.66 for CAC ≥400, [95% CI, 1.80-12.58]) mortality, with an increase in concordance probability in Model survey-LDCT compared with Model survey ( P <0.05). No significant association with LC incidence was found after adjustments. Both biomarkers negatively correlated with FEV 1 ( P <0.01). %LAA identified airflow obstruction with a moderate discriminative ability (AUC, 0.738). Automated CAC and %LAA added prognostic information to age, sex, and pack-years for predicting mortality but not LC incidence in an LC screening setting. Both biomarkers negatively correlated with FEV 1 , with %LAA enabling the identification of airflow obstruction with moderate discriminative ability.

Associations of the distance-saturation product and low-attenuation area percentage in pulmonary computed tomography with acute exacerbation in patients with chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) has high global health concerns, and previous research proposed various indicators to predict mortality, such as the distance-saturation product (DSP), derived from the 6-min walk test (6MWT), and the low-attenuation area percentage (LAA%) in pulmonary computed tomographic images. However, the feasibility of using these indicators to evaluate the stability of COPD still remains to be investigated. Associations of the DSP and LAA% with other COPD-related clinical parameters are also unknown. This study, thus, aimed to explore these associations. This retrospective study enrolled 111 patients with COPD from northern Taiwan. Individuals' data we collected included results of a pulmonary function test (PFT), 6MWT, life quality survey [i.e., the modified Medical Research Council (mMRC) scale and COPD assessment test (CAT)], history of acute exacerbation of COPD (AECOPD), and LAA%. Next, the DSP was derived by the distance walked and the lowest oxygen saturation recorded during the 6MWT. In addition, the DSP and clinical phenotype grouping based on clinically significant outcomes by previous study approaches were employed for further investigation (i.e., DSP of 290 m%, LAA% of 20%, and AECOPD frequency of ≥1). Mean comparisons and linear and logistic regression models were utilized to explore associations among the assessed variables. The low-DSP group (<290 m%) had significantly higher values for the mMRC, CAT, AECOPD frequency, and LAA% at different lung volume scales (total, right, and left), whereas it had lower values of the PFT and 6MWT parameters compared to the high-DSP group. Significant associations (with high odds ratios) were observed of the mMRC, CAT, AECOPD frequency, and PFT with low- and high-DSP groupings. Next, the risk of having AECOPD was associated with the mMRC, CAT, DSP, and LAA% (for the total, right, and left lungs). A lower value of the DSP was related to a greater worsening of symptoms, more-frequent exacerbations, poorer pulmonary function, and more-severe emphysema (higher LAA%). These readily determined parameters, including the DSP and LAA%, can serve as indicators for assessing the COPD clinical course and may can serve as a guide to corresponding treatments.

The Percentage of Low Attenuation Area on Computed Tomography to Detect Chronic Lung Allograft Dysfunction After Bilateral Lung Transplantation

<h3>Purpose</h3> Lung emphysematous changes may develop in patients with chronic lung allograft dysfunction (CLAD) after lung transplantation (LT). To evaluate the severity of lung emphysema, the percentage of low attenuation area (LAA%) of the bilateral lungs calculated on computed tomography has been shown to be a useful index. This study aimed to investigate whether the LAA% was associated with the development of CLAD after bilateral LT. <h3>Methods</h3> We conducted a single-center retrospective study of 75 recipients who underwent bilateral LT from May 2008 to August 2015. The LAA% on computed tomography were calculated and compared between the CLAD group (N = 30) and the non-CLAD group (N = 45) from 2 years before to 4 years after the diagnosis of CLAD. The LAA% at 5 years after bilateral LT was designated as the control value in the non-CLAD group. The Pearson product-moment correlation coefficient was calculated between the LAA% and the percent baseline values of the forced expiratory volume in 1 s (FEV1), the forced vital capacity (FVC), and the total lung capacity (TLC) at the diagnosis of CLAD after bilateral LT. <h3>Results</h3> The median observation period after LT was 3277 (380-7691) days. The LAA% in the CLAD group was significantly higher than that in the non-CLAD group from even 2 years before the diagnosis of CLAD to 2 years after the diagnosis of CLAD (P < 0.05) (Figure 1). The difference in the LAA% between the CLAD group and the non-CLAD group tended to increase after the onset of CLAD. Furthermore, the LAA% was significantly correlated with the percent baseline values of the FEV1, the FVC, and the TLC (FEV1, r = -0.36, P = 0.0031; FVC, r = -0.27, P = 0.027; TLC, r = -0.40, P < 0.001) (Figure 2). <h3>Conclusion</h3> The LAA% was associated with the development of CLAD and increased after the diagnosis of CLAD. Moreover, the LAA% was associated with declines in the FEV1, FVC and TLC at the time of CLAD diagnosis. The LAA% appears to have the potential to predict CLAD after bilateral LT.

Prediction of Postoperative Respiratory Complications after Lobectomy in Lung Cancer Patients with COPD by Quantitative Image Analysis: A Historical Cohort Study.

We examined whether preoperative assessment of percentage of low attenuation area (LAA%) on the non-resected side can predict postoperative respiratory complications (PRC) after lobectomy. We conducted a historical cohort study of 217 smokers (175 males and 42 females) who underwent lobectomy for primary lung cancer at our hospital between January 2014 and March 2021. First, the relationship between LAA% and respiratory function parameters (RFPs) calculated for both the bilateral and non-resected sides was used to estimate the most effective patient group. Next, multivariate analyses of the relationship between LAA% of the non-resected side and PRC were performed using logistic regression analysis after adjusting for basic patient attributes and respiratory function. A correlation was found between LAA% and RFP in smoking males. Multivariate analysis showed a strong relationship between model 3, adjusted for basic patient attributes and lung function factors, and PRC (odds ratio, 2.43; 95% confidence interval, 1.05-5.63). LAA% of the non-resected side suggested that it may be able to predict the occurrence of PRC after lung cancer lobectomy.

Predicting Respiratory Complications Following Lobectomy Using Quantitative CT Measures of Emphysema.

PurposeIn performing surgery for lung cancer, emphysema is a risk factor related to postoperative respiratory complications (PRC). However, few studies have addressed the risk of radiological emphysematous volume affecting PRC. The aim of this study was to investigate the relationship between emphysematous volume as measured on 3-dimensional computed tomography and PRC.Patients and MethodsWe reviewed 342 lung cancer patients undergoing lobectomy between 2013 and 2018. The percentage of low attenuation area (LAA%) was defined as the percentage of the lung area showing attenuation of −950 Hounsfield units or lower. Preoperative factors including age, sex, body mass index, smoking index, respiratory function, tumour histology, and LAA% were evaluated. PRC included pneumonia, atelectasis, prolonged air leakage, empyema, hypoxia, ischemic bronchitis, bronchopleural fistula, and exacerbation of interstitial pneumonia. Uni- and multivariable analyses were performed to investigate the relationship between independent clinical variables and postoperative adverse events.ResultsMedian LAA% was 5.0% (range, 0–40%) and PRC was observed in 50 patients (14.6%). Patients who presented with PRC showed significantly high LAA% compared to those without complications (median: 8.1% vs 3.8%; p < 0.001). Based on univariable analysis, age, sex, smoking index, percentage of forced expiratory volume in 1 s (FEV1.0%), histology, and LAA% were significant predictors for PRC. Multivariable analysis revealed higher LAA% as a significant risk factor for PRC (odds ratio = 1.040; 95% confidence interval, 1.001–1.080; p = 0.046).ConclusionIn addition to respiratory function with spirometry, LAA% can be used as a predictor of PRC.

Parenchymal destruction in asthma: Fixed airflow obstruction and lung function trajectory

Fixed airflow obstruction (FAO) in asthma, particularly in nonsmokers, is generally believed to be caused by airway remodeling. However, parenchymal destruction may also contribute to FAO and longitudinal decline in forced expiratory volume in 1 second (FEV1). To evaluate parenchymal destruction, we used emphysema indices, exponent D, and low-attenuation area percentage (LAA%) on computed tomography (CT), and test whether the parenchymal destruction and airway disease are independently associated with FAO and FEV1 decline in both smoking and nonsmoking asthma. Exponent D, LAA%, wall area percentage at segmental airways, and airway fractal dimension (AFD) in those with asthma were measured on inspiratory CT and compared to those in patients with chronic obstructive pulmonary disease (COPD). Exponent D was lower and LAA% was higher in COPD (n= 42) and asthma with FAO (n= 101) than in asthma without FAO (n= 88). The decreased exponent D and increased LAA% were associated with FAO regardless of smoking status or asthma severity. In multivariable analysis, decreased exponent D and increased LAA% were associated with an increased odds ratio of FAO and decreased FEV1, irrespective of wall area percentage and airway fractal dimension. Moreover, decreased exponent D affected the longitudinal decline in FEV1 in those with severe asthma, independent of smoking status. Patients with asthma with FAO showed parenchymal destruction regardless of smoking status and asthma severity. Parenchymal destruction was associated with an accelerated FEV1 decline, suggesting the involvements of both airway and parenchyma in the pathophysiology of a subgroup of asthma.

Follow-up study of patients with chronic obstructive pulmonary disease complicated with pulmonary hypertension

Objective: To investigate the relationship between clinical characteristics of patients with chronic obstructive pulmonary disease (COPD) with pulmonary hypertension (PH) and COPD exacerbation over a three-year observation period. Methods: A total of 366 cases of stable COPD patients were enrolled from the Department of Respiratory Medicine of the First Affiliated Hospital of Henan University of Science and Technology. The patients underwent pulmonary function tests(PFT), COPD assessment test (CAT), Saint George's respiratory questionnaire (SGRQ), transthoracic echocardiogrophy(TTE), chest CT and biochemical detection. The likelihood of PH was evaluated based on the peak tricuspid regurgitation velocity (TRV) measured by echocardiography at rest and other indicators, which were represented by low, medium, and high probability, respectively. Highly probability was defined as PH. The mean values of the groups were compared using a two-tailed unpaired t test for normally distributed variables. Qualitative data were assessed using a χ2 test. Pearson correlation analysis was performed, and risk factors were analyzed using logistic regression analysis and stepwise regression analysis. P<0.05 was considered to indicate statistical significance. Results: The prevalence of patients with high likelihood of PH was 18.3% (n=67) in a series of 366 patients with COPD. The median estimated systolic pulmonary artery pressure in patients with PH was (51.7±6.7) mmHg(1mmHg=0.133 kPa). There were differences between patients with high likelihood of PH and those with low to moderate likelihood of PH for the following factors: age (76.0 vs. 64.0), body mass index (BMI) [(21.4±6.0) kg/m2 vs. (22.6±7.2)kg/m2], brain natriureticpeptide (BNP) [(50.8±9.1) pg/ml vs. (36.4±8.1) pg/ml], toral number of acute exacerbation in three-year [(6.1±0.1) times vs. (2.8±0.4) times], CAT (17.0 vs. 10.0), SGRQ (48.9 vs. 32.1), carbon monoxide diffusion percentage of predicted value (DLCO%) [(51.9±21.9)% vs. (67.0±22.1)%]; all the differences being statistically significant(mean P<0.05).There was a negative correlation between DLCO% and SPAP (r=-0.28, P<0.01).In patients with high likelihood of PH, the percentage of low attenuation area (LAA%) and interstitial abnormalities in chest CT were higher than those in patients with low to moderate likelihood of PH (56.1% vs. 34.3% and 30.8% vs. 15.6%, mean P<0.05).LAA% ≥ 30% and pulmonary interstitial abnormalities were independent risk factors for pH [beta value were 1.479, 1.065, OR value was (3.640-5.720), 95%CI (1.462-8.571), mean P<0.01]. The ratio of main pulmonary diameter to aortic artery diameter was significantly correlated with estimated systolic pulmonary artery pressure(r=-0.35, P<0.01).Age ≥75 years, FEV1%predicted value<50% and the presence of PH increased the likelihood of exacerbations of COPD over three years[beta value (0.459-1.211), OR value (3.643-5.722), 95%CI (1.463-8.904), mean P<0.01]. Conclusions: COPD patients with high likelihood of PH assessed by echocardiography were older, had a lower BMI, and presented with a worse health status compared to those with low to moderate likelihood of PH. The presence of PH assessed by echocardiography was related to future COPD exacerbations in COPD patients, and emphysema was closely related to PH assessed by echocardiography.

Characteristics of chronic obstructive pulmonary disease patients with robust progression of emphysematous change

Emphysema is a major pathological change in chronic obstructive pulmonary disease (COPD). However, the annual changes in the progression of emphysematous have not been investigated. We aimed to determine possible baseline predicting factors of the change in emphysematous progression in a subgroup of COPD patients who demonstrated rapid progression. In this observational study, we analyzed patients with COPD who were followed up by computed tomography (CT) at least two times over a 3-year period (n = 217). We divided the annual change in the low attenuation area percentage (LAA%) into quartiles and defined a rapid progression group (n = 54) and a non-progression group (n = 163). Predictors of future changes in emphysematous progression differed from predictors of high LAA% at baseline. On multivariate logistic regression analysis, low blood eosinophilic count (odds ratio [OR], 3.22; P = 0.04) and having osteoporosis (OR, 2.13; P = 0.03) were related to rapid changes in emphysematous progression. There was no difference in baseline nutritional parameters, but nutritional parameters deteriorated in parallel with changes in emphysematous progression. Herein, we clarified the predictors of changes in emphysematous progression and concomitant deterioration of nutritional status in COPD patients.

Independent Associations of Tumor Necrosis Factor-Alpha and Interleukin-1 Beta With Radiographic Emphysema in People Living With HIV.

BackgroundPeople living with HIV (PLWH) have increased systemic inflammation, and inflammation has been suggested to contribute to the pathogenesis of emphysema. We investigated whether elevated cytokine concentrations (interleukin (IL)-1β, IL-1 receptor antagonist (IL-1RA), IL-2, IL-4, IL-6, IL-10, IL-17A, tumor necrosis factor-alpha (TNFα), interferon-gamma (IFNγ), soluble CD14 (sCD14) and sCD163 were independently associated with radiographic emphysema in PLWH.MethodsWe included PLWH from the Copenhagen Comorbidity in HIV Infection (COCOMO) Study without hepatitis B and C co-infection and with a plasma sample and a chest computed tomography scan available. Emphysema plus trace emphysema was defined as the percentage of low attenuation area under −950 Houndsfield Unit (%LAA-950) using a cut-off at 5%. Cytokine concentrations were measured by ELISA or Luminex immunoassays. An elevated cytokine concentration was defined as above the 75th percentile.ResultsOf 783 PLWH, 147 (18.8%) had emphysema. PLWH were predominantly male (86.0%) and 743 (94.9%) had undetectable viral replication. PLWH with emphysema had higher concentrations of TNFα (median (IQR): 8.2 (6.4-9.8) versus 7.1 (5.7-8.6) pg/ml, p<0.001), IL-1β (0.21 (0.1-0.4) versus 0.17 (0.1-0.3) pg/ml, p=0.004) and IL-6 (3.6 (2.6-4.9) versus 3.1 (2.0-4.3) pg/ml, p=0.023) than PLWH without. In a logistic regression model adjusted for age, sex, ethnicity, smoking status, BMI and CD4 nadir, elevated TNFα (adjusted odds ratio (aOR): 1.78 [95%CI: 1.14-2.76], p=0.011) and IL-1β (aOR: 1.81 [95%CI: 1.16-2.81], p=0.009) were independently associated with emphysema. The association between IL-1β and emphysema was modified by smoking (p-interaction=0.020) with a more pronounced association in never-smokers (aOR: 4.53 [95%CI: 2.05-9.98], p<0.001).ConclusionTwo markers of systemic inflammation, TNFα and IL-1β, were independently associated with emphysema in PLWH and may contribute to the pathogenesis of emphysema. Importantly, the effect of IL-1β seems to be mediated through pathways that are independent of excessive smoking.Clinical Trial Registrationclinicaltrials.gov, identifier NCT02382822.

Three-Dimensional CT for Quantification of Longitudinal Lung and Pneumonia Variations in COVID-19 Patients.

Objectives: Visual chest CT is subjective with interobserver variability. We aimed to quantify the dynamic changes of lung and pneumonia on three-dimensional CT (3D-CT) images in coronavirus disease 2019 (COVID-19) patients during hospitalization.Methods: A total of 110 laboratory-confirmed COVID-19 patients who underwent chest CT from January 3 to February 29, 2020 were retrospectively reviewed. Pneumonia lesions were classified as four stages: early, progressive, peak, and absorption stages on chest CT. A computer-aided diagnostic (CAD) system calculated the total lung volume (TLV), the percentage of low attenuation areas (LAA%), the volume of pneumonia, the volume of ground-glass opacities (GGO), the volume of consolidation plus the GGO/consolidation ratio. The CT score was visually assessed by radiologists. Comparisons of lung and pneumonia parameters among the four stages were performed by one-way ANOVA with post-hoc tests. The relationship between the CT score and the volume of pneumonia, and between LAA% and the volume of pneumonia in four stages was assessed by Spearman's rank correlation analysis.Results: A total of 534 chest CT scans were performed with a median interval of 4 days. TLV, LAA%, and the GGO/consolidation ratio were significantly decreased, while the volume of pneumonia, GGO, and consolidation were significantly increased in the progressive and peak stages (for all, P < 0.05). The CT score was significantly correlated with the pneumonia volume in the four stages (r = 0.731, 0.761, 0.715, and 0.669, respectively, P < 0.001).Conclusion: 3D-CT could be used as a useful quantification method in monitoring the dynamic changes of COVID-19 pneumonia.

&lt;p&gt;Relationship Between Proteinase with a Disintegrin and a Metalloproteinase Domain-9 (ADAM9), Inflammation, Airway Remodeling, and Emphysema in COPD Patients&lt;/p&gt;

Background and ObjectiveThe link between ADAM9 and airway remodeling and emphysema severity in COPD patients has not been elucidated. Here, we investigated the relationship between ADAM9 levels in sputum and airway epithelium and the clinical characteristics of COPD patients.MethodsA sputum cohort and a lung tissue cohort were included in the study. Pulmonary function and computed tomography data were analyzed in COPD patients, non-COPD smokers, and non-smokers. Soluble ADAM9 and interleukin 8 (IL-8) levels in sputum supernatants as well as surface ADAM9 expression in airway epithelium were detected. Emphysema scores were calculated by the percentage of low attenuation area (%LAA-950), and airway remodeling was measured via airway thickening and loss of airway counts.ResultsBoth soluble ADAM9 levels in sputum and relative surface ADAM9 expression in airway epithelium were increased in COPD patients. Sputum ADAM9 levels were negatively correlated with forced expiratory volume in 1 s of predicted (FEV1% of predicted) and positively correlated with sputum IL-8 levels, but not with CT measured emphysema nor airway remodeling. The ADAM9 expression in airway epithelia was positively correlated with %LAA-950 and airway wall thickening parameters (wall area percentage, WA%; the square root of the wall area in a standard airway with a 10 mm internal perimeter, Pi-10), while negatively correlated with airway counts derived from the 4th to 9th bronchial generations.ConclusionAirway ADAM9 levels in sputum and airway epithelium were both elevated in COPD patients compared to non-COPD controls. Sputum ADAM9 seemed to be associated with inflammatory responses in COPD, while epithelial ADAM9 was more correlated with emphysema and airway remodeling.

3D Oxygen-Enhanced MRI at 3T MR System: Comparison With Thin-Section CT of Quantitative Capability for Pulmonary Functional Loss Assessment and Clinical Stage Classification of COPD in Smokers.

Oxygen (O2 )-enhanced MRI is mainly performed by a 2D sequence using 1.5T MR systems but trying to be obtained by a 3D sequence using a 3T MR system. To compare the capability of 3D O2 -enhanced MRI and that of thin-section computed tomography (CT) for pulmonary functional loss assessment and clinical stage classification of chronic obstructive pulmonary disease (COPD) in smokers. Prospective study. Fifty six smokers were included. 3T, 3D O2 -enhanced MRIs were performed with a 3D T1 -weighted fast field echo pulse sequence using the multiple flip angles. Smokers were classified into four stages ("Without COPD," "Mild COPD," "Moderate COPD," "Severe or very severe COPD"). Maps of regional changes in T1 values were generated from O2 -enhanced MR data. Regions of interest (ROIs) were then placed over the lung on all slices and averaged to determine mean T1 value change (ΔT1 ). Quantitative CT used the percentage of low attenuation areas within the entire lung (LAA%). ΔT1 and LAA% were correlated with pulmonary functional parameters, and compared for four stages using Tukey's Honestly Significant Difference test. Discrimination analyses were performed and McNemar's test was used for a comparison of the accuracy of the indexes. There were significantly higher correlations between ΔT1 and pulmonary functional parameters (-0.83 ≤ r ≤ -0.71, P < 0.05) than between LAA% and the same pulmonary functional parameters (-0.76 ≤ r ≤ -0.69, P < 0.05). ΔT1 and LAA% of the "Mild COPD" and "Moderate COPD" groups were significantly different from those of the "Severe or Very Severe COPD" group (P < 0.05). Discriminatory accuracy of ΔT1 (62.5%) and ΔT1 with LAA% (67.9%) was significantly greater than that of LAA% (48.2%, P < 0.05). Compared with thin-section CT, 3D O2 -enhanced MRI has a similar capability for pulmonary functional assessment but better potential for clinical stage classification in smokers. 2 TECHNICAL EFFICACY STAGE: 1.

Correlation between quantitative multi-detector computed tomography lung analysis and pulmonary function tests in chronic obstructive pulmonary disease patients

BackgroundChronic obstructive pulmonary disease [COPD] is a very common disease in developing as well as in developed countries. Using CT has a growing interest to give a phenotypic classification helping the clinical characterization of COPD patients. So, the aim of the present study was to evaluate whether there was a significant correlation between quantitative computed tomography lung analysis and pulmonary function tests in chronic obstructive pulmonary disease patients.ResultsThe study included 50 male patients with a mean age of 62.82 years ± 8.65 years standard deviation [SD]. Significant correlation was found between the pulmonary function tests [FEV1 and FEV1/FVC ratio], and all parameters of quantitative assessment with – 950 HU [the percentage of low-attenuation areas (% LAA)]. Pulmonary function tests according to GOLD [Global Initiative for Chronic Obstructive Lung Disease] guidelines revealed that 4% had normal pulmonary function, 8% had mild obstructive defect, 32% had moderate obstructive defect, 26% had severe obstructive defect, and 30% had very severe obstructive defect.ConclusionAutomated CT densitometry defining the emphysema severity was significantly correlated with the parameters of pulmonary function tests and providing an alternative, quick, simple, non-invasive study for evaluation of emphysema severity. Its main importance was the determination of the extent and distribution of affected emphysematous parts of the lungs especially for selecting the patients suitable for the lung volume reduction surgery.

Small airway immunoglobulin A profile in emphysema-predominant chronic obstructive pulmonary disease.

BackgroundDue to airway remodeling and emphysematous destruction in the lung, the two classical clinical phenotypes of chronic obstructive pulmonary disease (COPD) are emphysema and bronchiolitis. The present study was designed to investigate the levels of small airway immunoglobulin A (IgA) in COPD with “emphysema phenotype.” The study also evaluated the associations between the small airway IgA levels and the severity of disease by the extent of emphysema versus airflow limitation.MethodsThirty patients (20 with COPD and ten healthy smokers) undergoing lung resection surgery for a solitary peripheral nodule were included. The study was conducted from January 2015 to December 2018 in the Shanxi Dayi Hospital. The presence of small airway IgA expression was determined in the lung by immunohistochemistry. In vivo, Wistar rats were exposed to silica by intratracheal instillation. Rats were sacrificed at 15 and 30 days after exposure of silica (n = 10 for each group). We also evaluated airway IgA from rats.ResultsSmall airway secretory IgA (sIgA), dimeric IgA (dIgA), and dIgA/sIgA of Global Initiative for Chronic Obstructive Lung Disease grade 1–2 COPD patients showed no difference compared with smoking control subjects (5.15 ± 1.53 vs. 6.03 ± 0.85; 1.94 ± 0.66 vs. 1.67 ± 0.04; 41.69 ± 21.02 vs. 28.44 ± 9.45, all P > 0.05). dIgA/sIgA level in the lung of COPD patients with emphysema showed higher levels than that of COPD patients without emphysema (51.89 ± 24.81 vs. 31.49 ± 9.28, P = 0.03). The percentage of low-attenuation area below 950 Hounsfield units was positively correlated with dIgA/sIgA levels (r = 0.45, P = 0.047), but not associated with the severity of disease by spirometric measurements (forced expiratory volume in the first second %pred, P > 0.05). Likewise, in the rat study, significant differences in sIgA, dIgA, dIgA/sIgA, mean linear intercept, mean alveoli number, and mean airway thickness of bronchioles (VV airway, all P < 0.01) were only observed between control rats and those exposed for 30 days. However, in the group exposed for 15 days, although the VV airway was higher than that in normal rats (27.61 ± 2.26 vs. 20.39 ± 1.99, P < 0.01), there were no significant differences in IgA and emphysema parameters between the two groups (all P > 0.05).ConclusionAirway IgA concentrations in mild and moderate COPD patients are directly associated with the severity of COPD with “emphysema phenotype” preceding severe airway limitation. This finding suggests that small airway IgA might play an important role in the pathophysiology of COPD, especially emphysema phenotype.

Quantitative analysis of computed tomography of the lungs in patients with lymphangioleiomyomatosis treated with sirolimus

ObjectivesWe aimed to study sirolimus-related lung parenchymal changes by quantitative analysis of computed tomography (CT) of the lungs in patients with lymphangioleiomyomatosis (LAM). MethodsWe studied 20 participants from the Multicenter Lymphangioleiomyomatosis Sirolimus Trial for Safety study, who had undergone both thin-section CT scans and pulmonary function tests at baseline, 12, and 24 months. Quantitative CT parameters such as CT-derived total lung capacity, percentage of low attenuation area (LAA%), lung density histogram, fractal property of low attenuation area, and airway dimensions were analyzed, and correlations were conducted between the longitudinal change in each quantitative CT measurement and changes in pulmonary function were examined. Among 20 participants, pre-trial (n = 8) and post-trial (n = 16) CT data were also analyzed to deduce pathophysiologic implications of the serial changes in CT parameters during trial periods. ResultsFEV1 significantly increased from baseline to 24 months (slope 3.71 ± 1.50 ml/month) whereas FVC didn't during sirolimus therapy. Strikingly, LAA%, and skewness and kurtosis of density histogram significantly increased from baseline to 24 months, while mean and mode CT values significantly decreased from baseline to 24 months. Statistically significant positive correlations were found between ΔFEV1 and Δskewness (r = 0.465, p = 0.045). Taking the changes in lung density during pre-trial period into consideration, sirolimus decreases the area of -800 to -750 Housefield unit (HU) density and inhibits the decrease of -950 to -800 HU area during treatment, then producing the increased LAA% during the trial and post-trial periods. Given few sirolimus-related changes in airway dimensions, possible changes in lung mechanics may have contributed to increased FEV1. ConclusionOur study suggests that the lung density histogram parameters, kurtosis, and skewness, may be useful as indicators of the efficacy of sirolimus.

Luminal Plugging on Chest CT Scan: Association With Lung Function, Quality of Life, and COPD Clinical Phenotypes

Mucous exudates occluding the lumen of small airways are associated with reduced lung function and mortality in subjects with COPD; however, luminal plugs in large airways have not been widely studied. We aimed to examine the associations of chest CT scan-identified luminal plugging with lung function, health-related quality of life, and COPD phenotypes. We randomly selected 100 smokers without COPD and 400 smokers with COPD from the COPDGene Study. Luminal plugging was visually identified on inspiratory CT scans at baseline and 5-year follow-up. The relationships of luminal plugging to FEV1, St. George's Respiratory Questionnaire (SGRQ) score, emphysema on CT scan (defined as the percentage of low attenuation area< 950 Hounsfield units [%LAA-950]), and chronic bronchitis were assessed using linear and logistic multivariable analyses. Overall, 111 subjects (22%) had luminal plugging. The prevalence of luminal plugging was higher in subjects with COPD than those without COPD (25%vs10%, respectively; P= .001). In subjects with COPD, luminal plugging was significantly associated with FEV1 %predicted (estimate,-6.1; SE, 2.1; P= .004) and SGRQ score (estimate, 4.9; SE, 2.4; P= .04) in adjusted models. Although luminal plugging was associated with log %LAA-950 (estimate, 0.43; SE, 0.16; P= .007), its relationship with chronic bronchitis did not reach statistical significance (P= .07). Seventy-three percent of subjects with COPD with luminal plugging at baseline had it 5 years later. In subjects with COPD, CT-identified luminal plugging is associated with airflow obstruction, worse health-related quality of life, and emphysema phenotype. This imaging feature may supplement the current clinical assessment of chronic mucus hypersecretion in COPD.