Area Of Small Pulmonary Vessels Research Articles

Quantitative Assessment Characteristics of Small Pulmonary Vessel Remodelling in Populations at High Risk for COPD and Smokers Using Low-Dose CT.

To explore the morphological alterations in small pulmonary vessels in populations at high risk for chronic obstructive pulmonary disease (COPD) and smokers based on multiple computed tomography (CT) quantitative parameters. A total of 1969 Three Major Chest Diseases Screening Study participants with available demographic data and smoking history who underwent low-dose chest CT from 2018 to 2020 were included. All subjects were divided into normal, high risk for COPD, and COPD groups according to their pulmonary function test (PFT) results. Furthermore, the three groups were further subdivided into never-smokers, current smokers, and former smokers subgroups according to their smoking history. Quantitative parameters, such as the number, area at 6 mm~24 mm subpleura and volume of small pulmonary vessels, were extracted by computer software. Differences in small pulmonary vessel parameters among the groups were compared using two-way ANOVA. The number, area at 6 mm~24 mm subpleura and volume of small pulmonary vessels in the group at high risk for COPD were lower than those in the normal group (P<0.05). The number, area at 6 mm~24 mm subpleura and volume of small pulmonary vessels in the COPD group were higher than those in the normal group (P<0.05). The number, area of small pulmonary vessels at 6 mm~12 mm subpleura in current smokers with high risk for COPD were higher than those in former smokers with high risk for COPD (P<0.05). The number, area, and volume of small pulmonary vessels in populations at high risk for COPD were decreased. Smoking cessation may impede structural changes in small pulmonary vessels in populations at high risk for COPD.

Prognostic Significance of Small Pulmonary Vessel Alteration Measured by Chest Computed Tomography in Connective Tissue Diseases With Pulmonary Arterial Hypertension.

Pulmonary arterial hypertension (PAH) is characterized by structural alterations of pulmonary vessels. Few studies have explored the clinical significance of quantitative assessment of pulmonary small vessels by chest computed tomography (CT). Our aim was to assess whether the prognosis of connective tissue diseases (CTD)-PAH patients could be assessed through pulmonary small vessels measured by chest CT. In all, 42 CTD-PAH patients diagnosed based on right heart catheterization were retrospectively investigated. All patients underwent a chest CT within 1 month before and after right heart catheterization examination. Main pulmonary artery (MPA) and the cross-sectional area of small pulmonary vessels <5 mm2 as a percentage of total lung area (%CSA <5) were measured. The primary endpoint was a composite clinical worsening endpoint. After a median follow-up time of 30.5 (interquartile range, 8.5 to 45.25) months, endpoint events occurred in 16 (38.1%) patients after 19.5 (interquartile range, 10.0 to 45.5) months. Cox univariate proportional hazard analysis showed that pulmonary vascular resistance, MPA diameter, and %CSA <5 were associated with the end point. A combination of MPA diameter and %CSA < 5 was the independent risk factor for the prognosis (hazard ratio, 2.180 [95% confidence interval, 1.405-3.383], P=0.001). Kaplan-Meier analysis showed that CTD-PAH patients satisfying %CSA < 5 of <0.382 and MPA >36.75 mm had the highest risk of experiencing the endpoint. Among the pulmonary vascular indicators measured by chest CT, in addition to MPA, %CSA < 5 may be a potential independent risk factor for poor long-term prognosis in Chinese CTD-PAH patients.

Use of small pulmonary vascular alterations to identify different types of pulmonary hypertension: a quantitative computed tomography analysis.

The morphological alterations of small pulmonary vessels measured by computed tomography (CT) is increasingly used in evaluation of suspected pulmonary hypertension (PH). To investigate the significance alterations of quantitative assessment of small pulmonary vessels on chest CT in distinguishing different types of PH and their severity. We retrospectively analyzed a dataset of 120 healthy controls (HCs) and 91 PH patients, including 34 patients with connective tissue diseases-related PH (CTD-PH), 26 patients with idiopathic pulmonary arterial hypertension (iPAH), and 31 patients with chronic obstructive pulmonary disease-related PH (COPD-PH). The CTD-PH patients were divided into mild to moderate PH (CTD-LM-PH) group (n = 17) and severe PH (CTD-S-PH) group (n = 17). A total of 53 CTD patients without PH (CTD-nPH) were enrolled for comparison with the CTD-PH. We measured the cross-sectional area of small pulmonary vessels < 5 mm2 (%CSA<5) and between 5-10 mm2 (%CSA5-10) as a percentage of total lung area among the populations included above and compared %CSA in different types of PH groups and HCs group. The mean pulmonary arterial pressure (mPAP) was measured by right heart catheterization. The %CSA5-10 of COPD-PH, CTD-PH, and iPAH patients increased (0.21±0.09, 0.49±0.20 and 0.61±0.20, p < 0.02) sequentially, while the %CSA<5 of CTD-PH, iPAH, and COPD-PH patients decreased (0.79±0.65, 0.65±0.38 and 0.52±0.27, p < 0.05) sequentially. The %CSA5-10 was significantly higher in CTD-S-PH patients than CTD-LM-PH patients and CTD-nPH patients (0.51±0.21, 0.31±0.15 and 0.28±0.12, p < 0.01). The %CSA5-10 was positively correlated with mPAP in the CTD-PH group. The quantitative parameters %CSA<5 and %CSA5-10 assessed by chest CT are useful for distinguishing different types of PH. In addition, the %CSA5-10 can provide information for identification of CTD-PH severity.

Evaluation of the cross-sectional area of small pulmonary vessels in the diagnosis of chronic obstructive pulmonary disease by quantitative computed tomography: A case-control study.

Patients with chronic obstructive pulmonary disease (COPD) have a reduced cross-sectional area (CSA) of small pulmonary vessels and decreased pulmonary function test (PFT) indexes. This study investigated the value of small pulmonary vessel CSA in diagnosing and evaluating the severity of COPD and its correlation with PFT.This retrospective case-control study included patients with COPD who underwent multi-slice spiral computed tomography (CT) between March 2015 and December 2018. COPD severity was graded. Patients with normal CT results were included as controls. The CSA of small pulmonary vessels at the sub-segmental (5–10 mm2) and sub-sub-segmental (<5 mm2) levels was measured. Receiver operating characteristic (ROC) curves were used to evaluate the effect of CSA for COPD risk prediction. The correlation between CSA% and PFT indexes was evaluated.There were 124 and 106 patients in the COPD and control groups, respectively. The %CSA <5 and %CSA5–10 were smaller in the COPD group than in controls (P < .05). The %CSA <5 in each subgroup stratified by COPD severity was smaller than in controls (P < .05). The % CSA5–10 was significantly smaller in the moderate and severe groups than in controls (P < .05). At 0.655%CSA <5 cut-off, the ROC area under the curve (AUC) was 0.765. For %CSA5–10, a 0.565 cut-off led to an AUC of 0.752. Both %CSA <5 and %CSA5–10 were positively correlated with all PFT indexes (r = 0.180–0.462, all P < .05).CSA was positively correlated with PFT. Analysis of small pulmonary vessel CSA based on CT images contributes to diagnosing and assessing the severity of COPD.

Quantitative measurement of cross-sectional area of small pulmonary vessels in pulmonary embolism

Objective: The relationship between the percentage of total cross-sectional area (% CSA) of small pulmonary vessels for the lung area in CTPA and the right ventricular function parameters in patients with pulmonary embolism. Methods: 120 patients with PE and 72 healthy subjects underwent CTPA and all date were analyzed Retrospectively. The main pulmonary artery diameter (mPA), the ratio of the main pulmonary artery to the ascending aorta diameter (rPA), right ventricle/left ventricular diameter ratio (RVd/LVd), and the pulmonary artery obstruction index (PAOI) in the PE group were measured for all subjects. The %CSA<5 mm(2) and 5-10 mm(2) for the lung area (%CSA(<5) and %CSA(5-10)) of small pulmonary vessels were measured with Image J image-processing program. According to the risk stratification of the 2018 Guidelines for the Diagnosis and Treatment of Pulmonary Thromboembolism, PE patients were divided into medium-high risk group (RVd/LVd>1) and low-risk group (RVd/LVd<1). The indexes of PE in medium-high risk group, low risk group and control group were compared by ANOVA, and the indexes among PE subgroups were compared by independent sample t-test. Spearman correlation method was used to analyze the correlation between %CSA and right ventricular function parameters of PE patients. Results: %CSA(<5) of medium-high risk group, low-risk group and control group were (0.69±0.19)%, (0.95±0.27)% and (0.99±0.30)% (P<0.01), respectively. %CSA(5-10) of three groups were (0.63±0.15)%, (0.84±0.18)%, and (0.85±0.25)% (P<0.01), respectively; %CSA(<5) and %CSA(5-10) of medium-high risk group were lower than low-risk group and control group. %CSA(<5) and %CSA(5-10) in PE patients correlated negatively with RVd/LVd, rPA and mPA (r=-0.545/-0.549, -0.235/-0.352, -0.239/-0.298, respectively). Conclusion: The measurement of % CSA<(5) and %CSA (5-10) in CTPA were negatively correlated with RVd/LVd in patients with pulmonary embolism, which indirectly reflected the severity of the pulmonary embolism patients.

Quantitative computed tomography measurement of cross-sectional area of small pulmonary vessels in asthmatic patients.

Background:Cross-sectional area (CSA) for small pulmonary vessels is considered a parameter of pulmonary vessel alterations in patients with chronic obstructive pulmonary disease. This study was to evaluate the correlation of CSA with airflow obstruction parameters in asthma. Furthermore, we aimed to measure the difference in vascular alteration between asthma phenotypes and evaluate its relation with cytokine levels.Methods:We consecutively enrolled 20 adult asthmatic patients (13 women: age range, 26–80 years) and 20 healthy controls (8 women: age range, 23–61 years) from Peking University Third Hospital. Total CSA <5 mm2 (CSA<5) was measured with 64-slice spiral computed tomography, and the percentage CSA <5 for the lung area (%CSA<5) was calculated. Data were corrected for body surface area to obtain sixth-generation airway luminal diameter (LDcor), luminal area (Aicor), and airway wall thickness, and airway wall area percentage (WA%) was calculated. Enzyme-linked immunosorbent assay was used to detect the expression of leptin, total immunoglobulin E, periostin, and transforming growth factor β1 in serum and matrix metalloproteinase 9 in induced sputum supernatant of asthmatic patients. The differences in %CSA<5 between subgroups were assessed by independent samples Student's t test, and Spearman correlation analysis was used to analyze the correlation of %CSA<5 with clinical indexes and inflammatory cytokine levels.Results:Patients with asthma and controls did not differ in %CSA<5. In asthma patients, %CSA<5 was lower with initial onset age ≤12 years old, airflow restriction and uncontrolled Global Initiative for Asthma classification (all P < 0.05). Moreover, it was positively correlated with forced vital capacity ratio in 1 s (FEV1)/forced expiratory volume ratio, FEV1%, LDcor, Aicor, and serum leptin level (all P < 0.05) and negatively with total lung WA% (P = 0.007).Conclusions:%CSA<5 of pulmonary small vessels was well correlated with airflow limitation indexes and sixth-generation airway parameters. It has certain significance in predicting the clinical control of asthma.

Adverse effect of smoking on cross-sectional area of small pulmonary vessel and arterial stiffness in healthy smokers without COPD.

Because it induces systemic inflammation, smoking is a risk factor of atherosclerosis and pulmonary hypertension. The brachial-ankle pulse wave velocity (baPWV) and cross-sectional area (CSA) of small pulmonary vessels can be useful markers to assess early changes of arterial stiffness and pulmonary vascular alteration in smokers. This study aimed to explore association between the CSA of small pulmonary vessel and arterial stiffness in healthy male smokers. We enrolled 90 male non-smokers and 90 male smokers (age: 51.5±9.7 years and 52.1±7.9 years, respectively). All subjects underwent chest computed tomography (CT), pulmonary function test and baPWV measurement. We evaluated the total CSAs less than 5 mm2 using ImageJ software and divided by the total lung area (%CSA<5). We compared the association between baPWV and %CSA<5 in two groups as well as correlations among the amount of smoking, baPWV and %CSA<5. Multiple linear regression analysis using %CSA<5 as the dependent variable was also performed. The mean baPWV and mean %CSA<5 were significantly different between the smokers and non-smokers. The pack-years was significantly correlated with %CSA<5 (r=-0.631, P<0.001) and baPWV (r=0.534, P<0.001) in smokers. In multiple linear regression analysis, age, pack-years, FEV1 /FVC and baPWV were associated with %CSA<5, regardless of body mass index, blood pressure and heart rate. There is a dose-response relationship between cigarette smoking and the CSA of small pulmonary vessels and arterial stiffness, respectively. Arterial stiffness, age, pack-years and mild airflow impairment are independent predictors of small pulmonary vascular destruction in smokers.

Transfer coefficients better reflect emphysematous changes than carbon monoxide diffusing capacity in obstructive lung diseases.

The overlap between asthma and chronic obstructive pulmonary disease (COPD) has attracted the interest of pulmonary physicians; thus, measurement of carbon monoxide diffusion capacity (DLco) and/or transfer coefficients (Kco, DLco/VA) may become valuable in clinical settings. How these parameters behave in chronic obstructive lung diseases is poorly understood. We predicted that Kco might more accurately reflect emphysematous changes in the lungs than DLco. We examined DLco and Kco in nonsmokers and smokers with asthma and investigated their relationships with forced expiratory volume in 1 s (%FEV1) by group. We then selected nonsmokers (As-NS) and smokers with asthma (As-Sm) in both groups and those with COPD while controlling for the degree of airflow limitation across groups. Emphysema volumes [%lung attenuation volume (%LAV)] and percentage of cross-sectional area of small pulmonary vessels <5 mm2 (%CSA<5) were measured by computed tomography. In As-NS, %Kco was significantly higher when FEV1% was reduced, but such a correlation was not seen in As-Sm. %Kco successfully differentiated among the three groups when airflow limitation levels were matched. However, %DLc, was significantly reduced only in patients with COPD. Both %LAV and %CSA<5 were better correlated with %Kco than with %DLco. There was discordance between %DLCO and %Kco in As-Sm, which was not seen in As-NS. Overall, %Kco better reflects emphysematous changes in obstructive lung diseases than %DLco. NEW & NOTEWORTHY Despite differing behaviors of %Kco and %DLco in several diseases, the characteristics of these parameters have not been fully examined in smokers with asthma. Here, we demonstrated that %Kco is a more sensitive parameter of pathophysiology, better reflecting emphysematous changes in chronic obstructive lung diseases overall, compared with %DLco. Thus, more precise interpretations of %DLco and %Kco may provide clues for understanding the pathophysiology of obstructive lung diseases.

Heterogeneity in pulmonary emphysema: Analysis of CT attenuation using Gaussian mixture model.

PurposeTo utilize Gaussian mixture model (GMM) for the quantification of chronic obstructive pulmonary disease (COPD) and to evaluate the combined use of multiple types of quantification.Materials and methodsEighty-seven patients (67 men, 20 women; age, 67.4 ± 11.0 years) who had undergone computed tomography (CT) and pulmonary function test (PFT) were included. The heterogeneity of CT attenuation in emphysema (HC) was obtained by analyzing a distribution of CT attenuation with GMM. The percentages of low-attenuation volume in the lungs (LAV), wall area of bronchi (WA), and the cross-sectional area of small pulmonary vessels (CSA) were also calculated. The relationships between COPD quantifications and the PFT results were evaluated by Pearson’s correlation coefficients and through linear models, with the best models selected using Akaike information criterion (AIC).ResultsThe correlation coefficients with FEV1 were as follows: LAV, −0.505; HC, −0.277; CSA, 0.384; WA, –0.196. The correlation coefficients with FEV1/FVC were: LAV, –0.640; HC, –0.136; CSA, 0.288; WA, –0.131. For predicting FEV1, the smallest AIC values were obtained in the model with LAV, HC, CSA, and WA. For predicting FEV1/FVC, the smallest AIC values were obtained in the model with LAV and HC. In both models, the coefficient of HC was statistically significant (P-values = 0.000880 and 0.0441 for FEV1 and FEV1/FVC, respectively).ConclusionGMM was applied to COPD quantification. The results of this study show that COPD severity was associated with HC. In addition, it is shown that the combined use of multiple types of quantification made the evaluation of COPD severity more reliable.

Performance of computed tomography-derived pulmonary vasculature metrics in the diagnosis and haemodynamic assessment of pulmonary arterial hypertension

BackgroundFew studies have addressed the value of combining computed tomography-derived pulmonary vasculature metrics for the diagnosis and haemodynamic evaluation of pulmonary arterial hypertension (PAH). Materials and methodsWe measured three computed tomography parameters for the pulmonary artery, peripheral vessels, and pulmonary veins: the ratio of the diameter of the pulmonary artery to the aorta (PA/Ao), the cross-sectional area of small pulmonary vessels <5mm2 as a percentage of total lung area (%CSA<5), and the diameter of the right inferior pulmonary vein (PVD). The measured quantities were compared between patients with PAH (n=45) and control subjects (n=56), and their diagnostic performance and associations with PAH-related clinical indices, including right heart catheterization measurements, were examined. ResultsPA/Ao and %CSA<5 were significantly higher in patients with PAH than in controls. Receiver-operating characteristic curve analysis for ability to diagnose PAH showed a high area under the curve (AUC) for PA/Ao (0.95) and modest AUCs for %CSA<5 (0.75) and PVD (0.56). PA/Ao correlated positively with mean pulmonary arterial pressure and PVD correlated negatively with pulmonary vascular resistance. The %CSA<5 correlated negatively with mean pulmonary arterial pressure and pulmonary vascular resistance and positively with cardiac index. Notably, the PA/Ao and PVD values divided by %CSA<5 correlated better with right heart catheterization indices than the non-divided values. ConclusionPA/Ao, %CSA<5, and PVD are useful non-invasive pulmonary vasculature metrics, both alone and in combination, for diagnosis and haemodynamic assessment of PAH.

The Relationship of Bone Mineral Density in Men with Chronic Obstructive Pulmonary Disease Classified According to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) Combined Chronic Obstructive Pulmonary Disease (COPD) Assessment System.

Objective Osteoporosis, which is now recognized as a major comorbidity of chronic obstructive pulmonary disease (COPD), must be diagnosed by appropriate methods. The aims of this study were to clarify the relationships between bone mineral density (BMD) and COPD-related clinical variables and to explore the association of BMD with the updated Global Initiative for Chronic Obstructive Lung Disease (GOLD) classification in men. Methods We enrolled 50 Japanese men with clinically stable COPD who underwent dual-energy X-ray absorptiometry (DEXA), pulmonary function testing, and computerized tomography (CT) and who had completed a questionnaire (COPD assessment test [CAT]). We determined the association between the T-score and other tested parameters and compared the BMD of patients in each GOLD category. Results Twenty-three of the 50 patients (46.0%) were diagnosed with osteopenia, and 7 (14.0%) were diagnosed with osteoporosis. The BMD findings were significantly correlated with the CAT score, forced expiratory volume in 1 second percentage predicted (FEV1% predicted), low attenuation volume percentage (LAV%), and percentage of cross-sectional area of small pulmonary vessels (%CSA) on CT images. Notably, the median T-score of the GOLD category D participants was significantly lower than that of the participants in each of the other categories (A [-0.98], B [-1.06], C [-1.05], and D [-2.19], p<0.05). Conclusion Reduced BMD was associated with airflow limitation, extent of radiographic findings, and a poor quality of life (QOL) in patients with COPD. The BMD of GOLD category D patients was the lowest of all of the patients evaluated, and category D patients may benefit from active intervention for osteoporosis.

Evaluation of the severity of chronic obstructive pulmonary disease with the percentage of the total cross-sectional area of small pulmonary vessels for the lung area in multi-slice CT

Objective To investigate the role of the percentage of the total cross-sectional area of small pulmonary vessels for the lung area (%CSA) from multi-slice CT (MSCT) in evaluating the severity of chronic obstructive pulmonary disease (COPD). Methods One hundred and sixty-six COPD patients and 166 normal subjects underwent chest MSCT scans and all data were analyzed retrospectively. COPD patients underwent pulmonary function tests (PFT), including forced expiratory volume in one second (FEV1%) and FEV1/forced vital capacity (FEV1/FVC), and were classified into mild (n=32), moderate (n=65), severe (n= 69) groups according to pulmonary function results, respectively. The %CSA less than 5 mm2 and 5–10 mm2 for the lung area (% CSA<5 and % CSA5-10) of small pulmonary vessels were measured with Image J image-processing program. Comparison of %CSA<5 and %CSA5-10 between the COPD and control groups was perfomred using t test, and the comparison between the 3 COPD subgroups and control group were carried out using ANOVA test. The correlation between % CSA and PFT was evaluated by the Spearman rank correlation test. The sensitivity and specificity of % CSA to diagnose COPD and the best cutoff were calculated from areas under the ROC curves. Results % CSA 0.05). FEV1% and FEV1/FVC in COPD patients were (60.38±15.52)% and 57.95±22.27. %CSA<5 in COPD patients correlated positively with both FEV1% and FEV1/FVC (r=0.609 and 0.721, P<0.01, respectively). %CSA5-10 in COPD patients correlated positively with both FEV1% and FEV1/FVC (r=0.271 and 0.288, P<0.01, respectively). Conclusion The measurement of %CSA<5 and %CSA5-10 in MSCT images correlated with PFTs and %CSA<5, which may play an important role in evaluating the severity of COPD. Key words: Pulmonary disease, chronic obstructive; Respiratory function tests; Tomography, X-ray computed

Optimal Minimum Number of CT Slices Required to Measure Cross Sectional Areas of Small Pulmonary Vessels

The cross-sectional area (CSA) of small pulmonary vessels can be quantified by CT, which is a reliable method of evaluating vascular alterations in such vessels. However, the optimal number of slices required for accurate quantitation remains unknown. We evaluated relationships among all slices at 10-mm interval and all slices at 3-cm interval, 6-cm interval, and 3-slices and found the closest correlation (0.939) between all slices at 10-mm intervals and 3-cm intervals. Thus, all slices at 3-cm intervals are suitable for accurately measuring CSA.

Abstract 13796: Quantitative Measurement of Cross sectional Area of Small Pulmonary Vessels Using High-resolution Ct in Chronic Thromboembolic Pulmonary Hypertension

Background: It is generally recognized that there is narrowing and diminution of the small vessels on pulmonary angiography in patients with chronic thromboembolic pulmonary hypertension (CTEPH). Previous studies have shown that these vascular alterations could be assessed by the cross-sectional area of small pulmonary vessels (CSA) on high-resolution CT (HRCT) in patients with COPD. However, it is unknown whether there is a correlation between CSA and hemodynamics in patients with CTEPH. Aims: We retrospectively evaluated the relationship between the CSA on HRCT and hemodynamics measured by right heart catheterization (RHC). Materials and Methods: 61 patients (61±12 yrs, 13 male) with proven CTEPH underwent non-enhanced 64-slice HRCT (Aquilion ONE, Toshiba) and RHC. The HRCT images with 0.5 mm section thickness and 10 mm spacing were selected from all of the CT images in each patient. Using a semiautomatic image-processing program (Image J), CSA less than 5mm2 and 5-10mm2 , and total lung area were measured, and the percentage of the total CSA less than 5mm2 and 5-10mm2 for the lung area (%CSA&lt;5 and %CSA5-10, respectively) were calculated. The correlations of %CSA with hemodynamics measured by RHC were evaluated. Results: Mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR) from RHC were 41±9 mmHg and 8.3±3.0 Wood Units, respectively. %CSA&lt;5 and %CSA5-10 were 1.095±0.166% and 0.447±0.093 %, respectively. The correlation coefficients of %CSA&lt;5 with mPAP and PVR were -0.45 (P&lt;0.001) and -0.64 (P&lt;0.001), respectively. The correlation coefficients of %CSA5-10 with mPAP and PVR were -0.20 (P=0.1) and -0.38 (P=0.002), respectively. Conclusions: This study suggests that %CSA&lt;5 measured on HRCT is inversely correlated with PVR and can be used to evaluate hemodynamics in CTEPH subjects.

Usefulness of Coronal Reconstruction CT Images for Quantitative Evaluation of the Cross-Sectional Area of Small Pulmonary Vessels

Cross-sectional area <5 mm(2) (CSA<5) is a computed tomography (CT) metric that has been used for the evaluation of pulmonary vessel alterations and perfusion. CSA<5 is calculated from three axial slices; thus, whether CSA<5 represents the small pulmonary vessel alterations in the whole lung remains unclear. The purpose of this study was to compare the measurements of CSA<5 using three axial slices and coronal reconstructed slices in the relationship between the measured CSA<5 and pulmonary perfusion measured using lung perfusion scintigraphy. This study comprised 28 subjects who underwent both noncontrast CT and lung perfusion scintigraphy. The present study measured CSA<5 using both three axial CT images and coronal reconstruction images and then obtained the percentage of the CSA in right lung to that in whole lung (R/W-CSA<5). Using anteroposterior and posteroanterior projections on technetium-99m macroaggregated albumin (MAA) lung perfusion scintigraphy, we obtained right and total lung counts and calculated the percentage of the right to whole lung counts (R/W-MAA). The correlations of the R/W-CSA<5 calculated using three axial slices (R/W-CSA(A)x<5) and coronal reconstructed slices (R/W-CSA(COR)<5) with R/W-MAA were evaluated using Spearman rank correlation analysis. Both R/W-CSA(Ax)<5 and R/W-CSA(COR)<5 were significantly correlated with R/W-MAA; however, the correlation coefficient with R/W-CSA(COR)<5 (ρ = 0.842, P < .0001) was greater than that with R/W-CSA(Ax)<5 (ρ = 0.631, P = .0004). Coronal reconstruction images appear suitable for quantitative measurement of CSA of small pulmonary vessels.

Quantitative assessment of cross-sectional area of small pulmonary vessels in patients with COPD using inspiratory and expiratory MDCT

ObjectivesStructural and functional changes in pulmonary vessels are prevalent at the initial stages of chronic obstructive pulmonary disease (COPD). These vascular alterations can be assessed using cross-sectional area (CSA) of small pulmonary vessels. However, neither in non-COPD smokers nor in COPD patients it has been defined whether the structural changes of pulmonary vessels detected by paired inspiratory and expiratory CT scans are associated with emphysematous changes. We quantified the CSA and low attenuation area (LAA) and evaluated the changes in these parameters in the inspiratory and expiratory phases. Materials and methodsFifty consecutive non-COPD smokers and COPD patients were subjected to multi detector-row CT and the percentage of vessels with a CSA less than 5mm2 as well as the percentage LAA for total lung area (%CSA<5, %LAA, respectively) were calculated. ResultsThe %CSA<5 correlated negatively with %LAA. The %CSA<5 was lower in COPD patients with emphysema as compared with non-COPD smokers and COPD patients with or without mild emphysema. In addition, the %CSA<5 was lower in the no/mild emphysema subgroup as compared with non-COPD smokers. The respiratory phase change of %CSA<5 in COPD patients was greater than that in non-COPD smokers. ConclusionThe percentage of small pulmonary vessels decreased as emphysematous changes increase, and this decrease was observed even in patients with no/mild emphysema. Furthermore, respiratory phase changes in CSA were higher in COPD patients than in non-COPD smokers.

Quantitative Assessment of Cross-sectional Area of Small Pulmonary Vessels in Chronic Obstructive Pulmonary Disease Using Inspiratory and Expiratory MDCT

PURPOSE: Alteration in pulmonary vessel structure and function are highly prevalent in patient with chronic obstructive pulmonary disease (COPD). Pulmonary hypertension caused by vascular abnormalities is one of the factors associated with survival in COPD patients. Recently, it was reported these change observed in early stage of COPD. However, relationship of structural change and severity of COPD has not been assessed. We purposed to quantify cross-sectional area of small pulmonary vessels (CSA) and low attenuation area (LAA) in COPD using inspiratory and expiratory multi-detecter row CT (MDCT) scans and analyze the relationship between airflow limitation and these parameters.

The Relationship between Small Pulmonary Vascular Alteration and Aortic Atherosclerosis in Chronic Obstructive Pulmonary Disease: Quantitative CT Analysis

The relationship between chronic obstructive pulmonary disease (COPD) and atherosclerosis has been suggested; this association may relate to systemic inflammation and endothelial dysfunction, which can lead to alteration of small pulmonary vessels. The relationship between atherosclerosis and small pulmonary vessel alteration, however, has not been assessed in COPD patients. We tested the hypothesis that the severity of thoracic aortic calcification measured by computed tomography (CT) would be associated with the total cross-sectional area of small pulmonary vessels (CSA) on CT images. The study was approved by the institutional review board and was Health Insurance Portability and Accountability Act-compliant. Informed consent was waived. For 51 COPD patients enrolled in the National Heart, Lung, and Blood Institute Lung Tissue Research Consortium, we calculated the percentage of total CSAs of less than 5 mm² for the total lung area (%CSA<5). Thoracic aortic calcification, quantified by modified Agatston score, was measured. The correlations between thoracic aortic calcification score and %CSA<5, pulmonary function, and extent of emphysema were evaluated. Multiple linear regression analysis using aortic calcification score as the dependent outcome was also performed. The %CSA<5 had a significant negative correlation with the thoracic aortic calcification score (r = -0.566, P < .0001). Multiple linear regression analysis showed significant correlation between the aortic calcification score and %CSA<5 (P < .0001) independent of age, pack-years, extent of emphysema, and FEV1%. Atherosclerosis, assessed by aortic calcification, is associated with the small pulmonary vascular alteration in COPD. Systemic inflammation and endothelial dysfunction may cause the close relationship between atherosclerosis and small pulmonary vessel alteration.

Quantitative CT Measurement of Cross-sectional Area of Small Pulmonary Vessel in COPD: Correlations with Emphysema and Airflow Limitation

Pulmonary vascular alteration is one of the characteristic features of chronic obstructive pulmonary disease (COPD). Recent studies suggest that vascular alteration is closely related to endothelial dysfunction and may be further influenced by emphysema. However, the relationship between morphological alteration of small pulmonary vessels and the extent of emphysema has not been assessed in vivo. The objectives of this study are: to evaluate the correlation of total cross-sectional area (CSA) of small pulmonary vessels with the extent of emphysema and airflow obstruction using CT scans and to assess the difference of total CSA between COPD phenotypes. We measured CSA less than 5 mm(2) and 5-10 mm(2), and calculated the percentage of the total CSA for the lung area (%CSA < 5, and %CSA5-10, respectively) using CT scans in 191 subjects. The extent of emphysema (%LAA-950) was calculated, and the correlations of %CSA < 5 and %CSA5-10 with %LAA-950 and results of pulmonary function tests (PFTs) were evaluated. The differences in %CSA between COPD phenotypes were also assessed. The %CSA < 5 had significant negative correlations with %LAA-950 (r = -0.83, P < .0001). There was a weak but statistically significant correlation of %CSA < 5 with forced expiratory volume in 1 second (FEV1)% predicted (r = 0.29, P < .0001) and FEV1/forced vital capacity (r = 0.45, P < .0001). A %CSA 5-10 had weak correlations with %LAA-950 and results of PFTs. %CSA < 5 was significantly higher in bronchitis phenotype than in the emphysema phenotype (P < .0001). Total CSA of small pulmonary vessels at sub-subsegmental levels strongly correlates with the extent of emphysema (%LAA-950) and reflects differences between COPD phenotypes.