Asbestos-related lesions of the pleura: Parietal plaques compared to diffuse thickening studied with chest roentgenography, computed tomography, lung function, and gas exchange

1990 ◽  
Vol 18 (6) ◽  
pp. 627-639 ◽  
Author(s):  
Gunnar Hillerdal ◽  
Per Malmberg ◽  
Anders Hemmingsson
Keyword(s):  
Computed Tomography ◽  
Lung Function ◽  
Gas Exchange

scholarly journals Mechanisms of gas exchange response to lung volume reduction surgery in severe emphysema

2011 ◽  
Vol 110 (4) ◽  
pp. 1036-1045 ◽  
Author(s):  
George Cremona ◽  
Joan A. Barbara ◽  
Teresa Melgosa ◽  
Lorenzo Appendini ◽  
Josep Roca ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chronic Obstructive Pulmonary Disease ◽  
Lung Function ◽  
Gas Exchange ◽  
Pulmonary Disease ◽  
Lung Volume ◽  
Chronic Obstructive ◽  
Lung Volume Reduction Surgery ◽  
Lung Volume Reduction ◽  
Obstructive Pulmonary Disease

Lung volume reduction surgery (LVRS) improves lung function, respiratory symptoms, and exercise tolerance in selected patients with chronic obstructive pulmonary disease, who have heterogeneous emphysema. However, the reported effects of LVRS on gas exchange are variable, even when lung function is improved. To clarify how LVRS affects gas exchange in chronic obstructive pulmonary disease, 23 patients were studied before LVRS, 14 of whom were again studied afterwards. We performed measurements of lung mechanics, pulmonary hemodynamics, and ventilation-perfusion (V̇a/Q̇) inequality using the multiple inert-gas elimination technique. LVRS improved arterial Po2 (PaO2) by a mean of 6 Torr ( P = 0.04), with no significant effect on arterial Pco2 (PaCO2), but with great variability in both. Lung mechanical properties improved considerably more than did gas exchange. Post-LVRS PaO2 depended mostly on its pre-LVRS value, whereas improvement in PaO2 was explained mostly by improved V̇a/Q̇ inequality, with lesser contributions from both increased ventilation and higher mixed venous Po2. However, no index of lung mechanical properties correlated with PaO2. Conversely, post-LVRS PaCO2 bore no relationship to its pre-LVRS value, whereas changes in PaCO2 were tightly related ( r2 = 0.96) to variables, reflecting decrease in static lung hyperinflation (intrinsic positive end-expiratory pressure and residual volume/total lung capacity) and increase in airflow potential (tidal volume and maximal inspiratory pressure), but not to V̇a/Q̇ distribution changes. Individual gas exchange responses to LVRS vary greatly, but can be explained by changes in combinations of determining variables that are different for oxygen and carbon dioxide.

Respiration in man during metabolic alkalosis

1962 ◽  
Vol 17 (1) ◽  
pp. 33-37 ◽  
Author(s):  
Daniel J. Stone
Keyword(s):  
Carbon Dioxide ◽  
Steady State ◽  
Lung Function ◽  
Gas Exchange ◽  
Metabolic Alkalosis ◽  
Time Lag ◽  
Respiratory Compensation ◽  
Arterial Ph ◽  
Oral Sodium ◽  
Ventilation Response

A steady state metabolic alkalosis was induced in two subjects over a period of several days utilizing oral sodium bicarbonate in dosages of 50 g/day. The purpose of inducing steady state metabolic alkalosis was to study the effects of such a state on the respiratory center responses to inspired gas mixtures, containing carbon dioxide, and to contrast these results with the control studies. The experiment was so designed that the arterial pH in both subjects tended to return toward normal in the presence of significant increases in blood bicarbonate. Repeated study of ventilation responses with room air and 4% and 6% carbon dioxide in inspired air revealed a definite and significant decrease in ventilation response to carbon dioxide during the periods of steady state alkalosis as compared to the control periods. Normal responses returned after some time lag. A consistent rise in paCOCO2 occurred with alkalosis, thus demonstrating respiratory compensation. In neither subject was total lung function or gas exchange affected by the alkalosis. The experiment was confirmed on several occasions with reproducible results. Note: (With the Research Assistance of Mary Di Lieto) Submitted on May 22, 1961

scholarly journals Computed tomography-derived area and density of pectoralis muscle associated disease severity and longitudinal changes in chronic obstructive pulmonary disease: a case control study

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
So Hyeon Bak ◽  
Sung Ok Kwon ◽  
Seon-Sook Han ◽  
Woo Jin Kim
Keyword(s):  
Computed Tomography ◽  
Chronic Obstructive Pulmonary Disease ◽  
Lung Function ◽  
Pulmonary Function ◽  
Pulmonary Disease ◽  
Disease Severity ◽  
Chronic Obstructive ◽  
Pectoralis Muscle ◽  
Obstructive Pulmonary Disease ◽  
Longitudinal Changes

Abstract Background Muscle wasting is associated with prognosis in patients with chronic obstructive pulmonary disease (COPD). The cross-sectional area of skeletal muscles on computed tomography (CT) could serve as a method to evaluate body composition. The present study aimed to determine the ability of CT-derived pectoralis muscle area (PMA) and pectoralis muscle density (PMD) to determine the severity of COPD and change in longitudinal pulmonary function in patients with COPD. Methods A total of 293 participants were enrolled in this study, a whom 222 had undergone at least two spirometry measurements within 3 years after baseline data acquisition. PMA and PMD were measured from a single axial slice of chest CT above the aortic arch at baseline. The emphysema index and bronchial wall thickness were quantitatively assessed in all scans. The generalized linear model was used to determine the correlation between PMA and PMD measurements and pulmonary function. Results PMA and PMD were significantly associated with baseline lung function and the severity of emphysema (P < 0.05). Patients with the lowest PMA and PMD exhibited significantly more severe airflow obstruction (β = − 0.06; 95% confidence interval: − 0.09 to − 0.03]. PMA was statistically associated with COPD assessment test (CAT) score (P = 0.033). However, PMD did not exhibit statistically significant correlation with either CAT scores or modified Medical Research Council scores (P > 0.05). Furthermore, neither PMA nor PMD were associated with changes in forced expiratory volume in 1 s over a 3-year periods. Conclusions CT-derived features of the pectoralis muscle may be helpful in predicting disease severity in patients with COPD, but are not necessarily associated with longitudinal changes in lung function.

scholarly journals Damaged lung gas exchange function of discharged COVID-19 patients detected by hyperpolarized 129Xe MRI

2020 ◽  
Vol 7 (1) ◽  
pp. eabc8180
Author(s):  
Haidong Li ◽  
Xiuchao Zhao ◽  
Yujin Wang ◽  
Xin Lou ◽  
Shizhen Chen ◽  
...  
Keyword(s):  
Lung Function ◽  
Gas Exchange ◽  
Recovery Process ◽  
Blood Exchange ◽  
Structural Abnormalities ◽  
Hyperpolarized 129Xe ◽  
Magnetic Resonance Imaging Mri ◽  
And Function ◽  
Exchange Function ◽  
The Impact

The recovery process of COVID-19 patients is unclear. Some recovered patients complain of continued shortness of breath. Vasculopathy has been reported in COVID-19, stressing the importance of probing pulmonary microstructure and function at the alveolar-capillary interface. While computed tomography (CT) detects structural abnormalities, little is known about the impact of disease on lung function. 129Xe magnetic resonance imaging (MRI) is a technique uniquely capable of assessing ventilation, microstructure, and gas exchange. Using 129Xe MRI, we found that COVID-19 patients show a higher rate of ventilation defects (5.9% versus 3.7%), unchanged microstructure, and longer gas-blood exchange time (43.5 ms versus 32.5 ms) compared with healthy individuals. These findings suggest that regional ventilation and alveolar airspace dimensions are relatively normal around the time of discharge, while gas-blood exchange function is diminished. This study establishes the feasibility of localized lung function measurements in COVID-19 patients and their potential usefulness as a supplement to structural imaging.

scholarly journals Synchrotron-based dynamic computed tomography of tissue motion for regional lung function measurement

2012 ◽  
Vol 9 (74) ◽  
pp. 2213-2224 ◽  
Author(s):  
Stephen Dubsky ◽  
Stuart B. Hooper ◽  
Karen K. W. Siu ◽  
Andreas Fouras
Keyword(s):  
Computed Tomography ◽  
Lung Function ◽  
Ct Scanning ◽  
Bronchial Tree ◽  
Dynamic Computed Tomography ◽  
Lung Inflation ◽  
Regional Dynamics ◽  
Lung Expansion ◽  
Regional Lung

During breathing, lung inflation is a dynamic process involving a balance of mechanical factors, including trans-pulmonary pressure gradients, tissue compliance and airway resistance. Current techniques lack the capacity for dynamic measurement of ventilation in vivo at sufficient spatial and temporal resolution to allow the spatio-temporal patterns of ventilation to be precisely defined. As a result, little is known of the regional dynamics of lung inflation, in either health or disease. Using fast synchrotron-based imaging (up to 60 frames s −1 ), we have combined dynamic computed tomography (CT) with cross-correlation velocimetry to measure regional time constants and expansion within the mammalian lung in vivo . Additionally, our new technique provides estimation of the airflow distribution throughout the bronchial tree during the ventilation cycle. Measurements of lung expansion and airflow in mice and rabbit pups are shown to agree with independent measures. The ability to measure lung function at a regional level will provide invaluable information for studies into normal and pathological lung dynamics, and may provide new pathways for diagnosis of regional lung diseases. Although proof-of-concept data were acquired on a synchrotron, the methodology developed potentially lends itself to clinical CT scanning and therefore offers translational research opportunities.

scholarly journals Computed tomography patterns predict clinical course of idiopathic pulmonary fibrosis

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Byoung Soo Kwon ◽  
Jooae Choe ◽  
Kyung Hyun Do ◽  
Hee Sang Hwang ◽  
Eun Jin Chae ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Lung Function ◽  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Exercise Capacity ◽  
Clinical Course ◽  
Usual Interstitial Pneumonia ◽  
The Other ◽  
Hrct Patterns

Abstract Background A new clinical guideline for idiopathic pulmonary fibrosis (IPF) uses high-resolution computed tomography (HRCT) patterns for diagnostic purposes. However, it is unknown how they relate to the IPF clinical course. We aimed to investigate whether HRCT patterns could be used to predict lung function changes and survival in patients with IPF. Methods Clinical data were retrospectively reviewed in 337 patients with IPF (all biopsy-proven cases). HRCT patterns were classified according to the 2018 IPF diagnostic criteria. Results The median follow-up was 46.9 months. The mean age was 62.5 years, and 74.2% were men. Among the HRCT patterns, usual interstitial pneumonia (UIP), probable UIP, indeterminate for UIP, and an alternative diagnosis were identified in 163 (48.4%), 110 (32.6%), 33 (9.8%), and 31 (9.2%) patients, respectively. The indeterminate for UIP group showed higher lung function and exercise capacity and better prognosis than the other groups. They also had a lesser decline in lung function than the other groups during follow-up. In the multivariate Cox analysis, which was adjusted by age, smoking status, lung function, exercise capacity, and use of antifibrotic agents, indeterminate for UIP pattern was found to be an independent prognostic factor (hazard ratio 0.559, 95% confidence interval 0.335–0.933, P = 0.026). However, the probable UIP group had similar lung function changes and prognosis when compared the UIP group. Conclusions Our results suggest that indeterminate for UIP pattern on HRCT may predict a more favorable clinical course in patients with IPF, supporting the validity of the new IPF diagnostic guidelines.

scholarly journals Comparative analysis of density histograms and visual scores in incremental and volumetric high-resolution computed tomography of the chest in idiopathic pulmonary fibrosis patients

2020 ◽  
Author(s):  
Gaetano Rea ◽  
Marina De Martino ◽  
Annalisa Capaccio ◽  
Pasquale Dolce ◽  
Tullio Valente ◽  
...  
Keyword(s):  
Computed Tomography ◽  
High Resolution ◽  
Lung Function ◽  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Ct Scans ◽  
High Resolution Computed Tomography ◽  
Disease Extent ◽  
Single Breath ◽  
Volumetric Ct

Abstract Background Volumetric high-resolution computed tomography (HRCT) of the chest has recently replaced incremental CT in the diagnostic workup of idiopathic pulmonary fibrosis (IPF). Concomitantly, visual and quantitative scores have been proposed for disease extent assessment to ameliorate disease management. Purpose To compare the performance of density histograms (mean lung attenuation, skewness, and kurtosis) and visual scores, along with lung function correlations, in IPF patients submitted to incremental or volumetric thorax HRCT. Material and methods Clinical data and CT scans of 89 newly diagnosed and therapy-naive IPF patients were retrospectively evaluated. Results Forty-six incremental and 43 volumetric CT scans were reviewed. No differences of density histograms and visual scores estimates were found by comparing two HRCT techniques, with an optimal inter-operator agreement (concordance correlation coefficient >0.90 in all instances). Single-breath diffusing lung capacity for carbon monoxide (DLCOsb) was inversely related with the Best score (r = −00.416; p = 0.014), the Kazerooni fibrosis extent (r = −0.481; p = 0.004) and the mean lung attenuation (r = −0.382; p = 0.026), while a positive correlation was observed with skewness (r = 0.583; p = 0.001) and kurtosis (r = 0.543; p = 0.001) in the incremental HRCT sub-group. Similarly, in the volumetric CT sub-cohort, DLCOsb was significantly associated with skewness (r = 0.581; p = 0.007) and kurtosis (r = 0.549; p = 0.018). Correlations with visual scores were not confirmed. Forced vital capacity significantly related to all density indices independently on HRCT technique. Conclusions Density histograms and visual scores similarly perform in incremental and volumetric HRCT. Density quantification displays an optimal reproducibility and proves to be superior to visual scoring as more strongly correlated with lung function.

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