Quantitative CT analysis in patients with pulmonary emphysema: is lung function influenced by concomitant unspecific pulmonary fibrosis?

• Published in: International journal of chronic obstructive pulmonary disease Vol. 14; pp. 1583 - 1593
• Main Authors: Feldhaus, Felix W, Theilig, Dorothea Cornelia, Hubner, Ralf-Harto, Kuhnigk, Jan-Martin, Neumann, Konrad, Doellinger, Felix
• Format: Journal Article
• Language: English
• Published: New Zealand Dove Medical Press Ltd 01-01-2019; Dove; Dove Medical Press
• Subjects: Aged; Chronic obstructive pulmonary disease; COPD; Correlation of Data; CPFE; Emphysema; Female; Humans; Lung - diagnostic imaging; Lung - physiopathology; Lung diseases; Lung Volume Measurements - methods; Male; Medical imaging; Middle Aged; Original Research; Patient Acuity; Patients; Pneumonia; Pulmonary Disease, Chronic Obstructive - complications; Pulmonary Disease, Chronic Obstructive - diagnosis; Pulmonary Disease, Chronic Obstructive - physiopathology; pulmonary emphysema; Pulmonary Emphysema - diagnostic imaging; Pulmonary Emphysema - etiology; Pulmonary fibrosis; Pulmonary Fibrosis - diagnostic imaging; Pulmonary Fibrosis - etiology; quantitative CT; Respiratory Function Tests - methods; Severity of Illness Index; Software; Tomography, X-Ray Computed - methods; Tomography, X-Ray Computed - statistics & numerical data; quantitative CT; CPFE; pulmonary emphysema; pulmonary fibrosis; COPD
• ISSN: 1178-2005; 1176-9106; 1178-2005
• DOI: 10.2147/COPD.S204007

Quantitative analysis of CT scans has proven to be a reproducible technique, which might help to understand the pathophysiology of chronic obstructive pulmonary disease (COPD) and combined pulmonary fibrosis and emphysema. The aim of this retrospective study was to find out if the lung function of patients with COPD with Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages III or IV and pulmonary emphysema is measurably influenced by high attenuation areas as a correlate of concomitant unspecific fibrotic changes of lung parenchyma.
Eighty-eight patients with COPD GOLD stage III or IV underwent CT and pulmonary function tests. Quantitative CT analysis was performed to determine low attenuation volume (LAV) and high attenuation volume (HAV), which are considered to be equivalents of fibrotic (HAV) and emphysematous (LAV) changes of lung parenchyma. Both parameters were determined for the whole lung, as well as peripheral and central lung areas only. Multivariate regression analysis was used to correlate HAV with different parameters of lung function.
Unlike LAV, HAV did not show significant correlation with parameters of lung function. Even in patients with a relatively high HAV of more than 10%, in contrast to HAV (
=0.786) only LAV showed a significantly negative correlation with forced expiratory volume in 1 second (r=-0.309, R
=0.096,
=0.003). A severe decrease of DLCO% was associated with both larger HAV (
=0.045) and larger LAV (
=0.001). Residual volume and FVC were not influenced by LAV or HAV.
In patients with COPD GOLD stage III-IV, emphysematous changes of lung parenchyma seem to have such a strong influence on lung function, which is a possible effect of concomitant unspecific fibrosis is overwhelmed.