Aims and objectives
Lung emphysema is common in chronic obstructive pulmonary disease (COPD).
Pulmonary functional tests (PFT) are currently used for the clinical diagnosis of emphysema.
these tests show a high variability and are limited for the detection of early stage COPD.
computed tomography (CT) can be used to detect and quantify emphysema with very high accuracy.
It is hypothesized that not only the total volume but also de distribution of emphysema has an impact in the pulmonary function of the patient.
It has been demonstrated...
Methods and materials
This IRB-approved retrospective study included68 patients,
with respiratory functional tests and high-resolution CT scans (slice thickness ≤1.25 mm,
standard reconstruction kernel).
See figure 1 for a description of the patients and the emphysema characteristics.
whole lungs were segmented using a -500 HU threshold,
while emphysema was quantified using a standard threshold of -950 HU.
Then the ratio emphysema volume vs.
total lung volume was calculated as a percentage.
Central and peripheral volumes were obtained by applying a set of 3D morphological operations to the...
The correlation of DLCO/VA and total emphysema was r=-0.575 (p<0.001) (figure 3),
showing an inverse relationship between both variables.
Focusing on radial distribution,
correlations were r=-0.346 (p=0.004) and r=0.346 (p=0.004),
for central and peripheral emphysema,
respectively (figure 4),
with higher central concentration of emphysema showing worse DLCO,
and higher peripheral concentration associated to better DLCO.
The radial distribution of emphysema relates to pulmonary gas exchange.
Detailed quantitative assessment of central/peripheral emphysema distribution may have an impact on the management of diseases that affect the effective alveolar surface area.
Ju J et al.
Impact of emphysema heterogeneity on pulmonary function.
PLoS One 2014;9:e113320.
Wang Z et al.
Optimal threshold in CT quantification of emphysema.
Eur Radiol 2013;23:975-984.
Matsuoka S et al.
Quantitative CT assessment of chronic obstructive pulmonary disease.