Lung density analysis using quantitative computed tomography in children with pectus excavatum

Abstract

IntroductionTo evaluate the mean lung density in children with pectus excavatum (PE) and to assess the correlation between the cardiac rotation angle, Haller index, pulmonary function test, and lung density.Material and methodsThis retrospective study included 33 children with PE and 31 healthy controls. The densities of lung parenchyma were evaluated by quantitative computed tomography (CT). Three lung levels were determined: T4 vertebra level, T10 vertebra level, and the level of the measurement of the cardiac rotation angle. The cardiac rotation angle and the Haller index were calculated. All measurements were done by 2 radiologists, independently. Student’s t-test or the Mann-Whitney U test, intraclass correlation coefficients, Pearson or Spearman’s rank correlation coefficient, and Kruskal-Wallis test were used for statistical analysis. A p-value less than 0.05 was considered as statistically significant.ResultsAll the lung levels in the PE group had lower mean densities than healthy children, with statistical significance in the right lung at the T10 vertebra level (−818.60 ± 33.49 HU, −798.45 ± 40.24 HU; p = 0.028). There was a correlation between the cardiac rotation angle and the Haller index (ρ = 0.593; p < 0.001). There were no correlations between mean lung density and cardiac rotation angle, Haller index, and pulmonary function tests.ConclusionsThe lower mean lung densities were found in PE, especially in the right lower lobe. The parenchymal aeration should be considered independently from the severity of PE.

Quantitative CT lung volumetry and densitometry in pediatric pectus excavatum

“…Therefore, in addition to the existing CT analysis, there have been several attempts to obtain additional information on the lung parenchyma through quantitative CT. Quantitative CT measurements of the lung volume and density are sensitive and objective methods for the evaluation of lung parenchymal and structural abnormality. So far, there have only been a few reports on pediatric PE using this quantitative CT [ 5 , 7 ]. This study is meaningful in that it evaluated lung parenchymal changes in greater detail with respect to the severity of PE through quantitative CT analysis.…”

“…Sarioglu et al reported that patients with PE had decreased mean lung density [ 5 ]. Singh et al proposed a radiologic sign of the PE severity as CT finding of hyperinflation of the left lower lobe anterior basal segment [ 17 ], which was measured using local lung density in the selected area.…”

“…This approach tends to neglect the evaluation of accompanying deterioration in lung function [ 23 ]. Although pulmonary function tests are used in adults for functional evaluation [ 12 ], only one study has been conducted to evaluate the association between pulmonary function tests and quantitative CT measurements in patients with PE [ 5 ].…”

“…Recently, few studies have reported lung volume or density analysis in patients with PE using quantitative CT [ 5 – 7 ]. However, there still is a relative lack of comparative studies on PE, assessing lung parenchymal density in patients with many acquired pulmonary diseases such as chronic obstructive pulmonary disease and interstitial lung disease [ 8 – 11 ].…”