Abstract
Background: The purpose of this study was to evaluate the
quantitative diagnostic performance of computed tomography (CT)
densitometry in pediatric bronchiolitis obliterans (BO) patients.
Methods: A retrospective chart review was performed on 109
children under age 18 who underwent 3D chest CT from March 2019 to March
2021. We measured the mean lung density (MLD) and calculated the
difference of MLD (MLDD) in expiratory and inspiratory phase, the
expiratory to inspiratory ratio of mean lung density (E/I MLD), and the
relative volume percentage of lung density at 50 HU intervals (E600 to
E950). We calculated the sensitivity, specificity, and diagnostic
accuracy of lung density indices for the diagnosis of BO.
Results: A total of 81 patients, 51 BO patients and 30
controls, were included in this study (mean age: 12.7 vs 11.4 years).
Expiratory (EXP) MLD, MLDD, E/I MLD, and E900 were all statistically
significantly worse in the BO group. Multivariate logistic regression
analysis showed that MLDD (odds ratio [OR] = 0.98, p
< .001), E/I MLD (OR = 1.39, p < .001), and E850 (OR
= 1.54, p = 0.003) were significant densitometry parameters for BO
diagnosis. In ROC analysis, E900 (cut-off 1.4%; AUC = 0.920), E/I MLD
(cut-off 0.87; AUC = 0.887), and MLDD (cut-off 109 HU; AUC = 0.867)
showed high accuracy in diagnosis of BO.
Conclusion: The quantification of lung density with chest CT
complements the diagnosis by providing additional indications of
expiratory airflow limitation in pediatric BO patients.