Comparative assessment of expiratory ground-glass lesion changes across pulmonary disease subtypes on Quantitative CT at Ngoc Minh clinic, Vietnam
Main Article Content
Abstract
Background:
Quantitative Computed Tomography (QCT) enables sensitive detection of parenchymal abnormalities in diffuse lung diseases. However, comparative analysis of expiratory ground-glass (GG) lesion changes among various disease groups remains underexplored.
Objective:
To evaluate and compare the percentage change in ground-glass lesions between inspiratory and expiratory phases across four key pulmonary disease groups: Air Trapping +, Emphysema, Interstitial Lung Disease (ILD – fibrotic and non-fibrotic), and Normal lungs.
Methods:
Forty-six patients undergoing paired inspiratory-expiratory chest CT at Ngoc Minh Clinic were retrospectively analyzed. QCT-derived GG lesion percentages were extracted for both lungs. Patients were categorized into four major groups based on QCT findings. The percentage change in GG lesion area between inspiratory and expiratory scans was computed for both lungs separately. Kruskal-Wallis tests and a Linear Mixed Effects Model (LME) were used to assess between-group and within-subject (lung-side) differences.
Results:
The Air Trapping + group exhibited the highest mean increase in GG lesions during expiration in both lungs (Right: 100.4%; Left: 81.6%), significantly higher than other groups (p < 0.01). In contrast, the ILD, Emphysema, and Normal groups demonstrated modest changes (Right: 35.7–42.6%; Left: 39.3–53.5%). Repeated measures analysis using LME confirmed a significant within-subject effect (greater GG change in right lungs, p = 0.024) and a significant group-by-lung-side interaction, particularly in the Normal group (p = 0.048). Boxplots visually emphasized these trends.
Conclusion:
Expiratory GG lesion changes differ significantly across lung disease phenotypes, with Air Trapping + cases showing the most pronounced increases. This pattern supports the utility of paired inspiratory-expiratory QCT in detecting occult small airway disease. The side-dominant pattern observed also suggests potential regional ventilation heterogeneity. These findings underscore the clinical relevance of expiratory CT in functional phenotyping of lung disease.
Keywords
Quantitative computer tomography, Aitr trapping, Emphysema, Interstitial lung disease, Ground-glass lesion
Article Details
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