Air trapping in sarcoidosis on computed tomography: correlation with lung function.

Area of Science:

• Pulmonary Medicine
• Radiology
• Respiratory Diseases

Background:

• Pulmonary sarcoidosis is a multisystem granulomatous disease that can affect the lungs.
• High-resolution computed tomography (HRCT) is a key imaging modality for assessing lung involvement in sarcoidosis.
• Air trapping is a potential indicator of small airways obstruction.

Purpose of the Study:

• To document the prevalence and extent of air trapping on HRCT in pulmonary sarcoidosis patients.
• To correlate HRCT findings, particularly air trapping, with pulmonary function test (PFT) results.
• To investigate other HRCT features and their relationship with PFTs.

Main Methods:

• Twenty-one patients with pulmonary sarcoidosis underwent inspiratory and expiratory HRCT and PFTs.
• HRCT scans were evaluated for air trapping, ground-glass opacification, nodularity, septal thickening, bronchiectasis, and parenchymal distortion.
• Statistical analysis was performed to correlate HRCT features with PFT parameters.

Main Results:

• Air trapping was identified in 95% (20/21) of patients on expiratory HRCT.
• The extent of air trapping significantly correlated with increased residual volume (RV)/total lung capacity (TLC) ratio and decreased maximal mid-expiratory flow rate (25-75% VC).
• Other HRCT findings like ground-glass opacification, nodularity, septal thickening, bronchiectasis, and distortion were common but did not show significant correlations with PFTs.

Conclusions:

• Air trapping is a highly prevalent finding in pulmonary sarcoidosis.
• HRCT-detected air trapping in sarcoidosis is associated with functional evidence of small airways disease.
• HRCT is valuable for characterizing lung abnormalities and their functional impact in sarcoidosis.