Correlation of HRCT Thorax and PFT Parameters in Diagnosing and Grading COPD Severity

Abstract

Purpose: To determine the link between high-resolution computed tomography (HRCT) parameters and pulmonary function test (PFT) indices in COPD patients and to find imaging signals that indicate disease severity.

Materials and Methods: Spirometry and HRCT thorax were performed on 130 clinically diagnosed COPD patients in this cross-sectional investigation. Quantitative HRCT parameters evaluated: anterior junction line length, sterno-aortic distance, thoracic cage ratio, TCSA/Ht², and tracheal index. Goddard's score, peribronchial thickening, bronchiectasis, and inhomogeneous attenuation were qualitative. We conducted Pearson and Spearman correlation studies between HRCT parameters and PFT indicators (FEV₁, FVC, and FEV₁/FVC).

Results: Significant negative correlations were observed between FEV₁ and structural parameters such as sterno-aortic distance ((r = –0.492, p < 0.001), thoracic cage ratio (r = –0.432, p < 0.001), and TCSA/Ht² (r = –0.501, p < 0.00). Goddard’s score and inhomogeneous attenuation showed the strongest inverse correlations with both FEV₁ (ρ = –0.704, –0.637) and FVC (ρ = –0.658, –0.638). The FEV₁/FVC ratio showed weaker but significant positive correlations with some HRCT features, notably inhomogeneous attenuation (ρ = 0.288, p = 0.001). Tracheal index showed no significant correlation with FEV₁ or FVC.

Conclusion: HRCT parameters, particularly TCSA/Ht² and Goddard’s scoring, correlate strongly with pulmonary function, indicating their utility as imaging biomarkers for disease severity in COPD. HRCT can complement spirometry in assessing structural and functional impairment, enabling a more comprehensive evaluation of COPD.