Association of the Severity of Emphysema Based on HRCT Scoring System with Clinical Profile and Pulmonary Function Test Parameters: A Cross-sectional Study

Abstract

Introduction: Chronic Obstructive Pulmonary Disease (COPD) is commonly observed in middle aged and elderly individuals. Dyspnoea, with or without expectoration, or isolated dyspnoea, is the primary respiratory symptom. Clinical signs, symptoms, and Pulmonary Function Tests (PFTs) are non specific. Chest radiography poorly correlates with disease severity and extent compared to clinical and functional impairment. High-Resolution Computed Tomography (HRCT) has been widely adopted to detect, characterise, and quantify emphysema. HRCT scoring is a useful radiological method for assessing emphysema severity in COPD patients and can provide prognostic information. Aim: To assess the severity of emphysema based on the HRCT scoring system and its association with clinical profile and PFTs. Materials and Methods: The present cross-sectional observational study was conducted in the Department of Radiodiagnosis at Atal Bihari Vajpayee Institute of Medical Sciences and Ram Manohar Lohia Hospital, New Delhi, India. It included 30 clinically diagnosed COPD patients referred for HRCT lung scans from November 1,2018, to March 31, 2020. HRCT assessment was performed at three levels: carina, 5 cm above carina, and 5 cm below carina. The severity of lung parenchyma was evaluated using the “Sakai Scoring Method.” The emphysema score was correlated with clinical profile (duration of illness, COPD severity, smoking, and pack-years smoked) and PFT parameters (FEV1, FEV1/FVC). Results: The mean age of the cases was 60±9.44 years. There was a strong positive linear correlation between the duration of illness (r=0.67, p=0.001) and COPD severity (r=0.452, p=0.02) with HRCT emphysema score. Significant correlation was found between HRCT emphysema score and pack-years smoked (r=0.558, p=0.004). The emphysema score showed an inverse correlation with FEV1 (r= -0.56, p=0.002) but no correlation with Forced Expiratory Volume 1 / Forced Vital Capacity (FEV1/FVC) (r= -0.16, p=0.430). Conclusion: The HRCT semi-quantitative scoring system is valuable for the initial assessment of disease severity and is significantly correlated with the PFT parameter FEV1.