Performance of semi-quantitative lung ultrasound in the assessment of disease severity in interstitial lung disease

BACKGROUND: Accurate staging of disease severity and its serial monitoring thus is central to the effective management protocols of interstitial lung disease (ILD). PURPOSE: The aim is to evaluate the effectiveness of semi-quantitative parameters of lung ultrasound (LUS) in patients of ILD as a means of staging disease severity. MATERIALS AND METHODS: LUS of 47 patients of ILD and 20 age-matched controls was performed, and findings such as B-line distance, pleural thickening, subpleural changes, decreased lung sliding, and fragmented pleural lining were charted, and an LUS score was done using these parameters. Findings were compared with the Modified Medical Research Council (MMRC) dyspnea grade and spirometry parameters. RESULTS: The presence of B-lines and fragmented pleural lining were the most common findings observed in patients of ILD. Predicted forced vital capacity (FVC) and predicted forced expiratory volume in 1 s (FEV1) showed a good correlation with all the LUS parameters. B-line distance was the most significant LUS parameter to predict the variability in predicted FEVI, FVC, and MMRC dyspnea score. LUS severity score also showed good negative correlation with predicted FEV1 (r = -0.674, P < 0.001) and predicted FVC (r = -0.65, P < 0.001). LUS severity score of 4 or more predicted MMRC dyspnea score of > 3 with 82% sensitivity and 70% specificity. CONCLUSION: Semi-quantitative LUS score and B-line distance can provide a simple but effective estimate of disease severity in ILD.