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.

Transthoracic ultrasonography in patients with interstitial lung disease.

BACKGROUND: Transthoracic ultrasonography (TUS) is suggested as a noninvasive, radiation-free method for the assessment of interstitial lung disease (ILD). This study was designed to study TUS features of ILD. Furthermore, possible correlations of these features with parameters of spirometry, arterial blood gas (ABG) analysis and 6-min walk test (6MWT) were assessed. MATERIALS AND METHODS: Fifty patients with ILD were diagnosed based on history, examination, chest X-ray/high-resolution computed tomography, and spirometry. Each patient underwent 6MWT, ABG analysis, and TUS. TUS was also performed on 20 healthy volunteering controls. RESULTS: The TUS features among patients were B pattern in 40 patients (80.0%, P < 0.001), decreased lung sliding in 22 patients (44.0%, P < 0.001), pleural line thickening in 28 patients (56.0%, P < 0.001), pleural line irregularity in 39 patients (78.0%, P < 0.001) and subpleural changes in 22 patients (44.0%, P < 0.01). Increasing pleural line thickness was inversely correlated with forced vital capacity (FVC) percent predicted (r = -0.345, P < 0.05), pO2 (r = -0.335, P < 0.01), SpO2 at rest (r = -0.444, P < 0.01), 6-min walk distance (6MWD) (r = -0.554, P < 0.001) and distance-saturation product (DSP) (r = -0.572, P < 0.001). Increasing distance between B lines also correlated inversely with FVC percent predicted (r = -0.278), pO2 (r = -0.207), SpO2 at rest (r = -0.170), 6MWD (r = -0.209), and DSP (r = -0.214); however these correlations were not statistically significant (P > 0.05). CONCLUSION: TUS seems to be a useful imaging method for the diagnosis of ILD. It can be used to estimate the severity of ILD. It is simple, bedside, cost-effective, and radiation-free. It may be especially useful in the follow up of patients in low resource settings, pregnant females, and bed-ridden or unstable patients who cannot be shifted to radiology suite.