New Insight in The Use of Thoracic Ultrasonography in The Diagnosis of Interstitial Lung Diseases.

:-Background: The ultrasonographic evaluation of Interstitial lung diseases (ILD) depends on the appearance and the quantification of multiple B-lines; which are produced by the reflection of the ultrasonographic beams from the subpleural thickened interlobar septa on the lung surface interface. Aim:- This study was conducted to assess the usefulness of Thoracic Ultrasonography (TUS) in the diagnosis of ILD, and to assess the correlations of the ultrasonographic features with radiological and functional parameters of ILDs. Patient and method:- Forty-six patients with ILD were included in this prospective study; each patient underwent Lung Ultrasonography (LUS), Multi-Detector CT chest (MDCT), and spirometry. Results:- The ultrasonographic findings in ILD patients were B lines in 96%, pleural line irregularity in 70%, fragmentation in 26%, thickening in 91% of cases, subpleural lesions was present in 26% of cases, diminished lung sliding was in 17% of cases. Increasing the distance between B lines was negatively correlated with both ground-glass opacities and Forced Vital Capacity (FVC), and positively correlated with disease duration and reticular opacities in High-Resolution Computed Tomography (HRCT). Conclusion:- TUS can be used as a complementary imaging technique for the diagnosis of ILD besides HRCT. The B-lines distance is considered as a sign of pulmonary function deterioration and a sign of disease severity.