Rheumatic connective tissue diseases are commonly complicated with interstitial lung disease that is responsive to anti-inflammatory therapy and generally carries a better prognosis if diagnosed early.
The aim of our study was to determine the diagnostic value of lung ultrasound in the detection of interstitial pulmonary fibrosis in patients with rheumatic connective tissue diseases.
Sixty two subjects with rheumatic connective tissue diseases diagnosed according to the American College of Rheumatology criteria for each disease were enrolled (4 males, 58 females; mean age: 47.5 ± 8.9 years; range: 21 to 76 years). All subjects underwent high resolution computed tomography followed by transthoracic ultrasound for comet tail sign detection in order to predict the degree of lung fibrosis. The modified transthoracic ultrasound assessment was performed at 10 intercostal spaces level. The Warrick score was calculated according standard high-resolution chest computed tomography images that were evaluated independently from each other by a radiologist and a pulmonary disease specialist.
A significantly positive correlation between transthoracic ultrasound and the severity of pulmonary involvement (Spearman's correlation coefficient = 0.68, p < 0.001), (LR = 70.4, p < 0.001) was found. When compared with standard high-resolution chest computed tomography as the gold standard method, the sensitivity, specificity, and positive and negative predictive value of transthoracic ultrasound was 69.9%, 84.8%, 93.5%, and 49.7%, respectively.
Our study showed that the modified transthoracic ultrasound comet tails scoring system could be useful in the assessment of the pulmonary involvement in patients with rheumatic connective tissue diseases.