Background: Patients with systemic sclerosis (SSc) undergo chest radiographs and high-resolution computed tomography (HRCT) of the thorax both for interstitial lung disease (ILD) detection and for disease progression monitoring.
Objective: The aim of this study was to assess whether lung ultrasound (LUS) is a useful screening tool for ILD in patients with SSc in comparison with HRCT.
Methods: This was a longitudinal cohort study carried out from December 2015 to April 2016. An LUS was performed to examine B-lines in 67 consecutive patients who met the 2013 American College of Rheumatology/European League Against Rheumatism classification criteria for SSc and had a previous HRCT. B-lines were quantified and classified according to the score modified from Picano. Severity and extent of lung involvement on the HRCT were determined by means of the Warrick score.
Results: Twenty-nine patients had both abnormal HRCT (Warrick score >7) and abnormal LUS, 2 had a mild score (6-15 B-lines), and 27 had either moderate or severe scores (≥16 B-lines). Of the 38 patients with negative HRCT, 25 presented some degree of lung involvement on the LUS. Thus, LUS has a sensitivity of 100% and a specificity of 34%. Receiver operating characteristic curve analysis showed the analytic relation between the number of B-lines and the presence of ILD on the HRCT (area under the curve, 0.80; 95% confidence interval, 0.69-0.90).
Conclusions: Lung ultrasound may be a method to detect abnormal lung findings in a noninvasive manner in patients with SSc. Because of its high sensitivity, a low score almost rules out the need for an HRCT.