Abstract
OBJECTIVE: Interstitial lung disease (ILD) is a frequent complication of systemic sclerosis (SSc), and ILD screening, characterization, and monitoring are important for therapeutic decision-making and prognostication. Lung ultrasonography (US) is a potential alternative imaging modality for ILD detection. In this study, our objective was to develop and test a novel lung US examination technique and interpretation criteria for detecting SSc-ILD. METHODS: Lung US acquisition was performed by collecting short US movies at 14 lung positions. Lung US interpretation criteria for SSc-ILD detection focused on visualized pleural changes. To assess the performance of our methodology for SSc-ILD detection, we prospectively enrolled SSc patients with high-resolution computed tomography (HRCT) imaging within 3 months of lung US. Lung US examinations were scored independently by 2 blinded readers (1 ultrasonographer and 1 nonultrasonographer). The sensitivity and specificity for SSc-ILD detection were assessed, and agreement was measured with Cohen's kappa statistic. RESULTS: To test the performance of our lung US acquisition technique and interpretation criteria, 20 SSc patients were evaluated by lung US (278 lung zones) and HRCT. HRCT confirmed ILD in 9 patients (45%). Lung US was positive for SSc-ILD in 11 patients (55%) with a sensitivity of 100% and specificity of 82% versus HRCT, with perfect agreement between the 2 readers (κ = 1). Analysis by individual lung zones found excellent agreement between readers, with 93.8% concordance and κ = 0.82. CONCLUSION: We developed a novel lung US examination technique and interpretation criteria that are highly sensitive and specific for SSc-ILD detection in an SSc cohort, affording perfect agreement between ultrasonographer and nonultrasonographer readers.