Esophageal Dilatation as a Predictor of Systemic Sclerosis in Patients with Interstitial Lung Disease

To determine the predictive value of esophageal dilatation as observed in high-resolution computed tomography (HRCT) for the diagnosis of systemic sclerosis (SSc) in patients with interstitial lung disease (ILD). Our sample consisted of patients diagnosed with SSc and proven interstitial lung involvement with available HRCT exams (n = 20). Individuals with other forms of rheumatic ILD were included as a control group (n = 20). Two blinded radiologists independently reviewed the images for the presence of esophageal dilatation, measured at 3 different levels. Interobserver agreement was tested with Lin's concordance correlation coefficient (CCC). Independent t-test was used to compare maximum esophageal diameters between groups. Friedman's test was used to evaluate differences between the 3-level measurements. Receiver operating characteristic analysis was performed. There was a substantial correlation between both readers (CCC = 0.9802-0.9919). Esophageal dilatation was significantly associated with SSc (P = .0012). The optimal calculated cut-off value to differentiate SSc from other ILDs was 18.5 mm (sensitivity and specificity of 70 and 90%, respectively; area under the curve 0.819), measured 1 cm above the diaphragmatic hiatus. HRCT may have a discriminative role in the presence of both ILD and esophageal dilatation for the diagnosis of SSc. Our results suggest that a cut-off value for the esophageal diameter of 18.5 mm might propose the diagnosis of SSc with reasonable confidence.