Abstract
Background/Objectives: The prevalence of bronchiectasis is increasing globally, and early detection using chest imaging has been encouraged to improve its prognosis. However, the sensitivity of a chest X-ray as a screening tool remains unclear. This study examined the chest X-ray features predictive of bronchiectasis. Methods: We retrospectively reviewed the chest X-rays of patients with bronchiectasis diagnosed using high-resolution computed tomography who visited our institute from January 2013 to March 2020. Patients with cardiac pacemakers, lung cancer, and interstitial pneumonia, which might bias the detection of bronchiectasis, were excluded. Two respiratory physicians independently determined the presence or absence of potential features reflecting bronchiectasis, including a vague cardiac silhouette on chest X-rays. Results: The study enrolled 130 patients, including 72 women (55.4%), with a mean age of 72 years. The features observed on chest X-rays included granular shadows (88.5%, n = 115), vague cardiac silhouettes (48.5%, n = 64), nodular shadows (45.4%, n = 59), a tram-track appearance (35.4%, n = 46), pleural thickening (26.9%, n = 35), vague diaphragm silhouettes (25.4%, n = 33), and a ring sign (24.6%, n = 32). The kappa values for these features were 0.271, 0.344, 0.646, 0.256, 0.312, 0.514, and 0.376, respectively. Conclusions: Although traditional chest X-ray features believed to reflect bronchiectasis, such as the tram-track appearance or ring sign, were not frequently seen, vague cardiac silhouettes and granular shadows had high positivity rates, indicating their potential utility for bronchiectasis screening. However, the interobserver concordance rates were unsatisfactory.