The sensitivity of chest radiography for airway abnormalities was found to be 69% to 71% when referenced to helical CT in 70 patients with known airway abnormalities and lesions [33]. In a retrospective analysis of elderly emergency room patients who were evaluated for acute respiratory infection, Park et al [26] showed that chest radiographs were normal in 49 out of 166 confirmed cases on LDCT. Chest radiography was more often normal when LDCT identified ground-glass opacity (GGO), bronchial wall thickening, centrilobular nodules, and small and dependent consolidations. Chest radiography was also found to have poor correlation with chest CT for the presence of pulmonary opacities [34,35], with a positive predictive value of only 27% when compared with chest CT in a secondary analysis of a large retrospective cohort of 3,400 patients. Limitations of chest radiography reflect superimposed soft-tissue structures, radiographic findings related to comorbidities, and limited contrast resolution. Unfortunately, there are no high-quality studies evaluating the clinical efficacy of chest radiography in the early evaluation of patients with chronic cough, and this may be an area of future investigation. Based on the available literature, there is a suggestion that initial evaluation of chronic cough with chest radiography is beneficial in the clinical setting. There does remain question regarding the sensitivity of chest radiography in this group [3], which is likely skewed toward early disease and airway abnormalities. This could potentially result in delayed diagnosis for a small percent of patients with chronic cough. CT Chest There is no high-quality evidence to support the use of chest CT in the initial evaluation of patients presenting with chronic cough. No studies have directly compared the utility of contrast-enhanced versus noncontrast-enhanced CT imaging in regard to chronic cough.
Chronic Cough. The sensitivity of chest radiography for airway abnormalities was found to be 69% to 71% when referenced to helical CT in 70 patients with known airway abnormalities and lesions [33]. In a retrospective analysis of elderly emergency room patients who were evaluated for acute respiratory infection, Park et al [26] showed that chest radiographs were normal in 49 out of 166 confirmed cases on LDCT. Chest radiography was more often normal when LDCT identified ground-glass opacity (GGO), bronchial wall thickening, centrilobular nodules, and small and dependent consolidations. Chest radiography was also found to have poor correlation with chest CT for the presence of pulmonary opacities [34,35], with a positive predictive value of only 27% when compared with chest CT in a secondary analysis of a large retrospective cohort of 3,400 patients. Limitations of chest radiography reflect superimposed soft-tissue structures, radiographic findings related to comorbidities, and limited contrast resolution. Unfortunately, there are no high-quality studies evaluating the clinical efficacy of chest radiography in the early evaluation of patients with chronic cough, and this may be an area of future investigation. Based on the available literature, there is a suggestion that initial evaluation of chronic cough with chest radiography is beneficial in the clinical setting. There does remain question regarding the sensitivity of chest radiography in this group [3], which is likely skewed toward early disease and airway abnormalities. This could potentially result in delayed diagnosis for a small percent of patients with chronic cough. CT Chest There is no high-quality evidence to support the use of chest CT in the initial evaluation of patients presenting with chronic cough. No studies have directly compared the utility of contrast-enhanced versus noncontrast-enhanced CT imaging in regard to chronic cough.