Park et al [26] showed that 49 out of 166 elderly patients presenting to the emergency room who had normal chest radiographs were subsequently diagnosed with acute respiratory infection from findings on LDCT. In a prospective case comparison, Christe et al [27] showed good correlation between standard dose (150 mAs) and low-dose (40 mAs) CT protocols for evaluating the majority of pulmonary abnormalities, including bronchiectasis, air trapping, and pleural disease. Investigators did identify a drop in sensitivity in low-dose scans for ground-glass nodules, reticulation, and mucus plugging [27]. Ultra-low- dose CT demonstrated 91% sensitivity and 100% specificity in identifying asbestos-related lung abnormalities in a prospective cohort of 55 asymptomatic persons with relevant exposure history [28]. To our knowledge, there is no relevant literature to support the use of LDCT in the evaluation of chronic cough, and further research into this topic may be warranted. OR Discussion of Procedures by Variant Variant 1: Chronic cough lasting more than 8 weeks. No known risk factors for lung cancer. Initial imaging. Radiography Chest Chest radiography is recommended by numerous pulmonary and thoracic societies for the evaluation of chronic cough [1,10,15,29], although the exact timing of imaging has varied between groups. The American College of Chest Physicians (ACCP) includes a recommendation for an initial chest radiograph in their chronic cough algorithm [1]. The evidence supporting chest radiography at initial evaluation of chronic cough is limited to case series, observational studies, and retrospective analysis. Initial evaluation with posteroanterior chest radiography has been included as part of two investigative case series using standardized clinical protocols for chronic cough [7,17].
Chronic Cough. Park et al [26] showed that 49 out of 166 elderly patients presenting to the emergency room who had normal chest radiographs were subsequently diagnosed with acute respiratory infection from findings on LDCT. In a prospective case comparison, Christe et al [27] showed good correlation between standard dose (150 mAs) and low-dose (40 mAs) CT protocols for evaluating the majority of pulmonary abnormalities, including bronchiectasis, air trapping, and pleural disease. Investigators did identify a drop in sensitivity in low-dose scans for ground-glass nodules, reticulation, and mucus plugging [27]. Ultra-low- dose CT demonstrated 91% sensitivity and 100% specificity in identifying asbestos-related lung abnormalities in a prospective cohort of 55 asymptomatic persons with relevant exposure history [28]. To our knowledge, there is no relevant literature to support the use of LDCT in the evaluation of chronic cough, and further research into this topic may be warranted. OR Discussion of Procedures by Variant Variant 1: Chronic cough lasting more than 8 weeks. No known risk factors for lung cancer. Initial imaging. Radiography Chest Chest radiography is recommended by numerous pulmonary and thoracic societies for the evaluation of chronic cough [1,10,15,29], although the exact timing of imaging has varied between groups. The American College of Chest Physicians (ACCP) includes a recommendation for an initial chest radiograph in their chronic cough algorithm [1]. The evidence supporting chest radiography at initial evaluation of chronic cough is limited to case series, observational studies, and retrospective analysis. Initial evaluation with posteroanterior chest radiography has been included as part of two investigative case series using standardized clinical protocols for chronic cough [7,17].