The major pulmonary societies recommend noncontrast chest CT for the evaluation of chronic cough when the more common causes are excluded or empirically treated [1,10,15,29], and this is usually preceded by a chest radiograph. Of the studies evaluating the clinical management of patients with chronic cough, none utilized chest CT in the initial workup [3,7,16,17], and two studies specifically addressed a cohort of patients with normal chest radiography findings [3,16]. Kastelik et al [7] utilized a probability-based clinical algorithm in the prospective treatment of 131 patients presenting with cough lasting >8 weeks. All patients were initially evaluated with chest radiography and empirically treated based on the probability of underlying etiologies. Chest CT was performed in those patients with clinical suspicion of underlying disease (n = 29) as well as in those with indications or negative initial workup otherwise (n = 17). Of these, 26 out of 29 patients (positive predictive value of 90%) suspected of having underlying pulmonary disease were diagnosed and treated as appropriate; however, 17 patients in whom chest CT was performed without cause and as part of the algorithmic evaluation did not have findings relevant to their management. The authors concluded that chest CT should be performed only in selected patients and those with abnormal chest radiographs. In another prospective observational study, Ojoo et al [17] evaluated 112 consecutive patients with chronic cough. All patients were evaluated with chest radiography. Chest CT was performed only based on clinical suspicion. The authors reported that 74 out of 81 patients managed clinically without the need for chest CT examination, suggesting chest CT would not have made a difference in these patients. It should be noted that both studies did identify primary pulmonary etiologies felt to be associated with chronic cough, of which bronchiectasis and interstitial lung disease were the two most common.
Chronic Cough. The major pulmonary societies recommend noncontrast chest CT for the evaluation of chronic cough when the more common causes are excluded or empirically treated [1,10,15,29], and this is usually preceded by a chest radiograph. Of the studies evaluating the clinical management of patients with chronic cough, none utilized chest CT in the initial workup [3,7,16,17], and two studies specifically addressed a cohort of patients with normal chest radiography findings [3,16]. Kastelik et al [7] utilized a probability-based clinical algorithm in the prospective treatment of 131 patients presenting with cough lasting >8 weeks. All patients were initially evaluated with chest radiography and empirically treated based on the probability of underlying etiologies. Chest CT was performed in those patients with clinical suspicion of underlying disease (n = 29) as well as in those with indications or negative initial workup otherwise (n = 17). Of these, 26 out of 29 patients (positive predictive value of 90%) suspected of having underlying pulmonary disease were diagnosed and treated as appropriate; however, 17 patients in whom chest CT was performed without cause and as part of the algorithmic evaluation did not have findings relevant to their management. The authors concluded that chest CT should be performed only in selected patients and those with abnormal chest radiographs. In another prospective observational study, Ojoo et al [17] evaluated 112 consecutive patients with chronic cough. All patients were evaluated with chest radiography. Chest CT was performed only based on clinical suspicion. The authors reported that 74 out of 81 patients managed clinically without the need for chest CT examination, suggesting chest CT would not have made a difference in these patients. It should be noted that both studies did identify primary pulmonary etiologies felt to be associated with chronic cough, of which bronchiectasis and interstitial lung disease were the two most common.