Eosinophilic lung diseases: Diagnostic accuracy of thin-section CT in 111 patients

PURPOSE: To determine whether various eosinophilic lung diseases can be dif ferentiated by means of thin-section computed tomography (CT). MATERIALS AND METHODS: Thin-section CT scans in 111 patients with eosinophi lic lung diseases-40 with chronic eosinophilic pneumonia, 16 with Churg-Str auss syndrome, 16 with allergic bronchopulmonary aspergillosis (ABPA), 13 w ith acute eosinophilic pneumonia, 12 with simple pulmonary eosinophilia, 11 with drug-induced eosinophilic pneumonia, and three with hypereosinophilic syndrome-were assessed independently by two observers. The observers recor ded the abnormalities, diagnosis, and degree of confidence in the diagnosis . RESULTS: The two observers made a correct first-choice diagnosis on average in 61% of readings. The correct diagnosis was made in 78% of cases of chro nic eosinophilic pneumonia; 81%, acute eosinophilic pneumonia; 44%, Churg-S trauss syndrome; 84%, ABPA; 17%, simple pulmonary eosinophilia; 27%, drug-i nduced eosinophilic pneumonia; and 33%, hypereosinophilic syndrome. The two observers made a correct diagnosis with a high degree of confidence in 36% of readings. There was moderate agreement between the observers for the co rrect diagnosis (kappa, 0.47) and for the correct diagnosis with a high deg ree of confidence (kappa, 0.59). CONCLUSION: Although eosinophilic lung diseases often can be differentiated by means of thin-section CT, correlation between CT findings and careful c linical evaluation are required for a definitive diagnosis.