Chronic infiltrative lung disease: Comparison of diagnostic accuracies of radiography and low- and conventional-dose thin-section CT

PURPOSE: To compare the accuracy of low-dose thin-section computed tomography (CT), chest radiography, and conventional-dose thin-section CT in diagnosis of chronic infiltrative lung disease (CILD). MATERIALS AND METHODS: Chest radiographs and low-dose (80-mAs) and conventional-dose (340-mAs) thin- section (1.5-mm) CT scans from 50 patients with CILD and 10 healthy control subjects were randomized and analyzed retrospectively. For CT, three images were obtained: at the aortic arch, at the tracheal carina, and 1 cm above the right hemidiaphragm. Two independent observers listed three likely diagnoses and recorded the degree of confidence in their first choice. RESULTS: A correct first-choice diagnosis was made more often with either CT technique than with radiography (P < .02). A high confidence level in the diagnosis was reached in 42% of radiographic, 61% of low-dose CT, and 63% of conventional- dose CT interpretations, which were correct in 92%, 90%, and 96% of the studies, respectively. CONCLUSION: The superior diagnostic accuracy of low- dose thin-section CT was achieved without an increase in effective radiation dose.