We wanted to evaluate the usefulness of low-dose multidetector CT for the detection and follow-up of pulmonary metastatic nodules in patients suffering with malignancy.

We retrospectively reviewed the conventional chest radiographs and low-dose multi-detector CT (low-dose CT) scans of 81 patients who had been under the diagnosis of malignancy. We reviewed the detection of pulmonary nodules and we counted the number of nodules detected by each method. The nodules were confirmed by surgical operation and by the radiologic criteria. The accuracy, sensitivity, specificity and positive and negative predictive values of each method for detecting metastatic nodules were compared with x2 tests.

Low-dose CT depicted more nodules than did chest radiograph, and the indeterminate nodules seen on chest radiograph may be clearly benign on low-dose CT (eg. calcified granulomas or bony lesions). The accuracy of low-dose CT (75.3%) was significantly higher than that of chest radiograph (49.4%) for the detection for metastatic nodules (p <0.05).

Low-dose CT may provide better information than does chest radiograph for diagnosing pulmonary metastasis.