Twenty four solitary pulmonary nodules of uncertain or equivocal nature detected by conventional chest roentgenography were evaluated by computed tomography CT. Based on the location, size. shape, margin, and CI number of the lesions. CT was able to predict better than conventional radiography whether a solitary nodule was a cancer, a noncalcified granuloma. a calcified granuloma, a lipoma, a mediastinal neurogenic tumor, or a loculated pleural fluid in most cases. Its major limitation was the distinction between a small, well demarcated cancer and a noncalcified granuloma with a similar CT number. © Lippincott-Raven Publishers.