AbstractBoth computed tomography (CT) and magnetic resonance imaging (MRI) can provide important information not obtainable by chest radiography regarding staging of patients with bronchogenic carcinoma. However, while CT and MRI can both detect enlarged mediastinal nodes, this only approximately indicates tumor involvement. For example, enlarged nodes do not necessarily contain tumor, so biopsy is necessary before declaring the patient inoperable. As well, normal‐sized nodes may contain tumor, and whether mediastinoscopy is required in such situations is controversial. Similarly, neither MRI nor CT is highly accurate in detecting mediastinal or chest‐wall involvement, although certain specific features can occasionally be highly predictive of invasion.