Imaging of the Mediastinum

Abstract

Mediastinal abnormalities are generally uncommon—the most frequently encountered abnormality being mediastinal masses. Chest radiograph still remains the initial investigation of choice in patients with mediastinal abnormalities. Rarely, a mediastinal mass may be identified in an asymptomatic patient on routine screening chest radiograph. Hence, the radiologist must be aware of the signs of identifying and localizing mediastinal masses. The signs may not be specific; hence a sign in isolation is inadequate in diagnosis. However, a combination of imaging signs helps in accurate localization of a mediastinal mass on a chest radiograph. The absence of a sign is equally important in localization of an abnormality. CT is the investigation of choice for further characterization, assessing the extent of disease, and staging of mediastinal masses. Similarly, mediastinitis and pneumomediastinum are initially evaluated by chest radiographs and usually followed by a CT examination.