COMPUTED-TOMOGRAPHY IN CHEST DISEASES

The fundamental principles of computed tomography (CT), its clinical a pplications and costs are presented followed by the indications and re sults in diseases of the mediastinum, the oesophagus, heart and great vessels, and the lung and pleura. The CT scan can give the precise loc alization and density of mediastinal tumours and be used to distinguis h thymomas, goiters, lymph nodes, lymphomas, neurinomas and different bronchogenic and pleuropericardial cystic formations. The operability of oesophageal cancer can also be determined. In cardiovascular diseas es, the CT scan is particularly useful to identify inborn anomalies, a neurysms, aortic dissection or caval compression or thrombus formation . In lung diseases, the indications for a CT scan are particularly imp ortant in broncho pulmonary cancer, tuberculosis, bronchopathies and c hronic lung diseases. In bronchogenic cancer, for example, the CT scan is not only a major diagnostic tool but is also particularly useful i n determining the prognosis and for following the effectiveness of tre atment. The CT scan can be used to identify both effusions of liquid a nd gas as well as pleural reactions producing thick membranes of impor tance for both aetiology and later follow-up. Bronchectasis can be ide ntified on serial sections where the degree of extension can be measur ed. CT scan is also indicated in patients with emphysema, both for eva luating extension and follow-up. Finally the indications and contraind ications for interventional computed tomography, particularly in guidi ng needle biopsies, is presented.