[Diagnosis of diseases of the lung, the mediastinum and the pleura].

Computed tomography of the thorax seems to have proceeded in a straight line from standard radiography of the chest. With its transverse axial sections, it provides a better understanding of spatial displacements and a better localization of thoracic lesions. In most cases, the lesional diagnosis can be approached more directly, so that tomography is no longer used while the number of bronchographies and pulmonary angiographies has been drastically reduced. Finally, computed tomography offers an excellent guidance to the percutaneous or endoscopic collection of samples for cytological and histological examinations. Ultrasounds are particularly used in the diagnosis and drainage of pleural effusions. Magnetic resonance imaging has not yet replaced all other techniques, but it is one of the most helpful examinations for the diagnosis and assessment of mediastinal vascular diseases.