[Correlation between standard radiology and computed tomography in the demonstration of mediastinal lines]

The mediastinal lines correspond to the contours of the middle and upper mediastinum, and represent the edges of a dense, pleural covered structure marginated by the air within the lung. The mediastinal lines derive their names from the adjacent organs: 1) The posterior mediastinal junction line (where both lungs meet posteriorly, just before the vertebral column). 2) The anterior mediastinal junction line (where both lungs meet anteriorly, behind the sternum). 3) The right paratracheal stripe (where the right lung meets the trachea). 4) The esophageal-pleural stripe (which disappears at the level of the arch of the Azygos vein that divides the right lung from the esophagus. 5) The Azygos-pleural line (where the arch of the Azygos vein meets the right lung). 6) The esophageal-pleural line (where the right esophageal wall meets the right lung). 7) The para-aortic line (that is the most constant). 8) and 9) The left and right paraspinous lines (whereof the right is the most often visible). The absence of one of the mediastinal lines is sometimes insignificant, since it can be caused by anatomical variations or by the conditions of the picture. C.T. explains the formation's mechanism of these mediastinal lines, explains the anatomic reasons for their possible absence or displacement and often provides us with their etiology. C.T. offers a simple, reliable and atraumatic method in cases of displaced or vanished mediastinal lines, and should replace standard tomography of the mediastinum.