Displaced Anterior junctional line.

The two lungs are separated anteriorly by four layers of pleura that forms the anterior junction line. It extends from the level of clavicle till the RVOT.

Similar such line is seen posteriorly , that separates the two lungs called the posterior junction line.

The importance of knowledge of junctional lines is that a mass or space occupying process in the junctional lines can widen them or displace them.The junctional lines are inconsistently visualised on plain frontal chest radiograph.