Presentation
Incidental finding, CXR performed to exclude TB
Patient Data
Heart is not enlarged. Lungs and pleural spaces clear. Anterior junctional line in evidence.
Case Discussion
The anterior junctional (or junction) line is the radiographic visibility of the median/paramedian meeting of the parietal and visceral pleuras. It is "never" seen superior to the level of the sternal notch 1. A small layer of fat may be interposed between the pleurae and it is usually easier to appreciate when more fat is present. Studies have shown it to be present on about four in ten PA chest radiographs. It is usually impossible to see in infants as it is obscured by the normal thymic shadow 1.