anterior junction line

The anterior junction (or junctional) line is a feature of frontal chest radiographs and chest CTs. It is a result of the parietal and visceral pleura meeting anteromedially. It normally contains a small amount of fat but can form a stripe of variable thickness if there is a lot of fat present or by the presence of the thymus in young patients .

Anterior mediastinal masses can cause obliteration of the anterior junction line .

Occasionally the anterior junction line may mimic pneumomediastinum, so called pseudopneumomediastinum.

Radiological appearance

Plain radiograph

• seen on ~40% (range 25-57%) of frontal chest x-rays
• oblique course crossing the upper two-thirds of the sternum from the upper right to lower left and does not extend above the manubriosternal joint

CT

• seen as a thin, dense line separating the two lungs in the anterosuperior portion of the chest

Siehe auch:

• Thymus
• stripe

und weiter:

• right paratracheal stripe
• CXR lines and stripes