Kerley lines

Kerley lines are a sign seen on chest radiographs with interstitial pulmonary edema.

They are thin linear pulmonary opacities caused by fluid or cellular infiltration into the interstitium of the lungs.

[1][2] They are suggestive for the diagnosis of congestive heart failure, but are also seen in various non-cardiac conditions such as pulmonary fibrosis, interstitial deposition of heavy metal particles or carcinomatosis of the lung.

These lines represent interlobular septa, which are usually less than 1 cm in length and parallel to one another at right angles to the pleura.

They are located peripherally in contact with the pleura, but are generally absent along fissural surfaces.