Kerley lines are a

sign A sign is an object, quality, event, or entity whose presence or occurrence indicates the probable presence or occurrence of something else. A natural sign bears a causal relation to its object—for instance, thunder is a sign of storm, or me ...

seen on

chest radiograph A chest radiograph, called a chest X-ray (CXR), or chest film, is a projection radiograph of the chest used to diagnose conditions affecting the chest, its contents, and nearby structures. Chest radiographs are the most common film taken in med ...

s with interstitial

pulmonary edema Pulmonary edema, also known as pulmonary congestion, is excessive edema, liquid accumulation in the parenchyma, tissue and pulmonary alveolus, air spaces (usually alveoli) of the lungs. It leads to impaired gas exchange and may cause hypoxemia an ...

. They are thin linear pulmonary opacities caused by fluid or cellular infiltration into the interstitium of the lungs. They are named after Irish neurologist and radiologist

Peter Kerley Sir Peter James Kerley KCVO CBE (1900–1979) was an Irish radiologist famous for his role in the lung surgery of King George VI and the naming of the radiological sign in heart failure, Kerley lines. Kerley had his initial radiological tr ...

Associated conditions

They are suggestive for the diagnosis of

congestive heart failure Heart failure (HF), also known as congestive heart failure (CHF), is a syndrome, a group of signs and symptoms caused by an impairment of the heart's blood pumping function. Symptoms typically include shortness of breath, excessive fatigue, a ...

, but are also seen in various non-cardiac conditions such as pulmonary fibrosis, interstitial deposition of heavy metal particles or carcinomatosis of the lung. Chronic Kerley B lines may be caused by fibrosis or

hemosiderin Hemosiderin image of a kidney viewed under a microscope. The brown areas represent hemosiderin Hemosiderin or haemosiderin is an iron-storage complex that is composed of partially digested ferritin and lysosomes. The breakdown of heme gives rise ...

deposition caused by recurrent

Types

Kerley A lines

These are longer (at least 2cm and up to 6cm) unbranching lines coursing diagonally from the hila out to the periphery of the lungs. They are caused by distension of anastomotic channels between peripheral and central lymphatics of the lungs. Kerley A lines are less commonly seen than Kerley B lines. Kerley A lines are never seen without Kerley B or C lines. Chest radiograph of a lung with Kerley B lines - annotated

Kerley B lines

These are short parallel lines at the lung periphery. 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 The pulmonary pleurae (''sing.'' pleura) are the two opposing layers of serous membrane overlying the lungs and the inside of the surrounding chest walls. The inner pleura, called the visceral pleura, covers the surface of each lung and dips bet ...

. They are located peripherally in contact with the pleura, but are generally absent along fissural surfaces. They may be seen in any zone but are most frequently observed at the lung bases at the

costophrenic angles The costodiaphragmatic recess, also called the costophrenic recess or phrenicocostal sinus, costodiaphragmatic-recess Retrieved May 2011 Imaging In anatomy, the costophrenic angles are the places where the diaphragm (''-phrenic'') meets the ribs ...

on the PA radiograph, and in the substernal region on lateral radiographs. Causes of Kerley B lines include pulmonary edema, lymphangitis carcinomatosa and malignant lymphoma, viral and mycoplasmal pneumonia, interstitial pulmonary fibrosis, pneumoconiosis, and sarcoidosis. They can be an evanescent sign on the chest x-ray of a patient in and out of heart failure.

Kerley C lines

These are the least commonly seen of the Kerley lines. They are short, fine lines throughout the lungs, with a reticular appearance. They may represent thickening of anastomotic lymphatics or superimposition of many Kerley B lines.

References

External links

Kerley B lines
- GPNotebook

- FPNotebook
Kerley B lines image
- catscanman.net

- medstudents.com.br
Kerley's A, B, and C lines
- Images in Clinical Medicine, New England Journal of Medicine website.

- Swimming Induced Pulmonary Edema - MedPix Database {{Radiologic signs Radiologic signs