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, 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 medicine. L ...

s with interstitial

pulmonary edema Pulmonary edema (British English: oedema), also known as pulmonary congestion, is excessive fluid accumulation in the tissue or air spaces (usually alveoli) of the lungs. This leads to impaired gas exchange, most often leading to shortness ...

. 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 (27 October 1900 – 14 May 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 ini ...

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 caused by an impairment in the heart's ability to fill with and pump blood. Although symptoms vary based on which side of the heart is affected, HF typically pr ...

, but are also seen in various non-cardiac conditions such as

pulmonary fibrosis Pulmonary fibrosis is a condition in which the lungs become scarred over time. Symptoms include shortness of breath, a dry cough, feeling tired, weight loss, and nail clubbing. Complications may include pulmonary hypertension, respiratory ...

, interstitial deposition of heavy metal particles or

carcinomatosis Carcinosis, or carcinomatosis, is disseminated cancer, forms of metastasis, whether used generally or in specific patterns of spread. Usage Carcinomatosis is often restricted to tumors of epithelial origin, adenocarcinomas, while sarcomatosis desc ...

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 ri ...

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 Hila may refer to: *plural form of Hilum (disambiguation), Hilum *Village in Israel: Mitzpe Hila *Hila (given name), in Hebrew * For the Islamic concept of "stratagem", see Ḥiyal *Hila, Ambon, the town on the Indonesian island of Ambon where Fort ...

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 pleurae (: pleura) are the two flattened closed sacs filled with pleural fluid, each ensheathing each lung and lining their surrounding tissues, locally appearing as two opposing layers of serous membrane separating the lungs from the med ...

. 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 rib ...

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