B-line (ultrasound)

Last revised by Francis Fortin on 28 Mar 2021

Citation, DOI, disclosures and article data

Citation:

Carroll D, Fortin F, Bell D, et al. B-line (ultrasound). Reference article, Radiopaedia.org (Accessed on 18 Apr 2024) https://doi.org/10.53347/rID-64319

DOI:

https://doi.org/10.53347/rID-64319

Permalink:

https://radiopaedia.org/articles/64319

rID:

64319

Article created:

16 Nov 2018, David Carroll ◉

Disclosures:

At the time the article was created David Carroll had no recorded disclosures.

View David Carroll's current disclosures

Last revised:

28 Mar 2021, Francis Fortin

Disclosures:

At the time the article was last revised Francis Fortin had no recorded disclosures.

View Francis Fortin's current disclosures

Revisions:

6 times, by 5 contributors - see full revision history and disclosures

Systems:

Chest

Sections:

Signs

Tags:

lung, pocus

Synonyms:

B-lines (ultrasound)

The B-line is an artifact relevant in lung ultrasonography. As originally described, it has seven defining features ¹:

a hydroaeric comet-tail artifact
arising from the pleural line
hyperechoic
well-deﬁned
extending indeﬁnitely
erasing A-lines
moving in concert with lung sliding, if lung sliding is present

B-line distribution corresponds with sub-pleural thickened interlobular septa, as demonstrated by CT, and are absent under normal conditions and present in alveolar-interstitial syndromes ². Subpleural septal edema is postulated to provide a bubble-tetrahedron interface, generating a series of very closely spaced reverberations at a distance below the resolution of ultrasound which is interpreted as a confluent vertical echo which does not fade with increasing depth ³.

A few B-lines (<3/field of view) can often be found under normal circumstances, especially in the elderly, and around the base of the lungs ⁴.