This site is targeted at medical and radiology professionals, contains user contributed content, and material that may be confusing to a lay audience. Use of this site implies acceptance of our Terms of Use.

Anterior bronchus sign

The anterior bronchus sign refers to the appearance of the anterior segmental bronchus of the upper lobes as seen on a frontal chest radiograph.

Normal anatomy

The anterior segment bronchus of the upper lobes courses anteriorly and laterally. When the orientation is predominantly anteriorly the bronchus is seen end on as a ring shadow. This occurs in approximately 50% of the time.

Upper limit in adjacent soft tissue thickness

Normally there is at most 3 mm of soft tissue lateral to the bronchus. Presence of more than 6 mm of soft tissue implies the presences of a mass, and warrants cross-sectional imaging.

Updating… Please wait.
Loadinganimation

 Details successfully updated.

Error Unable to process the form. Check for errors and try again.

 Thank you for updating your details.