Fundamental Radiological Findings: Silhouette Sign (Right Heart Border)

OVERVIEW

This page is dedicated to covering the important radiological finding of a silhouette sign at the right heart border

WHAT IS IT?

A silhouette sign refers to the loss of a border between two structures radiologically: In the case of a silhouette sign at the right heart border the clear sharp margin between the right heart border and the right lung field is obscured. This is typically a finding appreciated on a chest X-ray. 

DIFFERENTIAL DIAGNOSIS FOR THIS FINDING

When seeing a silhouette sign at the right heart border, it is important to keep in mind the following possible causes of this finding:

  • Right middle lobe pneumonia 
  • Right middle lobe atelectasis 
KEY FEATURES TO LOOK FOR WHEN CHARACTERIZING THE FINDING

When seeing a silhouette sign at the right heart border, there are a few important radiological features one should look at to try and characterize the finding. These features can help navigate the differential diagnosis above.

 

Page Updated: 03.01.2017