This page is dedicated to covering the important radiological finding of a silhouette sign at the left hemidiaphragm.
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 left hemidiaphragm the clear sharp margin between the left hemidiaphragm and the left 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 left hemidiaphragm, it is important to keep in mind the following possible causes of this finding:
- Left lower lobe pneumonia
- Left lower lobe atelectasis
- Left sided pleural effusion
KEY FEATURES TO LOOK FOR WHEN CHARACTERIZING THE FINDING
When seeing a silhouette sign at the right hemidiaphragm, 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