Preferred Label : half moon sign (chest);
Definition : The half-moon sign is defined as a shadow seen on the lateral chest radiograph consisting
of a smooth, partially demarcated opacity with the rounded portion of the half moon
projecting over the aortic lumen at the level of the aortic arch, but the rest of
the opacity merging with the aorta. The half-moon sign shown on the lateral chest
radiograph is highly suggestive of the saccular aortic arch aneurysm.;
Source : Chest. 1996 Jan;109(1):127-30.;
Origin ID : RID35254;
Associated condition(s)
The half-moon sign is defined as a shadow seen on the lateral chest radiograph consisting
of a smooth, partially demarcated opacity with the rounded portion of the half moon
projecting over the aortic lumen at the level of the aortic arch, but the rest of
the opacity merging with the aorta. The half-moon sign shown on the lateral chest
radiograph is highly suggestive of the saccular aortic arch aneurysm.
