silhouette sign

[sil′o̅o̅·et′]

a radiographic artifact caused by an infiltrate that obscures the demarcating line between lung segments.

silhouette

outline of a figure. The sharpness of the silhouette is a function of the shape, size and density of the object. This is most marked in radiography.

basketball-shaped silhouette

the enlarged cardiac outline seen in the dorsal-ventral view of the thorax in a dog with chronic pericardial effusion.

silhouette sign

produced when two fluid densities are contiguous and the individual outline of each is lost. Commonly used in the evaluation of chest problems.