Shmoo sign (annotated image)

Case contributed by Dr Vincent Tatco
Annotated image

Annotated image showing the Shmoo sign for left ventricular enlargement. The shape of the Shmoo superimposed over the radiograph demonstrates the origin of this sign.

Author: Vincent Tatco

License: CC-NC-BY-SA

Case Discussion

Shmoo sign refers to the configuration of the heart with left ventricular enlargement and dilated aorta on AP chest radiographs. The "Shmoo" is a fictional cartoon creature from Al Capp's Li'l Abner comic strip in the 1940s. The prominent left heart border and dilated aorta correspond to the Shmoo’s body and head, respectively.

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