Continued...

Diagnosis

View a crescent sign example.

This radiograph shows a classic crescent sign in the left upper quadrant. This radiograph indicates that the head of the intussusception is in the distal transverse colon. Also note that this radiograph demonstrates the target sign and the absent liver edge sign. The target sign is again subtle and less noticeable in this film. You may need to adjust the contrast control on your monitor to appreciate it. Go back to the target sign radiograph to see if you can appreciate the crescent sign on this radiograph (left upper quadrant). In this case, the crescent is not as crescent shaped, because the colonic air pocket surrounding the intussusceptum is larger than in the crescent sign film.

View an atypical crescent sign.

This radiograph shows an atypical crescent sign in the right upper quadrant just below the liver. The head of the intussusception is coming up the ascending colon. It can be seen protruding upward into the gas-filled transverse colon at the hepatic flexure.