" Hitting the bullseye - what's the target sign on an AXR? "
The target sign consists of two approximately concentric circles of fat density to the right of the spine, due to layers of peritoneal fat surrounding and within the intussusceptum alternating with layers of mucosa and muscle. This sign resembles a very faint target, or bull’s eye, or doughnut appearance.
This radiograph shows a classic target sign in the right upper quadrant just below the liver. It resembles a chubby doughnut with a puffy center. It is very subtle. You may need to adjust the contrast control on your monitor to appreciate it. This radiograph also shows the absent liver edge sign and the crescent sign. A paucity of bowel gas is also noted.