Bull's eye sign of rectus femoris injury


The rectus femoris has two separate origins, the direct head originates from the anteroinferior iliac spine and indirect head from the superior acetabular ridge. Both these heads unite to form the deep musculotendinous junction.

The "bull's eye sign" was a term coined by Hughes et al to represent increased signal around the deep musculotendinous junction, which is thought to represent an intramuscular degloving injury of the muscle fibers from the indirect head, while the peripheral direct head fibers remain intact.