Preferred Label : inverted Napoleon hat sign;
RADLEX synonyms : bow sign; Napoleon hat sign;
Definition : Anterior body of L5 vertebra is anteriorly displaced over top of sacrum. Transverse
processes resemble the brim, superimposition of L5 and sacrum resemble dome. Indicates
spondylolisthesis at the lumbosacral junction.;
Origin ID : RID34410;
Associated condition(s)
Anterior body of L5 vertebra is anteriorly displaced over top of sacrum. Transverse
processes resemble the brim, superimposition of L5 and sacrum resemble dome. Indicates
spondylolisthesis at the lumbosacral junction.