title: The inverted Napoleon's hat sign.
authors: Department of Radiology, Monmouth Medical Center, 300 Second Ave, Long Branch, NJ 07740, USA. Leizle_t@yahoo.com
authors: Leizle E
authors: LE
authors: Talangbayan
mesh_terms: D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging*; D011859:Radiography; D012447:Sacrum / Q000000981:diagnostic imaging*; D013168:Spondylolisthesis / Q000000981:diagnostic imaging*