Radiology Matrix - medical education - Matrix Case 334: - Inverted Napoleon hat sign - It is seen when there is bilateral spondylolysis with marked anterolisthesis of L5 on S1 The "brim"
![Angel Gómez-Cintrón, MD, MPH on X: "Because I'm a radiology nerd and love Roentgen classic signs.... Inverted Napoleon Hat Sign. Seen on lumbar/spine AP views with L5-S1 bilateral spondylolysis and pronounced spondylolisthesis Angel Gómez-Cintrón, MD, MPH on X: "Because I'm a radiology nerd and love Roentgen classic signs.... Inverted Napoleon Hat Sign. Seen on lumbar/spine AP views with L5-S1 bilateral spondylolysis and pronounced spondylolisthesis](https://pbs.twimg.com/media/E5KXU98X0AEgJ5I.jpg)
Angel Gómez-Cintrón, MD, MPH on X: "Because I'm a radiology nerd and love Roentgen classic signs.... Inverted Napoleon Hat Sign. Seen on lumbar/spine AP views with L5-S1 bilateral spondylolysis and pronounced spondylolisthesis
![Inverted Napoleon Hat Sign (L5-S1 spondylosis and spondylolisthesis) USMLE, NEET PG, NCLEX, INICET - YouTube Inverted Napoleon Hat Sign (L5-S1 spondylosis and spondylolisthesis) USMLE, NEET PG, NCLEX, INICET - YouTube](https://i.ytimg.com/vi/Oo6W7Rf5MsQ/maxres2.jpg?sqp=-oaymwEoCIAKENAF8quKqQMcGADwAQH4AbYIgAKAD4oCDAgAEAEYDyBlKF0wDw==&rs=AOn4CLD0sg2cvxu2HTShItqerBiFNHSB_g)