![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
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"
![Spondylolysis and spondylolisthesis in children and adolescents | Revista Española de Cirugía Ortopédica y Traumatología (English Edition) Spondylolysis and spondylolisthesis in children and adolescents | Revista Española de Cirugía Ortopédica y Traumatología (English Edition)](https://multimedia.elsevier.es/PublicationsMultimediaV1/file//19888856/0000005800000006/v1_201411090023/S1988885614001138/v1_201411090023/en/main.assets/gr4.jpeg?xkr=ue/ImdikoIMrsJoerZ+w997EogCnBdOOD93cPFbanNdV4B9vwZQjgKcZv3MP4Cds3qiLBpJmV7qW2dfcCTNKQBAhOLAElphHsTuvDyoKm4Hgqa3Sw2zZqglxEyjtieaS/dPTNXygKp63POJvod4Y2EpxFdPX5Ye5PNCb12VcnCvypkrg7lGxZB3E0PTUAkyLuyB36mBiQdD5uwm+AKyJJY8wS7DnCn+dBY8uTWm4HXLrCV4Egh2P4pZe1NZfHFyGe23H9nnYDEhvpPzgNRBy90STkdPYOpuJbENdanMzI0gUmEoQlYlkbvtzsyTC/O4k)