Ankylosing Spondylitis 90% HLA-B27 + young 15-35 yo adult M:F = 15:1, pseudowidening, erosion (Rosary bead sign), ankylosis (SIJ Star sign), Destruction inf & sup corner of VBs (Romanus lesion), reactive sclerosis (Shiny corner), squaring of VB, marginal syndesmophyte, bamboo spine, Trolley Track & Dagger signs