Normal chest plain radiograph Soft tissue ■breast and nipple ■Companion shadows ■Bone Ribs:Calcification of the cartilage Congenital rib abnormality:cervical rib,fused rib,bifid rib Clavicle Scapula ■Sterni:manubrium柄、corpus体 Thoracic vertebral bodies Normal chest plain radiograph ◼ Soft tissue ◼ breast and nipple ◼ Companion shadows ◼ Bone ◼ Ribs: Calcification of the cartilage ◼ Congenital rib abnormality：cervical rib, fused rib, bifid rib ◼ Clavicle ◼ Scapula ◼ Sterni：manubrium柄、corpus体 ◼ Thoracic vertebral bodies