Christmas inspired signs

There are many signs in radiology that are related to Christmas:

• snowcap sign in avascular necrosis
• snowman sign
  • in total anomalous pulmonary venous return
  • in pituitary macroadenomas
• snowstorm appearance in complete hydatidiform and testicular microlithiasis
• holly leaf sign in calcified pleural plaques
• ivy sign in leptomeningeal enhancement
• Christmas tree bladder in neurogenic bladder
• shepherd's crook deformity of the femur in fibrous dysplasia
• nutcracker esophagus in esophageal dysmotility