Anatomic variations

Anatomic variations(normal anatomic variations)

• Ossicles은 해당 링크 참조

Spine

• limbus vertebra: ddx. intercalary bone, limbus fracture, teardrop fracture(cervical spine)
• Lumbosacral transitional vertebra(LSTV)
• Block vertebra
• Atlantoaxial assimilation
• Neural arch cleft
• Os odontoideum, condylus tertius, posterior onticulus

Hip

• Herniation pit: usually bilateral, 5~15mm sized, oval or round shaped, lucent lesion with thin sclerotic rim at the anterosuperior femoral neck.
• Supraacetabula fossa(pseudo defect of acetabular cartilage)

Pelvis

• ischiopubic synchondrosis: [1]
  • a temporary hyaline cartilaginous joint, occurring in childhood prior to fusion of the ischial and pubic bones

Skull

• Posterior occipital protuberance

PNS

• Haller cell
• Concha bullosa

Sacroiliac joint

• Accessory sacroiliac joint

knee

• bipartite patella

Head and neck

• Accessory parotid gland: masseter muscle 옆의 mass 처럼 보일 수 있음. neurogenic tumor 등과 감별 필요.

Brain

• BESS(Benign enlargement of the subarachnoid space): interhemispheric width >5mm

Vessel

• aberrent arteries
• intracranial artery fenestration: segmental duplication
• The artery of Percheron
  • posterior cerebral circulation characterized by a solitary arterial trunk
  • supplies blood to the paramedian thalami and the rostral midbrain bilaterally.