Anatomic variations

Anatomic variations(normal anatomic variations)

Spine

• Lumbosacral transitional vertebra(LSTV)

Ossicles

• Os trigonum

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
  • a temporary hyaline cartilaginous joint, occurring in childhood prior to fusion of the ischial and pubic bones

Skull

• Posterior occipital protuberance

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.

Sacroiliac joint

• Accessory sacroiliac joint

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

Spine

• Block vertebra
• atlantoaxial Assimilation
• Os odontoideum, condylus tertius, posterior onticulus
• Neural arch cleft