Chiari 1 malformation

  • Protrusion of tonsils > 5 mm below foramen magnum
  • Tonsils are sharp and pointed inferiorly
  • Fourth ventricle is slightly low in position
  • Tonsil descent may cause mild medullary compression
  • Cervical cord syrinx may be seen
  • Tectal plate is normal
  • Corpus callosum is normal
Read more

Elster, Allen D., and M. Y. Chen. “Chiari I malformations: clinical and radiologic reappraisal.” Radiology 183.2 (1992): 347-353.

Hofkes, Shawn K., et al. “Differentiation between symptomatic Chiari I malformation and asymptomatic tonsilar ectopia by using cerebrospinal fluid flow imaging: initial estimate of imaging accuracy.” Radiology 245.2 (2007): 532-540.