Position of Cerebellar Tonsils in the Normal Population and in Patients with Chiari Malformation: A Quantitative Approach with MR Imaging

  title={Position of Cerebellar Tonsils in the Normal Population and in Patients with Chiari Malformation: A Quantitative Approach with MR Imaging},
  author={Amr Aboulezz and Klaus Sartor and Carl A. Geyer and Mokhtar H. Gado},
  journal={Journal of Computer Assisted Tomography},
Magnetic resonance imaging was used to define quantitatively the position of the cerebellar tonsils in the normal population and in patients with Chiari malformations. The average distance of the tonsillar tips from the foramen magnum was 2.9 ± 3.4 mm above the foramen in 82 subjects without posterior fossa abnormality or increased intracranial pressure, and 10.3 ± 4.6 mm below the foramen in 13 patients with Chiari malformations (p < 0.005). Consequently, extension of the tonsils below the… 
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