Paediatric Imaging

Platybasia

flattening of the skull base. This is assessed radiographically by drawing a line from the nasion to the tuberculum sella and then to the anterior margin of the foramen magnum. The angle formed is normally between 125 to 143. An increased basal angle of more than 143 is regarded as platybasia. Platybasia may occur as an isolated congenital abnormality or be part of a skeletal syndrome. It is also commonly seen in association with Arnold Chiari malformation.

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