Two odontoid synchondroses in the same C2 vertebra (white arrows) shown in a midsagittal magnetic resonance imaging image. The upper white arrow notes the accessory synchondrosis. Note the cerebellar tonsils (asterisk), and the lower part of the brainstem (red star) located below the foramen magnum i.e., Chiari 1.5 malformation. The anterior arch of the atlas (yellow arrow) is not ossified. The posterior arch of C1 and spinous process of C2 are also shown.