Neuroimaging and calvarial findings in achondroplasia.

Achondroplasia is the most common hereditary form of dwarfism and is characterized by short stature, macrocephaly and various skeletal abnormalities. The phenotypic changes are mainly related to the inhibition of endochondral bone growth. Besides the several commonly known physical features that are characteristic of this syndrome, achondroplasia can affect the central nervous system. The impact on the central nervous system can cause some important clinical conditions. Thus, awareness of detailed neuroimaging features is helpful for the follow-up and management of complications. Although the neuroimaging findings in children with achondroplasia have been noted recently, no literature has specifically reviewed these findings extensively. Radiologists should be familiar of these findings because they have an important role in the diagnosis of achondroplasia and the recognition of complications. The aim of this pictorial essay is to review and systematize the distinctive characteristics and abnormalities of the central nervous system and the calvarium in children with achondroplasia.