[Pericochlear hypodensity on CT: normal variant in childhood].

OBJECTIVE

Evaluation of the prevalence of a pericochlear hypodensity on CT in children. Materials and methods. This study correlates the findings on temporal bone CT to the indications for CT (headache, trauma). Helical CT acquisitions using 0,5 mm, 0,6 mm or 0,75 mm slice thickness according to the material available, with multiplanar reconstructions. Only patients with significant pericochlear hypodensity, larger or equal to 0,4 mm, were taken into account, and the curvilinear or nodular nature of the lesion on axial and coronal sections was recorded.

RESULTS

A pericochlear hypodensity was identified in nearly 40% of cases. There was no population predominence according to the indication for the CT. The curvilinear type was more frequent on coronal images, with unilateral and bilateral involvement being equally frequent. There was no significant difference according to the sex. Patients of all ages showed lesions, from newborns to adolescents, with increased frequency in childhood.

CONCLUSIONS

This study confirms a high prevalence of pericochlear hypodensity in a paediatric population, without clinical correlation, which requires prudence when interpreting the significance of this CT sign commonly described in association with pericochlear otosclerosis and the pericochlear form of osteogenesis imperfecta.