Basion-Cartilaginous Dens Interval: An Imaging Parameter for Craniovertebral Junction Assessment in Children.

BACKGROUND AND PURPOSE Widening of the basion-dens interval is an important sign of cranioverterbral junction injury. The current literature on basion-dens interval in children is sparse and based on bony measurements with variable values. Our goal was to establish the normal values of a recently described new imaging parameter, the basion-cartilaginous dens interval in children. MATERIALS AND METHODS Three hundred healthy pediatric patients (0-10 years of age) were selected retrospectively. These patients were divided into 3 different groups: A (0-3 years), B (3-6 years), and C (6-10 years). The basion-cartilaginous dens interval was calculated on the sagittal MPR image of cervical spine CT in a soft-tissue window. The mean, SD, and the upper limit of normal (mean +2 SDs) of the 3 groups were calculated, and statistical tests were used to check for significant differences of the basion-cartilaginous dens interval among these 3 groups. RESULTS The upper limits of the basion-cartilaginous dens interval for the 3 groups were 5.34 mm in group A, 5.64 mm in group B, and 7.24 mm in group C. There were statistically significant differences in the basion-cartilaginous dens interval values among the 3 groups. There was no statistically significant difference in basion-cartilaginous dens interval values between groups A and B; however, values in group C were significantly different from those in both A and B. There was no statistically significant difference in the basion-cartilaginous dens interval values between males and females. CONCLUSIONS The basion-cartilaginous dens interval is a novel imaging parameter to assess cranioverterbral junction integrity in children, which includes the nonossified cartilage in the measurement.