Abstract:

Objective To explore the difference of corticospinal tract in age and sex in children using diffusion tensor imaging. Methods Ninty children (age ranged from 5 days to 18 years) without abnormal central nervous system signs and symptoms and with normal head MRI were classified into 5 age groups:.infant group (group 1, ≤1 year old), young child group (group 2, ＞1-3 years old), pre-school age group (group 3, ＞3-6 years old), school age group (group 4, ＞6-12 years old) and adolescence group (group 5, ＞12-18 years old). Each age group was further subdivided into the gender subgroups. Diffusion tensor imaging (DTI) was performed and the regions of interest (ROI) were selected according to ROI method to reconstruct corticospinal tracts. All the diffusion coefficients of tracts were measured and analyzed statistically. Results The apparent diffusion coefficient(ADC) value, fractional anisotropy(FA) value, average length,Tracks and volume of tracts showed significance in different age groups (P<0.01). Post-Hoc test revealed that ADC value, FA value and average length were significantly different between age group 1 and 2. FA value presented significantly different between group 2 and 3. The differences of ADC value, FA value, average length, tracks and volume of tract were found between group 3 and 4. ADC value was negatively correlative with age. FA value, average length, tracks and volume of tract were all positively correlative with age. Conclusion Development of the corticospinal tract shows periodicity with periodic features. Diffusion tensor imaging can be used as a tool to observe and evaluate development of corticospinal tract in children.

Key words: Corticospinal tract, Sex difference, Diffusion tensor imaging, Magnetic resonance imaging, Child