Normative volumetric data of the developing hippocampus in children based on magnetic resonance imaging

Purpose: To acquire normative data of the hippocampus and its postnatal gro wth in 50 children (age, 1 month to 15 years) without epilepsy. Methods: Morphometry of the hippocampus was carried out by using a spoiled FLASH 3D sequence (sagittal orientation), whereas the Volume of the brain w as assessed with a T-2-weighted spin-echo sequence (transverse orientation) . The volume of the hippocampus and the brain was determined by following C avalieri's principle. Growth curves of the brain and hippocampus were fitte d to a nonlinear Boltzmann sigmoidal equation. Results: Intra-/interobserver coefficient of variation was 2.0/4.9% for hip pocampal volume measurements and 2.0/2.1% for brain volumetry. A significan t difference in Volume was noted between the right and left hippocampus (p < 0.001), with the right side being larger on average by 0.10 cc. Correlati on coefficients of growth curves ranged between 0.71 and 0.94. Growth curve s demonstrated a faster development of the hippocampus in girls. A steeper slope of hippocampal growth as compared with brain growth was found in girl s, whereas in boys, the slope of brain growth was steeper. Conclusions: Our findings will be of help in evaluating vulnerable phases o f the hippocampal formation with accelerated growth, thereby leading to a b etter understanding of the development of hippocampal sclerosis in early ch ildhood.