Craniometric measures during development using MRI.

Developmental changes in brain volume and shape in infants, children, and adolescents were ascertained with MRI, using craniometric (linear brain) measures in 118 individuals, ages 1 postnatal week to 18.7years. Collected clinical data included age, sex, weight, height, body mass index, occipito-frontal circumference (OFC), and diagnosis prompting the MRI scan. Twenty craniometric measures were obtained to allow for the determination of specific ratios as well as sex and age-related changes in brain shape and size. Analysis of the cohort showed that OFC is larger today than 40years ago, likely related to a concomitant increase in body stature. The data indicated a wide variation in the maturational pattern of several specific craniometric ratios, which reflects changes in the volume and configuration of the brain with advancing age. The increases in brain volume and changes in brain shape were most dramatic during infancy, with continued minor escalations in volume and reshaping during childhood and adolescence. Sex differences existed both in brain volume and shape, as well as evidence of sexual dimorphism. Changes in cerebellar volume and shape lagged behind the corresponding changes in the cerebral hemispheres. These collective data in living developing individuals allow for comparisons of clinical or craniometric measures in distant and more recent humans.