VOLUMETRIC-ANALYSIS OF THE NORMAL INFANT BRAIN AND IN INTRAUTERINE GROWTH-RETARDATION

Twenty-eight infants with postmenstrual ages (PMA) in the range of 32- 80 weeks were investigated. Twenty were newborn; among these the obser ved birth weight divided by the expected weight ranged from 0.31 to 1. 1. Axial magnetic resonance images were recorded with a triple spin-ec ho sequence and the volumes were determined by encircling each structu re of interest on every slice, Segmentation into grey matter, white ma tter and CSF was done by semi-automatic discriminant analysis, Growth charts for the cerebrum, cerebellum, corpora striata, thalami, ventric les, and grey and white matter are provided for infants with appropria te birth weight. The striatal (P = 0.02) and thalamic (P < 0.001) perc entage of the hemispheric volume decreased with age, whereas the ratio of grey matter to white matter (G/W-ratio) increased (P = 0.01). In t he neonatal patients, brain volumes were independently associated with both PMA and the degree of growth retardation. It was calculated that the hemispheric volume was reduced by from 16% to 23% if the total bo dyweight was reduced by 40%, The G/W-ratio was found to be independent ly associated with the PMA (P < 0.05) and the degree of IUGR (P < 0.1) suggesting that fetal growth retardation reduces grey matter volume m ore than white matter.