Multivariate Longitudinal Shape Analysis of Human Lateral Ventricles during the First Twenty-Four Months of Life

Background: Little is known about the temporospatial shape characteristics of human lateral ventricles (LVs) during the first two years of life. This study aimed to delineate the morphological growth characteristics of LVs during early infancy using longitudinally acquired MR images in normal healthy infants. Methods: 24 healthy infants were MR imaged starting from 2 weeks old every 3 months during the first and every 6 months during the second year. Bilateral LVs were segmented and longitudinal morphological and shape analysis were conducted using longitudinal mixed effect models. Results: A significant bilateral ventricular volume increase (p,0.0001) is observed in year one (Left: 126651 % and Right: 145662%), followed by a significant reduction (p,0.02) during the second year of life (Left: 224627 % and Right: 220618%) despite the continuing increase of intracranial volume. Morphological analysis reveals that the ventricular growth is spatially non-uniform, and that the most significant growth occurs during the first 6 months. The first 3 months of life exhibit a significant (p,0.01) bilateral lengthening of the anterior lateral ventricle and a significant increase of radius (p,0.01) and area (p,0.01) at the posterior portion of the ventricle. Shape analysis shows that the horns exhibit a faste