Age- and sex-specific normative curves for intracranial and ventricular volumes from head CT scans

This study aims to establish age- and sex-specific normative curves for intracranial (ICV) and lateral ventricular volumes (LVV) using computed tomography (CT), addressing a significant gap in the literature. A total of 2153 head CT scans were analyzed, using the Generalized Additive Model for Location, Scale, and Shape (GAMLSS) to model the nonlinear relationship between age and volume of the brain structures, independently by sex. Model quality was evaluated through chi-square adherence test and residual analysis. Bootstrap resampling was used to generate 95% confidence intervals for the centile estimates. The results reveal distinct growth patterns for ICV, which peaks early in life, and LVV, which increases throughout life. Significant sexual dimorphism was found, with males showing larger volumes for both structures. Brain charts detailing the mean and median trends and coefficient of variation are presented and compared with previously published normative ranges. These normative curves have the potential to serve as important tools for research and clinical practice, facilitating the differentiation between normal and pathological brain changes, particularly in settings where CT is more accessible than magnetic resonance imaging (MRI).