Outcome Classification of Preschool Children With Autism Spectrum Disorders Using MRI Brain Measures

To test the hypothesis that a combination of magnetic resonance imaging (MRI) brain measures obtained during early childhood distinguish children with autism spectrum disorders (ASD) from typically developing children and is associated with functional outcome. Quantitative MRI technology was used to measure gray and white matter volumes (cerebrum and cerebellum), total brain volume, and the area of the cerebellar vermis in 52 boys with a provisional diagnosis of autism (aged 1.9–5.2 years) and 15 typically developing young children (aged 1.7–5.2 years). Diagnostic confirmation and cognitive outcome data were obtained after the children reached 5 years of age. A discriminant function analysis of the MRI brain measures correctly classified 95.8% of the ASD cases and 92.3% of the control cases. This set of variables also correctly classified 85% of the ASD cases as lower functioning and 68% of the ASD cases as higher functioning. These results indicate that variability in cerebellar and cerebral size is correlated with diagnostic and functional outcome in very young children with ASD.