The parasagittal dura (PSD), a tissue that lines the walls of the superior sagittal sinus, acts as an active site for immune-surveillance, promotes the reabsorption of cerebrospinal fluid (CSF), and facilitates the removal of metabolic waste products from the brain. CSF is important for the distribution of growth factors that signal immature neurons to proliferate and migrate. Autism spectrum disorder (ASD) is characterized by altered CSF dynamics. In this retrospective study, we investigated potential correlations between PSD volume, brain structure volumes, and clinical severity scales in young children with ASD. We employed a Deep Learning based approach to extract PSD volume from 3D-T2 Fluid Attenuated Inversion Recovery sequences. PSD volumes did not change with age but was significantly correlated with extra-axial CSF volume and severity of developmental delay. These findings suggest that children with ASD may have a maldeveloped PSD that potentially perturbs CSF dynamics affecting neurodevelopment.