Paediatric optic pathway glioma (OPG) is a low-grade glioma whose cells likely originate from the subventricular zone of the third ventricle (TVZ). Neurofibromatosis type-1 (NF1) OPG is less clinically aggressive than sporadic OPG, being less likely to cause visual function deficit. Using measures of migrating tumour activity, this study analysed the imaging profiles at the TVZ. Apparent diffusion coefficient (ADC) and cerebral blood flow (CBF) profiles associated with migrative tumour cell activity were detected at the TVZ and correlated with poor visual function in sporadic, but not NF1-associated, cases. These results suggest that MRI can identify imaging characteristics that differentiate sporadic and NF1-associated OPG.