Fig. 3

Typical MRI features of tectal glioma. a Sagittal post-contrast T1-weighted image shows a typical non-enhancing, T1 hypointense lesion obstructing the cerebral aqueduct (*). b Axial T2-weighted image shows typical T2 hyperintensity of the lesion (*), and periventricular CSF accumulation indicative of hydrocephalus. c on ADC map, tectal gliomas (*) are typically high in signal (“facilitated” diffusion)