Gadolinium-enhanced magnetic resonance imaging (MRI) of the head showed a solid, enhancing lesion on the T1-weighted sequence, with a butterfly appearance that extended across the corpus callosum (Panel A). Hyperintensity of the mass was observed on the T2-weighted sequence (Panel B), and restricted diffusion was seen on diffusion-weighted MRI. #Radiology #MRI #ButterflyGlioma #Glioblastoma #NEJM