Magnetic resonance image (MRI) of cystic glioblastoma. A T1-weighted MRI obtained after intravenous infusion of a gadolinium-based contrast agent shows a contrast-enhancing cystic glioblastoma in the right temporal lobe. The arrow indicates the cyst. Arrowheads indicate contrast-enhancing tumor, in which leaky capillaries allow the contrast agent to escape into the tumor tissue. Asterisks indicate the peri-tumoral edema, which appears darker than the surrounding brain tissue