FIGURE 1.

Illustrations of (a). A pseudoprogression resulting from radiation‐induced inflamed necrosis. Magnetic resonance (MR) images taken post‐operatively show axial T2, fluid attenuated inversion recovery (FLAIR), T1 contrast‐enhanced and perfusion, with enhancement in the right temporal lobe and areas of T2/FLAIR hyperintensity in the surrounding parenchyma, indicating a lesion induced by radiation therapy. There is no increase in relative cerebral blood volume in the enhancing portion of the lesion, which further suggests pseudoprogression. (b) A tumor relapse shown by images taken from the same patient 3 months later. MR images taken post‐operatively show axial T2, FLAIR, T1 contrast‐enhanced and perfusion, with heterogeneous enhancement in the right temporal lobe and great extension of the T2/FLAIR hyperintensity area, indicating a combination of tumor spread and vasogenic edema involving the right peritrigonal and insular regions. There is increased relative cerebral blood volume in the enhancing portion of the lesion, representing tumoral progression. Anonymised image.