Fig. 18

Radiation necrosis with dementia. A 52-year-old male with history of nasopharyngeal carcinoma with radiotherapy developed progressive decline in cognition after 7 years of treatment. a axial post contrast T1W image at the level of skull base (2003) shows heterogeneously enhancing right side nasopharyngeal carcinoma (black arrow). b axial post contrast T1W image of the skull base (2007) reveals complete resolution of the mass lesion (white arrow). c & d axial FLAIR and post contrast T1W images of the brain at the level of middle cranial fossa (2010) demonstrate extensive white matter hyperintensity (black arrows) and heterogeneous enhancement—“Swiss-cheese” pattern in bilateral temporal lobes (white arrows)