Grey-white differentiation refers to the appearance of the interface between cerebral and cerebellar white matter and grey matter on brain CT and MRI.
The term is most often used when trying to differentiate cytotoxic from vasogenic edema.
- cytotoxic edema (see ionic edema), where there is a loss of grey-white differentiation (i.e. inability to distinguish white matter from grey matter which is typical for infarction and hypoxic-ischemic encephalopathy) and
- vasogenic edema where there is an accentuation of grey-white differentiation (which is typical for a tumor or abscess)