Presentation
Fall with head strike.
Patient Data
Normal small deposit of fat within the anterior portion of the falx and posterior portions of both cavernous sinuses.
Case Discussion
It is not uncommon for small deposits of fat to exist intracranially within the falx and around the cavernous sinuses. With standard CT brain window settings these fat deposits appear black and can be misinterpreted as being air (pneumocephalus) by the inexperienced reader. If there is any doubt, switching to lung or bone windows will allow the density difference between air and fat to be readily appreciated, as fat will turn grey and air will stay black.