Incidence, radiographical features, and proposed mechanism for pneumocephalus from intravenous injection of air.

Background: Pneumocephalus typically implies a traumatic breach in the meningeal layer or an intracranial gas-producing infection. Unexplained pneumocephalus on a head computed tomography (CT) in an emergency setting often compels emergency physicians to undertake aggressive evaluation and consultation.

Methods: In this paper, we report three cases of pneumocephalus that appear to result from retrograde injection of air through an intravenous (IV) catheter.