Presentation
Patient comatose on arrival in the emergency department following a cardiac arrest with prolonged downtime at the scene.
Patient Data

Generalized cerebral edema. The basal cisterns appear dense (pseudo-subarachnoid hemorrhage) likely due to combination of cistern effacement, possible thrombus within intracranial vessels and surrounding relatively low attenuating brain.
Case Discussion
Non-contrast CT Brain shows generalized sulcal effacement and cerebral hypoattenuation with loss of grey-white differentiation consistent with cerebral edema secondary to intracranial hypoxia. The basal cisterns appear dense likely due to combination of cistern effacement, possible thrombus within intracranial vessels and surrounding relatively low attenuating brain. This appearance has been termed pseudo-subarachnoid hemorrhage. Brain death was subsequently confirmed with nuclear medicine cerebral perfusion scan.