Visualization of Cerebral Aneurysm on Tc-99m HMPAO Brain Perfusion Scintigram for Brain Death

A 58-year-old previously healthy woman without a history of trauma was brought to the emergency room unconscious, intubated, and unresponsive with both pupils fixed and dilated (Glasgow coma score 2-3) after collapsing in her office. Emergent CT scan showed a 2.5-cm giant aneurysm at the bifurcation of the right internal carotid artery with associated large subarachnoid hemorrhage. A Tc-99m hexamethlypropylene amineoxime (HMPAO) brain perfusion scan demonstrated radiotracer activity in the region of the giant aneurysm with no demonstrable cerebral or cerebellar hemispheric activity. A repeat Tc-99m HMPAO scan 24 hours later showed complete absence of radiotracer activity in the cerebral or cerebellar hemispheres, including the region of the giant aneurysm, and so the patient was diagnosed as brain dead.