Technetium-99m-HMPAO cerebral perfusion scintigraphy: considerations for timely brain death declaration.

The lipophilic cerebral perfusion agent 99mTc-hexamethylpropylene amine oxime (HMPAO) is increasingly used to demonstrate the absence of blood flow for the declaration of brain death. We report a case that illustrates how the timing of such studies is important when organ harvesting is the underlying emergent indication. If performed too early, a study showing the presence of cerebral perfusion may not expedite the declaration of brain death, but instead may complicate patient assessment and unnecessarily delay the process.