Death by neurologic criteria: a nuclear medicine approach based on the 2023 AAN/AAP/CNS/SCCM Guideline and 2025 SNMMI...

Death by neurologic criteria, previously called brain death, is a medicolegal concept, fraught with legal, ethical, and emotional considerations. The diagnosis is established clinically as described in the appropriate interdisciplinary guidelines. When adequate clinical evaluation cannot be performed, imaging including radionuclide brain perfusion scintigraphy (RBPS), four-vessel catheter angiography, or transcranial Doppler can be used as ancillary tests. Of these, RBPS is the more commonly performed test, used to establish the presence or absence of intracranial perfusion. Scintigraphic imaging for the presence or absence of intracranial perfusion is infrequently requested, which limits familiarity with both performing and interpreting these studies. The purpose of this article is to help the radiologist and nuclear medicine physician better understand the concept of death by neurologic criteria and the role of scintigraphic imaging in supporting the clinical diagnosis in the light of most recent multidisciplinary guidelines. A second goal is to describe how to interpret and report the relevant imaging studies, emphasizing differences between children and adults where applicable.