Confirmation of brain death using brain radionuclide perfusion imaging technique.

OBJECTIVE To determine the reliability of radionuclide cerebral blood perfusion imaging in confirming brain death irrespective of continued heartbeat. SUBJECTS AND METHODS Twenty-eight patients (19 male and 9 female, aged 17-63 years) with severe brain injury and fully supported until the final cardiac asystole were included in the study. Two sets of clinical tests aimed at ascertaining brain death in each subject were performed separately for each case within an interval of 24 h. Dynamic, planar and single photon emission computed tomographic (SPECT) brain scintigraphy were also performed after intravenous administration of 550 MBq (15 mCi) technetium-99m hexamethyl propyleneamine oxime. RESULTS Following the clinical diagnosis of brain death, none of the patients was withdrawn from cardiopulmonary support or had any organ harvested. Dynamic, planar and SPECT imaging performed thereafter did not reveal any intracranial cerebral perfusion in any of the subjects, except in 1 patient where the initial scan showed posterior fossa activity that ceased, in a subsequent scan obtained after 24 h. All of the patients were declared dead only after the emergence of cardiac asystole. CONCLUSION The findings indicate that radionuclide brain perfusion imaging is reliable, reproducible, noninvasive and simple to perform for the confirmation of brain death and as such we recommend it as an alternative to exhaustive neurophysiological tests and invasive catheter angiography.