Confirmation of Brain Death Using Brain Radionuclide Perfusion Imaging Technique

Abstract

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 Results: Following the clinical diagnosis of brain death, none of the patients was withdrawn from cardiopulmonary support or had any organ harvested.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.

Confirmatory tests in the diagnosis of brain death: Comparison between SPECT and contrast angiography

“…These data empirically showed good SPECT sensitivity in lowflow states progressing toward zero flow. Furthermore, in a recent study (34) from Kuwait, all brain dead patients with absent brain perfusion by SPECT had terminal cardiac arrest despite being fully supported.…”

Radionuclide Evaluation of Brain Death in the Post-McMath Era

“…These definitions are not congruent, with internal inconsistencies that can ultimately lead to contradictory conclusions (15). Reports in the literature persist of patients in whom the physical examination unequivocally demonstrated brain death, yet specific confirmatory tests indicated the presence of blood flow, electrical activity, or other phenomena (15,53,81,96). Although erroneous performance of either the physical examination or the confirmatory test is a possible cause of conflicting findings, Wijdicks believes that the clinical entity of brain death can coexist with preserved blood flow on ancillary examinations and should not deter a physician from declaring patients dead after complete and properly conducted physical examinations and apnea testing (57,97).…”

Clinical Utility of Arterial Spin-Labeling as a Confirmatory Test for Suspected Brain Death

“…The finding was modified from the hollow skull sign described in scintigraphy for the diagnosis of brain death. 10,12,16,17 Figure 1 shows representative images of each criterion. All images were spatially normalized to the ethnicity-specific T1 template before determining CBF by using SPM5 software (http://www.fil.ion.ucl.ac.uk/spm/software/spm5) and custom scripts in Matlab 7.6.0, R2008 (MathWorks, Natick, Massachusetts).…”