Radionuclide Evaluation of Brain Death in the Post-McMath Era

Abstract

Learning Objectives: On successful completion of this activity, participants should be able to (1) relate the diagnostic protocols and recommendations regarding the clinical diagnosis of brain death; (2) list the relative advantages and disadvantages of lipophilic and nonlipophilic blood flow radiopharmaceuticals for brain blood flow studies; and (3) consider how the nuclear medicine blood flow study could assist the clinician in making the difficult diagnosis of brain death.Financial Disclosure: The author of this article has indicated no relevant relationships that could be perceived as a real or apparent conflict of interest. CME Credit: SNMMI is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to sponsor continuing education for physicians. SNMMI designates each JNM continuing education article for a maximum of 2.0 AMA PRA Category 1 Credits. Physicians should claim only credit commensurate with the extent of their participation in the activity. For CE credit, SAM, and other credit types, participants can access this activity through the SNMMI website (http://www.snmmilearningcenter.org) through October 2019.The pronouncement of death is a determination of paramount social, legal, and ethical import. The novel construct of "brain death" was introduced 50 years ago, yet there persist gaps in understanding regarding this diagnosis on the part of medical caregivers and families. The tragic, much-publicized case of Jahi McMath typifies potential problems that can be encountered with this diagnosis and serves as an effective point of departure for discussion. This article recapitulates the historical development of brain death and the evolution of scintigraphic examinations as ancillary or confirmatory studies, emphasizing updated clinical and imaging practice guidelines and the current role of scintigraphy. The limitations of clinical and radionuclide studies are then reviewed. Finally, the article examines whether radionuclide examinations might be able to play an expanded role in the determination of brain death by improving accuracy and facilitating effective communication with family members.

Effects on organ donation of transition from apnoeic-oxygenation to radioisotope brain scanning to diagnose brain death in children

“…Although it is possible to observe an initial angiographic dynamic phase of perfusion in a dead brain [4] in the absence of intracranial hypertension, there will be no uptake of tracer and no radioactivity detected on delayed scanning. Other imaging techniques with computerised tomography or magnetic resonance, scanning with nonlipophilic radiopharmaceuticals and ultrasound techniques are less suitable for assessing brain function in the context of possible brain death because they can only yield initial angiographic data [4,13].…”

“…Importantly, images from brain scanning showing complete lack of tracer uptake are convincing evidence that a condition necessary for brain survival, i.e., brain blood fl ow or brain blood fl ow with uptake of tracer, is not present. It may be thus convincing not only for medical and nursing personnel that the affl icted child is dead and but also facilitate effective communication with family members [13,21] and is helpful in brain death donor counselling [22]. If limited tracer uptake and hence some blood fl ow is present, it reinforces clinical assessment and other imaging results which suggest the futility of continuing active treatment.…”

It is time to abandon apneic-oxygenation testing for brain death

“…A test for absence of brain blood fl ow may be a more stringent test for brain death than the apneic-oxygenation test because some brain blood fl ow may still remain when brain stem refl exes are absent [29][30][31]. Consequently, the rate of organ donation as a percentage of deaths may decrease.…”

Ethical aporia of organ donation development

“…Дело Джахи Мак Мат, равно как и аналогичные случаи, породило всплеск интереса к проблеме смерти мозга, и в частности, к исследованиям о необходимости уточнения порядка констатации диагноза «смерть мозга», унификации неврологических стандартов, использовании в процессе диагностики новых дополнительных подтверждающих методов. В отношении последних академическая публицистика запестрела различными обескураживающими заголовками статей, например, такими как «Радионуклидное исследование смерти мозга в эру пост-Мак Мат» [6].…”