Table 1.

Ancillary tests recommended in Brazilian Federal Council of Medicine Resolution 2.173.^*

Ancillary test	Purpose
Cerebral DSA	To demonstrate the absence of intracranial flow in the internal carotid and vertebral arteries, above the ophthalmic artery and basilar artery, respectively, according to the technical standards of the Brazilian College of Radiology
Electroencephalography	To verify electrical inactivity or electrical silence in the brain, according to the technical standards of the Brazilian Society of Clinical Neurophysiology
Transcranial Doppler ultrasound	To verify the absence of intracranial blood flow due to the presence of reverberant diastolic flow, or small peaks in the initial phase of systole, as established by the Scientific Department of Neurosonology of the Brazilian Academy of Neurology
Brain scintigraphy/SPECT	To demonstrate the absence of brain perfusion or metabolism, according to the technical standards of the Brazilian Society of Nuclear Medicine

^*In Brazil, the diagnosis of brain death is based on the presence of coma, absence of brainstem function, and absence of respiratory movements on an apnea test in two different clinical examinations. The performance of at least one ancillary test to unequivocally demonstrate the absence of blood perfusion or electrical or metabolic brain activity is mandatory.