Brain death test. Frontal angiogram (blood vessel X-ray) of the neck, skull and brain of a 72-year-old woman in a stage IV coma being tested for brain death. Confirmation that the patient is brain dead includes the absence of blood flowing into the brain, i.e. a lack of vascularization (blood supply) to the cerebral hemispheres from the internal carotid arteries and other supra-aortic blood vessels.