Abstract
Ancillary tests can be used for the diagnosis of brain death in cases wherein uncertainty exists regarding the neurological examination and apnoea test cannot be performed. Transcranial Doppler ultrasonography (TCD) is a useful, valid, non-invasive, portable, and repeatable ancillary test for the confirmation of brain death. Despite its varying sensitivity and specificity rates with regard to the diagnosis of the brain death, its clinical use has steadily increased in the intensive care unit because of its numerous superior properties. The use of TCD as an ancillary test for the diagnosis of brain death and cerebral circulatory arrest is discussed in the current review.