and the interpretation of transcranial Doppler in the context of brain death were answered.The basic consensus statements are the following: cerebral circulatory arrest is the final stage in the evolution of progressive intracranial hypertension, which is visualized with transcranial Doppler as a "pattern of cerebral circulatory arrest".The following are accepted as the standard of cerebral circulatory arrest: reverberant pattern, systolic spikes, and absence of previously demonstrated flow.Ultrasonography should be used -in acceptable hemodynamic conditions -in the anterior circulation bilaterally (middle cerebral artery) and in the posterior (basilar artery) territory.If no ultrasonographic images are found in any or all of these vessels, their proximal arteries are acceptable to be studied to look for a a pattern of cerebral circulatory arrest.