Dynamic CT with brain death

Dynamic CT studies were performed on three patients who were diagnosed symptomatically as ''brain-dead'' and on another patient whose EEG was flat due to an overdosage of a barbiturate. Dynamic studies in two of the three patients with presumed brain death revealed no increase in attenuation values, and EEG studies showed no electrical activities of the brain. However, in the one remaining patient whose EEG retained some activity, a dynamic study showed an increase in attenuation values in the circle of Willis. In contrast, the patient whose EEG was flat due to a barbiturate overdosage had a somewhat slowed, but still significant, increase in attenuation values, indicating a decreased but maintained cerebral circulation. Although brain death has been accepted as a concept, no criteria for its diagnosis are widely agreed on, and the necessity for a more refined confirmatory test is increasing. The advantage of this method is that the circulation in the posterior fossa including the brainstem can be evaluated simultaneously if an appropriate slice is selected. Because this method is relatively non-invasive and technically simple, we consider it valuable as an aid in the diagnosis of brain death. (author)