Detection of intracranial circulatory arrest in brain death using cranial CT-angiography
Background and purpose
Computed tomographic-angiography (CT-A) is becoming more accepted in detecting intracranial circulatory arrest in brain death (BD). An international consensus about the use and the parameters of this technique is currently not established. We examined intracranial contrast enhancement in CT-A after clinically confirmed BD, compared the results with electroencephalography (EEG) and Transcranial Doppler Ultrasonography (TCD) findings and developed a commonly applicable CT-A protocol.
Prospective, monocentric study between April 2008 and October 2011. EEG, TCD and CT-A were performed in 63 patients aged between 18 and 88 years (mean, 55 years) who fulfilled clinical criteria of BD. Evaluation of opacification of cerebral vascular territories in CT-A was performed in arterial as well as in venous scanning series by a neuroradiologist and a neurointensivist/neurosurgeon together.
CT-A demonstrated a 95% sensitivity in detecting intracranial circulatory arrest when analysing arterial scanning series. We never observed venous blood return in internal cerebral veins. In three cases, BD confirmation by EEG failed because of artefacts. Confirmation of BD by TCD failed in two cases because of absent temporal window. In three cases, TCD demonstrated residual blood flow.
CT-A is easily accessible in almost every hospital, offers a high spatio-temporal resolution, is operator independent and inexpensive. The results of CT-A are comparable to other established brain perfusion techniques in BD. An international consensus should be established to ascertain consistent parameters similar to fixed guidelines for other ancillary procedures to determine BD in order to prevent different scanning and evaluation protocols for detecting intracranial circulatory arrest.