167468.fig.001
Figure 1: Middle cerebral artery (M1) shows a minimal retrograde diastolic flow but the rest of the cycle shows a persistent diastolic flow that is not compatible with cerebral circulatory arrest. This was a 23-year-old male who suffered a traumatic brain injury developing refractory intracranial pressure that was treated with high-dose barbiturates. This pattern reflected high intracranial pressure (ICP 43 mmHg at the time of examination) with a pulsatility index of 2.14.