Aneurysmal subarachnoid hemorrhage (SAH) is a devastating form of stroke, with three major complications : early brain injury (EBI), vasospasm and delayed cerebral ischemia (DCI). Those patients are often given care in neurocritical care. Imaging is particularly useful to diagnose these complications. Brain imaging includes CT scan, MRI and arteriography which are not easily available and need an intrahospital transportation. Furthermore, intrahospital transportation of critically ill patients is associated with significant complications Here, investigators try to show that a new non-invasive bedside device, based on 3D enhanced ultrasonography, is able to detect principal arteries of anterior circulation of the brain.