Inclusion Criteria:  All patients in an emergency situation with a head trauma requiring a scan, i.e. moderate or severe skull trauma, Group 1 or 2 according to the Brain Trauma Task Force classification (Guidelines for management of severe head injury. J Neurotrauma 2000 ; 17 : 507-11) as described by P. Schoettker et al. 2001). Patient with an isolated skull trauma or polytraumatized patient including skull trauma. Patient capable of giving informed consent or for whom a person of confidence or legal representative / family member has given informed consent and signed the consent form on the patient's behalf if the patient has been included in an emergency. Patients affiliated to or beneficiary of a health insurance scheme. All adult patients aged 18 or over.  Exclusion Criteria:  Patients already taking part in another study for which it is not allowed to participate in other clinical studies. Patients in an exclusion period determined by another study. Patients who are pregnant, breastfeeding or about to give birth.