Confounding Factors in the Detection of Intracranial Hemorrhage With the Infrascanner

The investigators prospectively want to use the Infrascanner in patients with ischemic stroke, patients with brain surgery, patients with brain tumors, patients with intracranial hemorrhage and patients with a normal CT scan of the brain as part of a diagnostic work-up after head trauma or headache to determine to positive and negative predictive value of the Infrascanner in these different settings.