When a child has lost consciousness due to a head injury—even for a short period of time—doctors will run a battery of diagnostic tests in order to determine the type, location, and severity of the injury. Tests may include:

• X-rays. These “photograph” the bones of the skull, and can determine whether fractures are present.

• Computerized Tomography (CT) scan. This test looks at the structure of the brain by photographing it in “slices.” The CT scan is the best test for detecting blood in and around the brain.

• Magnetic Resonance Imaging (MRI) scan. This scan also looks at the structure of the brain in “slices,” but does so using magnetic fields. The MRI scan is significantly more detailed than the CT scan, and can pick up things that the CT scan can’t. The MRI does not detect fresh blood in and around the brain as well as the CT scan.

• Electroencephalogram (EEG). An EEG shows the brain’s activity via wires that are attached to the scalp of the child.