NICE guidelines for Head injury scanning for children:
Children
1.4.9For children who have sustained a head injury and have any of the following risk factors, perform a CT head scan within 1 hour of the risk factor being identified:
Suspicion of non-accidental injury
Post-traumatic seizure but no history of epilepsy.
On initial emergency department assessment, GCS less than 14, or for children under 1 year GCS (paediatric) less than 15.
At 2 hours after the injury, GCS less than 15.
Suspected open or depressed skull fracture or tense fontanelle.
Any sign of basal skull fracture (haemotympanum, 'panda' eyes, cerebrospinal fluid leakage from the ear or nose, Battle's sign).
Focal neurological deficit.
For children under 1 year, presence of bruise, swelling or laceration of more than 5 cm on the head.
A provisional written radiology report should be made available within 1 hour of the scan being performed. [new 2014]
1.4.10For children who have sustained a head injury and have more than 1 of the following risk factors (and none of those in recommendation 1.4.9), perform a CT head scan within 1 hour of the risk factors being identified:
Loss of consciousness lasting more than 5 minutes (witnessed).
Abnormal drowsiness.
Three or more discrete episodes of vomiting.
Dangerous mechanism of injury (high-speed road traffic accident either as pedestrian, cyclist or vehicle occupant, fall from a height of greater than 3 metres, high-speed injury from a projectile or other object).
Amnesia (antegrade or retrograde) lasting more than 5 minutes[4].
A provisional written radiology report should be made available within 1 hour of the scan being performed. [new 2014]
1.4.11Children who have sustained a head injury and have only 1 of the risk factors in recommendation 1.4.10 (and none of those in recommendation 1.4.9) should be observed for a minimum of 4 hours after the head injury. If during observation any of the risk factors below are identified, perform a CT head scan within 1 hour:
GCS less than 15.
Further vomiting.
A further episode of abnormal drowsiness.
A provisional written radiology report should be made available within 1 hour of the scan being performed. If none of these risk factors occur during observation, use clinical judgement to determine whether a longer period of observation is needed. [new 2014]