Deciding who needs exposure to radiation after blunt head injury has been looked at by both the Canadian Head Injury Guidelines as well as NEXUS. This website has excellent graphics outlining the rules. Note age over 65 alone is predictive of significant intracranial injury. All recent studies indicate age over 65 even with a low suspicion mechanism such as fall from standing is still a significant risk for intracranial pathology.
https://www.nuemblog.com/blog/emergency-neuroimaging-pt2
