From the Guidelines
Head CT scans are indicated for patients with head injuries who meet specific clinical criteria, including a Glasgow Coma Scale (GCS) score less than 15, suspected skull fracture, or signs of basilar skull fracture, as recommended by the American College of Radiology Appropriateness Criteria (1).
Indications for Head CT
The following are indications for head CT in patients with head injuries:
- Glasgow Coma Scale (GCS) score less than 15
- Suspected skull fracture
- Signs of basilar skull fracture (raccoon eyes, Battle's sign, hemotympanum, CSF otorrhea or rhinorrhea)
- Post-traumatic seizure
- Focal neurological deficits
- Persistent vomiting (two or more episodes)
- Age over 65 years
- Anticoagulant use or coagulopathy
- Dangerous mechanism of injury (pedestrian struck by vehicle, ejection from vehicle, fall from height greater than 3 feet or 5 stairs)
- Retrograde amnesia greater than 30 minutes
- Persistent severe headache ### Clinical Decision Rules Clinical decision rules, such as the Canadian CT Head Rule and the New Orleans Criteria, have been developed to help clinicians determine when CT imaging is necessary while minimizing unnecessary radiation exposure (2).
Rationale for Indications
The rationale for these indications is to identify potentially life-threatening intracranial injuries that require urgent intervention, such as epidural hematomas, subdural hematomas, subarachnoid hemorrhage, cerebral contusions, or skull fractures with depression or CSF leak (3).
Importance of Early Detection
Early detection of these conditions can significantly improve patient outcomes by enabling timely neurosurgical intervention when needed (4).
Additional Considerations
Additionally, patients with intoxication, multiple injuries, or those in whom reliable follow-up cannot be ensured may warrant CT imaging (5).
From the Research
Indications for Head CT in Head Injuries
The following are indications for head CT in the case of head injuries:
- Patients with a Glasgow Coma Score (GCS) of 14 or 15, with a skull fracture and/or neurological deficits 6
- Patients with a GCS of 15 and one or more of the following symptoms: loss of consciousness, amnesia, vomiting, or diffuse headache, where there is one computed tomography (CT) scanner available in an area for 100,000 people or less 6
- Patients with loss of consciousness or post-traumatic amnesia, as these are strongly associated with traumatic findings on CT 7
- Patients with disorientation, abnormal alertness, somnolentia, and neurological deficits, as these are features most predictive for intracranial injuries 8
- Patients with coagulopathy, drug or alcohol consumption, previous neurosurgical procedures, pretrauma epilepsy, or age over 60 years, as these are risk factors for intracranial hematoma requiring surgical evacuation 6
Routine Repeat Head CT
Routine repeat head CT is indicated for:
- Patients with a GCS score < or =8, as results might lead to intervention without neurologic change 9
- Patients who undergo neurologic deterioration, as it leads to intervention in over one-third of patients 9
- Patients with mild to moderate head injury and an initial positive abnormal CT scan, to identify the possible progression of injury 10
Clinical Decision Rules
Clinical decision rules, such as the Canadian Computed Tomography Head Rule, can be used to determine indications for performing head CT following minor head injuries, and can help reduce the number of imaging studies performed 8