What are the indications for imaging in patients with trauma, and which imaging modalities are preferred?

The indications for imaging in trauma patients and the preferred modalities vary depending on the body region and the patient's age ¹,²,³.

• Head Injury
  • Preferred Modality: Computed Tomography (CT) imaging of the head is the primary investigation for detecting acute clinically important traumatic brain injury ¹. Magnetic Resonance Imaging (MRI) is not the primary investigation but can provide additional prognostic information ¹. Plain X-rays of the skull should not be used to diagnose important traumatic brain injury ¹.
  • Indications for CT Head (People 16 and over): A CT head scan should be performed within 1 hour if any of the following risk factors are identified: a GCS score of 12 or less on initial assessment, a GCS score of less than 15 at 2 hours after injury, suspected open or depressed skull fracture, any sign of basal skull fracture (e.g., haemotympanum, 'panda' eyes, CSF leakage, Battle's sign), post-traumatic seizure, focal neurological deficit, or more than 1 episode of vomiting ¹. A CT head scan should be performed within 8 hours (or within 1 hour if presenting more than 8 hours after injury) for those with some loss of consciousness or amnesia since the injury, if they have any of these risk factors: age 65 or over, any current bleeding or clotting disorders, dangerous mechanism of injury (e.g., pedestrian/cyclist struck by vehicle, occupant ejected from vehicle, fall from >1m or 5 stairs), or more than 30 minutes' retrograde amnesia ¹.
  • Indications for CT Head (People under 16): A CT head scan should be performed within 1 hour if any of these risk factors are identified: suspicion of non-accidental injury, post-traumatic seizure, a GCS score of less than 14 (or less than 15 for babies under 1 year) on initial assessment, a GCS score of less than 15 at 2 hours after injury, suspected open or depressed skull fracture or tense fontanelle, any sign of basal skull fracture, focal neurological deficit, or for babies under 1 year, a bruise, swelling or laceration of more than 5 cm on the head ¹.
• Spinal Injury
  • Preferred Modality: For adults (16 or over), CT is performed if imaging for cervical spine injury is indicated by the Canadian C-spine rule, or if there is a strong suspicion of thoracic or lumbosacral spine injury associated with abnormal neurological signs or symptoms ². If a neurological abnormality attributable to spinal cord injury is present, MRI should be performed after CT ². For suspected spinal column injury without abnormal neurological signs or symptoms in the thoracic or lumbosacral regions, an X-ray is the first-line investigation ². If the X-ray is abnormal or clinical signs/symptoms of a spinal column injury are present, CT should be performed ². For children (under 16) with head injury and suspected cervical spine injury, the head injury guidelines should be followed ². Plain X-rays can be considered in children who do not meet MRI criteria but have persistent clinical suspicion after repeated assessment ².
  • Indications for CT Spine (Adults 16+): Indicated by the Canadian C-spine rule for cervical spine injury, or strong suspicion of thoracic or lumbosacral spine injury with abnormal neurological signs or symptoms ².
  • Indications for MRI Spine (Adults 16+): Performed after CT if there is a neurological abnormality which could be attributable to spinal cord injury ².
  • Indications for X-ray Spine (Adults 16+): First-line for suspected spinal column injury without abnormal neurological signs or symptoms in the thoracic or lumbosacral regions (T1–L3) ².
  • Indications for CT Spine (Children under 16): Follow head injury guidelines for cervical spine injury ². Perform CT if an X-ray is abnormal or there are clinical signs or symptoms of a spinal column injury ².
  • Indications for X-ray Spine (Children under 16): Consider if MRI criteria are not met but clinical suspicion remains after repeated clinical assessment ².
• Pelvic Fractures
  • Preferred Modality: CT is used for first-line imaging in adults (16 or over) with suspected high-energy pelvic fractures ³. For children (under 16) with suspected high-energy pelvic fractures, CT is preferred over X-ray when CT of the abdomen or pelvis is already indicated for other injuries, or can be considered when not indicated for other injuries, with clinical judgement to limit CT to necessary areas ³.
  • Indications for CT Pelvis (Adults 16+): Suspected high-energy pelvic fractures ³.
  • Indications for CT Pelvis (Children under 16): Suspected high-energy pelvic fractures, especially if CT of the abdomen or pelvis is already indicated for assessing other injuries ³.
• Whole-Body CT
  • Preferred Modality: Whole-body CT consists of a vertex-to-toes scanogram followed by CT from vertex to mid-thigh ²,³.
  • Indications for Whole-Body CT (Adults 16+): Used in adults (16 or over) with blunt major trauma and suspected multiple injuries ²,³.
  • Indications for Whole-Body CT (Children under 16): Not routinely used; clinical judgement should be used to limit CT to the body areas where assessment is needed ²,³.