What type of CT (Computed Tomography) scan is recommended for concussion symptoms?

Appropriate CT Scan Type for Concussion Symptoms

For patients with concussion symptoms, a noncontrast head CT is the most appropriate initial imaging modality when imaging is indicated by clinical decision rules. 1

Clinical Decision Rules for Determining Need for CT Imaging

The need for CT imaging in concussion should be guided by validated clinical decision rules:

• For adults with mild head trauma (GCS 13-15) with loss of consciousness (LOC) or post-traumatic amnesia (PTA), a noncontrast head CT is indicated if any of these risk factors are present:

  • Headache
  • Vomiting
  • Age >60 years
  • Drug or alcohol intoxication
  • Short-term memory deficits
  • Physical trauma evidence above the clavicle
  • Post-traumatic seizure
  • GCS score <15
  • Focal neurologic deficit
  • Coagulopathy 1

• For adults with mild head trauma without LOC or PTA, a noncontrast head CT should be considered with any of these factors:

  • Focal neurologic deficit
  • Vomiting
  • Severe headache
  • Age ≥65 years
  • Signs of basilar skull fracture
  • GCS score <15
  • Coagulopathy
  • Dangerous mechanism of injury (e.g., ejection from vehicle, pedestrian struck, fall >3 feet) 1

Imaging Recommendations Based on Trauma Severity

The imaging approach should be tailored to the severity of head trauma:

• Mild head trauma (GCS 13-15):

  • No imaging when clinical decision rules indicate low risk 1
  • Noncontrast head CT when clinical decision rules indicate moderate to high risk 1

• Moderate head trauma (GCS 9-12) or severe head trauma (GCS 3-8):

  • Noncontrast head CT is always appropriate as the initial imaging study 1

• Subacute or chronic head trauma with persistent symptoms:

  • Noncontrast brain MRI or noncontrast head CT are appropriate options 1
  • MRI is more sensitive for subtle findings and small white matter lesions that may explain persistent symptoms 1

Important Clinical Considerations

• Despite the increasing awareness of concussions, studies show a concerning trend of increased head CT utilization (35.7% increase from 2006 to 2011) despite decreasing injury severity 2

• Contrast-enhanced CT provides minimal additional value in the initial evaluation of concussion and represents unnecessary cost and radiation exposure 3

• For most concussions (which are mild TBIs), conventional CT and MRI are typically normal despite clinical symptoms, as these modalities cannot detect microstructural and functional brain pathology 4, 5

• In pediatric patients, clinical decision rules such as PECARN criteria should be used to determine the need for imaging, with a focus on minimizing radiation exposure 1

Follow-up Imaging Considerations

• Noncontrast head CT is appropriate for short-term follow-up in patients with:

  • Positive findings on initial imaging (e.g., subdural hematoma) 1
  • New or progressive neurologic deficits 1

• For persistent symptoms beyond the acute phase, noncontrast brain MRI may be more appropriate than repeat CT as it offers superior soft tissue contrast and can detect subtle abnormalities not visible on CT 1, 5