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Difficulty: HardOrdering Imaging Studies

A 28-year-old man is evaluated in the emergency department following a high-speed motor vehicle collision in which he was the restrained driver. He reports mild neck pain but denies headache, visual changes, or numbness. Vital signs are temperature 37.0 C (98.6 F), heart rate 102/min, blood pressure 138/85 mm Hg, and respiratory rate 16/min. His Glasgow Coma Scale score is 15. Physical examination is notable for an extensive oblique ecchymosis and abrasion across the anterior left neck corresponding to a seatbelt mark. Neurological examination reveals normal cranial nerve function and 5/5 motor strength in all extremities. Laboratory testing shows a hemoglobin of 13.5 g/dL and normal coagulation parameters. A non-contrast computed tomography (CT) scan of the head and cervical spine reveals a fracture of the petrous portion of the left temporal bone extending into the carotid canal, with no evidence of intracranial hemorrhage or cervical spine fractures. Which of the following is the most appropriate next imaging study?

  1. Computed tomography angiography of the neckAnswer
  2. B
    Catheter-directed digital subtraction angiography
  3. C
    Duplex ultrasonography of the carotid arteries
  4. D
    Magnetic resonance angiography of the head and neck
  5. E
    Repeat non-contrast computed tomography of the head in 24 hours

Answer

Computed tomography angiography of the neck is the most appropriate next imaging study to actively screen for blunt cerebrovascular injury (BCVI).
The correct response is computed tomography angiography of the neck. This patient has multiple indications for blunt cerebrovascular injury (BCVI) screening, including a high-energy trauma mechanism, a soft-tissue seatbelt sign on the neck, and a petrous temporal bone fracture involving the carotid canal. Early recognition of BCVI is critical because prompt initiation of antithrombotic therapy can prevent devastating ischemic strokes. According to standard trauma guidelines (such as the modified Denver criteria), computed tomography angiography (CTA) of the neck is the most appropriate and widely accepted non-invasive screening modality. It is highly sensitive, rapidly available, and allows for simultaneous evaluation of the cervical spine.

Step-by-Step Solution

1
Analyze the patient's trauma mechanism and physical findings.
The patient experienced a high-speed collision and has a 'seatbelt sign' on the neck along with a basilar skull fracture (petrous temporal bone involving the carotid canal).
Identifying high-risk clinical features is required to apply evidence-based trauma screening guidelines.
2
Correlate findings with the risk of vascular injury.
These findings fulfill the established screening criteria (e.g., Denver criteria) for suspected blunt cerebrovascular injury (BCVI).
BCVI, such as carotid or vertebral artery dissection, can present without immediate neurological deficits but risks subsequent severe ischemic stroke.
3
Determine the optimal diagnostic imaging study.
Computed tomography angiography (CTA) of the neck is selected as the initial modality.
CTA is highly sensitive, non-invasive, rapidly acquirable in a trauma bay, and is the standard of care for BCVI screening.

Key Concept

Screening for Blunt Cerebrovascular Injury (BCVI)
Estimated Time:1m 30s
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Topics

Ordering Imaging Studies

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