CT Maxillofacial (Facial CT) Without Contrast
For a significant facial hematoma, obtain a CT maxillofacial (facial CT) without contrast as the first-line imaging study to evaluate for underlying fractures, assess the extent of soft tissue injury, and identify any complications requiring urgent intervention 1.
Rationale and Clinical Approach
Why CT Maxillofacial is the Primary Study
Multidetector CT (MDCT) provides superb delineation of both osseous and soft-tissue structures with high image resolution that allows detection of subtle nondisplaced fractures 1. The key advantages include:
- Fast acquisition time compared to other modalities, critical in trauma settings
- Multiplanar and 3-D reconstructions that characterize complex injuries and guide surgical planning
- Less reliant on patient positioning than radiography
- Identifies penetrating foreign bodies and determines their trajectory 1
Critical Assessment: What You're Looking For
When evaluating a significant facial hematoma, the CT helps identify:
- Underlying fractures that caused or are associated with the hematoma
- Extent of soft tissue injury and hematoma size
- Complications requiring intervention:
- Airway compromise from expanding hematoma
- Vascular injury (vessel wall hematoma, infiltration of perivascular fat)
- Orbital involvement affecting vision
- Foreign bodies
When to Add CT Head
Add a CT head (without contrast) if there are high-energy mechanism features 1:
- Frontal bone involvement (subdural or epidural hematoma occurs in 8-10% of frontal sinus fractures)
- Signs of intracranial injury (altered mental status, neurological deficits)
- High-velocity trauma mechanism
- Complex skull fractures
The forces creating significant facial hematomas with fractures are often high-energy and commonly associated with intracranial injury 1.
When to Consider Vascular Imaging (CTA)
Obtain CTA head and neck if you identify 1:
- Vessel wall hematoma on initial CT
- Perivascular fat infiltration
- Foreign bodies <5mm from vessel wall
- Complex skull fractures or scalp degloving (risk factors for blunt cerebrovascular injury)
- Expanding hematoma suggesting active bleeding
- Le Fort II or III fractures (if midface involved)
CTA is preferred over digital subtraction angiography for initial vascular evaluation due to short acquisition time and low complication rate 1.
Common Pitfalls to Avoid
Don't order plain radiographs - They cannot characterize the full extent of injury, miss subtle fractures, and cannot assess intracranial pathology. Approximately 3% of skull fractures are missed on radiographs, and half of those patients developed epidural hematomas 1.
Don't use IV contrast routinely - Contrast does not aid in detection of osseous facial injury or acute hematoma 1.
Don't defer imaging for "observation" - A significant facial hematoma warrants imaging to exclude underlying fractures and assess for complications that could affect morbidity and mortality.
Don't forget cervical spine evaluation - In high-velocity trauma with significant facial injury, concomitant cervical spine injury occurs in 6-19% of cases 1. Consider cervical spine CT if mechanism suggests it.
MRI: Reserved for Specific Scenarios
MRI is not useful for initial evaluation 1 but may be added later for:
- Cranial nerve deficits not explained by CT
- Suspected CSF leak from skull base fracture
- Subacute/chronic evaluation
- Detecting small asphalt foreign bodies
The acute diagnostic workup of facial trauma rarely requires MRI 1.
Algorithm Summary
- Significant facial hematoma → CT maxillofacial without contrast
- High-energy mechanism or frontal involvement → Add CT head without contrast
- Vascular injury signs on CT → Add CTA head and neck
- High-velocity trauma → Consider cervical spine CT
This approach prioritizes mortality (identifying life-threatening intracranial hemorrhage, vascular injury), morbidity (detecting fractures requiring surgical intervention), and quality of life (preventing complications through early detection).