CT Maxillofacial Without IV Contrast
For a patient with eye trauma and facial concerns, order a CT maxillofacial without IV contrast as the primary imaging study 1.
Rationale and Clinical Approach
The 2025 ACR Appropriateness Criteria explicitly state that concurrent head and maxillofacial CT scans without IV contrast are usually indicated for orbital trauma scenarios 1. This recommendation is based on the comprehensive nature of combined eye and facial injuries, where:
Why CT Maxillofacial Over CT Orbits Alone
CT maxillofacial is superior to isolated orbital CT when facial injuries are present because 1:
- Orbital fractures commonly occur with midface fractures (zygomaticomaxillary complex, Le Fort II/III, nasoethmoidal fractures)
- The mandible may be involved and is often not included in orbital CT field of view
- If any clinical concern for additional facial injuries exists, the more comprehensive maxillofacial CT is more useful 1
What This Scan Detects (Critical for Morbidity/Mortality)
The non-contrast CT maxillofacial identifies vision-threatening and life-altering injuries 1:
Immediate surgical emergencies:
- Orbital compartment syndrome (retrobulbar hematoma with proptosis and posterior globe tenting)
- Trapdoor fractures with muscle entrapment
- Open globe injuries
- Bone fragments impinging on the optic nerve
Fracture patterns requiring urgent intervention:
- Optic canal fractures (risk of traumatic optic neuropathy)
- Lateral and superior orbital wall fractures (associated with increased traumatic optic neuropathy risk)
- Orbital floor fractures >2 cm (associated with enophthalmos)
Additional critical findings:
- Radio-opaque foreign bodies and their trajectory
- Lens dislocations
- Intraocular hemorrhage and detachments
- Extraocular muscle injury or herniation
- Retrobulbar and subperiosteal hematomas
Technical Specifications
Multidetector CT (MDCT) provides 1:
- Rapid acquisition (critical in trauma)
- Multiplanar reformatted images from single acquisition
- Thin-section imaging to detect subtle non-displaced fractures
- Concurrent imaging of multiple body parts in polytrauma settings
Why NOT Contrast
There is no relevant literature supporting IV contrast use in initial posttraumatic vision loss imaging 1. Contrast does not improve detection of:
- Fractures
- Hemorrhage
- Globe injuries
- Soft tissue trauma
Common Pitfalls to Avoid
Don't order isolated orbital CT if facial injuries are suspected - you'll miss midface and mandibular fractures that commonly coexist 1
Don't rely on imaging alone for orbital compartment syndrome - this is a clinical diagnosis; retrobulbar hemorrhage on imaging is not sensitive for subsequent compartment syndrome development 1
Don't order plain radiographs - they are insufficient and have been supplanted by CT 2
Don't delay imaging for contrast administration - non-contrast is the standard and speeds diagnosis 1
When to Add Head CT
If mechanism suggests intracranial injury or the patient has altered mental status, add CT head without contrast concurrently 1, 3. Studies show 68% of maxillofacial injuries have associated head injury 4.
Alternative: CT Orbits Without Contrast
Only use isolated CT orbits without contrast if 1:
- Direct impact to orbit alone
- Penetrating injury isolated to orbit
- No clinical concern for additional facial fractures
This narrower field of view suffices for isolated orbital trauma but misses associated facial injuries.