In a patient with a traumatic orbital hematoma, which radiographic study should be ordered?

CT Orbits Without IV Contrast

For a patient with traumatic orbital hematoma, order a CT orbits without IV contrast as the initial imaging study. This is the most accurate and appropriate modality for evaluating orbital trauma, including hematomas, fractures, and associated soft tissue injuries 1, 2.

Why CT Orbits Without Contrast is the Gold Standard

CT is considered the most useful imaging modality in evaluating orbital trauma and provides critical information about:

• Soft tissue injuries including hematomas (retrobulbar and subperiosteal), extraocular muscle injury or herniation 2
• Hemorrhage detection with 94.9% sensitivity for identifying complications 1
• Fracture identification - CT is the most accurate method for detecting orbital fractures 1
• Globe injuries including rupture, intraocular hemorrhage, lens dislocations 2
• Foreign body detection - especially metallic or glass (94.9% sensitive) 1

The study can be acquired quickly with multiplanar reformatted images generated from a single acquisition, which is crucial in trauma settings 2.

When to Expand the Field of View

Consider CT maxillofacial without IV contrast instead if:

• Mechanism suggests broader facial injury (motor vehicle collision, high-impact trauma)
• Clinical signs of midface fractures (malocclusion, facial asymmetry, palpable step-offs)
• Need to evaluate mandible or extensive facial bones 2

Add CT head only when:

• Suspected orbital roof fracture (more common in children <8 years) 1
• Signs of intracranial injury or traumatic brain injury 1
• Altered mental status or neurological deficits 2

Critical Findings Requiring Urgent Intervention

Watch for these vision-threatening complications on CT:

• Retrobulbar hematoma with proptosis - requires emergent orbital decompression within 60-100 minutes to prevent permanent vision loss 3
• Trapdoor fractures with muscle entrapment - can cause rapid ischemic injury to extraocular muscles 1
• Globe rupture or open globe injury 1, 2
• Optic canal fractures with bone fragment impingement 2
• Orbital compartment syndrome - diagnosed clinically but CT shows contributing factors 2

What NOT to Order

Avoid these studies for initial evaluation:

• Plain radiography - insufficient for detecting orbital pathology and has been replaced by CT in current practice 1, 4
• Contrast-enhanced CT - no role in initial orbital trauma evaluation 1, 2
• MRI orbits - provides superior soft tissue detail but remains supplementary to CT; too time-consuming for acute trauma 1
• CTA or MRA - no role in initial orbital trauma imaging unless vascular injury suspected in broader trauma context 1, 2

Common Pitfalls to Avoid

• Don't wait for imaging if orbital compartment syndrome is suspected clinically - this is a clinical diagnosis requiring immediate lateral canthotomy and cantholysis; imaging is not sensitive for predicting who will develop this complication 2
• Don't order MRI if metallic foreign body is suspected - absolute contraindication 4
• Don't assume hematoma alone requires surgery - most orbital hematomas resolve without intervention unless causing retinal ischemia or optic nerve compression 3
• Remember the 100-minute window - optic nerve and retina can only tolerate increased intraocular pressure for 60-100 minutes before permanent damage occurs 3