What is the recommended imaging for suspected Epidural Hematoma (EDH)?

Imaging for Suspected Epidural Hematoma (EDH)

Non-contrast CT of the head is the gold standard and mandatory first-line imaging for suspected epidural hematoma, providing rapid, accurate diagnosis that directly guides surgical decision-making. 1

Primary Imaging Recommendation

CT head without IV contrast is the definitive initial study for suspected EDH and should be performed immediately 1:

• Rated 9/9 ("usually appropriate") by the American College of Radiology for suspected parenchymal hemorrhage including EDH 1
• Provides rapid acquisition critical in trauma settings where time to diagnosis directly impacts mortality 1
• Demonstrates the characteristic lenticular or biconvex high-density collection between skull and dura 1
• Identifies associated skull fractures, which are present in the majority of EDH cases and predict arterial bleeding sources 1, 2
• Allows immediate assessment of mass effect, midline shift, and need for emergent surgical evacuation 2

When to Add Vascular Imaging

CT angiography (CTA) head with IV contrast should be obtained concurrently when 1:

• Skull fracture crosses a dural venous sinus or involves the jugular bulb/foramen (41% risk of venous sinus thrombosis) 1
• Active contrast extravasation ("spot sign") is suspected, which predicts EDH expansion and need for surgery 2
• The study can be performed immediately after non-contrast CT while the patient remains on the table 1

Follow-Up Imaging Protocol

Repeat non-contrast CT head at 6-13 hours after initial scan is critical for 2:

• Patients managed non-operatively with initial small EDH
• Those with concurrent subarachnoid hemorrhage (SAH), which is the strongest predictor of EDH enlargement (OR 2.60) 2
• This timing window captures nearly all cases of EDH expansion that may require delayed surgery 2

Immediate post-operative CT should be standard practice following EDH evacuation when 3:

• Any contralateral skull fracture is present
• There is suspicion of bilateral bleeding
• Asynchronous contralateral EDH, though rare, can develop and requires immediate detection 3

Role of MRI

MRI is NOT indicated for acute suspected intracranial EDH 1:

• CT remains superior for acute hemorrhage detection and surgical planning 1
• MRI is too slow in the acute trauma setting where rapid diagnosis is essential 1
• MRI head without IV contrast is rated only 8/9 (versus CT's 9/9) for parenchymal hemorrhage 1

MRI has a specific role only for spinal EDH when 4, 5:

• Acute cauda equina syndrome or progressive myelopathy is present
• T2-weighted sequences show characteristic heterogeneous hyperintensity with focal hypointensity 4
• However, severity of neurologic deficit—not imaging findings—drives management decisions 4

Critical Imaging Predictors of Poor Outcome

The following CT findings mandate immediate neurosurgical consultation 2:

• Large initial EDH size (>20 mL volume threshold historically associated with worse outcomes) 6
• Arterial bleeding source identified by skull fracture location crossing meningeal artery grooves 2
• Mixed attenuation or "spot sign" indicating active hemorrhage 2
• Midline shift of any degree 2
• EDH enlargement on follow-up imaging, which is the only predictor of need for delayed surgery 2

Common Pitfalls to Avoid

• Never obtain MRI as initial imaging in acute head trauma with suspected EDH—this delays life-saving diagnosis 1
• Do not skip follow-up CT at 6-13 hours in non-operative cases, especially with concurrent SAH 2
• Do not assume small EDH is safe—28% enlarge on follow-up, and expansion predicts need for surgery 2
• Always obtain immediate post-operative CT when contralateral fracture is present to detect asynchronous bilateral EDH 3
• Do not use contrast-enhanced CT initially—it adds no value and delays diagnosis; non-contrast CT is sufficient and faster 1