Epidural Hematoma (EDH) — CT Brain (Non-contrast)

Epidural Hematoma (EDH) — CT Brain (Non-contrast)





Core CT Features (Acute EDH)

  • Shape: Biconvex / lentiform (lens-shaped)
  • Density: Homogeneous hyperdense (acute blood)
  • Location: Extra-axial, between skull and dura
  • Suture relation: Does NOT cross sutures (tight dural attachment)
    (may cross dural reflections rarely if large)
  • Midline shift / mass effect: Common → sulcal effacement, ventricular compression
  • Underlying skull fracture: Frequently present (esp. temporal bone)

Additional Signs

  • “Swirl sign” → hypodense areas within hematoma (active bleeding)
  • Lucid interval correlation (clinical, not CT but supportive)
  • Effacement of cisterns if severe

Evolution

  • Acute (0–3 days): Hyperdense
  • Subacute: Isodense → may be missed without contrast
  • Chronic (rare for EDH): Hypodense

Key Differentiation (vs SDH)

  • EDH → Biconvex, limited by sutures
  • SDH → Crescentic, crosses sutures but not midline (falx limit)

Rapid Mnemonic

“EDH = Egg-shaped, Does NOT cross sutures, High density”

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