74-year-old male with a headache after a fall that became progressively worse. Started becoming sleepier and more confused. History of atrial fibrillation and warfarin use.
Hemorrhage
Stroke
There is a large extra-axial hyperdense collection that is crescent shaped that overlies the left cerebral hemisphere. Notice how the collection extends beyond the sutures and extends along the falx and left tentorium. There is associated midline shift and left lateral ventricular effacement.
Subdural hematoma
Depends on size/neurologic impact. Smaller subdural hematomas are monitored with CT scans. Symptomatic acute subdural hematomas are surgically evacuated with craniotomy. Symptomatic subacute or chronic subdural hematomas can be treated with burr holes.
Predominantly unilateral in adults, and bilateral in infants.
Subdural hematomas are often presented in textbooks/board review material as slow-bleeding and relatively innocuous. However, symptomatic subdural hematomas in the acute phase have a 50-90% mortality, with a anticoagulated patients comprising the highest risk category. There is also significant morbidity in these cases, even in those that survive.
Recommendations for optimal image interpretation:
Acute phase (several hours – 3 days): crescent-shaped, homogenously hyperdense, diffuse spread over affected hemisphere. As clotting occurs, appears more hyperdense relative to surrounding cortex.
Subacute (3-21 days): Degradation of clot leads to decreasing density, which will eventually become isodense to surrounding cortex. Contrast may help in this case – look for a fade of CSF in sulci adjacent to skull.
Chronic (3+ weeks): Becomes isodense relative to CSF, may change from crescent to biconvex shape. Periphery may calcify in rarer cases.
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