Cerebral Edema
- 10-20% of moderate to severe brain injuries
- Traumatic edema is usually cytotoxic (due to intracellular edema)
- Children and young adults are most commonly affected
- Develops within the first 2-3 days after trauma
- Can be focal or diffuse
Neuroimaging
- CT findings
- Low-density brain
- Decreased gray-white differentiation
- Effacement of sulci
- Effacement of subarachnoid spaces
- Compressed ventricles
- Vasogenic edema, which is more prominent in the white matter
- Cytotoxic edema, which is more prominent in the gray matter
- Secondary effects of cerebral edema include brain herniation, vascular compression and infarction
- MRI findings
- Hypointense edema on T1 weighted imaging
- Hyperintense edema on T2 weighted imaging
- DWI with ADC maps demonstrate
- High ADC values in vasogenic edema due to extracellular edema
- Low ADC values in cytotoxic edema due to intracellular edema
- MR Angiography helps identify secondary effects of vascular compression
- MR Venography helps determine secondary effects of dural venous sinus compression
- MR Spectroscopy
- Decreased NAA, elevated Choline from membrane breakdown
- Lactate indicates cell death and hence poor prognosis
- Nuclear Medicine findings
- PET and PET/SPECT may show decreased regional cerebral blood volume
- Differential for traumatic cerebral edema
- Anoxic encephalopathy
- Metabolic encephalopathy
- Pressure-related edema
For more information, please see the corresponding chapter in Radiopaedia.
Contributor: Priya Rajagopalan, MD
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