Diagnosis & Imaging
Transependymal edema (periventricular lucency)
Transependymal edema is fluid forced into the brain tissue around the ventricles under pressure, an imaging sign that can indicate active hydrocephalus.
In short: Transependymal edema (periventricular lucency)
- It is fluid in the brain tissue around the ventricles.
- It results from CSF being forced across the ventricle lining under pressure.
- It can indicate active or raised-pressure hydrocephalus.
- It appears as a rim around the ventricles on imaging.
What it is
Transependymal edema (also called periventricular lucency or interstitial edema) is fluid that has been forced from the ventricles into the surrounding brain tissue under pressure. On imaging, it appears as a rim of altered signal or density around the ventricles, and it can indicate active hydrocephalus.
Understanding Transependymal edema (periventricular lucency)
When CSF pressure within the ventricles is high, fluid can be pushed across the ventricle lining (the ependyma) into the adjacent brain tissue, producing transependymal edema. On CT or MRI, this shows up as a rim around the ventricles. Its presence can support the idea that hydrocephalus is active and under pressure (rather than stable or due to atrophy), and it can be a clue when evaluating for a shunt malfunction or new hydrocephalus. Like other imaging findings, it is interpreted alongside the clinical picture and the appearance of the ventricles. Transependymal edema is one of the signs that help distinguish active hydrocephalus.
Why it matters
Understanding transependymal edema helps families interpret imaging that describes a rim around the ventricles, and see how this sign can indicate active, raised-pressure hydrocephalus — useful when evaluating for a shunt problem or new hydrocephalus.
Common questions
What is transependymal edema?
Fluid forced into the brain tissue around the ventricles under pressure.
What does it indicate?
It can indicate active or raised-pressure hydrocephalus.
How does it appear on imaging?
As a rim around the ventricles.
Bottom line
Transependymal edema is fluid forced into the tissue around the ventricles under pressure, an imaging sign that can indicate active hydrocephalus.
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