Periventricular echogenicity that persists beyond 7 days or evolves into cysts (cystic PVL) on serial cranial ultrasound; MRI at term-equivalent age shows the full extent of white matter injury.
Orient first
- Ischaemic injury of the preterm periventricular white matter; the precursor of spastic diplegia.
- Transient "flare" often resolves; cysts appear at 2–4 weeks.
- Diffuse non-cystic white matter injury is common and ultrasound underestimates it.
Acquire the study
- Cranial ultrasound through the anterior fontanelle, repeated at 1–2 weeks and around 4–6 weeks; posterior fontanelle view for the occipital horns.
The manoeuvre
- Parasagittal views: periventricular echogenicity compared with the choroid plexus — equal or brighter is abnormal.
- Persistence beyond 7 days and its extent (frontal, parietal, occipital).
- Cysts: size in mm and distribution; separation from the ventricle.
- Ventricular dilatation with irregular walls (white matter loss).
What confirms it
- Periventricular cysts on serial ultrasound, or white matter loss with irregular ventricles on MRI.
What licenses you to exclude it
- Serial normal cranial ultrasounds lower the likelihood of cystic PVL; they do not exclude diffuse white matter injury.
The classic misread
- Calling a single early flare PVL — it needs persistence or cysts.
- Relying on ultrasound alone for diffuse injury.