Accreta placentation
Ultrasound signs: Placental lacunae
- Placental lacunae are large, irregular sonolucent intraplacental spaces giving the placenta a moth-eaten appearance
- Lacunae are the most common ultrasound sign in PAS
- They are distorted cotyledons and interlobular septa
- Lacunae have direct high velocity maternal blood from a radial or arcuate artery. The peak systolic velocity is often >10 cm/sec
- Their shape is not influenced by the filling of the bladder or pressure from the probe
The difference between the appearance of lacunae in PAS and placental lakes in a normal placenta may not always be clear cut, but lacunae are larger, more irregular, contain high velocity turbulent blood flow.
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