Because ultrasound cannot penetrate bone,
cranial ultrasound can be performed only on babies whose skull (cranial) bones
have not yet grown together. But duplex
Doppler ultrasound can be done to evaluate blood flow
and vessel spasms in the brain in children and adults. For more information,
see the topic
leukomalacia (PVL) is not usually detectable until several weeks after birth.
For this reason, cranial ultrasound is generally done between 4 and 8 weeks
after delivery. Because cranial ultrasound may find suspicious areas in the
brain that may or may not be PVL, ultrasound testing may be repeated over
several weeks. Babies with PVL or intraventricular hemorrhage (IVH) may develop
normally or may have varying levels of disability, including
cerebral palsy or
an intellectual disability.