Can Ultrasound differentiate spina bifida in utero?
During routine second trimester US, the fetal spine is screened for any open or closed spinal defect. Open spina bifida containing only herniated meninges is a meningocele. If the herniated contents also include spinal cord elements, it is a myelomeningocele. On US, these defects usually appear as cystic structures bulging through splayed posterior osseous elements, most commonly in the lumbosacral region. If the contents of the cystic bulge are completely anechoic, this suggests a meningocele. If there are echogenic strands within the cystic bulge, this suggests herniated neural elements as well and therefore a myelomeningocele.