Diagnostic ultrasound ( PDFDrive )

CHAPTER 49 The Pediatric Spinal Canal 1683
A B C
FIG. 49.14 Lumbosacral Myelomeningocele in 18-Week Fetus. (A) Transverse view shows the open nature of the posterior elements of
the affected vertebral ring (arrow). (B) Sagittal view shows the protuberance of the covering membrane and neural placode (arrow). (C) Coronal
view shows the thin nature of the covering membrane (arrow).
Open Neral Tube Defects
A. Myelocele B. Myelomeningocele
Occult Dysraphisms
C. Intradural Lipoma D. Lipomyelocele E. Lipomyelomeningocele
FIG. 49.15 Examples of Open Neural Tube Defects (A and B) and Examples of Closed Spinal Defects Without a Subcutaneous Mass
(C) or With Subcutaneous Mass (D and E). Each diagram is positioned with the dorsal side up as one would scan the spine of an infant.
of a sacral meningocele. heir most common location is in the
lumbar or sacral spine, but they can be seen in the thoracic or
cervical spine. On ultrasound, the CSF-illed sac has a small
neck and is continuous with the thecal sac. Small bands of pia,
arachnoid, or dura can be seen, not nerves. An atretic meningocele
is the condition in which an aberrant nerve adheres to the neck
of the meningocele and is a cause of low conus with no apparent
cause of tethering. Atretic meningoceles are associated with a
midline scar that resembles a cigarette burn. 12
Myelocystocele is a rare malformation in which the dilated
central canal of the spinal cord protrudes dorsally through a
dorsal bony defect. Myelocystoceles can occur at the cervical,
thoracic, or lumbosacral levels. hey are distinct from myelomeningoceles
and are skin covered. 61,62 When occurring at the