Diagnostic ultrasound ( PDFDrive )

1210 PART IV Obstetric and Fetal Sonography
Acknowledgments
he advice and support of our colleagues Drs. Susan Blaser,
David Chitayat, Katherine Fong, Charles Raybaud, and Patrick
Shannon are acknowledged and appreciated.
FIG. 34.38 Lipoma. Midline lipoma forming an echogenic mass near
the foramina of Monro at the expected anterior end of the corpus callosum
(arrow). These are not neoplasms and represent abnormal differentiation
of meningeal anlagen (precursors) into fat. Midline lipomas are often
associated with dysgenesis of the corpus callosum, as in this fetus, in
which the cavum septi pellucidi is absent and the ventricles (calipers)
are dilated.
is common. Additional associations include aneurysms and other
midline brain and facial malformations. At ultrasound, intracranial
lipomas appear as early as 23 weeks as an echogenic mass or
plaque in the midline in the region of the corpus callosum with
occasional calciication and even ossiication. (Fig. 34.38). MRI
is helpful to conirm the fatty nature of the mass and to further
evaluate changes in the corpus callosum and remaining brain.
Most do not grow. Many patients are asymptomatic, but the
associated abnormalities may cause symptoms including seizures
and developmental delays. Surgical treatment of the lipoma is
generally not indicated and can be dangerous because of the
strong attachment of the lipoma to surrounding structures and
the nerves and vessels within the mass. 254,255
CONCLUSION
Assessment of the fetal CNS, more than any other organ system,
is frequently enhanced by the addition of fetal MRI. he combination
of ultrasound and MRI allows for many other experts to
aid in the investigation, diagnosis, and management of fetal
conditions, including pediatric neuroradiologists, neurologists,
neurosurgeons, geneticists, pathologists, and other specialists.
he understanding of the genetic basis, pathophysiology, natural
history, and prognosis of many conditions and syndromes is
increasing explosively as a result of this cross-fertilization
and collaboration. hose performing ultrasound are discovering
the complexities and large spectrum of neonatal diseases.
hose providing postnatal care are discovering that prenatal
conditions afecting the fetus are oten very diferent from conditions
that afect neonates who survive pregnancy. Best results
are obtained when there is multidisciplinary consultation and
collaboration.
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