Page 55 - SONO 260 The Fetal Head and Brain
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Acrania (Anenecephaly & Exencephaly)
Acrania remains one of the most common neural tube defects.
Acrania is defined as the absence of the cranial vault above the bony orbits.
It can be further divided into two main subtypes that are related to the amount of cerebral tissue present, anencephaly and exencephaly.
Anencephaly is considered when there are no cerebral hemispheres present, while exencephaly denotes the presence of a normal amount of cerebral tissue.
