Encephalocele

	A posterior encephalocele measuring approximately 4 cm is present in this 20 week fetus. Of note, the remainder of the intracranial anatomy including the cerebellum appears normal.
	There is a encephalocele off the posterosuperior aspect of the skull of this 23 week fetus. The skull defect measures 3.2 cm. The majority of the contents of the encephalocele are cystic, however an area of 1.5 cm of cortical tissue is seen extending into the defect. No normal CNS anatomy is visualized.
	This 23 week fetus has a high parieto-occipital encephalocele, with brain tissue and ventricle seen herniating into the cavity. There are fused frontal horns with almost complete absence of the septal leaflets.
	There is a posterior encephalocele with a 1cm region of absent occipital bone and neural tissue seen extending from the occipital region into the amniotic fluid. The largest mass of tissue outside of the skull measures 2 x 1.9 x 1.2cm. A large portion of the frontal lobe is displaced through the defect, simulating the appearance of anencephaly. Skull is seen to be present, however.
	This fetus was also imaged at 20 weeks gestation (see above).
	Sonograms of a 33 week fetus with orbital encephalocele. Left orbit is disrupted by encephalocele (arrow). Right orbit exhibits microtia.		Encephalocele of left frontal lobe resulting in protruding orbit. Note dysgenetic brain and severely sloping forehead.
	In the coronal plane, neural tissue is visible protruding from left orbit.
	Sagittal, coronal, and axial views demonstrate severely dysgenetic brain.
	Protrusion of frontal lobe through calveric defect results in dysmorphic left orbit.	Sagittal view demonstrates prominent orbits.
	Frontal lobe is entrapped by encephalocele, making neural tissue clearly visible outside the cranium, anterior to midface (arrow).
	Postnatal preoperative photograph and post-operative MRI demonstrate frontal encephalocele.