Midline Brain abnormalities
This structure connects the two cerebral hemispheres and is absent in agenesis.
What is the corpus callosum?
These cysts are found within the choroid plexus and are often benign.
What are choroid plexus cysts?
lateral ventricle measurement that is considered severe ventriculomegaly
What is greater than 15mm?
Paired ventricles located in each cerebral hemisphere. Produces and contain CSF.
What is are the Lateral Ventricles?
Characterized by the absence of the cranial vault and complete or partial absence of the forebrain.
What is anencephaly?
encompasses a range of abnormalities resulting from abnormal cleavage of the prosencephalon.
What is holoprosencephaly?
Cysts that communicate with the ventricular system or subarachnoid space and may results from hemorrhage, infarction, delivery trauma or inflammatory changes in the nervous system.
What are porencephalic cysts?
The three main types of holoprocencephaly
What is Alobar, Semilobar, and lobar?
The medial, midline portion of the cerebellum, a brain structure involved in balance, coordination, and motor control. Agenisis or hypoplasia of this structure is related to Dandy-Walker Malformation.
What is Cerebellar Vermis?
A lethal anomaly that manifests as the absence of the cranial bones, leaving brain tissue exposed.
What is acrania?
This mild brain defect may show an almost normal corpus callosum or one that is underdeveloped.
what is lobar holoprosencephaly?
This brain condition shows complete destruction of the cerebral hemispheres, replaced by cerebrospinal fluid.
What is hydranencephaly?
The shape the brain tissue typically takes on as it surrounds the mono ventricle in holoprocencephaly
What is a horsehoe shape?
A cavity located between the brainstem & cerebellum. Part of the ventricular system where CSF flows. Dilation of this structure is noted in conditions like Dandy-Walker Malformation.
What is the Fourth Ventricle?
This defect involves herniation of meninges, or meninges & brain, through a calvarial defect.
What is a cephalocele?
In alobar holoprosencephaly, this central ventricle forms due to lack of separation of the hemispheres.
What is a monoventicle?
Sonographic findings of this condition include flexion and adduction of the thumb, in addition to severe ventricular dilation.
There are two main findings that define hydrocephalus in a fetus
What is ventriculomegaly and enlargement of the fetal head?
Two oval, gray-matter structures located deep within the brain that is surrounded by white matter. Fusion of this structure is characteristic of alobar holoprosencephaly.
What is the Thalamus?
This is the herniation of the meninges AND brain though the defect.
What is an encephalocele?
The absence of this small midline brain cavity is seen in both holoprosencephaly & agenesis of the corpus callosum.
What is the cavum septum pellucidum?
This cystic midline vascular anomaly may cause cardiomegaly and fetal hydrops in utero.
What is a vein of Galen aneurysm?
This type of hydrocephalus results when CSF is blocked after it exits the fourth ventricle, typically due to subarachnoid hemorrhage or meningitis
What is communicating hydrocephalus?
Connects the third & fourth ventricles. Stenosis or blockage here is the leading cause of hydrocephalus.
What is the Aqueduct of Sylvius (Cerebral Aqueduct)?
The neural tube does not close completely, resulting in the spinal cord and surrounding tissues being exposed or protruding through the spine.
What is spina bifida?