Fetal Head And Brain Flashcards
Premature fusion of the sutures is called
Craniosynostosis
Prosencephalon develops into the
Forebrain
Mesencephalon develops into the
Midbrain
Rhombencephalon develops into the
Hindbrain
Spinal cord travels through
Foramen magnum
Largest part of the brain
Cerebrum
This structure connects the cerebral hemispheres
Corpus callosum
Protective tissue surrounding the brain
Meninges
How many layers of the meninges are there?
3
Inner layer of meninges
Pia mater
Middle layer of meninges
Arachnoid membrane
Outer layer of meninges
Dura mater
Corpus callosum should be complete by
18-20 weeks
Absense of the CSP is associated with
Agenesis of the corpus callosum
CSP does or doesn’t communicate with the ventricular system
Doesn’t
The 3rd and 4th ventricle are connected by the
Aqueduct of Sylvius or cerebral aqueduct
CSF moves from the lateral ventricles to the 3rd ventricle via the
Foramina of Monro
Anechoic, fluid filled space posterior to the cerebellum and cerebellar vermis
Cisterna magna
The normal cerebellum is ____ shaped
Dumbbell or figure 8
BPD is taken at the level of what structures
CSP, falx cerebri, thalamus, 3rd ventricle
BPD calipers are placed
Outer edge to inner
Dolichocephaly aka
Scaphocephaly
Tool to indicate shape of fetal head
Cephalic index
Dolichocephaly is when a cephalic index is:
Less than 75
Brachiocephalic head is when a cephalic index is:
Greater than 85
What head shape is this
Dolichocephaly or scaphocephaly
What head shape is this
Bracycephaly
Normal head shape is termed
Mesocephalic
Lateral ventricle measurement is taken at the level of the
Atrium
Lemon shaped head is associated with what anomaly
Chiari 2 malformation
Strawberry shaped head is associated with what anomaly
Trisomy 18
Cloverleaf shaped head is associated with what anomaly
Thanatophoric dysplasia
Microcephaly is associated with what anomalies
TORCH infections
Trisomy 13 & 18
Meckel-Gruber syndrome
Macrocephaly is associated with what anomalies
Beckwith- Wiedemann syndrome
Brachycephaly is associated with what anomaly
Trisomy 21
Dolichocephaly is associated with what anomaly
Craniosynostosis
Cerebellum grows at what rate between 14-21 weeks
1 mm per week
Cisterna magna should measure less than
<10mm
Large Cisterna magna measurement is associated with
- Dandy-Walker
- mega Cisterna magna
Cisterna magna should measure more than
More than 2mm
Cisterna magna measuring small is associated with
Chiari 2 malformation
Most common cranial abnormality
Ventriculomegaly
Sonographic sign of ventriculomegaly
Dangling choroid sign
Obstruction lies outside the ventricular system
Communicating hydrocephalus
Obstruction is within ventricular system
Noncommunicating hydrocephalus
Most common cause of hydrocephalus in utero
Aqueductal stenosis
Aqueductal stenosis will dialate:
Everything above the 4th ventricle
Two main parts of the brain
Cerebrum and cerebellum
Fatal condition in which the entire cerebrum is replaced by a large sac containing CSF
Hydranencephaly
Cytomegalovirus and toxoplasmosis as said to be related to what abnormality
Hydranencephaly
3 main types of holoprosencephaly
- Alobar
- Semilobar
- Lobar
Cerebral mantle/cortex shaped like a pancake, cup/horseshoe, ball
Alobar holoprosencephaly
Most severe holoprosencephaly
Alobar
Alobar holoprosencephaly
Horseshoe shaped monoventricle
Alobar holoprosencephaly
50-70% of holoprosencephaly patients have
Trisomy 13 or Patau
Posterior fossa abnormalities that involve cystic dilatation of the Cisterna magna and 4th ventricle
Dandy Walker
This is an example of
Dandy walker(splayed cerebellum)
Corpus callosum will be complete by
Week 18
Sulci have “spoke wheel” or radial pattern is a result of
Agenesis of the corpus callosum
Radial/spoke wheel pattern of sulci is called the _____ sign
Sunburst sign
Sunburst sign is the sonographic sign for
Agenesis of the corpus callosum
What sign is this? What abnormality causes this?
Sunburst sign— Agenesis of the corpus callosum
Development of fluid filled clefts within cerebrum
Schizencephaly
Cysts that communicate with the ventricular system
Porencephaly
Porencephaly is most often ___lateral
Unilateral
“Smooth brain”, no sulci or gyri
Lissencephaly
Choroid plexus cyst is associated with trisomy __
Trisomy 18
Most common neural tube defects:
Anencephaly and spina bifida
Supplement that helps reduce likelihood of neural tube defects
Folic acid(folate)
Condition that is associated with an absent or hypoplastic cerebellar vermis
Dandy walker
Type of acrania where there is a normal amount of cerebral tissue
Exencephaly
Type of acrania where there are no cerebral hemispheres
Anencephaly
Group of cranial abnormalities associated with spina bifida
Chiari 2
Most common location of spina bifida
Distal lumbosacral region
What is the banana sign
Cerebellum is shaped like a banana
Banana sign is associated with what
Spina bifida/ Chiari 2
Mass that protrudes containing spinal cord and meninges
Myelomeningocele
Hernition of meninges
Meningocele
Herniation of meninges and spinal cord
Myelomeningocele
What sign is this? What is it associated with?
Banana sign, spinach bifida/Chiari 2
Protrusions of intracranial contents through a defect in the skull
Cephalocele
The most common location of a cephalocele
Occipital region
Type of cephalocele that contains meninges only
Meningocele
Type of cephalocele that contains brain tissue only
Encephalocele
Type of cephalocele that contains meninges and brain tissue
Encephalomeningocele
Type of cephalocele that contains meninges, brain tissue, and lateral ventricle
Encephalomeningocystocele
Most common intracranial tumor found in utero
Teratoma
TORCH stands for
Toxoplasmosis Other Rubella Cytomegalovirus Herpes
Most common in utero infection
Cytomegalovirus
Most common risk factor for fetal intrauterine intracranial hemorrhage
Maternal platelet disorder
Normal MCA/umbilical artery resistive index is
Above 1
Vein of Galen aneurysm is associated with
Hydrops and cardiomegaly
What is this
Vein of Galen malformation
- microcephaly
- occipital encephalocele
- polydactyly
- polycystic kidneys
Meckel-Gruber