Normal fetal Brain

Question 1

Echogenic area located with in the atria of lateral veins bilaterally

Answer 1

Choroid plexus

Question 2

Located posterior portion of brain

should not exceed 10 mm

Answer 2

Lateral vents

Question 3

• Located in posterior portion of brain
• can be used to estimate GA up to 20 weeks
• Measurement not accurate after 30 weeks

Answer 3

Cerebellum

Question 4

Seen on sono after 30 weeks

Answer 4

Epiphyseal centered of bones (femur)

Question 5

o Anechoic area in posterior brain

o Should not exceed 10mm

Answer 5

Cistern Magna (posterior fossa)

Question 6

o Should be < 6 mm
o Not accurate after 21 weeks
o Measured outer edge to outer edge

Answer 6

Nuchal fold

Question 7

-)= Lateral vents > 10mm
• posterior lateral ventricular atria 1st place to enlarge due to ↑ CSF
• Often assoc. w/ other abnormalities
Classifications:
1. Aqueductal stenosis- caused by narrowing of 3rd ventricle outflow (Aqueduct of Sylvius)
2. Communicating hydrocephalus- dilation of all ventricles
3. Dandy Walker Malformation-
SONO: dilated ventricles, dangling choroid, POLY, fetal ascites and hepatomegaly

Answer 7

Ventriculomegaly (hydrocephaly)

Question 8

• Splaying of the cerebral vermis, communicating w/ a dilated 4th ventricle
• Increased cisterna magna >10mm
• Ventriculomegaly
• Assoc. w/ other abnormalities and possible agenesis of corpus callosum

Answer 8

Dandy walker syndrome

Question 9

• Can be complete or partial and assoc w/ other anomaly
• Cannot be diagnosed until after 18weeks
• Absence of cavum septum pellucidum
• “tear drop ventricles” Enlargement of posterior horn of lateral vents but not anterior
• 3rd ventricle enlarged and displaced superiorly

Answer 9

Agencies of corpus callous

Question 10

• Means- “water no brain”
• Absence of cerebral hemispheres w/ normal developed meninges and skull due to occlusion of ICA
• Cerebral cortex replaced by fluid causing macrocephaly and POLY
• Thalami, brain stem and cerebellum are spared

Answer 10

Hydrancephaly

Question 11

“the face predicts the brain”
• Cranial vault is formed BUT has a single large midline ventricle
• Most often assoc. w/ TRISOMY 13

-Alobar, semi lobar,lobar

Answer 11

Holoprosencephaly (3 classifications)

Question 12

Most severe
Large single cavity, fused thalami, absent 3rd ventricle and falx
Facial anomalies and hypotelorism

Answer 12

Alobar

Question 13

partial separation of hemispheres and lateral vents

Cleft palate and lip

Answer 13

Semilobar

Question 14

interhemisphere fissure developed except fused anterior horns of LV, and absent CSP

Answer 14

Lobar

Question 15

• Cystic areas with cerebral parenchyma

* Caused from cranial bleeds

Answer 15

Porencephaly

Question 16

• Rare malformation of abnormal clefts in cerebral hemisphere
• Usually bilateral the brain appears, “split”

Answer 16

Schizencephaly

Question 17

small head circumference below 3 standard deviations of normal

Answer 17

Microcephaly

Question 18

• Can be unilateral, bilateral, multiple or single, small or large
• Can be assoc w/ Trisomy 18 or 21 if other findings are present
• Resolve by 28 weeks / 3rd trimester

Answer 18

Choroid plexus cyst

Question 19

• BENIGN, anomaly, MC occurs in posterior neck
• Sac filled w/ lymphatic fluid due to obstruction
• Assoc. w/ DOWNS syndrome or TURNERS syndrome
• Can be assoc. w/ fetal hydrops and ascites

Answer 19

Cystic hygroma

Question 20

• “lateral cleft lip” is commonly isolated
• “medial cleft lip, assoc w/ chromosomal abnormalities”
• Possible, POLY bc they cant swallow properly

Answer 20

Cleft lip/Plate

Question 21

• A teratoma arising from the oral cavity or pharynx (soft palate, tongue or jaw)
• Assoc. w/ POLY

Answer 21

Epignathus

Question 22

• Complex, solid, cystic tumor seen near the fetal neck

* Spine will be normal

Answer 22

Cervical teratoma

Question 23

• Increased soft tissue thickness over the posterior aspect of the neck
• > 6mm is abnormal measured between 15-21weeks
• Assoc w/ chromosomal syndromes especially Trisomy 21
• Normal nuchal fold should be <6mm ** ON TEST **

 

Answer 23

Nuchal thickening