14. Congenital Fetal

Question 1

this anechoic area between the neck/ occiput and the skin

Answer 1

Nuchal lucency

should be < 3 mm.

Question 2

Nuckal lucency = > 3 mm =

Answer 2

Downs (Trisomy 21) or other chromosomal defect

Question 3

The ideal positioning in nuchal lucency

Answer 3

neutral neck, with the nasal bone visualized, and the head in the mid-sagittal position.

Question 4

If the amnion gets disrupted and the fetus wanders / floats into the chorionic cavity he/she can get caught in the sticky fibrous septa.

Answer 4

Amniotic Band Syndrome

All kinds o f terrible can result ranging from decapitation, to arm/leg amputation.

Question 5

the most common cause of Hydrops

Answer 5

Rh Sensitization from prior pregnancy

Question 6

Causes of hydrops

Answer 6

TORCHS, Turners, Twin Related Stuff, and Alpha Thalassemia.

Question 7

Answer 7

Fetal Hydrops

Diagnosis is made by the presence of 2 of the ff:
pleural effusion
ascites
pericardial effusion
Subcutaneous Edema.

Question 8

What is a useful finding occuring before hydrops?

Answer 8

MCA Doppler = increased peak in systolic flow

Question 9

You have a hole in your back from a neural tube defect (Step 1 trivia = not enough folate) = myelomeningocele = Lets CSF drip out = Low volume of CSF = Hindbrain structures drop to a caudal position (certein volume needed to distende the ventricular system) = caudal herniation of the Cerebellar vermis, brainstem and 4th ventricle

Answer 9

CHiari II

Question 10

caudal herniation of the Cerebellar vermis, brainstem and 4th ventricle

Answer 10

Chiari II / Open Neural tube defect

Question 11

Answer 11

Chari I

The sagittal T1-weighted image of the brain demonstrates cerebellar tonsillar ectopia, with extension of the tonsils 1 cm below the level of the foramen magnum

Question 12

This caudal herniation of the cerebellum into the foramen magnum obliterate the normal contour of the vermis, creating the contour of a BANANA

Answer 12

Chiari II

Question 13

The low pressure and abnormal distention of the developing brain results in

Answer 13

incomplete stretching of the rostral (front part) skull.

The result is a “lemon shaped” rostral skull

Question 14

The result is a “lemon shaped” rostral skull goes away in

Answer 14

the 3rd trimester

Its only present in the 2nd trimester

The problem is = lack of volume

Question 15

Both banana and lemon signs are classic for the

Answer 15

Chiari II / Spina Bifida Path

Question 16

The banana sign is present in what trimester?

Answer 16

2nd and 3rd trimester

Question 17

The lemon sign is only in ___ trimester

Answer 17

2nd

Question 18

What sign is more specific?

Answer 18

banana sign

Question 19

Lemon sign is more common in

Answer 19

Chiari II and NTD

Question 20

Can alse be seen in Chiar II + Open NTD but only later in gestation, when severe

Answer 20

HYdrocephalus

Question 21

Causes of Ventriculomegaly

Answer 21

Hydrocephalic (communicating and non communicating)
Cerebral atrophy

Question 22

most common cause of non-communicating hydrocephalus in a neonate

Answer 22

Aqueductul Stenosis

Question 23

When can you say that the Ventricular atrium is big?

Answer 23

If > 10 mm

Question 24

Answer 24

Ventriculomegaly

Dangling choroid hanging off the wall more than 3 mm

Question 25

This is one of those incidental findings that in isolation means nothing.

Answer 25

Choroid Plexus Cyst

Incidence o f this finding is increased in trisomy 18. trisomy 21, Turner’s Syndrome, and Klinefelter Syndrome.

Question 26

Answer 26

Choroid Plexus Cyst

Question 27

Around 80% of babies with cleft lips have __

Answer 27

Cerebral palsy

You can see cleft lips, but cleft palate (in isolation) is very hard to see.

Question 28

Answer 28

Cystic Hygroma

cystic mass in the posterior neck, in the antenatal period

Associated with Downs and Turners

Question 29

This is the most common neural tube defect

Answer 29

Anencephaly

Question 30

Answer 30

Anencephaly

total absence of the cranial vault and brain above the level of the orbits

Question 31

Nearly all Congenital Diaphragmatic Hernia are on whatside?

Answer 31

Left (85%)

Question 32

Congenital Diaphragmatic Hernia can cause:

Answer 32

(1) causes a high mortality = pulmonary hypoplasia

(2) that all the kids are malrotated (it messes with normal gut rotation).

Question 33

Answer 33

Echogenic intracardiac Focus (EIF)

This is a calcification seen in a papillary muscle (usually in the left ventricle).

Assoc: Trisomy 21 and Trisomy 13 = look for more features

Question 34

Answer 34

Duodenal Atresia

Double Bubble Sign

Question 35

DDx of Echogenic Bowel

Answer 35

CF, Downs and other Trisomies
Viral Infections
Bowel Atresia.

Question 36

Answer 36

Sacrococcygeal Teratoma

Location:
external to the pelvis (47%)
internal to the pelvis (9%)
dumbell’d both inside and outside (34%).

Question 37

This is the most common tumor in the fetus or infant.

Answer 37

Sacrococcygeal Teratoma

Question 38

Answer 38

Autosomal Recessive Polycystic Kidney Disease

massively enlarged bilateral kidneys with oligohydramnios.

Question 39

Answer 39

Posterior Urethral Valves

bilateral hydro on either fetal US or 3rd Trimester MRI.

Question 40

A short femur (below the percentile) can make you think of a

Answer 40

Skeletal Dysplasia