Fetal Abnormalities

Question 1

What is acromelia?

Answer 1

Shortening of the bones of the hands or feet

Question 2

What is the aqueduct of Sylvius?

Answer 2

A channel between the third and fourth ventricles of the brain

Question 3

What is the banana sign associated with?

Answer 3

Shows a crescent shape to the cerebellum when a neural tube defect is present

Question 4

The corpus collosum serves a function for what in the brain?

Answer 4

Learning and memory

Question 5

What is frontal bossing? What is it associated with?

Answer 5

Protrusion/bulging of the forehead, associated w/ hydrocephalus.

Question 6

What is the keyhole sign?

Answer 6

Appearance of the dilated bladder superior to the obstructed male urethra

Question 7

What is the lemon sign, and what is it associated with?

Answer 7

Concavity to front bones of the fetal skull, associated with spina bifida

Question 8

What is mesomelia?

Answer 8

Shortening of the middle portion of a limb

Question 9

What is micromelia?

Answer 9

Shortening of all portions of a limbW

Question 10

What is a myelomeningocele?

Answer 10

A developmental defect of the central nervous system where a hernial sac containing portion of spinal cord, meninges, and cerebrospinal fluid protrudes through a congenital cleft in the vertebral column

Question 11

What is nuchal thickness measuring?

Answer 11

The thickness between the calvaria and posterior skin line

Question 12

What is proboscis?

Answer 12

A protrusion of nasal tissue above the orbits ^:)

Question 13

What is rhizomelia?

Answer 13

Proximal portion limb shortening

Question 14

What is the steer sign, and what is it associated with?

Answer 14

Enlargement and upper displacement of third ventricle
associated w/ agenesis of the corpus callosum

Question 15

What is the vermis?

Answer 15

Structure located between the hemispheres of the cerebellum

Question 16

Arachnoid cyst

Answer 16

Congenital abnormality of the pia-arachnoid layer; result of trauma, infarction, or infection

Question 17

Arnold Chiari type II Malformation

Answer 17

Displacement of the cerebelluar vermis, fourth ventricle, medulla oblongata through the foramen of magna into the upper cervical canal
Can create the banana sign (compressed cerebellum), may cause a lemon shaped cranium

Question 18

Dandy-Walker syndrome

Answer 18

Congenital malformation of the cerebellum w/ associated maldevelopment of the fourth ventricle
Result of alcohol abuse, autosomal recessive disorder, or viral infection
CIsterna magna measures > 1.0cm in diameter

Question 19

Hydranencephaly

Answer 19

Destruction of the cerebral cortex resulting from vascular compromise or congenital infection (usually carotid area), and the brain tissue is replaced by cerebrospinal fluid

Anechoic brain tissue

Question 20

Hydrocephalus (ventriculomegaly)

Answer 20

Increase in ventricular volume caused by outflow obstruction, decrease in cerebrospinal fluid production or OVERproduction of CSP

Occipital horns dilate first

Typically symmetrical

associated w/ vein of Galen Aneurysm?

Question 21

What is the measurement for mild ventriculomegaly?

Answer 21

lat vents measuring 10-15 mm

Question 22

What is the measurement for severe ventriculomegaly?

Answer 22

lat vents measuring > 15 mm

might see dangling choroid plexus, echogenic rim of solid brain tissue

Question 23

Holoprosencephaly

Answer 23

Group of disorders arising from abnormal development of the forebrain

Question 24

Holoprosencephaly has a strong association with which trisomy?

Answer 24

Trisomy 13

Question 25

What are the types of holoprosencephaly?

Answer 25

Alobar - most severe, monoventricular cavity Semilobar - monoventreicular cavity, milder Lobar - two large lateral ventricles, mildest

Question 26

Alobar

Answer 26

Large central single ventricle, fused thalami, absence of CSP, falx, corpus callosum, 3rd ventricle Cerebellum is normal Proboscis Most severe

Question 27

Semilobar

Answer 27

Large central ventricle Occipital and temporal horns may be present Variable development of falx and interhemispheric fissure Associated w/ cleft lip and palate

Question 28

Lobar

Answer 28

Two large lateral ventricles Absent CSP and corpus callosum

Question 29

Microcephaly

Answer 29

Overall reduction in brain size, chromosomal aberration, intrauterine infection Difficult to defect microcephaly prior to 24wks

Question 30

Prosencephaly

Answer 30

A result of infarction or hemorrhage of the brain Shows as anechoic mass within an area of the brain tissue, midline brain shift

Question 31

The strawberry shape is associated with what trisomy?

Answer 31

Trisomy 18

Question 32

What is a vein of Galen Aneurysm?

Answer 32

Cerebral arteriovenous malformation where the vein of Galen becomes dilated due to increased flow from the malformation. Often associated with cardiomegaly, ventriculomegaly, and nonimmune hydrops

Question 33

Anencephaly

Answer 33

The cephalic end of the neural tube fails to close completely, therefore portions of midbrain and brainstem may be present Elevated AFP frog eyes look

Question 34

What is the most common neural tube defect?

Answer 34

Anencephaly

Question 35

Caudal regression

Answer 35

Structural abnormality of the caudal end of the neural tube, more common w/ patients with diabetes Associated w/ gentiourinary, gastro, neural tube, and cardiovasc abnormalities Will appear as absent sacrum, fused pelvis, and short femurs

Question 36

Encephalocele

Answer 36

Normal AFP level A defect in bony calvarium allows herniation of intracranial contents - brain tissue and cerebral spinal fluid - big sac in back of head M/C in occipital region Round fluid filled or complex mass extending from calvaria, bony calvarial defect

Question 37

What is a calvarium?

Answer 37

The top of the skull (skull cap)

Question 38

Spina bifida

Answer 38

Failure of the neural tube to close completely

Question 39

Spina bifida occulta

Answer 39

Defect is covered by normal soft tissue, normal AFP level

Question 40

Spina bifida Aperta

Answer 40

Defect is uncovered (not so secret), elevated AFP Associated w/ cleft lip and palate, cardiac defects, encephalocele, gastrointest anomalies, and CLUBfoot

Question 41

TRV appearance of spina bifida

Answer 41

Outward splaying of lateral posterior ossificiation centers into a U or V shape Cystic or complex mass protruding from spinal defect Cerebellum will take on BANANA sign MMMM LEMON SIGN