Chapter 65 Fetal Skeleton

Question 1

term used to describe abnormal growth and density of bones and cartilage

Answer 1

Skeletal dysplasia

Question 2

• refers to disproportionately short stature

- occurs secondary to skeletal dysplasia

Answer 2

dwarfism

Question 3

dysplasia is suspected when limb lengths fall more than ____ standard deviations below the mean

Answer 3

2

Question 4

when skeletal dysplasia is suspected, the protocol should be adjusted to include:

Answer 4

1. Asses limb shortening
2. Assess bone contour
3. Estimate degree of ossification
4. Evaluate thoracic circumference and shape
5. survey for coexistent hand and foot anomalies
6. evaluate face & profile
7. Survey for other anomalies

Question 5

when assesing the bone contour, you should note:

Answer 5

-fractures, thickness, abnormal bowing, ribbon-like appearance, curvature

Question 6

decreased attenuation of bones with decreased shadowing suggest _________

Answer 6

hypomineralization

Question 7

when evaluating the face & profile, be especially aware of:

Answer 7

facial clefts

Question 8

shortening of the humerus/femur(proximal segment)

Answer 8

rhizomelia

Question 9

shortening of the radius/ulna or tib/fib(middle)

Answer 9

mesomelia

Question 10

shortening of the proximal & middle segments

Answer 10

micromelia

Question 11

most common lethal skeletal dysplasia:

Answer 11

thanatophoric dysplasia

Question 12

subdivision of thanatophoric dysplasia that has short CURVED femurs and flat vertebral bodies.

Answer 12

Type 1

Question 13

subdivision of thanatophoric dysplasia that has short STRAIGHT femurs, flat vertebral bodies, and cloverleaf skull

Answer 13

Type 2

Question 14

Infants with thanatophoric dysplasia die shortly after birth due to:

Answer 14

pulmonary hypoplasia from the narrow thorax

Question 15

sonographically, thanatophoric dysplasia will have:

Answer 15

severve micromelia(especially proximal bones

• clover-leaf skull
• frontal bossing
• narrowed thorax and shortened ribs

Question 16

most common non-lethal skeletal dysplasia

Answer 16

achondroplasia

Question 17

_____ increases the risk of achondroplasia

Answer 17

advanced paternal age

Question 18

lethal form of achondroplasia

Answer 18

homozygous achondroplasia

Question 19

most common cause of achondroplasia

Answer 19

spontaneous mutation

Question 20

form of achondroplasia inherited from 1 parent, normal intelligence and life span

Answer 20

heterozygous achondroplasia

Question 21

sonographic findings of achondroplasia:

Answer 21

• rhizomelia
• macrocephally
• trident hands

Question 22

caused by cartilage abnormalities which result in abnormal bone formation & hypomineralization

Answer 22

achondrogenesis

Question 23

type 1 achondrogenesis:

Answer 23

• more severe

- autosomal-recessive

Question 24

type 2 achondrogenesis:

Answer 24

• less severe
• more common
• results from spontaneous mutation

Question 25

patients with achondrogenesis are either stillborn or die shortly after birth due to _____

Answer 25

pulmonary hypoplasia

Question 26

sonographic findings of achondrogenesis:

Answer 26

- severe micromelia - macrocephaly - micrognathia - decreased/absent ossification of spine

Question 27

disorder of collagen production leading to brittle-bones

Answer 27

Osteogenesis Imperfecta

Question 28

blue sclera(blue tint to the whites of the eyes) occurs with

Answer 28

osteogenesis imperfecta

Question 29

osteogenesis imperfecta classifications: _____ & ______ are the mildest forms

Answer 29

types 1 and 4

Question 30

osteogenesis imperfecta classifications: severe form, transmited autosomal-dominant/recessive manner

Answer 30

type 3

Question 31

osteogenesis imperfecta classifications: most severe form, lethal. Inherited autosomal dominant/recessive, or spontaneous mutation

Answer 31

type 2

Question 32

sonographic findings of osteogenesis imperfecta:

Answer 32

- increased NT in 1st trimester - hypomineralization, especially of the skull - multiple fractures - compressible skull bones

Question 33

Diffuse hypomineralization of bone caused by an alkaline phosphatase deficiency

Answer 33

congenital hypophosphatasia

Question 34

diagnosis of congenital hypophosphatasia is achieved through:

Answer 34

- fetal blood sampling - Chorionic Vili sampling(CVS) - DNA analysis

Question 35

sonographic findings of congenital hypophosphatasia:

Answer 35

- diffuse hypomineralization | - poorly ossified cranium with well visualized brain structures

Question 36

rare, characterized by micromelia, fixed abducted thumb(Hitch-hikers thumb), micrognathia

Answer 36

Diastropic Dysplasia

Question 37

Characterized by bowing of the long bones

Answer 37

Camptomelic Dysplasia

Question 38

Camptomelic dysplasia is also known as _________

Answer 38

Bent Bone Dysplasia

Question 39

infants with camptomelic dysplasia usually die in the neonatal period due to

Answer 39

pulmonary hypoplasia

Question 40

sonographic findings of camptomelic dysplasia

Answer 40

bowing of long bones(especially the lower extremities)

Question 41

characterized by: - absent segment of an extremity - hands & feet are attached to body like a flipper

Answer 41

Roberts syndrome

Question 42

Roberts syndrome is also known as

Answer 42

pseudothalidomide syndrome

Question 43

sonographic findings of roberts syndrome

Answer 43

phocomelia(absent segment of extremity) with the upper extremities more severely affected

Question 44

Characterized by: - short ribs - extra fingers(polydactyl) - short limbs

Answer 44

Short-Rib Polydactyl syndrome

Question 45

characterized by small/narrow thorax, renal dysplasia, rhizomelia

Answer 45

Jeune's syndrome

Question 46

Jeune's syndrome is also known as

Answer 46

asphyxiating thoracic dysplasia

Question 47

Increased frequency amoung amish community, presents with narrow thorax, heart defects, limb shortening, abnormal teeth, thin hair, hypoplastic nails

Answer 47

Ellis-Van Creveld Syndrome

Question 48

Ellis-Van Creveld syndrome is also known as

Answer 48

Chondroectodermal dysplasia

Question 49

most common heart defect with Ellis-Van Creveld syndrome:

Answer 49

atrial septal defect

Question 50

Range of malformations of the caudal end of the neural tube

Answer 50

Caudal Regression syndrome

Question 51

Caudal Regression syndrome is linked to _____

Answer 51

maternal diabetes

Question 52

Sonographic findings of caudal regression syndrome:

Answer 52

- absent sacrum and coccyx - decreased movement of lower extremities - abnormal lumbar vertebrae

Question 53

Fusion of the lower extremities

Answer 53

Sirenomelia

Question 54

Sirenomelia is also known as:

Answer 54

mermaid syndrome

Question 55

Sirenomelia is more common in:

Answer 55

males

Question 56

Sirenomelia is lethal due to:

Answer 56

-bilateral renal agenisis

Question 57

sirenomelia is associated with:

Answer 57

- diabetes - cocaine use - monozygotic twinning

Question 58

sonographic findings of sirenomelia

Answer 58

- bilateral renal agenesis - fusion of lower extremities - single umbilical artery

Question 59

VACTERL anomalies are:

Answer 59

``` Vertebral Anal atresia Cardiac TracheoEsophageal fistula Renal Limb dysplasia ```

Question 60

For VACTERL to be considered ________ features must be present

Answer 60

3 out of 5

Question 61

VACTERL-H is when VACTERL is seen with _____

Answer 61

hydrocephalus

Question 62

Severe contractures(hardening & shortening of muscles, tendons, or other tissue) of extremities

Answer 62

Athrogryposis Multiplex Congenita

Question 63

Sonographic findings of Athrogryposis Multiplex Congenita

Answer 63

- rigid extremities | - hyperextension of knees

Question 64

Athrogryposis Multiplex Congenita is due to:

Answer 64

- abnormal innervation | - disorders of muscles & connective tissue

Question 65

amputation defects may be seen in association to:

Answer 65

amniotic band syndrome

Question 66

congenital absence of 1 or all extremities

Answer 66

amelia

Question 67

fused digits

Answer 67

syndactyly

Question 68

overlapping digits

Answer 68

clinodactyly

Question 69

split hand/lobster claw deformity:

Answer 69

ectrodactyly

Question 70

abnormal inversion of the foot perpendicular to the lower leg

Answer 70

clubfoot

Question 71

rockerbottom foot is especially associated with

Answer 71

Trisomy 18

Question 72

hypoplasia or aplasia of the radius and thumb

Answer 72

Radial ray defects

Question 73

radial ray defects are associated with these chromosomal abnormalities:

Answer 73

- Trisomy 13 & 18 | - VACTERL

Question 74

radial ray defects are associated with these syndromes:

Answer 74

- Holt-Oram syndrome | - TAR(thrombocytopenia with Absect Radi syndrome)