anatomic & sonographic appearance of fetal head & face

Question 1

what is neurulation?

Answer 1

Formation of the neural plate, neural tube & somites

Closure begins in the region of the future neck & proceeds in cephalic & caudal directions

Question 2

what is this?

Answer 2

anencephaly

Question 3

what’s this?

Answer 3

spine bifida

Question 4

what does the prosencephalon divide into?

Answer 4

Telencephalon
• Cerebral hemispheres
• Lateral ventricles

Diencephalon
• Thalamus, hypothalamus, epithalamus, infundibulum
• 3rd Ventricle

Question 5

what 2 parts are of the mesencephalon?

Answer 5

– Midbrain
– Aqueduct of Sylvius

Question 6

what does the rhombencephalon divide into?

Answer 6

– Metencephalon
• Cerebellum, pons
– Myelencephalon
• Medulla oblongata
• 4th ventricle

Question 7

what does this show?

Answer 7

head anatomy superior to inferior

Question 8

what would see in a cross section of a fetal head from top to bottom

Answer 8

1st lateral ventricles & choroid plexus

Continuing inferior through the head
– 2nd Third ventricle and thalami

Continuing inferior through the head
Cerebellum, cisterna magna & medulla oblongata

Question 9

what is this?

Answer 9

lateral ventricles and choroid plexus

Question 10

what is the bottom arrow pointing to? where is anterior?

Answer 10

Question 11

what is the anatomy?

Answer 11

NOTE Thalamus isn’t labeled
LV = Lateral ventricle
AS = Aqueduct of Sylvius
TV = 3rd Ventricle
SF = Sylvian Fissure
H/PH = Posterior horn of ventricle

Question 12

what level is this and what is labeled?

Answer 12

BPD level

Question 13

what is being measured?

Answer 13

BPD

Question 14

what are the arrows pointing to?

Answer 14

top is cavus septum pellucidum (CSP)

bottom is thalamus

Question 15

BPD level. what do you see?

Answer 15

Question 16

what is the arrow pointing to?

Answer 16

cavus septum pellucidum

Question 17

what is cavum vergae (CV)?

Answer 17

Normal anechoic structure in the fetal head
• A posterior, curving inferiorly extension of the cavum septum pellucidum
• Tends to regress with advancing gestational age

Question 18

what is Cavum Velum Interpositi (CVI)?

Answer 18

Anechoic structure that is only seen when cavum
vergae is present because it closes early
• It courses inferior & posterior to cavum vergae
• Will regress with advancing gestational age
• Difficult to visualize

note the differences b/t CSP, CV and CVI

Question 19

what is this?

Answer 19

the circle of wilis.

Question 20

head anatomy: inferior

Question 21

what plane is this pic of the cerebellum taken in? where is the Td placed to get this image?

Answer 21

• Transverse plane
• Same level of BPD and angling transducer
back toward the posterior area of brain,
slightly inferior on fetus

Question 22

what is this?

Answer 22

cerebellum & medulla oblongata

Question 23

what is this?

Answer 23

cerebellum & cisterna magna

Question 24

what do you do if you are unable to document the cerebellum in the tranverse plane?

Answer 24

take it in coronal

Question 25

what measurement are usefule when ruling out hypotelorism or hypertelorism (abnormal distance + or - between organs or body parts. eg. eyes hypo often associated with FAS)?

Answer 25

lips, nose, orbits

Question 26

what can you see in this profile image of the face?

Answer 26

Question 27

what information can you get from the nose and lips? why is it important to image in detail?

Answer 27

Identify: – Each nares (nostril) – Nasal septum – Upper lip – Philtrum: Median groove on the external surface of the upper lip – Lower lip • Important to image in detail to exclude clefting

Question 28

what is this? what plane?

Answer 28

## Footnote nasal septum in coronal. you can also see the chin (posterior)

Question 29

what measurements do you take for inner orbital diameter? outer orbital diameter (aka biocular diameter)? what plane is the image in?

Answer 29

– Inner Orbital Diameter (IOD) • Is the distance between the two orbits • Measure medial border of one orbit to the opposite medial border of other orbit – Outer Orbital Diameter (OOD) or Biocular Diameter • A measurement of both orbits • Measure from lateral border of one orbit to the lateral border of Coronal the other orbit coronal

Question 30

what can be noted about the caliper placement in this image (1, 2, and 3)

Answer 30

– #1 is outer orbital diameter (OOD) labeled BD for biocular diameter – #2 is a single orbit diameter measurement – #3 is inner orbital diameter (IOD)

Question 31

what assessment says: • Each orbit & nasal bridge should be one-third of OOD (outer orbital diameter) per National Educational Curriculum • Inner & outer orbital distances are correlated to gestational age

Answer 31

qulitative assessment

Question 32

what is this image of? what plane?

Answer 32

coronal of face lens of eye

Question 33

what is this image of? what plane?

Answer 33

transverse of fetal orbits

Question 34

what plane was this cross section taken in?

Answer 34

saggital

Question 35

what is this image? what plane?

Answer 35

coronal face

Question 36

what is this? what plane?

Answer 36

coronal of nose and lip

Question 37

what are the arrows pointing to? what is this?

Answer 37

mandibles fetal tongue

Question 38

what is this?

Answer 38

fetal hair. do NOT incl in a BPD

Question 39

19.5 weeks

Answer 39

cerebellum

Question 40

lips

Answer 40

18.5 weeks, cerebellum

Question 41

18.5 weeks. lateral ventricles

Answer 41

18.5 weeks lips