anatomic & sonographic appearance of fetal head & face Flashcards
what is neurulation?
Formation of the neural plate, neural tube & somites
Closure begins in the region of the future neck & proceeds in cephalic & caudal directions
what is this?
anencephaly
what’s this?
spine bifida
what does the prosencephalon divide into?
Telencephalon
• Cerebral hemispheres
• Lateral ventricles
Diencephalon
• Thalamus, hypothalamus, epithalamus, infundibulum
• 3rd Ventricle
what 2 parts are of the mesencephalon?
– Midbrain
– Aqueduct of Sylvius
what does the rhombencephalon divide into?
– Metencephalon
• Cerebellum, pons
– Myelencephalon
• Medulla oblongata
• 4th ventricle
what does this show?
head anatomy superior to inferior
what would see in a cross section of a fetal head from top to bottom
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
what is this?
lateral ventricles and choroid plexus
what is the bottom arrow pointing to? where is anterior?
what is the anatomy?
NOTE Thalamus isn’t labeled
LV = Lateral ventricle
AS = Aqueduct of Sylvius
TV = 3rd Ventricle
SF = Sylvian Fissure
H/PH = Posterior horn of ventricle
what level is this and what is labeled?
BPD level
what is being measured?
BPD
what are the arrows pointing to?
top is cavus septum pellucidum (CSP)
bottom is thalamus
BPD level. what do you see?
what is the arrow pointing to?
cavus septum pellucidum
what is cavum vergae (CV)?
Normal anechoic structure in the fetal head
• A posterior, curving inferiorly extension of the cavum septum pellucidum
• Tends to regress with advancing gestational age
what is Cavum Velum Interpositi (CVI)?
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
what is this?
the circle of wilis.
head anatomy: inferior
what plane is this pic of the cerebellum taken in? where is the Td placed to get this image?
• Transverse plane
• Same level of BPD and angling transducer
back toward the posterior area of brain,
slightly inferior on fetus
what is this?
cerebellum & medulla oblongata
what is this?
cerebellum & cisterna magna
what do you do if you are unable to document the cerebellum in the tranverse plane?
take it in coronal
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)?
lips, nose, orbits
what can you see in this profile image of the face?
what information can you get from the nose and lips?
why is it important to image in detail?
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
what is this? what plane?
nasal septum in coronal. you can also see the chin (posterior)
what measurements do you take for inner orbital diameter? outer orbital diameter (aka biocular diameter)?
what plane is the image in?
– 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
what can be noted about the caliper placement in this image (1, 2, and 3)
– #1 is outer orbital diameter (OOD) labeled BD for biocular diameter
– #2 is a single orbit diameter measurement
– #3 is inner orbital diameter (IOD)
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
qulitative assessment
what is this image of? what plane?
coronal of face
lens of eye
what is this image of?
what plane?
transverse of fetal orbits
what plane was this cross section taken in?
saggital
what is this image?
what plane?
coronal face
what is this?
what plane?
coronal of nose and lip
what are the arrows pointing to?
what is this?
mandibles
fetal tongue
what is this?
fetal hair. do NOT incl in a BPD
19.5 weeks
cerebellum
lips
18.5 weeks, cerebellum
18.5 weeks. lateral ventricles
18.5 weeks lips
