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252 Cards in this Set
- Front
- Back
Transverse imaging of the cranium is known as ______.
|
occipitotransverse
|
|
The upper dome-like portion of the skull w/o the lower jaw or facial parts is known as the:
|
calvarium
|
|
What does the calvarium consist of?
|
frontal bone
parietal bone occipital bone |
|
What are the 2 parts of the cranium?
|
cranial vault & face
|
|
When does cranial ossification occur?
|
12 weeks
|
|
The texture characteristics of the cranium are determined by ____ weeks.
|
18
|
|
T or F. Most brain anomalies represent a symmetric process.
|
TRUE
|
|
What are the midline structures of the cranium?
|
cavum septum pellucidum
corpus collosum cerebellum & brain stem 3rd & 4th ventricles |
|
What are the 2 lateral structures of the cranium?
|
lateral ventricle, choroid plexus
|
|
The anterior portion of the cranium are the ____ ____.
|
frontal horns
|
|
The posterior portion of the cranium includes what 3 structures?
|
occipital horns of lateral ventricles
choroid plexus posterior fossa (cisterna magna) |
|
The echogenic cluster of cells important to the production of CSF is the ____ ____.
|
choroid plexus
|
|
Where is CSF (cerebrospinal fluid) produced?
|
by the choroid plexus within the lateral ventricles
|
|
The choroid plexus is a highly ____ tissue.
|
vascularized
|
|
The choroid plexus appear ____ in early pregnancy.
|
large
|
|
Where is the choroid plexus located?
|
within the roofs of each ventricle except @ the frontal horns
|
|
What are 4 characteristics of the choroid plexus?
|
echogenic, tear shaped, housed b/t medial & lateral ventricular borders, prominent in early pregnancy
|
|
The body of the choroid plexus is the ____.
|
glomus
|
|
What is a common normal variation within the choroid plexus?
|
cysts
|
|
Some CP cysts have a known association with _____ _____.
|
chromosomal abnormalities (trisomy 18)
|
|
The fetal ventricular system consists of what ventricles?
|
lateral ventricles 1 & 2, and the 3rd and 4th ventricle
|
|
What are the 5 regions of lateral ventricles?
|
frontal horns, lateral bodies, occipital horns, temporal, atria/trigone
|
|
The ____ ____ are the most superior regions of the lateral ventricles.
|
lateral bodies
|
|
The most lateral region of the lateral ventricles is the ____ region.
|
temporal
|
|
The juncture of the anterior, temporal, and occipital horns is known as the _____.
|
atria/trigone
|
|
The site for lateral ventricle measurement is @ the _____.
|
atria/trigone
|
|
Two diverging echo free structures within the frontal lobes of the brain are the ____ ____.
|
frontal horns
|
|
The frontal horns become prominent with ____ ____.
|
ventricular dilatation
|
|
This acts as a protective cushion encasing the brain & spinal cord:
|
CSF
|
|
CSF regulates ____ within the spaces it fills.
|
pressure
|
|
Proximal brain structures contain _____ artifacts.
|
reverberation
|
|
The lateral ventricle is more easily imaged in the ____ hemisphere.
|
distal
|
|
The _____ brain structures are better for sonographic evaluation.
|
distal
|
|
What causes reverberation?
|
sound passing out of a structure w/ acoustic impedance that is different from its neighbor causing alot of sound
|
|
How are the lateral ventricles measured?
|
in the axial plane
|
|
To measure the lateral ventricles you would measure across the ____ ____ perpendicular to the long axis of the ventricle.
|
posterior glomus
|
|
The normal measurements of the lateral ventricles are ____ mm or less.
|
10
|
|
What is the average normal measurement of the lateral ventricles?
|
6.5 mm
|
|
You must evaluate for ______ or ______ which are signs of CNS abnormalities.
|
ventriculomegaly or hydrocephalus
|
|
The midline anechoic fluid containing structure is known as the ____ ____ ____.
|
cavum septum pellucidum
|
|
What does the cavum septum pellucidum look like on US?
|
2 small bright lines separated by CSF & is box shaped
|
|
Where is the cavum septum pellucidum located?
|
parallel to the falx, anterior to the thalamus.
|
|
The cavum septum pellucidum lies between the ____ ____ & bodies of the ____ ____.
|
frontal horns, lateral ventricles
|
|
T or F. Viewing the cavum septum pellucidum signifies normal development of the frontal midline.
|
TRUE
|
|
What structure keeps the 2 lateral hemispheres of the cerebrum connected?
|
the corpus callosum
|
|
The ____ ____ is a band of tissue between the frontal ventricular horns.
|
corpus callosum
|
|
The echogenic fibrous structure separating the brain into 2 equal hemispheres is the ____ ____.
|
interhemispheric fissure (IHF)
|
|
The IHF is an important landmark and its presence implies that ____ of the ____ has occurred.
|
separation of the cerebrum
|
|
The ____ are the band of white matter joining different parts of the brain.
|
peduncles
|
|
The intrahemispheric fissure is a ____ echo & the ____ ____ diameter of the skull.
|
midline, widest transverse
|
|
The intrahemispheric fissure is the proper level to measure the ____ & assess midline fetal brain structures.
|
BPD
|
|
There is paired ____ on either side of the intrahemispheric fissure & the apex of them points towards the ____ ____.
|
thalamus, fetal occiput
|
|
The ____ aids in deciding which direction the face is positioned.
|
thalamus
|
|
What ventricle is located within the thalamus?
|
3rd ventricle
|
|
How does CSF travel?
|
thru choroid plexus to foramen of monro to the 3rd ventricle & aqueduct of sylvius to 4th ventricle
|
|
Pulsations from the ____ artery are observed b/t the lobes of the ____ @ the interpeduncular cistern.
|
basilar, peduncles
|
|
The cerebellum is located ____ to the cerebral peduncles in the ____ ____.
|
posterior, posterior fossa
|
|
The vascular network at the base of the brain that may be seen anterior to the midbrain is the:
|
circle of willis
|
|
The circle of willis is a ____ region that is highly ____ in the midline position.
|
triangular, pulsatile
|
|
The ____ ____ artery can be seen as a major lateral branch of the circle of willis.
|
middle cerebral artery
|
|
What is the middle cerebral artery used to evaluate for?
|
to evaluate for impending fetal demise
|
|
What is included within the posterior fossa?
|
cerebellum, 4th ventricle & cisterna magna (& nuchal fold- SDMS)
|
|
The ____ helps to coordinate movements, balance & posture.
|
cerebellum
|
|
Where is the cerebellum located?
|
w/in the posterior fossa and below the cerebrum & is posterior to the cerebral peduncles
|
|
The cerebellum is _____ to most of the brain stem.
|
superoposterior
|
|
What is the cerebellum composed of?
|
2 lateral hemispheres & the vermis
|
|
The small central lobe which relays info b/t the 2 hemispheres is the ____.
|
vermis
|
|
The cerebral hemispheres are joined together by the ____ ____.
|
cerebellar vernic
|
|
The primary reason for TCD (trans cerebellar diameter) is to detect for ____ of the ____.
|
malformations of the CNS
|
|
To measure the cerebellum w/ TCD you must obtain the measurement in the ____ ____ ____ plane.
|
fetal axial oblique
|
|
When measuring the cerebellum you must measure the ____ ____ diameter.
|
widest transverse
|
|
What is the shape of the cerebellum on US when measuring?
|
dumb bell or heart shape
|
|
The cerebellum is typically measured between ____ weeks.
|
14 - 30 weeks
|
|
The cerebellum measurement CAN be used for ____ ____ but not in the presence of an _____.
|
gestational dating, abnormality
|
|
Cisterns are areas where CSF ____.
|
pools
|
|
The ____ ____ is a posterior fossa cistern filled with CSF.
|
cisterna magna
|
|
The largest cistern in the brain is the ____ ____.
|
cisterna magna
|
|
A normal appearing cisterna magna may exclude almost all open ____ ____.
|
spinal defects
|
|
The cisterna magna is an ____ structure located ____ to the cerebellum.
|
anechoic, posterior
|
|
Linear echoes in the cisterna magna represent ____ ____ that attach the ____ ____.
|
dural folds, falx cerebelli
|
|
What are the normal measurements of the cisterna magna?
|
3 - 11 mm
|
|
The average size of the cisterna magna is:
|
5 - 6 mm
|
|
How do you measure the cisterna magna?
|
measure from the vernis to the inner skull of the occipital bone
|
|
The nuchal fold is NOT assessed in the ____ view.
|
sagittal
|
|
What view is the nuchal fold assessed?
|
axial
|
|
Nuchal skin fold thickness is measured in the ____ trimester up to ____ weeks.
|
2nd, 20
|
|
The nuchal fold is measured in the plane containing what 3 structures?
|
cavum septum pellucidum, cerebellum, cisterna magna
|
|
The normal range of nuchal fold measurements is ____.
|
less than 6 mm ( .6 cm)
|
|
What are 4 other structures that may be measured to estimate GA?
|
cerebellar length
binocular distance renal length humerus length |
|
1st trimester:
|
CRL +/- (3-5 days)
|
|
14 - 20 weeks
|
BPD, HC, AC, FL +/- 10 days
|
|
20 - 30 weeks
|
BPD, HC, AC, FL +/- 14 days
|
|
30 - 40 weeks
|
BPD, HC, AC, FL +/- 21 days
|
|
A tool used for GA determination is called _____ height.
|
symphysis-fundal
|
|
The first fetal motion felt by the mother is known as ____ & is used for GA determination.
|
quickening
|
|
What can cause increased fundal height?
|
macrosomic fetus
polyhydramnios twins, incorrect dates fibroids, molar pregnancy |
|
Decreased fundal height may be caused by:
|
SGA or IUGR fetus
oligohydramnios incorrect dates |
|
The measure of variation that is generally the most important & useful is:
|
standard deviation
|
|
What is standard deviation?
|
the measure of variation of values about the mean
|
|
Written representation by graphs, diagrams or charts w/ numbers is known as a _____.
|
nomogram
|
|
What are the 4 basic GA measurements?
|
BPD, HC, AC, and FL
|
|
What does BPD stand for?
|
biparietal diameter
|
|
The BPD is obtainable at ____ weeks TA.
|
10 - 12
|
|
The BPD is not typically measured until ____ weeks.
|
12
|
|
What 3 planes are used for BPD?
|
axial, transverse, or thalamic
|
|
What are the 3 landmarks used for BPD?
|
cavum septum pellucidum
thalamus cerebral peduncles |
|
Do not include ____ ____ when measuring BPD.
|
soft tissue
|
|
How do you measure the calvarium (parietal bone)?
|
from leading edge to leading edge
|
|
The most common way to measure the calvarium is ____ edge to ____ edge.
|
outer to inner
|
|
BPD reliability decreases after ____ weeks due to increased ____ ____.
|
26, biologic variability
|
|
BPD accuracy is greatest between _____ weeks and is affected by ____ shape.
|
12 - 28 (+/- 2, or 3 in 3rd trimester), head
|
|
BPD is not accurate with what 3 things?
|
severe ventriculomegaly
microcephaly skull altering head lesions |
|
BPD growth is ____ mm per week in the early 2nd trimester & ____ mm in the mid 2nd trimester.
|
5 mm, 3.6 mm
|
|
BPD growth is ____ mm per week in the 3rd trimester.
|
1.8 mm
|
|
The BPD is found at the level of ____ ____ ____.
|
midline echo complex
|
|
What are the 2 landmarks for BPD?
|
smooth symmetric head & well defined midline echo
|
|
A normal head shape is ____.
|
ovoid
|
|
A round shape head is called:
|
brachycephaly
|
|
Brachycephaly leads to _____ of GA.
|
overestimation
|
|
A flattened head is known as:
|
dolichocephaly
|
|
Dolichocephaly leads to ____ of GA.
|
underestimation
|
|
Dating by HC is unaffected by ____ ____.
|
head shape
|
|
Near term HC is more accurate than ____.
|
BPD
|
|
To measure HC you measure at the ____ level.
|
BPD
|
|
How do you measure HC?
|
from outer to outer border
|
|
What is the HC formula?
|
(D1 + D2) x 1.57
|
|
Measurement along the outer perimeter of the calvarium is known as ____ ____.
|
ellipse calculation
|
|
T or F. Prenatal compression of the head is normal
|
TRUE
|
|
The ____ is less affected by compression than ____.
|
HC, BPD
|
|
What are 4 reasons for head compression?
|
malpresentation
uterine crowding vertex position leiomyoma (fibroids) |
|
The ____ ____ evaluates head shaped for the reliability of BPD.
|
cephalic index
|
|
The cephalic index is performed to determine ____ ____.
|
head shape
|
|
The ratio of the BPD to fetal anterior-posterior diameter of the fetal skull is:
|
cephalic index
|
|
What does OFD stand for?
|
occipito-frontal diameter
|
|
What is the formula for cephalic index?
|
CI= BPD/OFD x 100
|
|
Abnormal cephalic index values may indicate what 2 things?
|
dolichocephaly
brachycephaly |
|
How do you measure OFD?
|
measure from the outer border of the occiput to the outer border of the frontal bone
|
|
What is a normal cephalic index (CI)?
|
80% +/- 1
range is 75-85% |
|
With dolicocephaly there is a small ____ and longer ____.
|
BPD, OFD
|
|
The cephalic index is ____ with dolicocephaly.
|
< 75%
|
|
Dolicocephaly is associated with ____ fetuses and ____.
|
breech & oligohydramnios
|
|
With brachycephaly there is a large ____ and shorter ____.
|
BPD, OFD
|
|
The cephalic index is ____ with brachycephaly.
|
> 85%
|
|
Brachycephaly is most commonly a ____ ____.
|
normal variant
|
|
Two associations with brachycephaly are:
|
trisomy 21 & spina bifida
|
|
The condition of having a malformed cranial vault with a peak appearance & vertical index above 77 is ______.
|
oxencephaly
|
|
What is oxencephaly caused by?
|
premature closure of the coronal, sagittal, and lambdoidal sutures
|
|
Face visualization is dependent on what 3 things?
|
fetal position
adequate amniotic fluid good acoustic windows |
|
What does a transverse view of facial anatomy demonstrate?
|
orbital abnormalities
intra-orbital distances maxilla mandible |
|
The orbits are inferior to or below the ____ ____.
|
cerebellar plane
|
|
The ocular diameter (OD) is the measurement of a ____ ____.
|
single orbit
|
|
How do you measure OD?
|
from medial to lateral wall of orbit
|
|
The inner orbital diameter (IOD) is the length between ____ ____.
|
two orbits
|
|
How do you measure IOD?
|
from medial wall of one orbit to the medial wall of the other
|
|
The binocular distance (OOD or BD) is the ____ to ____ orbital diameter.
|
outer to outer (lateral to lateral)
|
|
The _____ measurement is more strongly related to BPD & GA than other orbital measurements.
|
binocular distance (OOD or BD)
|
|
Orbits are accessible in all fetal positions except:
|
face down
|
|
Ocular biometry is helpful in identifying what 4 things?
|
hypotelorism (close orbits)
hypertelorism (spaced orbits) anophthalmia (absent eyes) micropthalmia (small eyes) |
|
Of the 4 basic GA measurements the ____ has the largest reported variability & is more affected by growth disturbances.
|
AC (abdominal circumference)
|
|
The ____ is most susceptible parameter to measurement error.
|
AC
|
|
The ____ size strongly influences AC.
|
liver
|
|
T or F. AC is a poor predictor of GA later in gestation.
|
TRUE
|
|
The term for large fetus is ____.
|
macrosomia
|
|
The equation for AC is:
|
(D1 + D2) x 1.57 = AC
|
|
To measure the AC in TRV you must use what 2 landmarks?
|
level of umbilical vein & portal sinus junction
(stomach & adrenal glands may be seen at this level) |
|
T or F. The AC includes the entire perimeter of the abdomen including soft tissue.
|
TRUE
|
|
A high AC/HC ratio implies ____ of the fetus.
|
malnutrition
|
|
The ____ length has the same accuracy as BPD measurements predicting GA.
|
femur
|
|
You must measure the femoral ____ from end to end.
|
diaphysis
|
|
What is the diaphysis?
|
shaft of a long bone
|
|
When measuring the femur what 3 things are not included with the measurement?
|
cartilaginous epiphysis, femoral head, distal femoral point
|
|
The ____ is the end of a long bone.
|
epiphysis
|
|
What is associated with advanced gestational age?
|
distal femoral & proximal tibial epiphyseal ossification centers
|
|
The distal femoral epiphyseal ossification center (DFE) is identified with gestations > than ____ weeks.
|
33
|
|
The proximal tibial epiphyseal ossification center (PTE) is identified with gestations > than ____ weeks.
|
35
|
|
What should be done if there is a 2 week or > measurement discrepancy b/t the femur & other biometric parameters?
|
all fetal long bones should be measured
|
|
The ____ ____ ____ may produce specular reflections that should not be included in the humerus measurement.
|
cartilaginous humeral head
|
|
The ____ ____ ____ should also not be included when measuring the humerus.
|
proximal humeral point
|
|
The ulna is ____ than the radius proximally but distally it is ____ to the radius.
|
larger, equal
|
|
The ____ is on the fetal thumb side.
|
radius
|
|
The tibia is ____ to, ____ & ____ than the fibula.
|
medial, longer, thicker
|
|
The fibula is ____ to the tibia.
|
lateral
|
|
When the EFW is above the 90th percentile for EGA it is considered to be:
|
macrosomia
|
|
If the EFW is below the 10th percentile for EGA it is considered to be:
|
IUGR
|
|
Another name for an exceptionally large baby (fat baby) is called:
|
macrosomia
|
|
206.7
This is the most widely recognized and most common stress reaction? |
alcohol consumption
|
|
The frequency of macrosomia in the offspring of diabetic mothers ranges from _____.
|
25% - 45%
|
|
When a fetus has macrosomia they have a birthweight > than ____.
|
4,000 grams
|
|
The placenta of the macrosomic fetus can become significantly ____ & ____.
|
large & thick
|
|
The most reliable sonographic assessment for macrosomia is ____ ____.
|
abdominal circumference
|
|
What are the 3 main complications associated with macrosomia?
|
fetal shoulder dystocia
increased mortality & morbidity prolonged labor |
|
What are 4 conditions potentially affecting fetal growth?
|
severe pre-eclampsia
chronic hypertension chronic renal disease severe diabetes |
|
What does EFW stand for?
|
estimated fetal weight
|
|
A normal but smaller fetus is known as ____.
|
SGA (small for gestational age)
|
|
What is a SGA fetus likely to have?
|
small placenta & low AFI
|
|
A fetus with IUGR is a subset of ____ fetuses.
|
SGA
|
|
IUGR is associated with:
|
SGA
maternal hypertension preeclampsia decreased fetal movement |
|
What are the 2 types of IUGR?
|
symmetric & asymmetric
|
|
For an accurate assessment with prior dating, ____ ____ are required.
|
serial exams
|
|
What are some risks & complications associated with IUGR?
|
asphyxia
meconium aspiration low birth weight stillborn/illness |
|
Symmetric IUGR makes up ____% of all IUGR cases.
|
25% - 30%
|
|
Asymmetric IUGR is the more common form and makes up ____%
|
70% - 75%
|
|
With symmetric IUGR all physical parameters are ____ in size.
|
decreased
|
|
Symmetric IUGR is associated with ____ ____ in the ____ trimester.
|
severe insult, 1st
|
|
Head sparing IUGR typically begins in the ____ or ____ trimester.
|
2nd or 3rd
|
|
The most common cause of asymmetric IUGR is ____ ____.
|
placental insufficiency
|
|
What are the 4 placental factors with asymmetric IUGR?
|
placental insufficiency
abruptio placenta infarcts placental neoplasms |
|
What are 3 fetal factors with asymmetric IUGR?
|
isoimunization
multiple gestation congenital anomalies |
|
IUGR is an indication for ___ ___ ___.
|
umbilical cord doppler
|
|
With monochorionic twins the EFW should be concordant & not differ by more than ____%.
|
20%
|
|
What is the formula for determining EFW discordance?
|
Largest EFW - smallest EFW/Largest EFW x 100
|
|
The assessment of fetal well being or distress is known as the:
|
BPP (biophysical profile)
|
|
When is a BPP performed?
|
after 28 weeks GA
|
|
BPP has ____ parameters worth ____ pts each.
|
5, 2
|
|
What are the 5 parameters for BPP?
|
cardiac non stress test
observation of breathing fetal movements & fetal tone amniotic fluid |
|
There is a ___ min time limit with BPP.
|
30
|
|
A BPP score of ____ is considered normal.
|
8 - 10
|
|
With a cardiac non stress test the BP is taken every ____ min.
|
8 - 10
|
|
What patient positions are used for a cardiac non stress test?
|
lateral recumbent, semi-fowlers
|
|
A NST may be performed 2 times a week on patients with ____, ___, or ____.
|
diabetes
IUGR postdate |
|
Fetal breathing must be observed for ____ seconds continuously.
|
30
|
|
How many points are given for one episode of breathing lasting 30 seconds? If not seen?
|
2 points, 0 points if not visualized
|
|
The fetal ____ initiates & regulates frequency of fetal breathing movements.
|
CNS
|
|
At least ___ discrete body movements must be visualized.
|
3
|
|
The ____ ____ system controls fetal body movements.
|
intact nervous
|
|
At least ____ episode of extension or flexion of limbs must be observed.
|
1
|
|
A normal amniotic fluid rating is one pocket of amniotic fluid @ least ____ cm or AFI total fluid measurement of ____ cm.
|
2 cm , 5-22 cm
|
|
Decreased amniotic fluid may represent ____ or ____ ____.
|
IUGR, or intrauterine stree
|
|
A decrease in blood to the kidneys causes a decrease in ____.
|
AFI
|
|
What is the L/S ratio?
|
lecithin/sphingomyelin ratio
|
|
Testing of the amniotic fluid to determine fetal lung maturity is known as the:
|
L/S ratio
|
|
Lecithin exceeds sphingomyelin by a _____ ratio.
|
2:1
|
|
A ____ ____ doppler is not recommended for routine fetal evaluation.
|
umbilical artery
|
|
What are the indications for doing a uterine artery doppler?
|
abnormal biophysical profile
abnormal AFI IUGR multiple gestation |
|
Umbilical artery doppler studies should be avoided during ____ ____.
|
fetal breathing
|
|
Diastolic flow is directly related to the flow resistance of the ____.
|
placenta
|
|
What does umbilical artery doppler measure?
|
the resistance of blood flow within the placenta.
|
|
As a pregnancy progresses, the resistance to flow ____.
|
decreases (due to increased numbers of tertiary stem villi)
|
|
Blood flow in the umbilical artery increases during ____.
|
diastole
|
|
End diastolic flow increases with ____ ____.
|
gestational age
|
|
Absence of effective diastolic flow is associated with ____ ____.
|
poor outcome
|
|
What are 2 serious findings with umbilical artery doppler?
|
absent end diastolic flow & reversed end diastolic flow
|
|
What is associated with the return of end diastolic flow in the umbilical artery?
|
prenatal glucocorticoid (used to prolong pregnancy)
|
|
Normal S/D ratio is less than ____ ratio during the 3rd trimester.
|
3:1
|
|
What is the formula for resistive index (RI)?
|
max systolic veloctiy- diastolic velocity/ systolic velocity
|
|
What is the normal range of resistive index?
|
0.45 - 0.58 after 26 weeks gestation
|
|
Low resistance has ____ diastole.
|
increased
|
|
High resistance has ____ or ____ diastole.
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decreases or reversed
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What type of flow is desirable for umbilical cord doppler?
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low resistance flow
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High resistance flow feeds a high resistance vascular bed including the ____ & ____ extremities.
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uterus & face
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Two examples of low resistance vascular beds include the ____ & ____.
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brain & organs
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What is the most severe doppler finding?
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complete reversal of end-diastolic velocity
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