2 -Chapter 49 - Sonography of the Second and Third Trimesters Flashcards
the ventricles of the heart come to a point called the __________; normally it is directed toward the __________
apex; left hip
the portion of the cerebral ventricular system where the lateral lobes, temporal lobes, and occipital lobes connect; located posterior and lateral to the thalami
atrium of the lateral ventricles
indicates that the fetal head is toward the fundus of the uterus
breech
a cavity within the septum pellucidum in the anterior midportion of the fetal brain
cavum septum pellucidum
echogenic tissue within the lateral ventricles that produces central nervous system fluid and is seen prominently during second-trimester fetal sonography
choroid plexus
a posterior fossa cistern that contains cerebrospinal fluid
cisterna magna
a narrow band of compact tissue forming a solid covering over the roof of the third ventricle and connecting the hemispheres of the brain
corpus callosum
structure that carries oxygenated blood from the pulmonary artery to the descending aorta
ductus arteriosus
structure that carries oxygenated blood from the umbilical vein to the inferior vena cava
ductus venosus
an echo within a fetal heart chamber that is as bright (echogenic) as bone and persists despite changes in the sonographic plane
echogenic intracardiac focus (EIF)
protrusion or bulging of the forehead
frontal bossing
adjusting an individual patient’s risk assessment for aneuploidy based on the presence or absence of sonographic markers
genetic sonogram
increased echogenicity of the bowel associated with aneuploidy risk and fetal pathology
hyperechoic bowel
the largest portion of the ventricular system in the fetal cranium
lateral ventricles
the probability that a fetus exhibiting a specific finding will be affected by a specific condition; likelihood ratios in pregnancy are typically used to predict risk for aneuploidy
likelihood ratio
a large tongue seen persistently extending outside of the fetal mouth
macroglossia
abnormally small chin
micrognathia
linear echoes located centrally in the fetal head that are produced by the borders of the opposing cerebral hemispheres
midline echo (the falx)
written representation by graphs, diagrams, or charts of the relationship between numeric variables
nomogram
typical position of the abdominal organs with the liver and inferior vena cava on the right, the stomach on the left, and the apex of the heart directed toward the left
normal situs
the thickness of fetal skin at the back of the fetal neck that may be visualized and measured between 16 and 20 weeks’ gestational age to assess aneuploidy risk
nuchal skin fold
mild dilation of the renal pelvis
pyelectasis
indicates that the fetus is lying transversely in the uterus, horizontally, or perpendicular to the maternal sagittal axis
transverse fetal lie
enlargement of the cerebral ventricles
ventriculomegaly
indicates that the fetus is positioned head down in the uterus
vertex
When evaluating the fetal spine, aligning the transducer in a(n) ___________ axis to the spinal elements is important.
Perpendicular
The profile view of the fetal face is important to examine to rule out all of the following abnormalities except: Select one: a. Frontal bossing b. Micrognathia c. Cephalocele d. Cleft soft palate
d. Cleft soft palate
Beyond 30 weeks’ gestation, a renal pelvis is considered abnormal when measuring greater than _____ millimeters (mm).
10
Normally, the fetal bladder empties at least every ______________.
60 minutes
Which one of the following statements about the fetal liver is FALSE?
Select one:
a. The fetal liver is the main storage site for glucose.
b. The texture of the fetal liver appears pebble gray.
c. The fetal liver is very sensitive to disturbances in growth.
d. The right lobe is larger than the left lobe in the fetal liver.
d. The right lobe is larger than the left lobe in the fetal liver.
The cerebrospinal fluid (CSF) travels from the lateral ventricles to the third ventricle via the
Foramen of Monro
Which structure shunts blood away from the lungs?
Ductus arteriosus
Nuchal skin fold thickness of 5 mm or less is normal up to _____ weeks’ gestation.
20
The widest transverse diameter of the skull and the proper level to measure the biparietal diameter (BPD)
Thalamus
The presentation of a fetus lying perpendicular to the maternal sagittal axis is in the ____________ position.
Transverse
Dilation of the entire ventricular system, including the fourth ventricle, is associated with what abnormality?
Spinal defects
The three vessels found in the umbilical cord
Two arteries and one vein
Indicates that the liver is on the right, the stomach is on the left, and the heart apex is on the left
Normal situs
At what gestational week does the volume of amniotic fluid stop increasing?
34th
The size of the cistern magna is obtained by measuring from the _____________ to the ______________.
Vermis; occipital bone
The cranial bones ossify by ______ weeks.
12
What structure carries oxygenated blood from the umbilical vein to the inferior vena cava (IVC)?
Ductus venosus
Especially in the third trimester, a fetus in the breech position may demonstrate a cranium shape of what?
Dolichocephalic
Fetal anatomy may be assessed accurately after _________________.
18 menstrual weeks
Visualization of the distal femoral epiphysis signifies a gestational age beyond:
33 to 35 weeks
The normal atrium of the lateral ventricle measures ______ mm and is considered abnormal when it reaches ______ mm.
6.5; 10
In the transverse plane, an abnormal fetal spine may appear splayed in all of the following configurations except: Select one: a. V-shaped b. Y-shaped c. C-shaped d. U-shaped
b. Y-shaped
The cavum septum pellucidi is observed anterior to the _______________.
Thalamus
Because of the low-density brain tissue, the texture of the brain may appear ______________.
Hypoechoic
Indicates that the fetal head is toward the fundus of the uterus
Breech
