Ch. 51 Test Flashcards
What biometric fetal measurements are routinely done in the 2nd and 3rd trimester
BPD, HC, AC, FL, HR, cerebellum, cistern magna, lateral ventricles
Should the sonographer routinely include evaluation of the adnexa, uterine walls and cervix on the OB sonogram
yes, to evaluate for masses, fibroids and cysts
Give a reason for evaluating each of the following fetal structures: CEREBRAL VENTRICLES
hydrocephalus
Give a reason for evaluating each of the following fetal structures: SPINE
spina bifida, sacrococcygeal teratoma
Give a reason for evaluating each of the following fetal structures: STOMACH
duodenal atresia, esophageal atresia, situs inversus, diaphragmatic hernia
Give a reason for evaluating each of the following fetal structures: HEART
4 chambers, great vessels
Give a reason for evaluating each of the following fetal structures: KIDNEYS/URINARY BLADDER
renal agenesis, hydrocephalus
Give a reason for evaluating each of the following fetal structures: UMBILICAL CORD INSERTION
omphalocele, gastroschisis
Give a reason for evaluating each of the following fetal structures: FACE
clef palate, other craniofacial malformation
Give a reason for evaluating each of the following fetal structures: CEREBELLUM
congenital anomalies
Give a reason for evaluating each of the following fetal structures: CISTERNA MAGNA
dandy walker malformation, spina bifida
Why is it important for the sonographer to have a systematic and organized approach to performing OB sonograms
ensure you document all criteria and dont forget to image a structure
If the LMP is unknown or the patient has irregular menstrual cycles, what are some other parameters that can be used to determine the due date
fundal height, doptones, lab tests, CRL, gest sac diameter
A post term pregnancy is defined as one that has gone beyond _____ weeks
42
Explain the gravidity and parity of a woman who is G5P3104
5th pregnancy, 3 full term pregnancies, 1 premature birth, 0 abortions/miscarriages, 4 living children
Fetal presentation refers to
the part of the fetus that is closest to the cervix
Fetal lie refers to
the direction the fetal body is lying in relation to the maternal spine
It is important to know which side of the baby is true left and true right in order to determine
situs
The major structures in the superior cut of the fetal cranium are the
lateral ventricles, choroid plexus, midline falx
The major structures evaluated in the mid cut of the fetal cranium are the
thalamus, CSP, BP, 3rd ventricle, falx
`The major structures evaluated in the inferior cut of the fetal cranium are the
cerebellum, cistern magna, circle of willis, cerebral pedicles
Which level of the cranium is the appropriate level for measurement of the BPD and HC
mid cut
Label the following as echogenic, hypoechoic or cystic: FALX CEREBRI
echogenic
Label the following as echogenic, hypoechoic or cystic: THALAMI
cystic
Label the following as echogenic, hypoechoic or cystic: CHOROID PLEXUS
echogenic
Label the following as echogenic, hypoechoic or cystic: LATERAL VENTRICLES
cystic
Label the following as echogenic, hypoechoic or cystic: CEREBELLUM
hypoechoic
Label the following as echogenic, hypoechoic or cystic: CIRCLE OF WILLIS
echogenic
Label the following as echogenic, hypoechoic or cystic: CAVUM SEPTUM PELLUCIDUM
echogenic with cystic border
Label the following as echogenic, hypoechoic or cystic: CRANIAL BONES
echogenic
Label the following as echogenic, hypoechoic or cystic: LENS OF THE EYES
echogenic
The upper limit of normal for the diameter of the lateral ventricle is
10mm
Define frontal bossing
lemon sign
Define micrognathia
underdeveloped lower jaw, receding chin
VUC transverse view vertebra is
abnormal
Rooftop transverse view vertebra is
normal
The spine should ________ at the sacrum
taper
The spine should _____ as it joins the skull
flare
Why is it important to image the fetal diaphragm
exclude diaphragmatic hernia
What structures should be superior to the diaphragm
lungs, heart
What structures should be inferior to the diaphragm
stomach, liver, bowel, spleen
The view of the heart that is common to the routine OB sonogram is
4 chamber view
The apex of the fetal heart should point toward the ____ of the fetus
left side
The foramen ovale should open into the _____ in the fetal heart
left atrium
As blood is shunted through the foramen ovale, it is bypassing the
lungs
The mitral and tricuspid valves should _____ during diastole and _____ during systole
open, closed
If the interventricular septum of the fetal heart is not a continuous line from the valves to the apex, what abnormality is most likely present
ventricular septal defect
______ is a specialized exam that is targeted to evaluate for fetal cardiac anomalies
fetal echocardiography
Visualization of the ______ inferior to the diaphragm generally excludes the presence of a left side diaphragmatic hernia
stomach
The aorta leaves the heart, loops posteriorly, and descends anterior to the spine, forming the _____ sign
candy cane
List the 3 vessels that arise from the aortic arch
brachiocephalic artery, left CCA, left subclavian artery
In the fetus, the hypogastric arteries can be seen diverging around the
bladder
Oxygen rich blood reaches the fetus via the
umbilical vein
Oxygen poor blood leaves the fetus via the
umbilical arteries
The ______ is a special connection for fetal circulation between the umbilical vein and the IVC
ductus venosus
The _____ is a special connection for fetal circulation between the aorta and the pulmonary artery
ductus arteriosis
The blood travels through the ductus venosus bypasses the
liver
The blood that travels through the ductus arteriosis bypasses the
lungs
How much of the fetal blood actually circulates through the fetal lungs
5-10%
The fetal liver is the main storage site for
glucose
The decreased abdominal circumference associated with IUGR is due to decreased size of the
liver
Is fluid around the fetal liver cause for concern? Why?
yes, ascites
Describe the appearance and location of the fetal gallbladder
anechoic, tear drop shaped, next to portal vein
Is the spleen often seen on the routine OB sonogram? What problems may be associated with enlargement of the fetal spleen
no, RA sensitivity and partial sinus inversus
List the components of the fetal GI tract
esophagus, stomach, small bowel, colon
Why is it important to visualize fluid in the fetal stomach
may indicate esophageal atresia, fetal swallowing, craniofacial abnormality
If the fetus is scanned and looks normal except for visualization of the stomach, what should be done first
have the pt come back, baby’s stomach could have just emptied and needs to swallow again to fill
The small bowel can be differentiated from the large bowel after ____ weeks
20
As the fetus matures, more and more ____ can be seen in the large bowel
meconium
Meconium is
fecal matter
In cases of _____ the fetus may pass meconium into the amniotic fluid
normal term fetus, fetal distress
The anatomical structure of the fetal kidneys becomes visible sonographically in the ____ trimester
2nd
If there is fluid in the renal pelvis that measures more than ____, it is considered hydronephrosis
10mm
Large echogenic kidneys in the fetus is indicative of
polycystic kidney disease, renal infection
In what cases is it normal to see fluid within the renal pelvis
polyhydramnios, mother has full bladder, late 3rd trimester
The fetal adrenal glands have a characteristic _____ appearance on sonogram by 23 weeks
rice grain
Which vessels are used as landmarks to locate the fetal adrenal glands
IVC and aorta
The fetal adrenal gland may sometimes be mistaken for the fetal
kidney
Why is it important to see the fetal bladder empty on sonogram when it appears to be large
can indicate urinary obstruction or polyhydramnios
What conditions can cause the normal fetal bladder to be large
polyhydramnios, mother has full bladder
At what gestational age should the sonographer tell the parent that the gender of the fetus should be visible for male
15 weeks
At what gestational age should the sonographer tell the parent that the gender of the fetus should be visible for female
20 weeks
In what cases would detecting the gender of the fetus be important
when there is a possibility of gender linked disorder
Should the sonographer guess at the fetal gender if he/she is not sure
no
What genital parts must be seen to determine that the fetus is male
penis and scrotum
Why may the labia majora on the female fetus be sometimes mistaken for scrotum
swollen due to increased maternal hormones
Why are hydroceles often seen in male fetuses
increased maternal hormones
The fetal long bones should be surveyed for
bowing, fractures, demineralization
Why is it important to do a thorough survey of the entire fetal skeleton
rule out skeletal dysplasia
Which long bone is typically measured in fetal biometry
femur
When should measurements of the other long bones be beneficial
suspected abnormality or skeletal dysplasia
If the sole of the fetal foot can be seen in the same image as the tibia and fibula of the same leg, what pathology is present
club foot
Why is it important to identify the placental insertion of the umbilical cord
evaluate for mass and velamentous insertion
The umbilical arteries and vein should spiral around each other. Is absence of the cord twists significant? Why or why not?
yes, may be associated with poor pregnancy outcome
How does the sonographer survey the gravid uterus
long, trans, placental location, placental grade, cervix, adnexa
Why is it important to try to locate the maternal ovaries when performing an OB sonogram
evaluate for ovarian mass or cyst
What is the major role of the placenta
nutrient, oxygen and waste exchange
How does the sonographer perform the AFI
measure A/P of all quadrants without fetal parts and add together
What is the normal range for AFI
5-22cm
When does the amniotic fluid volume peak
34 weeks
Amniotic fluid must be inhaled in order for the fetal lungs to develop properly
true
What may happen to the fetal lungs in the presence of oligohydramnios
small and hypoplastic
Describe the appearance of amniotic fluid volume in second trimester
surround fetus
Describe the appearance of amniotic fluid volume in early third trimester
generous
Describe the appearance of amniotic fluid volume in late third trimester
scanty/isolated pockets
Which has been shown to be more accurate in identifying oligohydramnios or polyhydramnios
AFI
_____ often is the cause of sparkly debris in the amniotic fluid, especially in late pregnancy
vernix caseosa
What broad category of fetal anomalies would be suspected with polyhydramnios
macrosomia, swelling, neural tube defects, GI tract
