Page 20 Flashcards
Fetal position where the thighs are flexed at the hips with the legs and knees extended
frank Breech
Thighs are flexed at the hips and there is flexion of the knees as well
complete breech (least common)
With what type of breech is the risk of cord prolapse greatest?
footling
-One or both hips and knees are extended
footling
With what type of breech is the risk of cord prolapse least?
frank
What variation of umbilical cord anatomy occurs when fetal vessels cross the internal cervical os in an attempt to reach the main substance of the placenta?
vasa previa
Name the aneuploidy: growth restriction, prominent occiput, small mandible, short sternum, clenched hands, rocker-bottom feet, choroid plexus cysts (25%)
trisomy 18
Name the aneuploidy: short stature, brachycephaly, flat occiput, short neck with redundant skin on the nape, short broad hands, and hypotonia
trisomy 21
Most efficient multiple-marker screening test in the 2nd tri
quad screen
Name the aneuploidy: severe CNS malformations such as holoprosencephaly, growth restriction, cleft lip and palate, microphthalmia, polydactly, clenched hands with overlapping digits, and renal abnormalities as polycystic kidneys
trisomy 13
Name the aneuploidy: short stature, ovarian dysgenesis, infertility, webbed neck, peripheral
lymphedema at birth, renal abnormalities. Prenatally, increased nuchal translucency or cystic hygroma, lymphangiectasia, CHDs particularly left-sided obstructive lesions such as COA
Turner (45, X)
Low levels of AFP and uE3 and elevated levels of hCG and inhibin A
Down
Embryonic development
- pre-organogenetic phase - conception untile somite formation - all or none period
- embryonic period - weeks 3 to 8 - organogenesis period, max sensitivity to teratogenicity 3. fetal phase
AFP, uE3, and hCG are all low
trisomy 18
Single most powerful marker for differentiating Down syndrome from euploid pregnancies
(1st tri sonographic measurement of the) fetal nuchal translucency space
Most powerful marker for general population screening for Down syndrome
nuchal translucency sonography
Ideal time to screen for fetal aneuploidy
1st tri
Aneuploidies associated with septated cystic hygroma
Down (mc), Turner, and trisomy 18
Most sensitive and specific single marker for the midtrimester detection of Down syndrome
thickened nuchal fold
Some of the MC sonographic markers seen in the 2nd tri
nuchal fold thickening, echogenic intracardiac focus, shortened long bones, hyperechoic bowel, renal pyelectasis, choroid plexus cysts, clinodactyly, hypoplastic or absent nasal bone
What term refers to the combination of generalized hydrops and cystic hygroma?
ymphangiectasia
What is associated with absence of the fetal nasal bones on 1st tri US?
Down
Most helpful in detecting trisomy 21 between 17 and 19 wks AOG
short femur
After gestational sac, what is the next visible landmark that can be used for pregnancy dating?
yolk sac
Position of cursors in measuring BPD
outer to inner, inner to outer, middle of wall to middle of wall
What is often the 1st feature of fetal hydrops revealed by US in early pregnancy?
generalized skin edema
Skin edema is best and most clearly observed where?
fetal head, more specifically, at the back of the neck
Classic triad of signs suggestive of congenital toxoplasmosis?
chorioretinitis, intracranial calcifications, hydrocephalus
Overall the most sensitive marker for trisomy 18
short ear length
Chorionicity and amnionicity of pregnancy in twin-to-twin transfusion syndrome
monochorionic diamniotic
Level of cervical fusion in Apert syndrome?
C5-C6
Often the first manifestation of hydrops?
ascites
(Which side of the body is more often affected in Poland syndrome?)
right
(1st sonographic finding in Meckel syndrome)
oligohydramnios
Most characteristic prenatal feature of monosomy X (Turner) syndrome?
cystic hygroma
What is the first definitive sonographic finding to suggest early pregnancy? / What is the earliest unequivocal sign of pregnancy using sonographic evaluation? / What is the first structure that can be measured for the purpose of calculating GA?
gestational sac / chorionic sac
Position of cursors in measuring HC
outer to outer
Describe the “arrow” that must be seen in measuring the HC
cavum septi pellucidi and frontal horns are the feathers 3rd ventricle and sylvian aqueduct are the shaft ambient and quadrigeminal cisterns and tentorial hiatus are the arrowhead
(Note: cavum septi pellucidi must be visible in the anterior portion of the brain and the tentorial
What is technically the easiest to measure among the common biometric measurements?
femur length
What is the most difficult of the four measurements that are ordinarily obtained?
abdominal circumference
In what plane should you measure the AC?
right and left portal veins are continous with one another
What is the type of placentation of conjoined twins?
monochorionic-monoamniotic
What is the only criteria diagnostic of monochorionic-monoamniotic twins?
single amniotic cavity
dichorionic-diamniotic
With rare exceptions, what is always the type of placentation of dizygotic twins?
dichorionic-diamniotic
What is the most important predictor of the pregnancy-related complications in twin gestations?
type of placentation (chorionicity, not zygosity)
What is the amnionicity if there are 2 yolk sacs?
diamniotic
What is the chorionicity if more than 2 membrane layers are seen?
dichorionic
What is the chorionicity if 2 layers in the dividing membrane / membrane layers are seen?
monochorionic
What type of placentation is more likely if there is a thicker dividing membrane?
dichorionic-diamniotic
What is the chorionicity if there are differing genders?
dichorionic
With what conditions has premature or accelerated placental calcification been associated?
chronic maternal HTN, preeclamppsia, IUGR, smoking
What is the most accurate predictors of dichorionic placentation?
twin-peak sign / separate placentas
What are the common etiologies for hypoechoic placental lesions which are often of no clinical significance?
intervillous thrombus and decidual septal cysts (others: perivillous fibrin deposition/placental surface cysts, placental/venous lakes)
The most informative areas to find the dividing membrane are near what fetal structures?
neck, chin, limbs
What hypoechoic placental lesions are typically located at the periphery of the placenta, resulting in triangular or rectangular areas of fibrin deposited under the fetal surface of the placenta, with the base of the triangle along the chorion?
perivillous fibrin deposition/placental surface cysts
What are sonolucent intraplacental spaces sometimes with swirling internal echoes and shape that may be modified with change in maternal position or uterine contractions?
placental / venous lakes (no clinical significance)
In what conditions have placental lakes been variably reported?
Rh incompatibility, elevated maternal serum AFP, edematous placentas
In what area of the placenta is placental infarction more commonly located
periphery
With what conditons have placental infarctions been associated?
post-term, maternal HTN, anticardiolipin
Appearance of most placental infarction on US?
isoechoic (rarely, slightly hyperechoic)
Which site of placental hematomas is of greatest clinical consequence?
retroplacental (can manifest as placental abruption)
When the retroplacental hypoechoic complex is thickened, what possibilities shoule be considered?
retroplacental hemorrhage, focal myometrial contraction, or leiomyoma
Associations of retroplacental hematomas?
HTN/preeclampsia, obstruction of venous drainage of the placenta, cocaine, smoking, anticardiolipin, trauma, chorioamnionitis
What are the best predictors of pregnancy outcome in placental abruption?
- extent of placental detachment - >50%
- volume of bleed - >50 mL 3. location of bleed - retroplacenta
Midportion of the placenta, not just the edge, completely covers the os?
central previa
Villi penetrate the decidua but not the myometrium?
accreta (often used interchangeably as a general term)
Villi penetrate and invade the myometrium but not the serosa?
increta
To which vessel does the umbilical vein connect?
left portal vein
Placenta extends into the LUS, usually >2 cm from the internal os, and does not cover or reach it?
low-lying placenta
What is the most predictive sonographic sign of accreta?
placental lacunae
At which end should SUA be confirmed?
fetal end
Villi penetrate throught the myometrium and may perforate the serosa, sometimes into the adjacent organs?
percreta
Exaggerated form of eccentric insertion of the cord, at the margin of the placenta?
battledore placenta
Cord inserts beyond the placental edge into the free membranes of the placenta?
velamentous insertion of the cord
Early in development, there are 2 umbilical veins. Which atrophies, left or right?
Right
Which direction of cord twist is more common?
left
5 parameters of BPP
breathing, movement, tone, HR, urine output (AFV)
Which variable/parameter was added in the modified BPP?
placental grading
What 2 urinary tract abnormalities may be associated with polyhydramnios?
congenital mesoblastic nephroma and unilateral UPJ obstruction
What is the 1st step in performing a BPP?
NST (continuous fetal HR tracing)
Which among the parameters of BPP evaluate the state of fetal well-being on an acute basis?
HR, breathing, movement, tone
Which of the parameters of BPP evaluates the chronic fetal threats to fetal health?
AFV, placental grading
What specific CNS centers are the different biophysical activities dependent on?
-tone - cortex (subcortical area) - 8 weeks
-movement - cortex nuclei - 9 weeks
-breathing - ventral surface of the 4th ventricle - 21 weeks
-NST - posterior hypothalamus, medulla - late 2nd tri or early 3rd tri
What is the earliest biophysical activity to appear during intrauterine life?
tone (>movement>breathing>NST)
What is the gradual hypoxia concept?
Biophysical activities that appear first during fetal life are the last to disappear when there is fetal asphyxia or intra-amniotic infection.
What are the first biophysical activities to become compromised in the presence of fetal acedemia/hypoxemia?
HR, breathing (>movement>tone)
What is the most caudal structure of the pelvic cavity?
pelvic diaphragm
What form the pelvic diaphragm?
levator ani and coccygeus muscles
The suspensory ligament of the ovary is usually not seen. But what structure within it is often
identified with TAS or TVS?
ovarian artery
What is the thickest layer of the myometrium?
intermediate / middle layer
Bordering structures of the ovarian fossa
anteriorly - obliterated umbilical artery posteriorly - ureter and internal iliac artery
superiorly - external iliac vein
Narrowest portion of the fallopian tube?
interstitial or intramural portion
(What portion of the fallopian tube can be normally demonstrated sonographically?)
interstitial or intramural portion (isthmus, ampulla, and infundiblum not usually seen unless there is tubal pathology or free fluid)
Ureter course
true pelvis - anterior to the internal iliac artery and posterior to the ovary
-courses anteriorly and medially to lie in the broad liagament where it is in close proximity to the uterine artery
-runs anterior, in front of the lateral fornices of the vagina and then passes medially to enter the trigone
Bladder shape/appearance on transverse scans
superiorly, rounded/oval; inferiorly, square
Where along the urethra are uretheral diverticula found?
posterior and lateral
Where does the rectum begin?
S3
Term for when the uterus becomes “trapped” in the sacral hollow during pregnancy?
incarcerated
Constellation of 3 findings on sonography diagnostic of an incarcerated uterus
- pregnancy is deep within the cul-de-sac 2. UB lies anteriorly rather than inferiorly to the uterus and marked bladder distension
- cervix (soft tissue structure) is seen between bladder and pregnancy
What separate the outer layer from the intermediate layer of the myometrium?
arcuate vessels
Which among the uterine anomalies has the poorest fetal survival? Most difficult to confidently diagnose on US?
unicornuate
Reproductive complications are greatest in this class of mullerian duct anomaly
septated
What congenital structural malformation has the strongest association with early miscarriage?
septate uteri (due to poorly vascularized septum)
Most consistent finding among polycystic ovaries?
increased stromal echogenicit
2003 definition of PCOS according to the Rotterdam consensus workshops
12 or > follicles measuring 2-9 mm, ovarian volume >10 cc
In which breast quadrant is most of the dense tissue found?
upper outer
Risk factors of ectopic preg
tubal surgery, sterilization, previous ectopic, DES, IUD, tubal disease - high risk
infertility, genital infection, multiple sexual partners - moderate pelvic/abdominal surgery, smoking, vaginal douching, <18 yo at first intercourse - slight
What is known as “no man’s land” in which no glandular tissue should be seen?
retroglandular fat
What is the earliest sign of IUP?
small fluid collection in the endometrium
Most specific finding of ectopic pregnancy?
extrauterine live embryo
(Arrangement of the 3 mammographic views for triangulation)
CC, MLO, ML
What are the 3 “danger zones”?
- medial portion of the breast 2. retroglandular fat 3. film edge at the chest wall
There should be only fatty tissue in the medial breast near the chest wall and in the retroglandular fat. What is the only normal exception?
sternalis muscle
What breast location is most often excluded by screening mammograms?
upper inner
What part of the breast is included more in the Cleopatra view?
outer
-pleomorphic
BI-RADS 4
What view can be utilized to display the lower inner portion of the breast
superior-inferior oblique view (reverse oblique)
large rodlike
BI-RADS 2
Eggshell-type or rimlike calcifications
calcifiying oil cysts, fat necrosis, intraparenchymal calci, skin calci
Mass with round, coarse peripheral calcifications
fibroadenoma
Needle-like or sausage-shaped calcifications pointing toward the nipple, usually asymptomatic
plasma cell mastitis or secretory disease
Linear calcis on ML view, can’t be seen or cloudlike/smudgy on CC view / Sedimented calcifications within tiny benign cysts
milk of calcium / (aka sedimented calcium - Brant)
What is historically the most difficult breast ca to see on mammograms?
invasive lobular ca
What malignancies were reported to metastasize to the breast hematogeneously (multiple new solid masses all over in a nonductal pattern)?
melanoma and RCC
What tumor can look like a “breast rock”? - entire mass replaced by dense calcification
fibroadenoma
Aka fibroadenolipoma?
hamartoma
Only fat-containing malignancy?
liposarcoma
AD inherited, characterized by multiple and extensive intradermal oil cysts bilaterally?
steatocystoma multiplex
fat-fluid or fluid-fluid level on lateral-medial view
galactocele
Cysts with fluid-fluid level…
acorn cysts
Complex masses
cancer, hematoma/seroma, abscess, Phyllodes tumor, intracystic papilloma or ca, galactocele
Giant fibroadenoma cutoff size
> 8 cm
In premenopausal women, when does the normal breast tissue enhance the most?
right before the onset of mense
In premenopausal women, when does the normal breast tissue enhance the least?
7-10 days after the onset of menses
Nonenhancing internal septations in smooth, oval, or lobulated masses are highly specific for?
fibroadenoma
Types of enhancement (Daniel)
type I - nonenhancing indicate type II - gradually enhancing benignancy
type III - rapidly enhancing with sustained gradual enhancement indeterminate
type IV - rapidly enhancing with plateau high likelihood of type V - rapidly enhancing with early washout
Types of enhancement curves (Kuhl)
type I curve - gradually enhancing with a late persistent plateau
type II - rapidly enhancing with a late plateau
type III - rapidly enahcning with a late rapid washout
Axillary LN levels
I - infralateral to lateral edge of the pectoralis minor muscle
II - behind the pectoralis minor muscle
III - between the pectoralis minor and subclavius muscles (Halsted ligament)
Mainstay for determining extent of disease?
Rupture, contraction of fibrous capsule, capsular calci, hematoma, infection, silicone gel bleed
What are the causes of implant rupture?
Subpectoral location, implant age, closed capsulotomy
How do you classify implant integrity?
Intact, intact with gel bleed, intracapsular rupture, extracapsular rupture
How do you differentiate radial folds from stepladder sign?
Multiple thin echogenic lines; radial folds - always extend to implant periphery, stepladder lines DO NOT
Most sensitive and specific finding for rupture?
linguine sign
Probably the most important characteristics to assess in a breast mass?
margins
With what malignancy are groups of pleomorphic calcifications that are more linear or dot-dash in appearance more commonly associated?
comedocarcinoma (high-nuclear-grade intraductal carcinomas that have
luminal necrosis) (note: pag lower-grade ie cribriform and micropapillary, punctate and granular appearing)
Which between prepectoral and subpectoral implants are subject to greater risk of fibrous and calcific contractures?
prepectoral
Which of the patterns of enhancement on delayed imaging are more likely demonstrated by most
invasive ca?
invasive ca? plateau (64%) and washout (87%) (persistent - benign)
Tell the displacement of the ureters in the presence of an ovarian mass? iliac lymph nodes?
ovarian mass - displace ureter posteriorly or posterolaterally; iliac LNs - medially or anteromedially
When is the signal intensity of the myometrium highest? And therefore, low-intensity myometrial
lesions (leiomyomas and adenomyomas) are best demonstrated during this time…
late proliferative and early secretory / mid-menstrual cycle
