Ob/Gyn Quiz Cards
Define the following terms associated with skeletal anomalies: -rhizomelia -mesomelia -acromelia -micromelia -phocomelia -amelia -polydactyly -syndactyly
-Rhizomelia is shortening of the proximal segment of an extremity (humerus, femur). -Mesomelia is the shortening of middle segment of an extremity (radius/ulna, tibia/fibula). -Acromelia is the shortening of distal segment of an extremity (hand, foot). -Micromelia means shortened extremities. -Phocomelia is the absence of a segment of an extremity. -Amelia is the absence of an entire extremity. -Polydactyly is the presence of more than five digits. -Syndactyly is the fusion of soft tissue or bone of digits.
Lethal skeletal dysplasia is associated with severe micromelia (extremity shortening) and a severely hypoplastic thorax. What specific additional features may be seen in the following types of lethal skeletal dysplasia? -thanatophoric dysplasia -achondrogenesis -osteogenesis imperfecta, type II -congenital hypophosphatasia -campomelic dysplasia -achondroplasia
-Thanatophoric dysplasia is the most common lethal dysplasia. It is sporadic in occurrence and associated with cloverleaf skull (Kleeblattschadel). -Achondrogenesis demonstrates lack of vertebral ossification with possible with decreased cranial ossification. -Osteogenesis imperfecta type II demonstrates findings related to in utero fractures: presence of fractures or "thick" bones due to callus formation, multiple rib fractures, and severe hypomineralization of the skull. -Congenital hypophosphatasia demonstrates decreased mineralization of bones and cranium. -Campomelic dysplasia (also called camptomelic dysplasia) is characterized by short bent or bowed bones (especially tibia and femurs). -Achondroplasia may be homozygous (lethal) or heterozygous (non-lethal), and is associated with rhizomelia and trident hand (short fingers with wide space between 3rd and 4th digits.
What is a chorioangioma? How does it appear sonographically? What associated clinical findings may be encountered?
A chorioangioma is a solid vascular tumor of the placenta. Sonographic findings include a well circumscribed placental mass. When tumors are large (> 5cm), complications may include polyhydramnios and fetal hydrops. Chorioangiomas are associated with increased MS-AFP.
What is a complete abortion? What clinical symptoms will a patient have? What sonographic findings will be demonstrated?
A complete abortion is pregnancy loss in which all products of conception are expelled. Clinical symptoms include heavy bleeding and cramping, and possible expulsion of tissue. Sonographic findings include an empty uterus with normal endometrial cavity, and possibly a small amount of fluid in endometrial cavity. The uterus may remain enlarged for up to 2 weeks following SAB with presence of trophoblastic waveforms surrounding endometrium remaining for up to 3 days post SAB.
How does a corpus luteal cyst appear sonographically?
A corpus luteal cyst occurs following ovulation of the dominant follicle. Their sonographic appearance is an ovarian mass with thick hyperechoic irregular walls and possible echogenic internal content.
Define the following terms: Gamete Zygote Blastomere Morula Blastocyst
A gamete is a male or female reproductive cell (i.e. ovum or spermatozoa). A zygote is the single celled fertilized ovum prior to mitotic division. A blastomere is the dividing fertilized ovum at 2-cell and 4-cell stages, located within ampulla of fallopian tube. A morula is mass of dividing cells (resembling a mulberry) located in isthmus of oviduct and entering the uterus. A blastocyst is organized collection of cells which has an outer lining of trophoblasts, a fluid filled cavity (blastocele), and the inner cell mass, which will become the primitive yolk sac, embryonic disk and amnion.
What hCG level is considered the discriminatory zone at which a gestational sac should be seen in the uterus in an IUP?
A gestational sac is expected to be visualized using transvaginal sonography when the hCG level reaches 1000-2000 mIU/ml 3IRP (discriminatory zone).
The gestation sac (GS) is the first sonographic evidence of pregnancy. When should a gestational sac be seen?
A gestational sac should be indentified within the uterus using transvaginal sonography with a normal IUP when the following discriminatory levels are reached: Serum BhCG > 1000-2000 mlu/ml (3IRP) Certain LMP > 5 weeks (with a normal 28-day cycle)
What is a missed abortion? What clinical symptoms will a patient have? What sonographic finding will be demonstrated?
A missed abortion is the presence of an embryo without cardiac activity. The embryo may be retained for several weeks before the patient experiences symptoms. Clinical symptoms include hCG levels less than expected for dates, loss of symptoms of pregnancy, decreased in uterine size or uterus measuring small for dates, and brownish vaginal discharge without frank bleeding. The sonographic finding is an embryo (measuring >7mm) without identifiable cardiac activity.
What is the most common cardiac defect identified postnatally and how does it appear sonographically? What is an atrial septal defect? Why might it be hard to diagnose prenatally?
A ventricular septal defect (VSD) is the most common defect postnatally. It is caused by incomplete closure of the interventricular (IV) foramen and failure of the membranous part of the IV septum. Sonographically a VSD appears as an opening between the ventricles on the 4-chamber view with bidirectional flow demonstrated across the defect with color Doppler. An atrial septal defect (ASD) is an abnormal opening between the atria. The are most commonly ostium secundum defects. Diagnosis is difficult because of the normal patent foramen ovale.
What is the ALARA principle? How can an obstetric sonographer adhere to the ALARA principle?
ALARA means As Low As Reasonably Achievable, which means keeping ultrasound exposure to a minimum. The ALARA principle can be followed by scanning when medically indicated, keeping the output power at a minimum setting and minimizing scanning time while obtaining high quality diagnostic images.
What is the difference between adenomyosis and endometriosis?
Adenomyosis is invasion of endometrial glands and stroma into myometrium, while endometriosis is the presence of functional endometrial tissue outside of the uterus.
Describe the methods used for sonographic estimation of amniotic fluid volume.
Amniotic fluid index (AFI) is calculated by dividing the uterus into four quadrants, and vertical (AP) measurement of fluid in each quadrant is obtained. Quadrants are added to obtain AFI. Charts for age related AFI exist, but a normal AFI range is 5-22cm. In addition to the AFI, single vertical pocket/maximum vertical pocket (MVP) measurements may be used: -MVP 2-8cm normal -MVP 8-12cm - mild polyhydramnios -MVP 12-16cm - moderate polyhydramnios -MVP >16cm - severe polyhydramnios
How does an ovarian fibroma appear sonographically?
An ovarian fibroma appears as a homogeneously hypoechoic mass with posterior acoustic shadowing (highly attenuating mass). It is associated with ascites and pleural effusion.
What is ascites and how does it appear sonographically?
Ascites is fluid in the peritoneal cavity, and appears anechoic, outlining bowel, liver and other abdominal organs. In the fetus, ascites is most often associated with hydrops fetalis.
What are the sonographic features of Beckwith-Wiedemann Syndrome? What are the sonographic features of Pentalogy of Cantrell?
Beckwith-Wiedemann syndrome is a group of congenital disorders characterized by the presence of EMG anomalies: -exomphalos (omphalocele) -macroglossia (large protruding tongue) -gigantism (fetus large for gestational age) Pentalogy of Cantrell is the association of two major defects: omphalocele and ectopia cordis. (Three other defects are also present involving the lower sternum, the anterior diaphragm and the pericardium.)
Describe the sonographic findings in serous ovarian tumors.
Benign serous tumors (serous cystadenomas) are sharply marginated, anechoic, may be large but are usually unilocular with possible internal thin-walled septations. Malignant serous tumors (serous cystadenocarcinoma) are usually multilocular with multiple papillary projections or septations. Echogenic material may be seen within the mass, and ascites may be present. Serous cystadenocarcinoma is the most common form of ovarian cancer.
What is the most common abnormality of the umbilical cord? What associated abnormalities may be visualized?
Bivascular cord or single umbilical artery (SUA) is the most commonly encountered umbilical cord abnormality (1% of pregnancies). A two-vessel cord is seen in transverse section. The diameter of the single umbilical artery may be as large as the umbilical vein. Associated abnormalities include: -GU anomalies (especially unilateral renal agenesis) -Trisomies 18 and 13 -Cardiovascular anomalies -CNS anomalies -Omphalocele
Trace the flow of blood through fetal circulation.
Blood flows from the placenta > umbilical vein > left portal vein > ductus venosus > right atrium. Right atrial blood takes two pathways: 60% of blood travels right atrium > foramen ovale > left atrium > left ventricle > aorta. 40% of right atrial blood travels from right atrium > right ventricle > pulmonary artery. The majority of blood in the pulmonary artery travels into the ductus arteriosus > aorta. A small amount of pulmonary arterial blood travels to the lungs > pulmonary veins > left atrium > left ventricle > aorta. Blood in the aorta perfuses fetal tissues and then travels through the internal iliac (hypogastric) arteries > umbilical arteries > placenta.
What is CA-125? What is the significance of an elevated serum level of CA-125?
CA-125 is a biological tumor marker that is elevated in the blood of most women with ovarian cancer. Serum testing for CA-125 has been found to be less effective in detecting early disease and certain types of tumors. Elevation is suggestive of the presence of carcinoma but may also be seen in patients with other malignancies, as well as benign GYN pathology. The use of serum CA-125 with sonography for screening has been more encouraging than the use of CA-125 alone.
List at least five causes of non-immune hydrops.
Causes of non-immune hydrops include: -cardiac anomalies/arrhythmia -infection (TORCH, Fifth disease) -chromosome abnormalities -congenital hematologic disorders -abdominal or pulmonary masses leading to venous obstruction -twin-to-twin transfusion syndrome Sonographic findings in hydrops fetalis include pericardial effusion (earliest sign), ascites, fetal skin thickening/anasarca (> 5mm), placental thickening (> 5cm AP), pleural effusion, polyhydramnios, hepatosplenomegaly and umbilical vein enlargement (> 1cm).
What are the clinical findings in gestational trophoblastic disease?
Clinical findings in gestational trophoblastic disease (GTD) include: enlarged uterus (uterus large for dates); markedly elevated hCG levels; vaginal bleeding/passage of tissue; hyperemesis gravidarum; absence of fetal heart tones; early onset of pre-eclampsia; hyperthyroidism; theca lutein cysts.
List possible symptoms of PID.
Clinical signs and symptoms include: fever, leukocytosis, lower abdominal pain, purulent vaginal discharge, bilateral diffuse pelvic tenderness, cervical motion tenderness, dyspareunia.
What is a cystic hygroma? Where might a cystic hygroma be located? What conditions are associated with cystic hygroma? How do cystic hygromas appear sonographically?
Cystic hygroma is a benign developmental anomaly of lymphatic system origin, usually found in the areas surrounding the neck (cystic hygroma colli). It has an association with chromosomal abnormalities, especially Turner and Down syndromes. Large hygromas are often associated with fetal hydrops. Sonographic findings typically include thin walled multiseptated mass at posterior aspect of neck and associated hydrops fetalis (ascites, anasacra, pleural effusions, etc.). Cystic hygromas may mimic cervical teratomas, encephaloceles, and cervical meningomyeloceles.
What is Dandy-Walker malformation (DWM)? What are the sonographic findings in DWM?
Dandy-Walker malformation is complete or partial absence of cerebellar vermis and posterior fossa cystic dilatation communicating with the 4th ventricle. Sonographic findings include complete or partial agenesis of the cerebellar vermis with flattened cerebellar hemispheres and large midline cystic structure in posterior fossa. DWM is often associated with hydrocephalus and polyhydramnios.
What sonographic findings may be encountered in a patient whose mother took DES?
Daughters of women who received DES (diethylstilbestrol) from late 1940s to early 1970s for TAB have an increased risk of having a T-shaped uterus with constricting bands in the uterus and intrauterine wall defects.
When is the placenta considered decreased in thickness? Name four causes of decreased placental thickness.
Decreased placental thickness is defined as AP placental measurement < 1.5cm. Causes of decreased placental thickness include: -pre-eclampsia -IUGR -diabetes mellitus predating pregnancy -intrauterine infection -possibly polyhydramnios (appears thinner)
What forms of diabetes mellitus might be encountered in pregnant patients?
Diabetes mellitus (DM) may occur prior to pregnancy or during pregnancy. There are two general types of DM that may be seen prior to pregnancy: -Type I - juvenile onset/insulin dependent -Type II - adult onset/non-insulin dependent (occasionally insulin dependent) Gestational diabetes is a term given to glucose intolerance of pregnancy. This is diagnosed with a glucose tolerance test in the late 2nd/early 3rd trimester.
What might dilated tortuous veins near the uterus and/or in the adnexa indicate?
Dilated veins near the uterus or in the adnexa are a significant finding and may be associated with pelvic congestion syndrome.
What is ectopic pregnancy? Name possible locations for ectopic pregnancies. Which site is the most common for an ectopic pregnancy? Which site is the most dangerous for the patient?
Ectopic pregnancy is implantation of the fertilized ovum at any site except the endometrium. Possible sites include: Adnexal: implantation in fallopian tube or ovary Uterine: implantation in cornua, uterine scar or cervix Abdominal: implantation within the peritoneal cavity The most common site of ectopic pregnancy is the ampulla of the fallopian tube (90%). The most dangerous location for an ectopic pregnancy is the uterine cornua/ interstitial region due to potential for hemorrhage.
Maternal serum alpha feto protein (MS-AFP) levels are reported in multiples of the median (MoM). What are causes of an elevated MS-AFP? What are causes of a decreased MS-AFP?
Elevated MS-AFP (>2.0-2.5 MoM) may be associated with: -incorrect dates (30-40%) -multiple gestation -open neural tube defects (anencephaly, open spina bifida) -abdominal wall defects (gastroschisis, omphalocele) -other fetal anomalies (such as sacrococcygeal teratoma) -placental chorioangioma -maternal-fetal hemorrhage -maternal hepatocellular carcinoma (HCC) {primary liver cancer} Decreased MS-AFP is associated with: -incorrect dates -chromosome abnormalities -fetal demise
What is endometriosis?
Endometriosis is the presence of functional endometrial tissue located outside of the endometrium and myometrium. The ectopic endometrial tissue responds to the hormonal influence of the ovulatory cycle.
Which organ in the reproductive system secretes estrogen and progesterone?
Estrogen and progesterone are secreted by the ovary. Estrogen is secreted by the developing follicles (and in lesser amounts by the corpus luteum). Progesterone is secreted by the corpus luteum.
Why might evaluation of the fetal genital tract be important? What are some potential abnormal findings sonographically?
Evaluation of the fetal genitalia is warranted in certain situations, such as when gender-linked anomalies (i.e. Turner syndrome, posterior urethral valve obstruction) are suspected, or in twin gestations for determination of zygosity. In male fetuses, findings may include undescended testes (normally descend into the scrotum between 26 and 34 weeks gestation), hydroceles (small hydroceles are common) or abnormal formation of the penis (hypospadias, epispadias, micropenis). In female fetuses, findings may include hydrometrocolpos or ovarian cysts (usually benign functional cysts that result from maternal hormone stimulation and resolve spontaneously after birth).
Name the uterine layers from outer (superficial) to inner (deep).
From outer to inner, the layers are perimetrium, myometrium, basal layer of endometrium, functional layer of endometrium (then the endometrial cavity).
What is gastroschisis? What findings are encountered sonographically?
Gastroschisis is a relatively small defect involving all 3 layers of the abdominal wall, which allows protrusion of the intestines into the amniotic cavity. It is lateral to the umbilical cord insertion, usually to the right, and is not covered by a membranous sac. There are generally no associated anomalies and no increased risk of chromosomal abnormalities. MS-AFP will be elevated. Sonographic findings include variable amount of bowel floating in amniotic fluid without a membranous sac covering the defect. The umbilical cord insertion is seen adjacent to the defect.
How can endometrial hyperplasia be differentiated from endometrial carcinoma?
Histologic evaluation of an endometrial sample ( from endometrial biopsy or curettage) is required for a definitive diagnosis.
What is hydrops fetalis? What is the difference between immune and non-immune hydrops?
Hydrops fetalis is an excessive accumulation of fluid in fetal tissues and body cavities. Typically, there is diffuse interstitial edema, pleural and pericardial effusions and ascites. Immune hydrops occurs due to Rh (Rhesus) incompatibility, also known as Rh isoimmunization. Occurs with Rh- mother and Rh+ father (Rh+ fetus). Maternal antibodies recognize Rh antigens on fetal RBCs as foreign, and attack and destroy them. The destruction of RBCs results in erythroblastosis fetalis and fetal anemia, which results in hydrops. RhoGam (Rh immunoglobulin) is given after each pregnancy (also after amniocentesis) to prevent antibodies from forming. Non-immune hydrops is due to any cause other than Rh sensitization.
Where might endometrial implants be located in the pelvis?
Implants may occur anywhere in the pelvis, occurring most commonly in the ovaries, fallopian tubes broad ligament, posterior cul-de-sac and pelvic peritoneum.
Describe the types of assisted reproductive technologies a fertility patient may undergo.
In vitro fertilization (IVF) consists of ovarian stimulation, needle aspiration of oocytes, incubation of oocytes with sperm, and catheter delivery of 2-4 embryos into the uterus. Zygote Intrafallopian Tube Transfer (ZIFT) is placement of the embryo (or zygote) into the fallopian tube (rather than the uterus, as with IVF). Gamete Intrafallopian Tube Transfer (GIFT) is when the sperm and ova are placed into the fallopian tube and to allow fertilization to occur in the fallopian tube. Intrauterine Insemination (IUI) is placement of a sperm preparation into the uterine fundus.
How is hyperechoic bowel determined sonographically? Name at least four common etiologies for hyperechoic bowel.
Increased echogenicity of or hyperechoic fetal bowel can be identified on second trimester sonographic examination located primarily in the lower fetal abdomen and pelvis. The simplest criterion for diagnosis of hyperechoic bowel is echogenicity similar to or greater than that of adjacent bone. Bowel tends to look more hyperechoic when suing higher frequencies and when employing harmonic imaging, so a lower frequency should be used to evaluate hyperechoic bowel. Hyperechoic bowl may be seen in association with: -normal variant -Trisomy 21 -CMV infection -cystic fibrosis -swallowed intra-amniotic blood (rare)
When is the placenta considered enlarged? Name ten causes of placental enlargement.
Increased placental thickness (placentomegaly) is defined as AP placental measurement > 5cm. Placentomegaly has multiple causes, including: -gestational diabetes mellitus -Rh isoimmunization -maternal infection -chorioangioma -multiple gestation -maternal anemia -hydrops fetalis -sacrococcygeal teratoma -partial mole -chromosome abnormalities -abruption (appears thick due to retroplacental clot)
What is a Krukenberg tumor?
Krukenberg tumors arise from a GI primary, usually gastric carcinoma, but also from carcinomas of the colon or appendix. Krukenberg tumors are usually bilateral and are more common on right if unilateral. They appear as solid hypoechoic or complex predominantly solid masses with possible ascites.
How is the location of a fibroid named?
Leiomyomas are described by their location in relationship to the uterine wall: submucous/submucosal: beneath the endometrial cavity and most commonly produce symptoms intramural-interstitial: within the uterine wall subserous/subserosal: beneath the perimetrium intraligamentous: between the layers of the broad ligament cervical: located in the cervix pedunculated: on a pedicle or stalk; only occurs with submucous and subserous; torsion may occur with pedunculated fibroids
How is human chorionic gonadotropin (hCG) measured in the blood? What might abnormal levels of hCG indicate?
Levels of hCG in the blood are usually measured using a radioimmunoassay method known as the 3rd IRP. Greater than expected levels are seen with incorrect dates (further along than expected), gestational trophoblastic disease and multiple gestations. Less than expected levels are associated with incorrect dates (not as far long as expected), ectopic pregnancy, embryonic demise or abnormal IUP.
What is Meigs syndrome?
Meigs syndrome is the association of ascites and pleural effusion with a fibrous ovarian tumor (most commonly a fibroma), which disappears after excision of the tumor.
What clinical findings may be observed in patients with leiomyomas?
Myomas are often asymptomatic. When symptoms are present, they may include: menometrorrhagia, frequent urination, enlarged uterus on pelvic exam, pain with degenerative changes, infertility or spontaneous abortions, and alteration in normal menstrual flow.
Nabothian cysts are commonly encountered sonographically. Where are Nabothian cysts located? How do they appear sonographically?
Nabothian cysts are mucus retention cysts in the cervix due to obstructed and dilated endocervical glands. They appear as small, well circumscribed, anechoic structures located within the cervical wall.
The four-chamber view is the most commonly acquired image of the fetal heart. Describe the anatomy seen on the 4-chamber view of the heart.
Normal features identified on the 4-chamber view include: -left atrium is the chamber closest to the spine and descending aorta -apex of the heart points 45 degrees to left anterior chest wall -ventricles are approximately same size -flap of foramen ovale opens into left atrium -prominent moderator bands present in apex of right ventricle -pulmonary veins drain into the left atrium -bicuspid/mitral valve separates left atrium and left ventricle -tricuspid valve separates right atrium and right ventricle -tricuspid valve inserts inferior to (more apical than) mitral valve -crux is junction of interatrial septum, interventricular septum, AV valves and 4 chambers
What is oligohydramnios? Name five conditions associated with oligohydramnios.
Oligohydramnios is an abnormally decreased amount of amniotic fluid, AFI <5cm. Oligohydramnios is associated with: demise, renal abnormalities, IUGR, post dates and PROM (premature rupture of membranes).
In medical models, ovulation occurs on which day of the menstrual cycle?
Ovulation occurs mid cycle, which is day 14 of a typical 28-day menstrual cycle.
When are pelvic ligaments visualized sonographically?
Pelvic ligaments are generally seen sonographically only in the presence of ascites.
What is polycystic ovarian syndrome? What are the clinical findings?
Polycystic ovarian syndrome (PCOS) or Stein-Leventhal syndrome is an endocrinologic disorder associated with chronic anovulation. Diagnosis of PCOS is actually made based on clinical and serologic finding. Clini9cal signs of PCOS include infertility, obesity, amenorrhea and hirsuitism.
What is polyhydramnios? Name maternal and fetal conditions associated with polyhydramnios.
Polyhydramnios (hydramnios) is an increased amount of amniotic fluid, AFI >22cm. Causes of polyhydramnios include: gestational DM; Rh incompatibility; CNS anomalies (spina bifida, anencephaly, hydrocephalus); GI anomalies (duodenal atresia, esophageal atresia); facial clefts/masses; fetal hydrops; twin-to-twin transfusion; sacrococcygeal teratoma; skeletal dysplasia.
What gender is affected by posterior urethral valve obstruction? What are the sonographic findings in posterior urethral valve obstruction?
Posterior urethral valve (PUV) obstruction occurs in male fetuses. Sonographic findings include massive bilateral hydronephrosis and hydroureter, a dilated bladder with "keyhole" sign (dilated bladder and prostatic urethra), and moderate to profound oligohydramnios.
Postpartum hemorrhage is the most lethal complication of the puerperal period. What sonographic findings may be present in a patient with postpartum hemorrhage?
Postpartum hemorrhage is defined as blood loss greater than 500 mL following vaginal delivery (or 1,000 mL for Cesarean section). Clinical signs include heavy vaginal bleeding, decreasing hematocrit and shock. Sonographic findings may include retained products of conception (i.e. succenturiate lobe), normal postpartum uterus, or endometrial fluid.
What is prune belly syndrome? What are the sonographic findings in prune belly syndrome?
Prune-belly syndrome or Eagle-Barrett syndrome is weakened abdominal wall musculature in conjunction with massively dilated bladder, ureters and kidneys. The most common cause of prune belly syndrome is PUVs. Decompression of hydronephrosis postnatally causes retraction and wrinkling of the skin, giving the appearance of a prune. It is associated with pulmonary hypoplasia because of prolonged or sever oligohydramnios. Sonographic findings include abnormal compression of abdominal wall by fetal small parts, oligohydramnios and bilateral hydronephrosis with a massively distended urinary bladder.
What is a septic abortion? What clinical symptoms will a patient have? What sonographic findings will be demonstrated?
Septic abortion is a condition resulting from abortion with non-sterile instruments or from infection of retained products of conception. Clinically the patient has signs of infection, such as fever and leukocytosis. Sonographic findings may include an enlarged uterus with heterogeneous contents. The endometrium may exhibit ring down or shadowing due to the presence of gas bubbles.
What are the serum findings of PCOS?
Serum findings in PCOS include decreased or normal FSH, increased LH, increased testosterone, and increased AMH.
What are the sonographic findings in endometrial cancer?
Sonographic findings include inhomogeneity and thickening of endometrial echoes (>4-5mm) especially in postmenopausal women (varies with patient's hormone status). There may also be possible alteration in sonographic texture of uterine parenchyma and possible fluid in endometrial cavity.
How does PCOS appear sonographically?
Sonographic findings of PCOS include enlarged (> 10cm^3) or normal sized ovaries with multiple small (<1cm) cysts in the periphery ("string of pearls"). There are more than 12 cysts per ovary and the findings are always bilateral.
What are the sonographic findings in ovarian torsion?
Sonographic findings often include an enlarged ovary, often with multiple follicles, and absence of color and spectral Doppler flow (varies depending on degree and chronicity of torsion). Other possible appearances include arterial Doppler flow but absent venous flow, "whirlpool" appearance of twisted vessels, adnexal mass and midline position of ovary (especially in pediatric patients).
Ovarian carcinoma is the most deadly GYN cancer. How can sonography be useful in screening for ovarian cancer?
Sonography cannot accurately distinguish benign from malignant masses. Sonographic features associated with benign masses include smooth walls, shadowing, thin or no septation, and anechoic echogenicity. Sonographic features associated with malignant masses include mixed or increased echogenicity, papillary projections and solid masses. Doppler evaluation may demonstrate that ovarian malignancies have low resistance in the tumor vessels. Ovarian arterial waveforms in menstruating patients vary with the phases of the menstrual cycle. There is high resistance flow during menstruation and the follicular phase, but low resistance flow patterns in the corpus luteum. In premenopausal women, ovarian Doppler assessment should be performed between days 3 and 7 of the cycle.
At which stage is endometriosis more likely to begin to have sonographic findings? At which stage is it more likely to encounter infertility?
Sonography is more likely to begin to detect endometriosis in Stage III, when the ovaries are involved. Infertility is also more likely when patients reach Stage III.
What is supine hypotensive syndrome (IVC syndrome)? What are symptoms of and treatment for this condition? Where should the fundal height be at 20 weeks?
Supine hypotensive syndrome occurs when the heavy gravid uterus compresses the inferior vena cava. Venous blood flow to the heart is decreased which may lower blood pressure. The patient may feel light-headed, nauseated or sweaty (diaphoretic). Turning the patient onto her left side decreases the IVC compression and alleviates the symptoms. Fundal height measurement is used to estimate fetal growth. At 20 weeks, the fundal height is at the level of the umbilicus.
What are the types of IUGR? What sonographic findings are seen in each type?
Symmetric IUGR is growth restriction affecting entire fetus and constitutes about 25% of cases of IUGR. The etiology is often genetic or due to maternal infection. The onset of symmetric IUGR may be earlier in gestation. All measurements are more than 2 weeks below expected gestational age (based on firm LMP or prior study). The transcerebellar diameter is consistent with dates when other parameters are less than expected. Asymmetric or "brain sparing" IUGR (75% of cases) occurs in the last 8 to 10 weeks of pregnancy. Hemodynamic patterns in the fetus attempt to protect the brain, which receives the most nutrient rich blood first. As a result, there is asymmetry between head size and abdominal size. Sonographic findings include asymmetry of head to body ratio (HC/AC) > 2 SD or AC measuring > 2 weeks behind HC.
How is the gestational sac measured? At what rate does the GS grow normally?
The GS should be measured inner-to-inner. The GS grows at a rate of 1 mm/day.
How does a sonographer determine when the bladder is full enough for a transabdominal sonographic examination?
The bladder is adequately full for transabdominal pelvic sonography when the dome of the bladder extends above the uterine fundus. The full bladder displaces bowel out of the lesser pelvis and may act as a point of reference.
How should the endometrium be measured sonographically?
The endometrium should be measured int he anteroposterior (AP) dimension on a sagittal image.
How should the femur length be measured? What is the importance of the ossification centers visualized sonographically?
The femur length (FL) is best obtained by measuring anterior (upside) femur to reduce artifactual bowing. The measurement includes only the ossified diaphysis, excluding epiphyseal cartilage. If femur length falls more than 2 SD below the mean, skeletal dysplasia may be present, and other long bones should be measured. Gestational age can be estimated by identifying the presence of ossification centers within various epiphyses. The distal femoral epiphysis (DFE) is seen by 33 weeks, the proximal tibial epiphysis (PTE) is seen by 35 weeks, and the proximal humeral epiphysis (PHE) is seen by 38 weeks.
Which portion of the fallopian tube is most closely related to the ovary?
The fimbriae are most closely related to the ovary. They help to maintain close proximity between the ovary and the fallopian tube.
Discuss possible causes of postmenopausal vaginal bleeding.
The most common cause of postmenopausal bleeding is hormone replacement therapy regimen (HRT) that causes bleeding. The most common cause in a patient not receiving HRT is atrophic endometrium. Other cause include endometrial cancer, cervical cancer and an estrogen producing tumor of the ovary.
Which vaginal fornix is most likely to contain fluid collections?
The posterior fornix is the largest and most likely to contain gravity-dependent fluid collections when the patient is supine.
What embryonic structures may be mistaken for pathology using transvaginal sonography in the first trimester?
The rhombencephalon is a part of the normal development of the central nervous system and is seen as an anechoic structure seen in posterior portion of embryonic/fetal brain from the 8th to the 11th weeks. This should not be confused with an abnormality, such as Dandy-Walker malformation or early ventriculomegaly. The physiologic omphalocele/midgut herniation is seen while the midgut is herniated into the base of the umbilical cord between 9th and 12th weeks. This herniation is necessary to allow for development of the abdominal viscera. An echogenic bulge should not be mistaken for an omphalocele or gastroschisis.
What are the stages of endometriosis?
The stages of endometriosis, as defined by the American Society for Reproductive Medicine, are: Stage I: Minimal. Few or superficial implants are evident in the early stages of endometriosis. Stage II: Mild. More implants and deeper involvement. Stage III: Moderate. More implants, with ovaries affected and the presence of adhesions. Stage IV: Severe. As in Stage III, but with multiple and more dense adhesions.
Describe the venous drainage of the uterus and ovaries.
The venous anatomy of the pelvis parallels the arterial anatomy. The uterine veins drain into the internal iliac veins. The right ovarian (gonadal) vein empties into the inferior vena cava, while the left gonadal vein empties into the left renal vein.
Describe the arterial supply to the uterus and ovaries.
Uterine blood supply is provided by the uterine arteries, which are branches of the internal iliac (hypogastric) artery. The uterine artery gives off branches to feed the uterus, which from superficial to deep are the arcuate, radial, and spiral arteries. The spiral arteries are most closely related to the endometrium. Arterial blood supply to the ovaries is primarily via the ovarian arteries (gonadal arteries), branches of the abdominal aorta.
Discuss the terms used to describe variations in uterine postion.
Uterine position is highly variable. Anteversion is forward placement of the uterus at the cervix (forming a 90-degree angle with the vagina). Retroversion is tilting backward of the uterus at the cervix. Anteflexion is bending forward of the uterus at the body, and retroflexion is bending backward of the uterus at the body.
How does an abdominal pregnancy appear sonographically?
Abdominal pregnancies may progress further in gestation than other ectopic pregnancies. Sonographic findings in abdominal ectopic pregnancy include: absence of myometrium surrounding pregnancy; poor visualization of placenta; presence of an empty uterus separate from the developed fetus; oligohydramnios; unusual fetal presentation.
What pelvic abnormalities occur from vestigial remnants of the Wolffian (mesonephric) ducts?
Abnormalities can result from failure of disappearance of structures that do not normally persist. The persistent structures are sometimes referred to as vestigial remnants. The most common example is the Gartner's duct cyst. This cyst occurs on the anterolateral wall of the vagina and arises from the caudal remnants of the mesonephric (Wolffian) duct. Parovarian (paraovarian) cysts arise from persistence of the cephalad portion of the Wolffian duct and appear as a cystic mass adjacent to (but not connected to) the ovary.
What is placental abruption? List several predisposing factors to placental abruption. How does placental abruption appear sonographically?
Abruptio placenta (placental abruption) is premature separation of all or part of a normally implanted placenta from the myometrium. The most common symptom is abdominal pain, with or without vaginal bleeding, depending on the location of the abruption. Predisposing conditions/factors include: maternal hypertension; advanced maternal age; multiparity; maternal vascular disease; cigarette smoking; trauma; cocaine use; uterine leiomyoma. Sonographic findings include elevation of the placenta from the uterine wall, retroplacental fluid collection of varying echogenicity (most likely hypoechoic), or a normal or thickened placenta.
What are the sonographic findings in adenomyosis?
Adenomyosis can be diffuse or focal, and most often affects posterior myometrium. It may appear as an enlarged uterus with normal contours, myometrial cysts, mottled inhomogeneous myometrium and/or "venetian blind" type shadowing.
How does agenesis of the corpus callosum appear sonographically? What is a vein of Galen aneurysm?
Agenesis of the corpus callosum may be complete or partial and is frequently associated with other anomalies and/or syndromes. Sonographic findings include absence of cavum septum pellucidum, elevated dilated third ventricle, widely separated frontal horns of lateral ventricles with enlarged occipital horn and "teardrop" shaped ventricles, displaced upward and outward (colpocephaly). A vein of Galen aneurysm is a rare arteriovenous malformation (AVM) causing increased flow through the vein of Galen. Sonography will reveal a well-defined midline vascular structure superior and posterior to thalamus with turbulent and/or arterial flow.
What is amniotic band syndrome (ABS)? What sonographic findings are associated with ABS?
Amniotic band syndrome (ABS ) is a rare condition caused by disruption of the amnion early in pregnancy that results in bands of tissue that trap and constrict portions of the fetal body. The most severe condition on the spectrum of ABS is limb-body wall complex (LBWC), which can include marked fetal scoliosis and evisceration. Multiple severe abnormalities result including asymmetric encephalocele and asymmetric facial clefts, extremity amputation defects, clubfeet, abdominal wall defects and ectopia cordis. Sonographic findings include echogenic amniotic bands attached to fetus, various fetal anomalies (as listed above), and fetal postural deformities (such as scoliosis).
What structures produce amniotic fluid? What are the functions of amniotic fluid? How does amniotic fluid appear sonographically?
Amniotic fluid is produced by the fetal kidneys, tissues, skin and fetal membranes. Amniotic fluid is removed from fetus by GI tract (to GU tract), lungs, membranes and cord. The functions of amniotic fluid include acting as a protective cushion, equalization of pressure/temperature, prevents adherence to membranes, reservoir for fetal metabolites, and is essential for development of fetal lungs.
What is an amniotic sheet? How does it differ from amniotic band syndrome?
An amniotic sheet (amniotic pillar) results from chorion and amnion covering an existing uterine scar (synechiae). The resulting echogenic linear projection into the uterine cavity does not attach to the fetus and has no associated fetal anomalies.
What is an encephalocele? Where are they most commonly located? How does an encephalocele appear sonographically? Where else should the sonographer look when an encephalocele is discovered?
An encephalocele (cephalocele) is a herniation of brain and meninges or meninges and CSF through a cranial defect. Encephaloceles are most commonly occipital and midline. Sonographic findings in encephalocele include a purely cystic extracranial mass (meningocele) or a solid mass contiguous with cranium (cephalocele). There is often associated hydrocephalus and may be polyhydramnios. Encephaloceles are associated with Meckel-Gruber syndrome, so the sonographer should examine the hands and feet (for polydactyly) and kidneys (for cystic renal dysplasia). If asymmetric or atypical location, amniotic band syndrome must be considered so potential sonographic findings of ABS must be evaluated.
What is an incompetent cervix? How is it treated? What are the sonographic findings in cervical incompetence?
An incompetent or insufficient cervix is premature dilatation and effacement of the uterine cervix. This may lead to abortion in the 2nd trimester. A cerclage (stitch to keep cervix closed) is placed and will appear sonographically as a hyperechoic focus in the cervix. Transperineal/translabial scanning can be performed but the preferred method to evaluate gravid cervix is transvaginal sonography. Sonographic findings in cervical incompetence include: -shortened cervix (less than 2.5 to 3cm craniocaudal) prior to 34 weeks -dilatation of the cervix > 2cm in 2nd trimester -"bulging" membranes/"hourglass sign" are a poor prognostic indicator
What is an incomplete abortion? What clinical symptoms will a patient have? What sonographic findings will be demonstrated?
An incomplete abortion is when part of the products of conception are expelled with a portion remining in uterus. Clinical symptoms include heavy bleeding and cramping, and possible expulsion of tissue. Sonographic findings include thickened or irregular endometrial echoes and possible fluid in the endometrial cavity, and trophoblastic flow patterns may persist for up to 5 days post event.
What is an inevitable abortion? How does this condition appear sonographically?
An inevitable abortion or abortion in progress is a condition when SAB is imminent and cannot be halted. Sonographic appearance is a gestational sac low in uterus or in cervix, often with downward movement of gestational sac during scan. Cervical dilatation or an anechoic crescent surrounding gestational sac (representing blood) may be seen. This condition can be distinguished from cervical ectopic using color Doppler.
What is an omphalocele? What findings are encountered sonographically? What is the significance of an omphalocele containing bowel only? When should an abdominal wall defect be diagnosed sonographically?
An omphalocele results from failure of the intestines to return to the abdomen during the second stage of intestinal rotation. Omphaloceles may contain a liver, bowel or a combination of abdominal organs, depending on the severity. The defect is covered by a "membrane", which is a layer of amnion and peritoneum, and is seen at the level of the umbilical cord insertion. Sonographic findings are an extra-abdominal mass contiguous with umbilical cord (liver, bowel or both), umbilical cord insertion directly into mass and a membranous sac covering herniated organs. Bowel-only omphaloceles have a greater risk of associated chromosome abnormalities. An abdominal wall defect should be diagnosed sonographically after 12 weeks (after resolution of midgut herniation).
What is an anembryonic gestation? What are clinical signs associated with this condition? How does anembryonic gestation appear sonogrpahically?
Anembryonic pregnancy ("blighted ovum") is a gestation in which the embryo does not develop or stops early in development and cannot be visualized. Clinical signs include BhCG levels that may rise but not as rapidly as expected, a uterus measuring small for dates, and vaginal spotting with a closed cervix. Sonographic findings include an empty gestation sac (>25mm) that may enlarge slightly on serial scans. Normally a yolk sac should be identified when the GS measures 8mm transvaginally or 20mm transabdominally. An embryo should be identified when teh GS measures 16mm TV or 25mm TA.
What is anencephaly? How does anencephaly appear sonographically? What is acrania? How does acrania appear sonographically?
Anencephaly is congenital absence of the cerebral hemispheres and cranial vault. Anencephaly is the most common neural tube defect. Sonographic findings are absence of the fetal cranium and cerebral hemispheres, and possible polyhydramnios. Acrania is an abnormality in which the cranium is partially or completely absent with the presence of abnormal brain tissue. Sonographic findings include lack of echogenic cranium with presence of a large amount of brain tissue. Both anencephaly and acrania are associated with an increased MS-AFP.
How can obstructive uropathy be assessed sonographically? Name possible causes of obstructive uropathy in a fetus.
Anteroposterior (AP) measurement of the fetal renal pelvis can be obtained to assess for obstruction. This measurement should not exceed 4-5mm in the second trimester and 7-8mm in the third trimester. An AP measurement exceeding 10mm is almost always associated with an anatomic abnormality. Ureteropelvic junction (UPJ) obstruction is the most common cause of fetal hydronephrosis. Ureterovesicular junction (UVJ) obstruction may be caused by ureteral duplication with ectopic ureterocele or UVJ stenosis. The dilated fetal ureter may become tortuous, and hydronephrosis is seen on the affected side.
Renal anomalies are usually associated with what amount of amniotic fluid? How does a patent urachus or urachal cyst appear sonographically?
Assessment of the amniotic fluid volume (AFV) is important because many renal abnormalities are associated with oligohydramnios. The urachus helps to develop the urinary bladder and closes in the second trimester. Patent urachus or urachal cysts may appear sonographically as a cystic mass between the fetal anterior abdominal wall and the anterior portion of the fetal urinary bladder.
Describe the normal fetal brain anatomy at the following levels: -BPD level? -Lateral ventricular level? -Posterior fossa level?
At the BPD level, the sonographer should demonstrate the thalamus, cavum septum pellucidum, third ventricle, falx cerebri and frontal horns of the lateral ventricles. At the lateral ventricular level, the falx cerebri should be visualized as well as the choroid plexus within both lateral ventricles. At the posterior fossa level, the midbrain (cerebral peduncles), cerebellar hemispheres, cerebellar vermis, and cisterna magna are evaluated.
What is autosomal recessive polycystic kidney disease (ARPKD)? What is multicystic dysplastic kidney (MCDK)?
Autosomal recessive polycystic kidney disease (ARPKD), also known as Potter's Type I, is an inherited disorder characterized by symmetric renal enlargement by multiple small cysts. Sonographic findings include enlarged echogenic (hyperechoic) kidneys due to multiple interfaces of cysts, oligohydramnios and small bladder. Multicystic dysplastic kidney (MCDK) is also known as Potter's Type II and has formation of cysts that replace renal parenchyma. A MCDK has minimal urine formation. The cysts may be large (up to 6cm) and may be unilateral, bilateral or segmental.
What is congenital pulmonary adenomatoid malformation (CPAM)? How does it appear sonographically?
CPAM (previously referred to as congenital cystic adenomatoid malformation or CCAM) is typically a unilateral condition characterized by the replacement of normal lung parenchyma by abnormal tissue, which often includes visible cysts. In cases where lesions are large enough, the mediastinum may be shifted away from midline. Sonographically three types of CPAM/CCAM exist based on the size of the cysts: -Type I - one or more large cysts, > 2cm -Type II - multiple small cysts < 1-2cm -Type III - multiple small cysts, too small to be resolved by ultrasound beam so lung appears hyperechoic Sonographic findings may also include lateral displacement of the heart, possible hydrops fetalis (most common with CPAM Type III) and possible associated polyhydramnios.
Cardiac tumors in utero are typically associated with what condition? What is an A-V canal defect? With what condition is an A-V canal defect associated? What anatomic abnormalities are present in Tetralogy of Fallot?
Cardiac tumors are rare and are usually rhabdomyomas in patients with tuberous sclerosis. Atrioventricular (A-V) canal defect, also known as endocardial cushion defect, is when the common AV orifice fails to separate into mitral and tricuspid valves, resulting in a defect in crux (center) of the heart. It is associated with an increased risk of Trisomy 21. Tetralogy of Fallot consists of four anatomic abnormalities: VSD, overriding aorta, stenosis of right outflow tract (pulmonic stenosis), and right ventricular hypertrophy.
What is the cephalic index? How is it used? How is the transcerebellar distance measured? In what conditions might this measurement be useful?
Cephalic index (CI) defines head shape and is determined by dividing BPD by OFD (occipital-frontal diameter). The normal range is 0.70-0.86 (70-86%). In cases of dolichocephaly (CI <0.70 or <70%) or brachycephaly (CI >0.86 or >86%), the BPD is eliminated from estimation of gestational age. Transcerebellar distance is measured from lateral aspects of cerebellum in axial plane. It may be useful in assessing gestational age in IUGR, or when other head measurements are impossible to obtain.
Trace the pathway of flow of cerebrospinal fluid (CSF) through the cerebral ventricular system.
Cerebrospinal fluid (CSF) is produced by the choroid plexi in the lateral ventricles. The lateral ventricles drain into the third ventricle through the interventricular foramen (foramen of Monro). CSF flows from the third ventricle into the fourth ventricle through the cerebral aqueduct (aqueduct of Sylvius).
How can chromosomal abnormalities be diagnosed prenatally?
Chromosomal abnormalities can be diagnosed through CVS or amniocentesis. Chorionic villus sampling (CVS) is typically performed between 9-12 weeks gestation and can be performed either transcervically or transabdominally using direct ultrasound guidance. Neural tube defects cannot be diagnosed with CVS. Genetic amniocentesis is usually performed at around 16 weeks gestation in women over 35 years of age and for younger women who are at an increased risk of carrying a fetus with chromosomal abnormalities. Amniocentesis is routinely performed using ultrasound guidance. When an amniocentesis is performed on a multiple gestation, a dye, such as indigo carmine, is used to ensure each sac is tapped only once.
What are the clinical signs and symptoms in ectopic pregnancy?
Clinical findings in ectopic gestation include: amenorrhea, positive pregnancy test, vaginal spotting or bleeding, adnexal tenderness or adnexal mass, pelvic pain and shoulder pain (referred pain from intraperitoneal bleeding).
Name potential clinical findings in multiple gestations. What fetal complications can occur in multiple gestations?
Clinical findings in multiple gestation include increased hCG levels, increased maternal serum AFP and increased uterine size ("large for dates"). Fetal complications include: prolapse, entanglement or compression of an umbilical cord; cord knots in monoamniotic twins; difficult delivery due to abnormal presentation; IUGR due to placental insufficiency; hypoxia; and increased risk of fetal anomalies.
What are the symptoms of endometrial cancer?
Clinical signs include postmenopausal vaginal bleeding, hypermenorrhea or intermenstrual bleeding in patients still having periods, and pain as a result of uterine distension.
What are the clinical signs of endometriosis?
Clinical signs include: chronic pain, infertility and the "4 Ds" of endometriosis: dysmenorrhea (painful menses); dyspareunia (painful intercourse); dysuria (difficult urination) and dyschezia (difficult defecation).
What are clinical signs and sonographic findings in postpartum infection? What are the clinical and sonographic findings in a postpartum hematoma?
Clinical signs of postpartum infection include elevated temperature, increased white blood cell count, tachycardia, uterine tenderness and malaise. Sonographic findings in postpartum infection may include normal postpartum uterus, uterus that does not involute, or the presence of fluid, pus or air in endometrial cavity. Clinical signs of a postpartum hematoma include pelvic mass and decreased hematocrit. The most common postpartum hematomas are bladder flap hematomas following C-section, located anterior to uterine incision and posterior to bladder (in anterior cul-de-sac). Hematomas are complex fluid collections with internal septations that cannot be sonographically differentiated from abscesses.
Describe possible lower extremity abnormalities that might be detected during an OB sonogram.
Clubfoot (usually talipes equinovarus) can be genetic or environmental. It is described as an abnormal relationship between the tarsal bones and calcaneus. Approximately 55% of clubfoot deformities are bilateral. Sonographic diagnosis relies on visualization of the long axis of the lower leg (tibia and fibula) and foot in the same scanning plane. Rocker bottom foot is when the bottom of the foot appears "rocker-bottom", or convexes outward. The defect can be associated with Trisomy 18 and numerous other anomalies. Sirenomelia or "mermaid syndrome" includes lower extremity fusion and abnormal or absent foot structures. It is associated with bilateral renal agenesis, oligohydramnios and skeletal abnormalities.
What is the most common form of gestational trophoblastic disease? What are its sonographic appearances?
Complete hydatidaform mole is the most common form of trophoblastic disease. The chorionic villi are hydropic without identifiable embryonic or fetal tissue. The sonographic findings in a complete hydatidaform mole include; enlarged uterus filled with echogenic mass with small cystic spaces; hypervascular, low resistance flow pattern with Doppler; ovarian theca lutein cysts.
What is the significance of sonographically complex free fluid in the pelvic recesses?
Complex free fluid is related to either hemorrhage (blood) or infection (pus).
How are conjoined twins named? What are common sites of conjoinment?
Conjoined twins are monozygotic twins in which incomplete division of embryonic disk occurs after 13 days gestation. Conjoined twins are described by the site of union: -thoracopagus: thorax (most common) -omphalopagus: xiphoid to umbilicus -pyopagus: sacrum -ischiopagus: ischium/pelvis -craniopagus: head
What hormonal secretion occurs from corpus luteal cysts?
Corpus luteal cysts secrete progesterone (and small amounts of estrogen), and normally persist during pregnancy until up to 16 weeks.
How do dizygotic twins appear sonographically? What does the "twin peaks" sign or "delta" sign mean in multiple gestations?
Dizygotic or "fraternal" twins occur when two ova are fertilized by two sperm. Sonographic findings in dizygotic twins: -two chorions and therefore two placentas (may be fused) -"thick" membrane (two layers of chorion and amnion) -only confirmed with fetuses of different genders Sonographic visualization of the "twin peaks" or "delta" sign is suggestive of dichorionic diamniotic pregnancy.
What is duodenal atresia? How does it appear sonographically? What associated condition might be present?
Duodenal atresia is the most common perinatal intestinal obstruction. Sonographic findings include the "double bubble" sign (dilated stomach and proximal duodenum) and polyhydramnios. 30% of infants with duodenal atresia have Trisomy 21.
Describe the sonographic findings during the ovarian phases of the menstrual cycle.
During the follicular phase (days 1-14), several developing follicles can be visualized. The dominant follicle will outgrow the other follicles and may contain a cumulus oophorus (mural nodule) just prior to ovulation. The dominant (Graafian) follicle may reach maximum diameter of 15-30mm. At ovulation (day 14), the dominant follicle will rapidly decrease in size, and free fluid may be seen in the posterior cul-de-sac. In the luteal phase (days 15-28), the corpus luteum will be visualized as a thick-walled cystic structure with internal echoes. The rim of the corpus luteum is hypervascular with a low resistance flow pattern.
Which malignant germ cell tumors of the ovary may be seen in younger women?
Dysgerminomas and endometrial sinus tumors may appear as solid ovarian tumors in women under the age of 30. Dysgerminomas are homologous to testicular seminomas and are radiosensitive. Patients with endodermal sinus tumors (also known as yolk sac tumors) may have elevated serum levels of alpha feto protein (AFP), lactic dehydrogenase (LDH) and possibly hCG.
What is ectopia cordis? With what anomaly is ectopia cordis associated?
Ectopia cordis is when all or part of the heart is located outside of the chest cavity. Sonographic diagnosis is made by visualization of soft tissue mass outside of the thorax exhibiting cardiac activity. It is associated with omphalocele in Pentalogy of Cantrell.
Describe endometrial hyperplasia, including causes, clinical signs, and sonographic findings.
Endometrial hyperplasia is proliferation of endometrial glandular tissue. About 25% of patients with atypical hyperplasia will progress to endometrial carcinoma. Causes include: unopposed estrogen HRT, anovulatory cycles, PCOS, obesity and estrogen producing ovarian tumors. The clinical signs of endometrial hyperplasia are similar to those in patients with endometrial carcinoma (abnormal bleeding). Sonography should be performed at the beginning of the hormone cycle (immediately following menses). Sonographic findings include thickened endometrium with smooth borders and a more homogeneous endometrial texture.
Endometrial polyps are localized overgrowths of endometrial tissue. How do they present clinically and sonographically?
Endometrial polyps are usually asymptomatic but may be associated with infertility or abnormal uterine bleeding. Sonographic findings may include a non-specific thickened endometrium, which may be indistinguishable from endometrial hyperplasia. A polyp may also appear as a focal discrete echogenic mass in the endometrium, focal, possible with a vascular stalk demonstrated with color Doppler. Saline infusion sonohysterography is ideal for demonstrating polyps.
How does esophageal atresia appear sonographically? Why isn't this anomaly always detectable with prenatal sonography?
Esophageal atresia is the discontinuity of the esophagus and may appear as a small to absent fetal stomach and polyhydramnios. 90% are accompanied by a distal tracheo-esophageal (TE) fistula. In the presence of a TE fistula, the stomach and AFV may appear normal.
What is the most common congenital facial abnormality? How does it appear sonographically?
Facial clefting is the most common congenital facial abnormality. Statistically, 25% is cleft lip only, 50% is cleft lip and palate, and 25% is cleft palate only. Sonographic findings include an anechoic cleft extending from nostril to lip with possible associated polyhydramnios. The normal philtrum should not be mistaken for a cleft. The palate is examined in an axial/transverse plane. Asymmetric facial clefts may be associated with amniotic band syndrome.
Fibroids are the most common tumor of the female pelvis. What are other names for fibroids?
Fibroids are benign smooth muscle (myometrial) tumors which are also known as leiomyomas, myomas and fibromyomas. Leiomyomas are usually located in the uterine corpus and can also be found in the cervix and broad ligament.
Describe the role of sonography in first trimester screening for chromosomal abnormalities.
First trimester screening involves two parts: a nuchal translucency scan and a maternal blood test of free or total beta-hCG and PAPP-A (pregnancy associated plasma protein A) to establish the statistical risk of Trisomies 18 and 21. The addition of other parameters, such as nasal bone, increase detection rate. Patients with abnormal results are offered chorionic villus sampling (CVS) to determine chromosomal abnormalities. A nuchal translucency scan measures the fluid filled area the back of the neck between 11.5 to 13+6 weeks (CRL 45-84mm). NT measurement is taken inner-to-inner. The normal amnion adjacent to the fetus should not be mistaken for increased NT. Abnormal (increased) NT in the presence of normal karyotype is associated with an increased incidence of congenital heart disease (CHD).
What is the patient preparation for a transvaginal sonographic examination? Why is this prep important?
For a transvaginal examination, the patient should have an empty urinary bladder. The empty bladder places pelvic viscera closer to the transducer. Transvaginal sonography uses higher transducer frequencies than transabdominal.
What hormones are responsible for regulating the menstrual cycle? From where are they secreted?
Gonadotropic releasing hormone (GnRH) is secreted by the hypothalamus when serum estradiol levels fall below a given concentration. GnRH signals the anterior pituitary gland to secrete gonadotropins: follicle stimulating hormone (FSH) and luteinizing hormone (LH). Follicle stimulating hormone (FSH) stimulates the growth and development of ovarian follicles. Luteinizing hormone (LH) stimulates maturation of follicle and is responsible for Graafian follicular rupture causing ovulation.
What is heterotopic pregnancy? In which patient population are heterotopic pregnancies most common?
Heterotopic pregnancies are coexisting intrauterine and extrauterine pregnancies. They can occur in the general population but are more common in fertility patients who have undergone zygote or gamete transfer. The risk of heterotopic pregnancies in assisted reproductive patients has been estimated at 1:2000 - 1:4000.
What are conditions that may be associated with holoprosencephaly?
Holoprosencephaly can be sporadic, due to chromosome abnormalities (especially Trisomy 13) or associated with maternal infection. Holoprosencephaly is associated with facial anomalies due to common embryonic origin ("the face predicts the brain"). Facial anomalies may range from cyclopia (single orbit) with a proboscis to hypotelorism (close-set eyes) to facial clefts.
What is hydranencephaly? How does hydranencephaly appear sonographically?
Hydranencephaly is a destructive disorder due to bilateral internal carotid artery occlusion or malformation. Hydranencephaly is characterized by near total lack of cerebral hemispheres with intact and normally developed meninges and skull. There are no associated anomalies or recurrence risk. Sonographic findings include a large fluid-filled cranium (macrocephaly) with absent cerebral tissue/cortical mantle and presence of the flax cerebri with normal midbrain and basal ganglia (thalami). Polyhydramnios may also be seen.
What is hydrocephalus? What are causes of hydrocephalus? What sonographic findings are present on hydrocephalus?
Hydrocephalus (ventriculomegaly) is dilatation of the ventricular system secondary to an increase in the volume of cerebrospinal fluid (CSF). Obstructive/non-communicating hydrocephalus is caused by obstruction of CSF flow due to aqueductal stenosis, CNS anomaly (spina bifida, encephalocele, Dandy-Walker malformation), or tumor. Non-obstructive/communicating hydrocephalus is dilatation of all ventricles caused by faulty absorption of CSF or increased CSF production. Sonographic findings include a presence of excess fluid in cerebral ventricles, lateral ventricular atrial width (LVAW) > 10mm, "dangling" choroid plexus, and > 3mm distance from medial wall of lateral ventricle to medical aspect of choroid plexus.
The right and left ventricles and right and left atria are symmetric throughout most of gestation. What are some cardiac abnormalities that may result in asymmetry of the ventricles or atria?
Hypoplastic right heart syndrome occurs due to pulmonary atresia with an intact interventricular septum. Sonographic findings include absent or very small right ventricle on 4 chamber view and absent or small pulmonary artery. Hypoplastic left heart syndrome is a small left ventricle due to decreased blood flow into or out of left ventricle. Primary abnormalities include aortic stenosis (aortic coarctation in 80% of cases) and mitral and/or aortic valve atresia. Sonographic findings include absent or very small left ventricle and hypoplastic/atretic mitral valve and aorta. Ebstein's anomaly is a grossly enlarged right atrium due to abnormal insertion of the tricuspid valves.
Describe conditions related to abnormal intraorbital distance. What is the preferred orbital measurement technique?
Hypotelorism is a decreased intraorbital distance. It is associated with holoprosencephaly and syndromes. Hypertelorism is an increased intraorbital distance and is associated with anterior cephalocele and many syndromes. Orbits may be measured inner-to-inner (inner orbital distance or IOD), but the preferred measurement technique is outer-to-outer (outer orbital distance or OOD).
How do intrauterine contraceptive devices (IUDs) appear sonographically? How might sonography be used in patients with IUDs?
IUDs are hyperechoic and may cast as acoustic shadow. They should be positioned within the endometrium in the fundus or midportion of the uterine body. Sonography is used to confirm IUD position in the uterus or evaluate for myometrial perforation. The use of 3D sonography may be helpful in determining exact location of an IUD.
What is intrauterine growth restriction (IUGR)/fetal growth restriction? List possible causes of IUGR.
IUGR is fetal weight below the 10th percentile for GA. Clinical signs of IUGR include uterus measuring small for dates and a history of a maternal condition associated with IUGR. Maternal causes of IUGR include: poor nutritional status, smoking, multiple gestation, drug or alcohol abuse severe anemia, diabetes that predates pregnancy, chronic asthma, under 17 or over 35 years of age, heart disease and high altitude. Placental factors include: placental infarcts and hemangiomas, small placenta, single umbilical artery, abruptio placenta and placental insufficiency. Fetal causes include: genetic or chromosomal abnormalities and intrauterine infection.
What are the typical sonographic findings in the uterus of a postmenopausal patient?
In a postmenopausal patient, the overall uterine size is decreased, and the uterine and cervical contours and proportions are maintained. The myometrium may have calcified arcuate arteries. A small amount of fluid in the endometrial cavity (hydrometra) is considered normal in an asymptomatic patient; this is often caused by cervical stenosis. Decreased estrogen levels result in a thinner endometrial striped. The normal endometrial thickness is less than 8mm in asymptomatic patient, and 4-5mm is considered upper limits of normal for the endometrium, if there is a history of bleeding. Patient who are receiving sequential estrogen/progesterone replacement demonstrate endometrial cyclic changes.
How can fetal lung maturity be assessed?
In the late second and third trimesters, amniocentesis can be performed to assess fetal lung maturity through the following tests: Lecithin/sphingomyelin ratio (LS ratio) - ratio greater than 2:1 indicates respiratory distress syndrome will be unlikely. This is the most accurate method to assess lung maturity. Phosphatidylglycerol (PG) - appears at about the time of lung maturity (35 weeks), so presence of PG is associated with lung maturity.
Describe the appearance of the normal pediatric uterus.
In the normal newborn female, the cervix comprises 2/3 of total uterine size and the body is 1/3. The newborn endometrium is hyperechoic, due to maternal hormonal influence in utero. From 2 to 3 months of age until puberty the uterus is 2.5 - 3cm total length, with the cervix 1/2 of total uterine size and the body 1/2. At puberty, the uterus gradually increases in length, to 5 - 7cm, and the body to cervix ratio becomes 3:1 (e.g. 2/3 body, 1/3 cervix). The endometrial echogenicity and thickness vary according to the phase of the menstrual cycle.
Hydrocolpos in adolescence is generally secondary to what condition? How does this present clinically? What are the sonographic findings in hydrocolpos? (***Flash card had hematocolpos in question and hydrocolpos in answer, so not 100% sure on this one***)
In the pediatric patient, hydrocolpos or hydrometrocolpos is usually secondary to an imperforate hymen. Clinical symptoms include primary amenorrhea with lower abdominal pain and mass. Sonographic findings include hypoechoic distention of vagina and/or endometrial cavity with posterior acoustic enhancement.
Name possible indications that may prompt sonographic imaging of the pediatric pelvis.
In the pediatric patient, indications for imaging include: possible ovarian cyst or complications of ovarian cysts; suspected polycystic ovarian syndrome; possible ovarian neoplasms; congenital uterine anomalies; determination of the presence or absence of uterus and vagina in newborns with ambiguous genitalia; evaluation of uterus and ovaries in patients with precocious puberty; hematocolpos in patients with imperforate hymen.
What is transposition of the great arteries (TGA)? How does it appear sonographically?
In transposition of the great arteries (TGA) the origins of the great vessels are transposed so the aorta arises from right ventricle and the pulmonary artery arises from the left ventricle. Sonographic findings include anomalous origin of the outflow tracts. The left and right ventricular outflow tracts are parallel (do not cross). This abnormality will demonstrate a normal 4 chamber view.
Name causes of hypoechoic intraplacental lesions and clinical associations, if any.
Intraplacental lesions include: Placental lakes: pools of maternal venous blood within the placenta that are of no consequence clinically and appear as anechoic/hypoechoic rounded areas in placenta. Slow venous flow patterns may be seen in real time. Fibrin deposition: pooling of maternal blood in the subchorionic space. this clinically insignificant finding appears as hypoechoic material beneath chorionic surface of placenta. Intervillous thrombosis: caused by fetal bleeding into intervillous space and increased association with Rh incompatibility. Placental infarcts: ischemic necrosis of placental villi seen more commonly in eclampsia/pre-eclampsia. When this condition is severe, placental insufficiency and IUGR may occur.
What hypertensive disorders may be encountered during pregnancy?
Maternal and fetal complications may result if maternal high blood pressure remains uncontrolled during pregnancy. The patient may present with: -essential hypertension or chronic hypertension - pre-existing HTN unrelated to the pregnancy -pregnancy induced hypertension (PIH)/gestational hypertension - hypertension during pregnancy without signs of pre-eclampsia -pre-eclampsia - hypertension, generalized edema, proteinuria and rapid weight gain secondary to edema -eclampsia - HTN, edema and proteinuria found in pre-eclampsia which progresses to include convulsions, coma and death
What sonographic findings are associated with Meckel-Gruber syndrome? What are the features of VATER (or VACTERL) association?
Meckel-Gruber syndrome is an autosomal recessive condition including: encephalocele, polycystic kidneys and polydactyly. VATER or VACTERL association includes: -Vertebral anomalies -Anal atresia/imperforate anus -Cardiac anomalies -T} tracheoesophageal -E} fistula -Renal anomalies -Limb deformities
What are sonographic findings in abnormal fetal facial profiles? What conditions may be associated with an abnormal facial profile?
Micrognathia is an abnormally small jaw, and is associated with syndromes and chromosomal abnormalities, especially Trisomy 18. Frontal bossing is a prominent forehead due to absent nasal bridge. It is associated with skeletal dysplasia and syndromes.
What are potential pitfalls in the sonographic diagnosis of ectopic pregnancy?
Misidentification of a cornual ectopic as an intrauterine pregnancy. For identification of cornual pregnancy, there is less than 5mm of myometrium surrounding any side of gestation sac. Misidentification of "ring of fire" in corpus luteal cysts as an ectopic pregnancy. Corpus luteal cysts will display a rim of low resistance flow similar to trophoblastic flow in an ectopic pregnancy.
What are the sonographic findings in monozygotic twins?
Monozygotic ("identical") twins arise from a single fertilized ovum and are always the same gender. Sonographic findings depend on when the zygote divides. Division during first 4 gestational days results in dichorionic diamniotic twins, with 2 yolk sacs, 2 gestational sacs, 2 placentas (may be fused and appear as 1), thick membrane (two layers of chorion and amnion). Di-di monozygotic twins are sonographically identical to dizygotic twins. Division during the first week results in monochorionic diamniotic twins, with yolk sacs, 2 gestational sacs, 2 placenta and a thin membrane (two layers of amnion). Division during second week results in monochorionic monoamniotic twins, with 1 yolk sac, 1 gestational sac, and 1 placenta.
What is the normal fetal heart rate in the second and third trimesters? Discuss abnormal fetal heart rates.
Normal fetal heart rate (FHR) is generally between 120-160 BPM. Arrhythmias (irregular rhythm) can be due to premature ventricular contractions (PVCs) or premature atrial contractions (PACs). They are associated with maternal caffeine intake, cigarette smoking and alcohol use. Fetal tachycardia is defined as a heart rate greater than 180 BPM. Fetal bradycardia is a prolonged fetal heart rate <100 BPM. Bradycardia is associated with complete heart block and sometimes with fetal asphyxia. Transient bradycardia may be seen in the second trimester in normal fetuses.
What is ovarian hyperstimulation syndrome?
Ovarian hyperstimulation syndrome (OHSS) is a condition resulting from excessive stimulation of the ovaries in women taking fertility drugs.
What is a partial molar pregnancy? What chromosomal abnormality is associated with a partial mole? How do the sonographic findings differ from a complete hydatidaform mole?
Partial molar pregnancy most commonly has one set of maternal chromosomes and two sets of paternal chromosomes, resulting in a triploidy (69 chromosomes). A fetus or embryo is present in a partial molar pregnancy, and the identified fetal tissue is anomalous. Sonographic findings may include: deformed gestational sac; growth restricted fetus with triploidy anomalies, including syndactyly and hydrocephalus; enlarged placenta with multiple cystic areas. The sonographic findings differ from a complete hydatidaform mole in that a partial mole has an embryo or fetus present, while a complete H-mole does not.
What is pelvic inflammatory disease (PID)? What causes PID?
Pelvic inflammatory disease is an inflammation of pelvic and adnexal structures, typically an ascending infection, spreading from cervix through endometrial cavity to the fallopian tubes and adnexae. The cause is most often sexually transmitted infections (chlamydia, neisseria gonorrhea, and E. coli). PID predisposes women to infertility, tubal scarring and ectopic pregnancy.
What are the two malignant forms of gestational trophoblastic disease?
Persistent trophoblastic neoplasia (PTN) are malignant forms of trophoblastic disease that may occur following H-mole, abortion or normal delivery. They are suspected when hCG levels do not decline to normal following pregnancy evacuation. Invasive mole (chorioadenoma destruens) is a malignant non-metastatic condition ad is the most common form of persistent trophoblastic disease (80-95%). the invasive mole penetrates the myometrium or adjacent structures. It appears sonographically as focal or diffuse echogenic material within the endometrial cavity that may be seen extending into myometrium. Choriocarcinoma is a very rare malignant metastatic gestational trophoblastic disease. Sonographic findings may include an enlarged uterus or irregular mass.
What is placenta previa? What is the classic symptom of placenta previa? When is the best times in gestation to evaluate placenta previa?
Placenta previa is placental tissue encroaching upon the cervix and/or crossing the internal cervical os. Current classifications include: -complete previa/total previa - placenta completely covering the internal cervical os -marginal placenta previa - placenta in lower uterine segment within 2cm of internal os The classic symptom is painless vaginal bleeding during the third trimester. Placenta previa is best diagnosed sonographically in the third trimester due to "placental migration".
What is the most commonly identified fetal intrathoracic abnormality? How does it appear sonographically?
Pleural effusion (hydrothorax) is the most commonly diagnosed fetal intrathoracic abnormality. Pleural effusion may be isolated or in association with other abnormalities, especially hydrops fetalis. Sonographic appearance is anechoic fluid seen in one or both sides of the thorax, conforming to the shape of the thoracic cavity.
What is polydactyly? What is arthrogryposis? How does it appear sonographically?
Polydactyly is more than the normal number of digits of the hand or foot. Extra digits may consist of soft tissue only or may contain bone. This is associated with Trisomy 13. Arthrogryposis is part of fetal akinesia deformation sequence characterized by multiple joint contractures. It is associated with lack of fetal movement. All four limbs are typically involved, with severity of deformities increasing distally. Sonographic findings include bilateral talipes, deformities of hips, knees, elbows and wrists and possible polyhydramnios.
What is precocious puberty?
Precocious puberty is the onset of secondary sexual characteristics before the age of 8. True precocious puberty results from an early but normal pattern of gonadotropin secretion from the pituitary. True precocious puberty may be secondary to hypothalamic disease, idiopathic (>80% of cases) or secondary to congenital adrenal hyperplasia. Precocious pseudopuberty is caused by an abnormal exposure to estrogen, often due to an estrogen secreting ovarian tumor.
Describe the stages of pelvic inflammatory disease (PID).
Progression of pelvic inflammatory disease is typically upward and outward. Stages of PID include: Stage I: early PID - endometritis Stage II: subacute or acute salpingitis - may produce pyosalpinx Stage III: sever PID - broad ligament and ovarian involvement. If purulent material leaks out fimbriated end of tube, tubo-ovarian abscess (TOA) may result. Patient may also develop peritonitis and acute perihepatitis (Fitz-Hugh-Curtis syndrome). Chronic: long standing, subacute condition which follows acute PID. Adhesions may cause pelvic organs to merge centrally.
What condition may occur in patients who have mucinous ovarian tumors?
Pseudomyxoma peritonei may occur in patients who have mucinous ovarian tumors. Tumor capsule rupture may spread mucin-secreting cells into the peritoneal cavity, filing it with a gelatinous material known as pseudomyxoma peritonei. It has a sonographic appearance similar to ascites, possibly with multiple septations.
What is pulmonary sequestration? How does it appear sonographically?
Pulmonary sequestration is an uncommon malformation in which a mass on non-functioning pulmonary tissue is separate from the lung. This "mass" receives its blood supply from the systemic circulation (aorta) and does not communicate with the bronchial tree. Sonographic findings include a homogeneous echogenic intrathoracic mass with color Doppler demonstrating an arterial vessel arising from the aorta into the mass, and no pulmonary artery branch supplying the mass. Pulmonary sequestration is rarely associated with hydrops fetalis.
What sonographic findings occur with renal agenesis?
Renal agenesis is congenital absence of one or both kidneys. Unilateral renal agenesis is very common. It appears as absence of a kidney and ipsilateral renal artery, with the adrenal gland positioned vertically in the renal fossa, It is associated with single umbilical artery. Bilateral renal agenesis (BRA) is associated with Potter's syndrome, which consists of bilateral renal agenesis, pulmonary hypoplasia, characteristic facies and limb deformities secondary to oligohydramnios. Sonographic findings include absence of both kidneys and renal arteries, severe oligohydramnios, and "lying down" adrenal glands in renal fossae, mimicking kidneys.
Endometrial carcinoma is the most common GYN malignancy. What are the risk factors for development of endometrial cancer?
Risk factors include obesity and anovulatory cycles in premenopausal women, postmenopausal patients on estrogen replacement therapy, history of Tamoxifen use or family history.
In addition to spina bifida, what other abnormalities of the spine might a sonographer encounter, and what important factors should be noted?
Sacrococcygeal teratoma (SCT) is a rare tumor arising from the sacrum/coccyx. SCTs may be external, intrapelvic and/or intra-abdominal. Sonographic findings include a complex large mass (external or internal) and polyhydramnios. SCTs are associated with increased MS-AFP and hydrops fetalis. Caudal regression syndrome includes a spectrum of skeletal anomalies of the lower spine and lower limbs, such as agenesis of the sacral and lumbar spine. It is associated with maternal diabetes mellitus and may be associated with anomalies of the GI and GU tracts, CNS and heart. Scoliosis and kyphosis are abnormal curvatures of the spine that are associated with structural defects (CNS and VACTREL). Severe curvatures are associated with limb-body wall complex and amniotic band syndrome.
List possible indications for the performance of saline infusion sonohysterography (SIS).
Saline infusion sonohysterography (SIS), also called hysterosonography, is a technique of introducing saline into the endometrial cavity to evaluate endometrium sonographically. Sterile saline is infused during real time transvaginal sonography. Indications for SIS include: infertility and habitual abortion; congenital anomalies and/or anatomic variants of the uterine cavity; pre- and post-operative evaluation of the uterine cavity; suspected uterine cavity synechiae (i.e. scarring associated with Asherman's syndrome); further evaluation of abnormalities detected sonographically.
Describe the difference between an autosomal dominant and an autosomal recessive inheritance.
Single gene defects are inherited one of two ways: In autosomal dominant inheritance, one parent is usually affected by trait and it is evident in each generation. Genetic expression rarely skips a generation. The probability of transmitting the trait to an offspring is 50% with each pregnancy. In autosomal recessive inheritance, parents are usually unaffected, and the trait may appear to skip a generation. After identification of the trait, the recurrence risk for homozygous affected offspring is 25% with each pregnancy.
What sonographic artifacts may be encountered during OB/GYN sonography?
Sonographers may encounter sonographic artifacts including: Posterior acoustic enhancement/increased through transmission: from fluid-filled structures such as cysts, amniotic fluid Shadowing: from fetal bones, calcified fibroids and teratomas, attenuation from ovarian fibromas Ring down: from air in infectious conditions and abscesses, as well as from bowel in pelvis Edge effect shadowing: from refraction encountered with round structures
Describe the possible sonographic appearances of leiomyomas.
Sonographic appearance depends on amount of degeneration, as well as size and location of the fibroid. Most common sonographic findings include; well circumscribed hypoechoic mass; lobulated uterine contour; shadowing (with increased attenuation and calcification); whorled internal architecture; displacement of endometrial echoes; extrinsic compression of posterior bladder wall; hypoechoic adnexal mass (if myoma is pedunculated).
Benign cystic teratomas are the most commonly encountered germ cell tumors of the ovary. Name 7 possible sonographic appearances of ovarian teratomas.
Sonographic appearance of a teratoma depends on composition and arrangement of contents, and includes: predominantly cystic adnexal mass; complex mass with calcifications; fat-fluid level (can be demonstrated by a change in patient position); diffusely echogenic; "tip of the iceberg" - highly echogenic mass that shadows and obscures the posterior wall of the lesion; "dermoid plug" - predominantly cystic mass with an echogenic mural nodule, typically casting an acoustic shadow; "dermoid mesh" - multiple echogenic linear interfaces floating within a cystic mass (hair fibers).
When is sonographic evaluation of chorionicity and amnionicity in multiple gestations best performed?
Sonographic evaluation of chorionicity and amnionicity is optimally performed in the first trimester when the chorion and amnion are readily visible as separate membranes.
Describe the sonographic findings in mucinous tumors.
Sonographic findings benign mucinous tumors (mucinous cystadenoma) include a multiloculated mass with thick and more numerous septations. Fine, gravity-dependent echoes are generally seen. Sonographic findings in malignant mucinous tumors (mucinous cystadenocarcinoma) include multiloculated cystic lesions with echogenic material and papillary excrescences.
What are the sonographic findings in the various stages of pelvic inflammatory disease (PID)?
Sonographic findings in PID may include: Stage I - thickened irregular endometrium with fluid, debris, or gas - fluid in posterior cul-de-sac (may be complex) Stage II - pyosalpinx - dilated tube with debris/echogenic material Stage III - TOA - complex adnexal mass(es) with indistinct walls or TOC (tubo-ovarian complex) - visible inflamed tube and ovary Chronic - hydrosalpinx - thin-walled dilated tube with anechoic fluid and/or uterus and ovaries located central in pelvis with irregular borders ("indefinite uterus" or "lobster claw" sign).
What are sonographic findings in hypertensive pregnancies? What is HELLP syndrome?
Sonographic findings in hypertensive pregnancies include: prematurely mature placenta (grade 3 later 2nd or early 3rd trimester); IUGR; increased risk of abruption; oligohydramnios; and fetal demise. HELLP syndrome is a complication of pre-eclampsia which includes: -Hemolysis -Elevated -Liver enzymes -Low -Platelets
How does a follicular cyst appear sonographically?
Sonographic findings include an anechoic, unilocular thin-walled cystic structure exceeding 3cm in diameter. (The maximum measurement of a normal dominant follicle is 3cm.)
What are the songoraphic findings in ovarian hyperstimulation syndrome (OHSS)?
Sonographic findings include bilateral large simple cysts with an ovarian diameter >5cm. The patient may also have ascites and pleural effusion.
Describe twin reversed arterial perfusion (TRAP) sequence (acardiac twinning).
TRAP sequence is a form of monozygotic monochorionic twinning in which the acardiac twin has no direct vascular connection with placenta. Umbilical arterial-to-arterial anastomosis shunts blood from the donor twin to acardiac twin. The donor (or "pump") twin is usually sonographically normal except for cardiomegaly and may develop heart failure and hydrops fetalis. Sonographic findings in the acardiac twin include multiple structural anomalies such as anencephaly or small head, limited upper extremity development, cystic hygroma and no cardiac motion.
What is Tamoxifen? What effects might it have on the uterus?
Tamoxifen is a nonsteroidal antiestrogen used as a chemotherapeutic agent in patients with certain types of breast cancer. In some patients, it may cause changes in the endometrium, and increase their risk for endometrial carcinoma. Sonographic findings in patients receiving Tamoxifen may include subendometrial cysts at the endometrial-myometrial junction, endometrial hyperplasia or endometrial carcinoma.
At what level should measurement of the abdominal circumference be taken?
The abdominal circumference (AC) is performed at level of stomach and portal sinus of umbilical vein. This measurement reflects fetal growth through fetal liver size. Measurement is taken along skin line to include soft tissue and subcutaneous fat. The AC is the least reliable measurement in establishing gestational age due to significant genetic and physiologic variations in size after 25 weeks.
Describe the anatomy of the arches seen sonographically arising from the fetal heart.
The aortic arch is visualized sonographically in an oblique sagittal plane as a "candy cane" appearance with head and neck vessels seen arising from aortic arch (innominate/brachiocephalic, left carotid and left subclavian arteries). The ductal arch seen sonographically in a sagittal plane is the ductus arteriosus emptying into the aorta. The ductal arch has a "hockey stick" appearance and arises more anteriorly in the heart, with no head/neck vessels seen.
Why is a biophysical profile (BPP) performed? Describe the scoring of a biophysical profile.
The biophysical profile (BPP) is designed to detect fetal asphyxia. Parameters are scored as 2 if observed, and 0 if not observed, over a 30-minute observation. The parameters are: -Fetal breathing movements - a continuous episode lasting as least 30 seconds -Gross body movements - at least three discrete episodes of fetal body and/or limb movement -Fetal tone - one episode of limb extension/flexion (last parameter to disappear with hypoxia) -Amniotic fluid - at least one pocket of amniotic fluid measuring 2cm in vertical axis of AFI >5.0cm -Non-stress test (NST) - demonstration of reactive fetal heart rate, consisting of 2 episodes of acceleration > 15bpm for 15 seconds (first parameter to disappear with hypoxia) The maximum score using ultrasound only is 8/8. The maximum score including NST is 10/10.
What structures should be visualized at the BPD level? How is BPD measured? How is the head circumference measured?
The biparietal diameter (BPD) is an axial measurement performed at the level of the thalami and cavum septum pellucidum. Calipers are placed "outer-to-inner" (leading edge to leading edge) perpendicular to the falx cerebri to ensure an exact BPD (angle of asynclitism 90 degrees). The head circumference (HC) is measured at the same level as the BPD, and calipers are placed outer-to-outer in the axial plane and occipital-frontal plane (or electronic ellipse software is used). The HC should be measured around the cranium and should not include soft tissue. HC is more accurate than BPD when the fetal head is dolichocephalic or brachycephalic.
Name the bones of the pelvic skeleton.
The bones of the pelvic are the sacrum (posterior), coccyx (posterior), and paired os coxae, also know as innominate bones (anterior, inferior and lateral). Each os coxae is composed of the ilium, ischium and pubic bones.
What are the sonographic findings in ectopic pregnancy?
The definitive sonogrpahic finding in ectopic pregnancy is a live extrauterine embryo., Suggestive findings of ectopic pregnancy are: -Empty uterus - intrauterine sac should be seen with transvaginal sonography when BhCG level reaches 1000-2000 mlu/ml (3IRP) -Presence of adnexal mass (adnexal donut/trophoblastic reaction, "ring of fire") -Presence of endometrial decidual reaction/ pseudosac -Free fluid in cul-de-sac, adnexae, pericolic gutters or Morison's pouch (may be complex)
How does the fetal diaphragm appear sonographically? What imagine plane best demonstrates the diaphragm? What anomaly results from failure of the diaphragm to fuse completely? Which type is most common? What sonographic findings result?
The diaphragm appears as a hypoechoic curved line separating the more echogenic lungs form the liver and stomach. The fetal diaphragm is best seen in coronal, when both right and left hemi-diaphragms can be seen simultaneously. Congenital diaphragmatic hernia (CDH) results from defective fusion or formation of the diaphragm, allowing stomach, spleen, liver and/or colon to herniate into the chest. The most common type is the left-sided Bochdalek hernia. Sonographic findings include identification of fluid-filled bowel and especially stomach in chest at the level of the four-chamber view of the heart, cardiac displacement and associated polyhydramnios.
Name the conduits (openings) that serve to allow blood to pass through the circulatory system in the fetus.
The ductus venosus allows blood to pass form the left portal vein to the inferior vena cava. The foramen ovale is the opening between the atria, which allows blood to pass from the right atrium to left atrium. The ductus arteriosus is the conduit from the pulmonary artery into the aorta.
What are the effects of diabetes mellitus in pregnancy?
The effects of diabetes mellitus in pregnancy include: Congenital anomalies: There is an increased risk of congenital anomalies including caudal regression syndrome, neural tube defects, cardiovascular malformations, genitourinary anomalies, single umbilical artery, gastrointestinal anomalies, and skeletal anomalies. Birth weight: IUGR is associated with maternal DM that predates the pregnancy, and macrosomia is associated with maternal gestational diabetes. macrosomia is defined as fetal weight > 4,000 grams or a birth weight > 90th percentile for gestational age. A thickened placenta and polyhydramnios are associated with gestational diabetes.
How should the embryo be measured? How accurate is this measurement?
The embryo should be seen sonographically when gestational sac measured 16mm TV or 25mm TA. The correct measurement is from the top of the head to the bottom of the rump, excluding legs. The crown-rump length (CRL) is the most accurate method of dating a pregnancy sonographically and is accurate within 3-5 days if measured properly. The embryo grows at a rate of 1mm per day.
Organogenesis occurs during the embryonic period. When does the embryonic period end?
The embryonic period ends at the end of the 10th menstrual week; this is when organogenesis is complete. The fetal period starts at the beginning of the 11th menstrual week.
Describe the sonographic findings in the endometrium during the uterine phases of the menstrual cycle.
The endometrium may be thickened at the beginning of menses and will be thinned with a maximum diameter of 2mm at the end of menses. The early proliferative phase endometrium will be hypoechoic. The later proliferative endometrium will be tri-layered in appearance. The diameter of the endometrium in the proliferative phase is 4-8mm. The secretory endometrium is homogeneously hyperechoic with and measures 8-16mm in thickness.
How do the fetal kidneys appear sonographically? How does the fetal bladder appear sonographically?
The fetal kidneys can be visualized sonographically as early as 12-14 weeks as hypoechoic structures adjacent to the spine in transverse section. Anechoic renal pyramids are distributed evenly throughout the parenchyma. Renal sinus fat is more echogenic and can be seen in the hilum of each kidney. occasionally the renal pelvis may contain a small amount of fluid. This is a normal finding and does not necessarily indicate obstructive uropathy. Renal arteries can be seen in a coronal plane utilizing color Doppler. The fetal urinary bladder should be routinely seen by 16 weeks. Its presence is an important indicator of active renal function. The fetus normally fills and empties its bladder every 20-30 minutes.
What are the sonographic findings in fetal demise during the second and third trimesters?
The first action a sonographer should always take during an OB exam is to evaluate for fetal cardiac activity. Sonographic findings in fetal demise include: absent cardiac activity; exaggerated fetal position (i.e. flexion); Robert's sign (echogenic foci representing gas in pulmonary vessels or abdomen); Spalding's sign (overlapping cranial bones); and fetal maceration. Robert's and Spalding's signs are delayed findings, occurring about one week after demise.
Describe the parts of the uterus.
The fundus (or dome) is the upper expanded portion of the uterus between the fallopian tubes. The body (or corpus) is the main portion of uterus. The isthmus is the area between body and cervix and is referred to as the lower uterine segment during pregnancy. The cervix is the cylindrical projection into the vagina. The cervix has two openings: the internal os (opening from the cervix into the uterus) and external os (opening from the vagina into the cervix).
What other system may have abnormalities in the presence of a bicornuate uterus?
The genitourinary system (kidneys) may be affected by unilateral renal agenesis, ectopia or duplication. Sonographers should evaluate the urinary tract in cases of uterine anomalies.
What is the name given to the gutters at the superior aspect of the vagina?
The gutters at the superior aspect of the vagina, surrounding the cervix, are the vaginal fornices. These consist of the anterior fornix, posterior fornix and two lateral fornices.
How much of the fetal thorax should be occupied by the heart? Where is the thymus gland seen sonographically?
The heart typically occupies about one-third of the fetal chest. The thymus gland is located in the anterior mediastinum at the level of the 3-vessel view.
Which pelvic muscle is most likely to be mistaken for an ovary?
The iliopsoas muscle may be mistaken for an ovary in transverse. Lengthening the muscle in the longitudinal/sagittal plane will avoid this error.
What other pathologies may the sonographer encounter while scanning the GYN pelvis?
The intestinal tract may demonstrate bowel wall thickening in diverticulitis or gastroenteritis. In acute appendicitis, the appendiceal diameter measures > 6mm with possible periappendiceal abscess. Evaluation of the lower urinary tract may reveal a distal ureteral stone at the ureterovesicular junction or a bladder stone. Interstitial cystitis appears as bladder wall thickening in a patient with a history of UTIs. A bladder wall neoplasm is seen as a region of bladder wall thickening or focal mass. A bladder diverticulum is a urine-filled outpouching of bladder wall connecting to the bladder lumen that may be mistaken for an ovarian or adnexal cyst. A neurogenic bladder may result in urinary bladder stasis, and sonographic findings may include enlarged bladder or presence of debris.
Which cardiac chamber is closest to the spine? How are the tricuspid valves positioned in relation to the mitral valves? How should an M-mode of the fetal heart be obtained?
The left atrium is closest to the spine. The cardia axis is oriented 45 degrees from midline toward the left side of the fetal thorax (with this position being called levocardia). The tricuspid valves are more apical (toward the apex of the heart) in position as compared to the mitral valves. An M-mode tracing should be obtained by placing the cursor through an atrium an a ventricle.
Describe the anatomy of the ventricular outflow tracts. What views can be used to demonstrate the ventricular outflow tracts?
The left ventricular outflow tract view (LVOT) identifies the origin of aorta arising from the left ventricle. The right ventricular outflow tract view (RVOT) identifies the origin of pulmonary artery arising from the right ventricle. The correct orientation of pulmonary a. is "draping" anterior to aorta when seen in cross-section (outflow tracts normally "cross"). The 3-vessel view and tracheal 3 vessel view are obtained above the level of the 4-chamber view and ensures orientation of outflow tracts on single image when visualizing the increasing diameter of superior vena cava (SVC), aorta and pulmonary artery.
The pelvic organs are held in place by several ligaments. Name the major suspensory ligaments of the uterus and ovaries.
The major suspensory ligaments of the uterus include the cardinal (lateral cervical), broad, sacrouterine and round ligaments. The ovarian position is maintained by the ovarian ligament, which attaches the inferior ovary to the uterine cornu; the mesovarium, which attaches the ovary to the posterior layer of the broad ligament on each side, and the infundibulopelvic (suspensory) ligament, which attaches the lateral ovary to posterolateral pelvic wall and transmits the ovarian vessels and nerves.
Describe the anatomy of the placenta. Where does oxygen and nutrient exchange occur? What is a succenturiate lobe of the placenta?
The maternal surface of the placenta is irregular and divided into cotyledons by septae. The fetal surface is smooth and covered by chorionic and amniotic membranes. The intervillous spaces serve as the site of exchange of oxygen, nutrients and wastes. A succenturiate lobe is an accessory cotyledon with vascular connections to the main placenta. A Braxton-Hicks contraction can be differentiated from a succenturiate lobe by demonstrating a change in the size of the contraction over the time of the sonographic exam.
Describe the membranes of pregnancy. At what gestational age should the membranes be fused?
The membranes of pregnancy are the chorion and amnion. The chorion is the outer membrane and is composed of the leafy chorion or chorion frondosum (fetal contribution to the placenta) and bald chorion or chorion laeve (the remainder of chorion surrounding the amniotic cavity). The amnion is the inner membrane and forms from the inner cell mass. The amniotic cavity expands to fill the chorionic cavity. Fusion of the chorion and amnion is complete by 12-16 weeks. Sonographic identification of the separation of the two membranes before 16 weeks is a normal finding.
What is the most accurate method of sonographically determining gestational age?
The most accurate sonographic method of estimating gestational age is measurement of the crown rump length in the first trimester (+/- 3-5 days). In the second and third trimesters, all of the measurement techniques (BPD, HC, AC, FL) have a range of approximately + 2-3 weeks.
The uterus, fallopian tubes and upper vagina develop from the Mullerian (paramesonephric) ducts. What sonographic findings may be present in Mullerian duct abnormalities?
The most common Mullerian anomaly is a bicornuate uterus in which there is a single vagina, one or two cervices, and two uterine horns. Uterus didelphys is the complete duplication of uterus, cervix and vagina. A septate uterine anomaly has a single vagina, cervix and uterus with an intrauterine septum. The least severe Mullerian anomaly is a septum slightly protruding into the uterine cavity, creating an arcuate uterus. The use of 3D sonography can be helpful in evaluation and differentiation of congenital uterine anomalies. MRI may be a useful adjunct imaging method in complex cases.
Presentation refers to the fetal part closest to the internal cervical os. What is the most common fetal presentation? What other fetal presentations and lie may be observed sonographically>
The most common of presentation is cephalic (head presenting). Most cephalic presentations at term are vertex (parietal bones presenting). Breech presentation is when the fetal head in fundus of uterus. Types of breech presentation include footling (hips extended, feet presenting), frank (hips flexed, knees extended), and complete (hips flexed, knees flexed). The fetus may also be in transverse lie, perpendicular to the maternal long axis.
Ovarian metastases are most likely to arise from which primary malignancies?
The most common primary sites of ovarian metastases are tumore of teh breast and gastrointestinal tract.
What infections may cause fetal anomalies? What sonographic findings may be observed in infection?
The most common significant in utero infections are the TORCH infections: -Toxoplasmosis -Other (i.e. syphilis, parvovirus, Fifth disease, varicella zoster {chicken pox}) -Rubella -Cytomegalovirus -Herpes (genital) Sonographic findings may include IUGR, cranial/cerebral anomalies, cardiac anomalies, visceral calcifications (brain, liver), hydrops fetalis, and increased or decreased placental thickness.
What is the most common uterine postion?
The most common uterine position is anteverted (and anteflexed).
What is spina bifida? What is the best scanning plane to demonstrate spina bifida? What are the sonographic findings in spina bifida?
The neural tube should be closed by 6 menstrual weeks. Spina bifida is a lack of closure of the vertebral column. The fetus may have herniation of meninges and CSF through the spinal defect (meningocele) or herniation of meninges and neural elements (spinal cord) through the spinal defect (meningomyelocele). The best scanning plane to demonstrate spina bifida is transverse (axial). Sonographic findings in spina bifida include splaying of posterior elements and a possible cystic structure or solid mass extending from the defect. Cranial findings in spina bifida result from the Arnold Chiari II malformation and include: the "lemon" sign (flattening of the temporal/frontal bones), the "banana" sign (obliteration of cisterna magna by abnormal configuration of cerebellum) and hydrocephalus (LVAW > 10mm).
What are normal ovarian volumes sonographically?
The normal ovary in a premenopausal patient measures 3.5 x 2.0 x 1.5cm with a maximum volume of 9.8 cubic cm. Up to 5cm in any one plane is considered a normal measurement. The normal ovary in a postmenopausal patient measures 2.0 x 1.0 x 0.5cm with a maximum volume of 5.8 cubic cm.
Describe the sonographic anatomy visualized at the level used to measure the nuchal fold. Why is the nuchal fold measured during the second trimester?
The nuchal fold is measured at the level of the midbrain (cerebral peduncles), cerebellum and cisterna magna. The measurement is taken from the outer edge of the skull to the edge of the nuchal skin. A nuchal fold measurement greater than 6mm between 15 and 21 weeks is associated with Trisomy 21.
When is the optimal time to evaluate the fetal heart sonographically? Is congenital heart disease common? What are risk factors for congenital heart disease?
The optimal period to evaluate the heart is between 18 - 22 weeks. The cardiac anatomy is large enough to be visualized without large amounts of shadowing form bony structures. Congenital heart disease (CHD) is relatively common, occurring 8 out of 1000 births. Risk factors for congenital heart disease include family history, maternal diabetes mellitus, teratogen exposure (including alcohol, lithium, vitamin A, anticonvulsants, thalidomide, steroids, amphetamines, narcotics, OCPs), chromosome abnormalities, maternal collagen vascular disease (e.g. lupus) and increased NT measurement.
Describe the layers of the uterus.
The outer serosal layer of the uterus is the perimetrium. The middle muscular layer is the myometrium. The inner mucous layer is the endometrium. The endometrium has two layers: the deeper permanent basal layer and the functional layer, which is in contact with the endometrial cavity.
Describe the structure of the ovaries.
The ovaries are composed of an outer parenchyma (cortex), where developing follicles are visualized sonographically, and an inner homogeneous medulla.
Ovarian cysts may undergo hemorrhage. What clinical symptoms are associated with a hemorrhagic cyst? Describe the sonographic findings that may be encountered in a hemorrhagic cyst.
The patient may experience an acute onset of pelvic pain. Sonographic findings depend on the age of hemorrhage and may include typical cystic characteristic (anechoic, smooth walls, increased through transmission). Acute hemorrhage appears as hyperechoic, mimicking a solid mass but with posterior acoustic enhancement. A subacute hemorrhagic cyst demonstrates a complex appearance with internal echoes, strands, and rarely a fluid-fluid level. The sonographic appearance will vary with time as clot lyses.
What is the function of the pelvic diaphragm? What orifices pass through the levator ani muscle?
The pelvic diaphragm is composed of the levator ani muscle group and the coccygeus muscle. Its functions are to resist increased intra-abdominal pressure and to resist gravity, providing support for the pelvic viscera. From anterior to posterior, the urethra, vagina and rectum pass through the levator ani muscle in the pelvic floor.
Describe the division of the pelvic cavity.
The pelvis is divided by an imaginary line from the sacral promontory to symphysis pubis. The area above this line is the false or greater pelvis. The area below this line is the true or lesser pelvis, where the uterus, ovaries and adnexae are found.
What forms the placenta? What are the functions of the placenta?
The placenta is formed by proliferation of the chorionic villi (chorion frondosum) and the maternal decidua basalis. Functions of the placenta include: conversion of fetal steroids to estrogen, secretion of progesterone, secretion of human chorionic gonadotropin and exchange of oxygen, waste products and nutrients between fetus and mother.
Name the parts of the fallopian tube from proximal to distal.
The portions of the fallopian tube include the interstitial/intramural portion (located within the uterine wall), isthmus (medial portion closest to the uterus - proximal 1/3), ampulla (middle 1/3), infundibulum (outer, trumpet-shaped end - distal 1/3) and the fimbriae (the finger-like projections which maintain a close relationship between the tube and ovary).
What does the "double decidual sign" represent?
The process of implantation of the fertilized ovum into the decidualized endometrium results in sonographic visualization of distinct decidual layers. These layers are: Decidua basalis: develops where the blastocyst implants; maternal contribution to placenta Decidua capsularis: closes over and surrounds the blastocyst Decidua parietalis/vera: results from hormonal influence on the uninvolved endometrial tissue The double decidual sign is seen with intrauterine (and not ectopic) pregnancies.
Describe the normal sonographic findings in a postpartum patient.
The puerperium or postpartum period consists of biochemical and physical changes and generally lasts 4-6 weeks after delivery. The adnexae are not well visualized until the uterus returns to normal size. Sonographic findings may include: large hypoechoic uterus (14x7x7cm in size), with varying uterine shape and position; fluid in endometrial cavity representing blood; AP endometrial thickness 5-13mm; and the internal os may be open.
What is a quad screen? What substances are measured?
The quad screen is a test of the maternal serum to evaluate the statistical risk of carrying a fetus with Trisomy 18 and Trisomy 21. The quad screen measures the levels of four substances: maternal serum alpha feto protein (MS-AFP), human chorionic gonadotropin (hCG), unconjugated estriol (uE3) and Inhibin-A. A patient with an abnormal quad screen will be referred for a targeted/detailed sonographic examination and may be offered amniocentesis.
Name the muscles that are sonographically visible when examining the female pelvis.
The recuts abdominus muscle is located anteriorly and may be responsible for the refraction/"ghosting" artifact occasionally seen while imagine the midline pelvis in a transverse plane. The psoas major muscle originates in the posterior abdomen and courses laterally and anteriorly through abdomen, joining with the iliacus muscle to form the iliopsoas muscle. The obturator internus muscle is visualized sonographically in the true pelvis. The piriformis and coccygeus muscles are not routinely visualized due to the deep location. The levator ani muscle is readily seen sonographically along the pelvic floor at the level of the vagina and rectum.
Skeletal dysplasia is suspected when the long bones measure > 2 SD below the mean for gestational age. What should the sonographer include in assessment for skeletal dysplasia?
The sonographer should evaluate for associated findings in skeletal dysplasia, including: -assess (measure) all long bones -assess bone contour -look for bowing, fractures, curvature -estimate degree of ossification of cranium, spine, ribs, long bones -evaluate thoracic circumference/shape -survey for hand and foot abnormalities (polydactyly, clubfoot) -evaluate face and facial profile (frontal bossing, clefts) -survey for other fetal anomalies
Name and describe the peritoneal recesses in the pelvis. Give other names for these spaces. Why are these spaces important?
The space of Retzius, also called the retropubic or prevesical space, is located between the pubic bone and the anterior urinary bladder wall. The vesicouterine space or anterior cul-de-sac is located anterior to the uterus and posterior to the urinary bladder. This space is usually empty but may contain loops of bowel. The rectouterine space is also called the posterior cul-de-sac or pouch of Douglas. It is located posterior to the uterine cervix and anterior to the rectum. This is the most dependent recess in the body, and therefore the most common site for free peritoneal fluid to collect.
Describe the sonographic appearance of the normal fetal abdomen.
The superior aspect of the abdominopelvic cavity is defined by the diaphragm, which appears sonographically as a hypoechoic curved line separating the more echogenic lungs from the liver and stomach. The liver is large and occupies most of the upper abdomen in the fetus. The left lobe is larger than the right in the fetus. The anechoic fluid-filled gallbladder is seen in the anterior right abdomen, inferior to the liver margin. The spleen is seen in the left upper quadrant and appears similar to the liver. The stomach is anechoic, and the intestines are visible in the abdominopelvic cavity as gestation progresses.
What are the sonographic appearances of endometriosis?
The typical sonographic appearance of an endometrioma is a well define unilocular or multilocular mass with diffuse, homogeneous, low-level echoes and posterior acoustic enhancement. The diffuse form is rarely detected sonographically.
How does the umbilical cord appear sonographically?
The umbilical cord is composed of two arteries and one vein, surrounded by Wharton's jelly and enclosed in a layer of amnion. The umbilical arteries are longer than the vein are are twisted around the vein, giving the cord its "braided" appearance. The umbilical arteries can be seen with color Doppler at the level of the fetal bladder.
Describe the sonographic bony anatomy of the extremities.
The upper extremity is composed of the: -humerus - attached to thorax; can be measured for GA -radius - thumb side; shorter bone in forearm -ulna - pinky side; longer bone in forearm The lower extremity is composed of the: -femur - attached to pelvis; routinely measure for GA -tibia - medial and larger bone in lower leg -fibula - lateral and thinner bone in lower leg
Describe the normal sonographic evaluation of the fetal facial structures.
The upper lip and nares may be visualized in an oblique coronal plane, which is useful in for facial clefts and proboscis. Measurement of the orbital distance is valuable in diagnosis of hypotelorism or hypertelorism (especially in conditions such as holoprosencephy and anterior cephalocele). The fetal facial profile is evaluated for micrognathia (in syndromes and chromosome abnormalities) and frontal bossing (in skeletal dysplasia). The lens of the eye can be visualized as a hyperechoic ring with an anechoic central portion.
Describe the spectral Doppler patterns associated with the non-gravid uterus and ovaries.
The uterine arteries exhibit moderate to high velocity/high resistance flow. The uterine and radial arteries exhibit flow that is higher resistance in the proliferative phase than in the secretory phase. Flow in the ovary during the follicular phase is often low velocity and high resistance. Following ovulation, the impedance drops dramatically on the side with the dominant follicle, resulting in low resistance flow. The ovaries display high resistance flow in postmenopausal. women.
How can fetal anemia be assessed with Doppler? How does the normal umbilical arterial waveform appear? How does the normal ductus venosum waveform appear?
The velocity in the middle cerebral artery (MCA) can help determine likelihood of fetal anemia in Rh isoimmunization. MCA is examined close to its origin from the internal carotid artery. The angle of the ultrasound beam and the direction of blood flow should be zero degrees. Risk of anemia is highest in fetuses with a pre-transfusion peak systolic velocity of 1.5 times the median or higher. The umbilical arterial waveform should demonstrate low resistance flow and an S/D (systolic/diastolic ratio) < 3.0 after 30 weeks. Absent or reversed diastolic flow in the umbilical artery is a poor prognostic indicator. Doppler evaluation of the ductus venosus should reveal triphasic flow that is forward throughout the cardiac cycle. Reversed flow in the ductus venosus is associated with IUGR and chromosome abnormalities.
What is the first structure to be identified sonographically within the gestational sac?
The yolk sac is the first structure seen within the gestational sac. With transvaginal sonography, the secondary yolk sac is visible at 5.5 weeks LMP, and is almost always seen when the MSD reaches 8mm. Transabdominally the yolk sac should be seen by 7 weeks LMP, when the MSD is 20mm. The yolk sac should be measured inner-to-inner.
What are theca lutein cysts? What serum finding is associated with theca lutein cysts? How do they appear sonographically?
Theca lutein cysts are the largest of functional cysts, associated with high levels of hCG in gestational trophoblastic disease or hCG administration during infertility treatment. Sonographic findings in theca lutein cysts include bilateral large multilocular ovarian cysts.
Hormone secreting ovarian tumors can cause symptoms related to hormonal activity. What hormones are secreted by the following ovarian tumors? Thecoma Granulosa cell tumor Androblastoma
Thecomas are estrogen producing tumors. Granulosa cell tumors produce estrogen. Androblastomas (also known as arrhenoblastomas or Sertoli-Leydig cell tumors) secrete testosterone.
What sonographic findings suggest a lethal skeletal dysplasia?
There are three distinct characteristics of lethality: 1. Severe micromelia - a long bone measuring more than 4 SD below the mean for gestational age. 2. Severely hypoplastic thorax - Thoracic circumference that is less than the 5th percentile for Ga is indicative of a lethal defect. The circumference is obtained around the perimeter of the ribs, not the soft tissues. 3. Identification of a specific feature of a lethal dysplasia - Sonographic findings associated with a specific dysplasia (i.e. multiple fractures in osteogenesis imperfecta type II or bent femur in campomelic dysplasia).
Describe what structures form from each primitive germ cell layer of the trilaminar embryonic disk.
There are three germ cell layers that comprise the embryonic disk by 5 weeks after LMP. The endoderm is the inner layer and forms GI and respiratory systems. The mesoderm is the middle layer and forms the musculoskeletal and circulatory systems. The ectoderm is the outer layer that forms the brain, nervous system and skin.
Describe the two types of endometrial implants.
There are two forms of endometriosis: diffuse (scattered minute implants), or localized (endometrioma), which is a discrete mass sometimes called a chocolate cyst.
Describe the conditions of morbidly adherent placenta (placenta accreta/increta/percreta). How can these conditions be diagnosed sonographically>
These relatively uncommon conditions result from defective decidual formation with abnormal attachment of the placenta to the uterine wall. More commonly found in patients with prior C-section who have placenta previa. Due to associated maternal hemorrhage, hysterectomy may be necessary. Three classifications, based on villous extension: -placenta accreta - chorionic villi are in direct contact with the myometrium but do not invade -placenta increta - chorionic villi invade the myometrium -placenta percreta - chorionic villi penetrate/perforate the myometrium Sonographic findings may include loss of normal hypoechoic retroplacental vascular complex in gray scale imagine, focal basal plate thinning (accreta), increased myometrial thickness and echogenicity (increta) or focal myometrial bulge (percreta). The use of color/power Doppler may be helpful.
What should the sonographer evaluate in a postmenopausal patient who is bleeding?
Thorough transvaginal evaluation of the endometrium with AP measurement in the sagittal plane should be performed, as well as evaluation of the myometrial echotexture.
How should fetal nasal bone be assessed? What does a small or absent nasal bone indicate?
To measure the nasal bone, a midsagittal image should be obtained. The angle between the fetal profile and the transducer should be 45 degrees. The presence of the nasal bone should be noted. Hypoplastic or absent nasal bones may be associated with Trisomy 21.
What is ovarian torsion? What factors may predispose a patient to ovarian torsion?
Torsion of the ovary is caused by rotation of the ovarian pedicle on its axis. Lymphatic and venous drainage is compromised, causing congestion and edema of the ovary, eventually leading to loss of arterial perfusion and resultant infarction. Risk factors for ovarian torsion include pre-existing ovarian cyst or mass (usually benign), children and young females with mobile adnexa and pregnancy.
What are the major sonographic features of Trisomy 13 (Patau's syndrome)?
Trisomy 13 or Patau's syndrome is the presence of an additional chromosome 13. This condition carries a poor prognosis. Pathologic/sonographic features include: -holoprosencephaly -cleft lip/palate (especially median cleft) -IUGR -polydactyly -single umbilical artery -omphalocele -cystic renal dysplasia -VSD or truncus arteriosus -agenesis of corpus callosum
What are the major sonographic features in Trisomy 18 (Edwards syndrome)?
Trisomy 18 or Edwards syndrome is the presence of an additional 18th chromosome. IUFD or stillbirth is common. Pathologic/sonographic features include: -overlapping fingers/flexed hands -IUGR -ASD, VSD -single umbilical artery -choroid plexus cysts -micrognathia -"strawberry" shaped cranium -rocker bottom feet -omphalocele -diaphragmatic hernia -hydronephrosis -enlarged cisterna magna
What are the major sonographic features in Trisomy 21 (Down Syndrome)?
Trisomy 21 or Down syndrome is the presence of an extra 21st chromosome and is the most common trisomy to survive to birth and beyond. Sonographic findings include: -nuchal fold measuring >6mm between 15-21 weeks -cystic hygroma -non-immune hydrops -ASD/VSD/endocardial cushion defect -duodenal atresia -pleural effusion -small or absent nasal bones -renal pyeliectasis -clinodactyly (hypoplastic middle 5th phalanx) -hyperechoic bowel -echogenic intracardiac focus (EIF)
What sonographic findings are seen in Turner syndrome?
Turner syndrome or monosomy X (45 XO) is a chromosomal syndrome attributed to complete or partial absence of an X chromosome. The fetus is always female. Sonographic findings in a fetus may include cystic hygroma, lymphedema, non-immune hydrops, cardiovascular malformations and horseshoe kidneys or renal agenesis. Sonographic findings postnatally include hypoplastic/aplastic uterus and ovarian dysgenesis/streak-like ovaries.
What is twin-to-twin transfusion syndrome (TTTS)/poly-oli sequence?
Twin-to-twin transfusion syndrome (TTTS) or Poly-Oli sequence occurs in monozygotic twins with shared vascular anastamoses in a monochorionic placenta. Sonographic findings include: 20% difference in EFW or 20 mm difference in AC Recipient twin: polyhydramnios; large for dates; edema; enlarged viscera; and hydrops. Donor twin: oligohydramnios; small for dates; may become "stuck" in severely oligohydramniotic sac.
Holoprosencephaly is a spectrum of disorders resulting from absent or incomplete diverticulation (division) of the forebrain (prosencephalon) into the cerebral hemispheres and lateral ventricles. Describe the types of holoprosencephaly.
Types of holoprosencephaly include alobar holoprosencephaly, which is the most severe form. Alobar holoprosencephaly has a monoventricle, fused thalami and absence of the falx cerebri. Semi-lobar holoprosencephaly has partial separation of ventricles & hemispheres with occipital lobe present and incompletely fused thalami. Lobar holoprosencephaly is the least severe form, and has normal separation of thalami, hemispheres and ventricles with absence of the cavum septum pellucidum and olfactory tracts.
Physiologic cysts are the most common cause of ovarian enlargement in young women. Name three types of physiologic cysts.
Types of physiologic or functional cysts include follicular cysts, corpus luteal cysts and theca lutein cysts. Follicular and corpus luteal cysts result from the menstrual cycle. Theca lutein cysts occur in patients with elevated levels of hCG. Follicular cysts are caused by overstimulation of a follicle that fails to rupture or involute.
Name potential maternal pelvic masses that may be encountered sonographically during pregnancy.
Uterine myomas enlarge during pregnancy due to estrogen stimulation. Myomas may cause pain durin gpregnancy due to degeneration, hemorrhage or tosion. The position of myoma relative to cervix should be determined as during delivery, a myoma may obstruct vaginal delivery. A myoma may be confused sonographically with Braxton-Hicks contraction (contraction will change over time of exam). Ovarian cysts may be corpus luteal or theca lutein cysts. Anatomic variations can also present as coexisting pelvic masses. These include pelvic kidney, wandering spleen, non-gravid horn of a bicornuate uterus, feces-filled colon or a dilated ureter.
What is vasa previa? In what cases may true umbilical cord knots be visualized sonographically?
Vasa previa is the presence of fetal vessels crossing the cervical os, passing between the cervix and presenting fetal part with the membranes intact. Vasa previa is associated with velamentous insertion. True umbilical cord knots are rare and are associated with monochorionic monoamniotic twins. Most sonographic appearances of umbilical cord knots are false positives due to multiple loops of cord seen in a single scan plane.
The umbilical cord normally inserts centrally into the placenta. What is the difference between velamentous insertion and marginal insertion?
Velamentous insertion is attachment of the cord to the membranes rather than to the placental mass. In velamentous insertion, the cord travels beneath the chorion for some distance before attaching to the edge of the placenta. Marginal or battledore insertion is attachment of the cord at the periphery of the placenta.
How should the endometrium be measured when there is fluid in the endometrial cavity?
When fluid is present in the endometrial cavity, measurements should be taken of each side of the endometrium and added together (not including the fluid in the measurement).