study guide chapter 60-62

Question 1

Which abnormality has a significantly narrower chest diameter?

Answer 1

asphyxiating thoracic dystrophy.
Several syndromes may be associated with this finding, including thanatophoric dwarfism

In the presence of oligohydramnios, resultant pulmonary hypoplasia may be seen with a reduction in overall thoracic size.

Question 2

What is the most important determinant for fetal viability?

Answer 2

Adequacy of pulmonary development single most important determinant for fetal viability

Question 3

Sonographic evaluation of a normal fetal thorax?

Answer 3

Normal thoracic cavity is symmetrically bell shaped:
Ribs form lateral margins
Clavicles form upper margins
Diaphragm forms lower margin

Size:Thorax normally slightly smaller than abdominal cavity
Ratio (thoracic circumference to abdominal circumference) reported to remain constant throughout pregnancy (0.94 ± 0.05)

sono:
Fetal lungs appear homogeneous on sonography, with moderate echogenicity

Early in gestation, lungs similar to or slightly less echogenic than liver

As gestation progresses, trend is toward increased pulmonary echogenicity relative to liver

Question 4

To evaluate normal fetal thorax:

Answer 4

Transverse, coronal, and/or parasagittal
Evaluate chest: Size, shape, symmetry
Evaluate heart: Position, size, rate, pericardial fluid
Evaluate pulmonary texture
Centrally positioned mediastinum

Question 5

Chest circumference measurements made in transverse plane at level of?

Answer 5

Chest circumference measurements made in transverse plane at level of four-chamber view of heart

Question 6

Fetal breathing..

Answer 6

Fetal breathing becomes more prominent in second and third trimesters

Mature fetus spends almost one-third of its time breathing

Fetal breathing movements documented if characteristic seesaw movements of fetal chest or abdomen sustained for at least 20 seconds

Fetal breathing movements considered absent if no such fetal activity noted during 20-minute observation period

Fetal respiration may vary in response to maternal activities and substance ingestion

Stimulated by increased sugar doses and decreased by smoking

Question 7

degree of cardiac axis?

Answer 7

45?
Apex of heart should be directed toward spleen
Base of heart lies horizontal to diaphragm

Question 8

Abnormalities associated with pulmonary hypoplasia?

Answer 8

pulmonary hypoplasia is:
Caused by decrease in number of lung cells, airways, and alveoli, with resulting decrease in organ size and weight

Most commonly occurs from prolonged oligohydramnios or secondary to small thoracic cavity as result of structural or chromosomal abnormality

Look for chromosome anomalies, renal anomalies, intrauterine growth restriction, premature rupture of membranes, masses within thoracic cavity

Prognosis grave; 80% die after birth

Question 9

sonographic findings in CCAM?

Answer 9

Is a multicystic mass within the lung.
Consists of primitive lung tissue and abnormal bronchial and bronchiolar-like structures. CCAM is one of the bronchopulmonary foregut malformations

sono:

Type I:(macrocystic) Single or multiple large cysts 2 cm in diameter; good prognosis after resection of affected lung

Type II: Multiple small cysts, <1 cm in diameter, echogenic; high incidence 25% of other congenital anomalies (renal, gastrointestinal)

Type III: Large, bulky, noncystic lesions producing mediastinal shift; poor prognosis
Usually only one lobe affected
Associated polyhydramnios and anasarca have poor prognosis

Question 10

Types of diaphragmatic hernias?

Answer 10

Sporadic defect; occurs in 1:2000 to 1:5000 births

herniation through foramen of:
Bochdalek:
Most common type of diaphragmatic defect occurs posteriorly and laterally in diaphragm

foramen of Morgagni:
May occur anteriorly and medially in diaphragm, through foramen of Morgagni, and may communicate with pericardial sac
In anteromedial defects, heart may be normally positioned but surrounded by pleural fluid, while fetal stomach may be located in its normal position in abdomen

Question 11

What lung cyst is the most common?

Answer 11

Bronchogenic Cysts

Occur as result of abnormal budding of foregut

Lack any communication with trachea or bronchial tree

Typically occur within mediastinum or lung

Infrequently found inferior to diaphragm

Question 12

The severity of pulmonary hypolasia depends on what?

Answer 12

Severity depends on when pulmonary hypoplasia occurred during pregnancy and its severity and duration

Other factors, such as pulmonary fluid dynamics, fetal breathing movements, and hormonal influences, may contribute

Question 13

The supernumerary lobe of the lung? sono?

Answer 13

pulmonary sequestration:
Extrapulmonary tissue present within the pleural lung sac or connected to the inferior bordr of the lung with its own pleural sac.

Extra lung tissue nonfunctional; receives its blood supply from systemic circulation

Arterial supply usually from thoracic aorta, with venous drainage into vena cava

sono:
Echogenic solid mass resembling lung tissue
Rarely occurs below diaphragm
Associated with hydrops and polyhydramnios, diaphragmatic hernia, gastrointestinal anomalies
Normal intra-abdominal anatomy

Question 14

If you see pleural fluid what should you look at?

Answer 14

Pleural Effusion (Hydrothorax):
Most common reason is chylothorax occurring as right-sided unilateral collection of fluid secondary to malformed thoracic duct. Hydramnios often accompanies chylothorax resulting from esophageal compression 

May result from immune causes(e.g., Rh hemolytic disease), nonimmune causes, or from CHF

Effusions may also occur in fetuses with chromosomal abnormalities (e.g., trisomy 21) or in fetus with cardiac mass

Once discovered, careful search for lung, cardiac, and diaphragmatic lesions should be attempted

Evaluation for signs of hydrops should be performed

Correlation with clinical parameters warranted to exclude immunologic causes of pleural effusions

Question 15

Congenital bronchial atresia is most commonly located where?

Answer 15

Pulmonary anomaly that resuls from focal obliteration of segment of the bronchial lumen.

Most common in left upper lobe

Appears on ultrasound as echogenic pulmonary mass lesion

Question 16

mortality rate at birth for a fetus with a diaphragmatic hernia is?

Answer 16

high (75%)

Question 17

What is diaphragmatic hernia associated with?

Answer 17

pulmonary hypertension, pulmonary hypoplasia or chromo

Hydrops usually not present with left-sided congenital diaphragmatic hernias unless associated fetal malformations are present

Presence of pulmonary hypoplasia and pulmonary hypertension is real issue that results from size of hernia

Pulmonary arteries become hypertrophied and thickened, resulting in pulmonary hypertension that after birth leads to persistent fetal circulation

Question 18

if pleural fluid what could happen?

Answer 18

Shift of mediastinal structures
Compression of heart
Inversion of diaphragm
compression of lungs

Question 19

rupture of amnion that leads to entanglement or entrapment of fetal parts to the sticky chorion?

Answer 19

Amniotic band syndrome

Question 20

Defect in the lower abdominal wall and anterior wall of the urinary bladder?

Answer 20

Cloacal exstrophy

Question 21

Anomaly with large cranial defects, facial cleft, large body wall defects and lib abnormalities?

Answer 21

limb-body wall complex

Question 22

Opening in the layers of the abdominal wall with evisceration of the bowel to the right of the umbilical cord?

Answer 22

Gastroshisis
Small bowel always found in herniation

Other organs that may be involved in herniation:
Large bowel
Stomach
Portions of genitourinary system
Liver

Question 23

If you have an omphalocele with scoliosis?

Answer 23

When scoliosis is found, consider limb-body wall complex (or body-stalk anomaly), a lethal disorder
This disorder also includes severe cranial defects, facial clefts, extensive abdominal wall defect of the chest, and abdomen and limb defects.
Abnormal fusion of the amnion and chorion extends as a sheet from the cord and adheres to the fetus and placenta

Question 24

If an omphalocele is low what should you consider?

Answer 24

When low omphalocele is observed, consider bladder or cloacal exstrophy.

Results in exstrophy of bladder in which two hemibladders are separated by intestinal mucosa

Other anomalies may include anal atresia, spina bifida, and lower-limb defects

Question 25

What does beckwith-wiedemann syndrome include?

Answer 25

coexistwnce of and omphalocel, macroglossia and visceromegaly

Question 26

Gastroschisis is from astrophia of what vessel?

Answer 26

right umbilical vein

Question 27

most common abdominal wall defects?

Answer 27

omphalocele, umbilical hernia, and gastroschisis

Question 28

critical part of the process of closing the abdominal wall?

Answer 28

In sixth week, process called folding helps embryo transform itself into cylindrical shape

This transformation is critical part of process of closing abdominal wall

Question 29

normal hernia of bowel to allow what?

Answer 29

permits development of intraabdominal organs and allows necessary bowel rotation

Umbilication hernia of bowel occurs during eighth week of development as midgut extends to extraembryonic coelom in proximal portion of umbilical cord

Midgut grows faster than abdominal cavity at this stage because of increased size of liver and kidneys
Herniation develops
Intestines return to abdominal cavity by 12th week of gestation

Question 30

omphalacele

Answer 30

When bowel loops fail to return to abdomen, bowel-containing omphalocele occurs

Membrane consisting of peritoneum and amnion forms omphalocele sac encasing herniated organs
Ascites may coexist with omphalocele
Hydramnios found in one third of fetuses

Associated anomalies include: 
Complex cardiac disease 
Gastrointestinal
Neural tube 
Genitourinary tract anomalies

Chromosomal anomalies occur in 35% to 60% of omphaloceles

Question 31

five defects of pentalogy of cantrell?

Answer 31

omphalocele
ectopic heart
lower sternum
anterior diaphragm
diaphragmatic pericardium

Question 32

prognosis of an infant with gastroschisis?

Answer 32

good prognosis

Free-floating herniated small bowel
Large bowel, stomach, gallbladder, urinary bladder, pelvic organs may be involved

Question 33

A high omphalacele is the primary finding in what condition?

Answer 33

pentalogy of cantrell

Question 34

Limb–Body Wall Complex defects more common on what side?

Answer 34

Occurs with fusion of amnion and chorion
Amnion does not cover umbilical cord normally
Extends as sheet from margin of cord
Is continuous with both body wall and placenta
Left-sided body wall defects three times more common than right-sided defects

Is associated with:
Large cranial defects
Facial cleft
Body wall complex defects involving thorax
Body wall complex defects involving abdomen
Limb defects

Question 35

common anomilies associated with gastrischsis?

Answer 35

When organs other than small or large bowel seen, body stalk anomalies should be suspected

or none?

Question 36

membrane of omphalacele is made up of?

Answer 36

Membrane consisting of peritoneum and amnion forms omphalocele sac encasing herniated organs

Question 37

What does the umbilical vein drain?

Answer 37

placenta???
After birth, umbilical vein collapses and becomes ligamentum teres hepatis

In fetus, umbilical vein courses cephalically in free, inferior margin of falciform ligament

Joins umbilical portion of left portal vein at caudal margin of left intersegmental fissure of liver

Question 38

the hepatic bud enlarges and the right umbilical vein atrophy during what week?

Answer 38

7th

Question 39

A fetus with partial situs inversus demonstrates what?

Answer 39

condition in which only the heart or the abdominal organs are reversed.
Asplenia (absence of spleen):
Abnormally positioned stomach and gallbladder
More centrally positioned liver
Abnormal positioning of aorta and IVC on same side

Polysplenia represented as transposition of liver, spleen, stomach, and absence of gallbladder. Interruption of IVC and azygos vein directly posterior to heart and in front of spine. At least two spleens present along greater curvature of stomach. Heart block common in polysplenia syndrome

Question 40

if you see evidence of a double bubble with tri 21 what is the condition?

Answer 40

Duodenal Atresia

Sonographic appearance termed “double bubble sign”

Hydramnios almost always seen with duodenal atresias later in pregnancy

Most cases found distal to ampulla and often coexist with annular pancreas

About 30% of fetuses with duodenal atresia have trisomy 21 (Down syndrome)
Cardiovascular anomalies frequent; fetal echocardiography invaluable in excluding cardiac lesions
Anomalies occur in approximately 50% of infants with duodenal atresia

Question 41

Fetus with dialated loops of echogenic bowel should be evaluated for what?

Answer 41

Meconium Ileus

Normal small bowel may appear echogenic during second trimester of pregnancy.
Other fetal conditions associated with echogenic small bowel (cytomegalovirus and trisomy 21)
Meconium peritonitis may occur secondary to perforation of obstructed bowel.
Inflammatory response occurs because of leakage of bowel contents, which may cause fibrosis of tissue and calcifications.

Question 42

where is the spleen visualized?

Answer 42

Imaged on transverse plane posterior and to left of fetal stomach

Spleen, like liver, may enlarge in fetuses with Rh-immune disease

Question 43

cause of areas of echogenicty in the fetal abdomen?

Answer 43

Meconium Ileus: dialated and echo bowel

Anorectal Atresia: dilated colon and calcified meconium

Question 44

cystic growth of the common bile duct?

Answer 44

choledochal cyst

Question 45

haustral folds can be found in which of the following structures?

Answer 45

colon

one of the sacculations of the colon caused by longitudinal bands that are shorter than the gut

Question 46

A remnant of the proximal part of the yolk sac?

Answer 46

Meckel’s diverticulum
Is the most common malformation of midgut

Usually small fingerlike sac, about 5 cm long, projects from border of ileum

Question 47

normal sono apearance of the esophagus during 2nd and 3rd tri?

Answer 47

Normal esophagus can be visualized in thorax during second and third trimesters as two or more parallel echogenic lines (“multilayered” pattern)

Sometimes possible to see fluid in esophagus as fetus swallows amniotic fluid

Question 48

when you can diff small bowel and large?

Answer 48

20weeks

Question 49

know about fetal stomach

Answer 49

Most fetuses older than 14 to 16 weeks should have fluid in their stomach

Question 50

transposition of liver, stomach, absent of gb and multi spleens

Answer 50

polysplenia

Question 51

sonolucent band near the fetal anterior abdominal wall from the abdominal wall muscles in the fetus over 18 weeks?

Answer 51

pseudoascites

Question 52

most reliable criteria for dialated bowel loops?

Answer 52

Normal diameter of small bowel lumen ≤5 mm, with length of 15 mm near term

Normal measurements of colon diameter range from 3 to 5 mm at 20 weeks to 23 mm or larger at term

Question 53

causes of double bubble?

Answer 53

Duodenal atresia
Duodenal stenosis
Annular pancreas
Ladd’s bands
Proximal jejunal atresia
Malrotation
Diaphragmatic hernia

Question 54

coexisting anomolies with Esophageal Atresia?

Answer 54

Coexisting anomalies common in 50% to 70% of fetuses with esophageal atresia

Most commonly observed anomaly is anorectal atresia and VACTERL

Growth restriction present in 40% of cases

Chromosomal trisomies (18 and 21) reported

Fistula may not be present and fluid will not reach stomach; stomach will not be visualized by ultrasound

Combination of polyhydramnios and absent stomach over repeated studies may be suggestive of esophageal atresia

Will not be diagnosed in majority of cases because of tracheoesophageal fistula

Upper neck sign has been observed as additional finding

Question 55

hindgut Derivatives

Answer 55

Derivatives of hindgut:
Left part of transverse colon
Descending colon
Sigmoid colon
Rectum
Superior portion of anal canal
Epithelium of urinary bladder
Most of urethra 

All of structures supplied by inferior mesenteric artery

Question 56

choledochal cyst sono:

Answer 56

close prox to neck of GB
ovoid RUQ
cyst entering bile duct
absence of peristalsis

Question 57

if you see peritoneal calcifications at 30 weeks what does it indicate?

Answer 57

Meconium Peritonitis
Calcifications seen on peritoneal surfaces or in scrotum via processus vaginalis

Ascitic fluid may be echogenic.

Is unusual to see calcification in meconium ileus in fetus with cystic fibrosis

Question 58

VACTERL is a group of anomalies association with what?

Answer 58

Anorectal Atresia

Presents as complex disorder of bowel and genitourinary tract
Imperforate anus is disorder that occurs when membrane covers anus, prohibiting expulsion of meconium
May present as part of VACTERL association or in caudal regression
Prognosis poor with anorectal atresia because of associated anomalies

Question 59

fetal liver:

Answer 59

Hemopoiesis (blood formation) begins during sixth week

Accounts for large size of liver between seventh and ninth weeks of development

By 12th week, bile formation by hepatic cells has begun
Accounts for 10% of total weight of fetus at 11 weeks and 5% of total weight at term

Left lobe of liver larger than right in utero secondary to greater supply of oxygenated blood

Question 60

describe situs inversus

Answer 60

heart and abd organs are completely reversed

Question 61

complex disorder of the bowel and genitourinary tract

Answer 61

anorectal atresia