Chapter 27: Sonographic Assessment of the Fetal Abdomen (Includes Abdominal wall) Flashcards
accumulation of fluid in the abdominal cavity
ascites
congenital blockage or absence of the bilde duct
biliary atresia
congenital absence or closing of the duodenal lumen
duodenal atresia
membrane-free ventral wall defect with protrusion of abdominal contents laterla to umbilical cord
gastroschisis
Half-Fourier acquisition single-shot turbo spin-echo; a fast spin method to obtain the MRI dataset
HASTE
Formation of blood cells
hematopoesis
congenital lack of nerves in the colon resulting in fetal impaction and a megacolon
Hirschprung disease
areas of high intensity or increased brightness on MRI image
hyperintense
areas of low intensity or decreased brightness on MRI iamge
hypointense
areas of similar intensity or increased brightness on MRI image
isointense
bowel obstructed by mucus
meconium ileus
Bowel obstructed owing to bowel twisting
midgut volvulus
congenital disorder where the spinal cord does not close before birth
myelomeningocele
membrane-covered ventral wall defect containing abdominal contents involving the umbilical cord
omphalocele
reversal of normal organ position
situs inversus
Genetic abnormality where there is a presence of three copies of a particular chromosome
Trisomy
radiographic study using barium sulfate as a contrast agent to outline and fill gastrointestinal tract
Upper GI
simple tool for evaluating the performance of each reference curve for a given population to optimize the sensitivity and specificity of screening for fetal growth abnormalities
Z-score
caused by:
fetal anemia
Rh incompatability
immune fetal hydrops
caused by:
heart arrythymias
intrauterine infections
chromosomal anomalies
masses causing venous obstruction
blood disorders
renal anomalies
maternal diabetes
nonimmune fetal hydrops
Sonographic features of fetal hydrops
anasarca
pleural effusion
ascites
hepatomegaly
splenomegaly
thick placenta
herniation of abdominal viscera into base of umbilical cord; liver involvement common
omphalocele
complex membrane, enclosed sac; midline anterior wall defect continuous with umbilical cord; size varies with amount of involved viscera
omphalocele
herniation of abdominal viscera through an off-midline defect in the abdominal wall, usually located just to the right of the umbilicus; liver involvement very unsual
gastrochiasis
free-floating bowel loops are not bound by a sac, normal umbilical cord insertion
gastroschisis
protrusion of a small amount of intestine at umbilicus; covered by skin and subcutaneous tissue; usually 2-4 cm
umbilical cord hernia
congenital failure of the abdominal wall to develop over bladder; urinary bladder may be everted; no fluid-filled intrapelvic bladder; most common in boys
bladder exstrophy
defect of lower sternum and anterior abdominal wall; heart protrudes into extrathoracic sac covered by skin or a thin membrane; the beating heart protrudes through the anterior abdominal wall into the amniotic fluid
ectopic cordis
a complex of anomalies including lateral body wall defects of thorax and abdomen with herniation of viscera;
limb-body wall complex
herniated viscera within a complex membrane involved mass, severe scoliosis, cranial, and spinal defects; severe form of amniotic band syndrome through to play a major role in pathogenesis
limb-body wall complex
stomach, bowel, or other abdominal organs within chest
peristalsis of structures within chest
small abdominal biometry
descension and ascension of organs with fetal breathing
pleural effusion
polydramnios
documentation of portal and umbilical vessels via color Doppler
sonographic features of congenital diaphragmatic hernia
fluid-filled proximal duodenum
polyhydramnios
echogenic mass inferior to liver
dilated bowel loops
whirlpool sign
twisted vessels with color Doppler
Midgut volvulus
fluid-filled stomach and duodenum creating the double-bubble sign
symmetric intrauterine growth retardation
polyhydramnios
Duodenal atresia
Dilated echogenic ileum
intraperitoneal fluid
possible pseudocyst
intra-abdominal calcifications
polyhydramnios
dilated small bowel
increased abdominal biometery
decreased bowel peristalsis
meconium ileus
Organs attain normal adult position when”
early 2nd trimester
Umbilical arteries course _____ to the fetal bladder
caudally
Umbilical vein runs course cephalic into the _____
portal vein
Right parasagittal views through thorax and abdomen allow evaluation of ____ and ____
fetal lung
liver
Left parasaggital views through thorax and abdomen allow evaluation of _____ and _____
stomach
left kidney
Midline sagittal views allow evaluation of ______ with _______
umbilicus
anterior abdominal wall
Which type of situs inversus has an increased incidence of abnormalities?
partial
mirror imaging or thoracic and abdominal contents
situs inversus totalis
With situs inversus totalis the heart is on the ____ side of the thorax and the abdominal organs are _____
right
transposed
Normal abdominal organs should be seen in cephalic position
spine, stomach, umbilical vein clockwise
outer echogenic skin line and a deeper 1-3 mm hypoechoic muscular layer
abdominal wall
3 main muscle groups of abdominal wall
internal oblique
transverse abdominal
external oblique
The hypoechoic muscular layer of the abdominal wall is also referred to as:
pseudoascites
caudal outpouching of yolk sac; involved in early blood production
allantois
The blood vessels of the allantois eventually become:
umbilical vessels
A two vessel cord is more common in ____ pregnancies
twin
acts as a conduit between portal and system veins
fetal ductus venossu
echogenic line in fissue of ligamentum venosum between left and caudate lobes
ductus venosus
carry most of fetal aortic blood to placenta
umbilical arteries
A fetus from a _____ mother will have increased abdominal tissue and larger AC measurements
diabetic
The liver, gallbladder, ducts, pancreas develop from ______
embryonic foregut
outgrowth development on caudal portion of foregut; the hepatic diverticulum
liver
In the second trimester the liver is ___% of the fetal weight.
1o
In the __ week hematopoeisis begins
6
In the ___ week the bile secretion begins
12
forms from caudal portion of hepatic diverticulum; ducts canalize through degeneration of epithelial cells
gallbladder
After ___ weeks, the biles empties into the duodenum
13
The spleen is part of the _____ system
lymphatic
The spleen develops during the __ weeks
5th
large, homogenously echogenic organ occupying RUQ
liver
located to the right of midline, separates the right lobe from the medial left lobe, tear drop shape, posteroinferior to the liver
gallbladder
homogenous, located posterior to stomach and superior to left kidney;
spleen
begins as dilation of stomach primordium site in fourth week
stomach
The _____ is the result of faster growth of dorsal border of stomach primordium
greater curvature
formed by the caudal portion of foregut, splanchnic mesenchyme, and cranial portion of the midgut
duodenum
During the __ to __ week, the duodenal lumen closes until degeneration of epithelial cells resulting in recanalized lumen at end of first trimester
5
6
The umbilical herniation begins during the first part of the __ week
6th
The umbilical herniation contains structures that will become the small intestine, these include:
most of the duodenum
cecum
appendix
ascending colon
2/3 transverse colon
provides communication between midgut and yolk sac through 10th week
yolk stalk or vitelline duct
After _______, structures return to abdomen.
midgut loop rotation
If there is echogenicity within the stomach:
swallowed blood or varix
Echogenicity within the stomach is indicative of:
placental abruption
Midgut herniation resolves by __ weeks
12
heterogenous echogenic pseudomass without shadowing occupying a substantial portion of the abdomen
small bowel
Z scores greater than 8 after 25 weeks gestation are indicative of:
small bowel pathology
long, continuous tubular structure with a hypoechoic lumen at abdominal periphery
colon
The transverse colon is just ____ to the liver
caudad
composed of materials fetus ingests during gestation
meconium
A thickened abdominal wall is visualized in fetuses:
fetal hydrops
offspring of gestational diabetic mothers
smaller AC owing to loss of glycogen stores in liver, decrease in liver size
asymmetric intrauterine growth retardation
Two most common types of ventral abdominal wall defects
omphaloceles
gastrochisis
linea alba defect and protruding bowel covered by skin and subcutaneous tissue
umbilical hernia
Four ectomesodermal layers aid in development of abdominal wall:
cephalic, caudal, pair of lateral folds
Abdominal wall defects have elevated _____ levels in amniotic fluid or maternal serum
alpha-fetoprotein
Midline defect where the bowel does not migrate back into abdomen and remnant in extraembryonic coelem of umbilical cord; may contain only bowel or organs and bowel
omphalocele
develops owing to body stalk persistence in an area normally occupied by abdominal wall
omphalocele
fusion failure of lateral ectodermal folds
Type I omphalocele
failure of muscle, fascia, and skin to fuse
type II omphalocele
Omphaloceles measure between __ and __ cm.
2
10
The membrane of an omphalocele is made up of _____ and _____
amnion
peritoneum
Omphalocele may be suggested early in pregnancy if cord containing midgut has a maximal dimension of ___ mm or greater
7
___-___% of omphaloceles are associated with other anomalies
50-70
omphalocele associated with ectopia cordis
pentalogy of Cantrell
Gastroshisis masses are between __-__ cm.
2
4
Typically occurs just to the right umbilical cord insertion; abnormal involution of right umbilical vein and disruption of omphalomesenteric artery
gastroshisis
comprise small or large bowel; free-floating; not covered by a membrane; leads to a development of fibrinous coating on bowel
herniated viscera (gastroshisis)
Gastroshisis images as early as __-__ week.
14-16
fluid within the peritoneum
ascites
Ascites is seen best within the _____, flanks, _____, and pelvis
subhepatic space
abdominal cavity
results from bladder outlet obstruction or renal forniceal rupture
urinary ascites
result of bowel obstruction, or dilatation of the pyelocaliceal system or bladder indicating a GU problem
Bowel dilatation
may cause walls for form around areas of greatest meconium concentration within peritoneum, forming meconium pseudocysts
localized fibrotic reactions
simulation of fluid that lies along the inner aspect of the abdominal wall; fetuses over 18 weeks gestation; created by hypoechoic quality of abdominal wall musculature sandwiched between the highly echogenic subcuteaneous and preperitoneal tissue
pseudoascites
The liver enlarges in association with ____
hydrops
Growth retarded infants have ___ livers.
small
Diabetic mothers and macromsomic fetuses have ____ livers.
large
may develop because of interruption of development of intrahepatic biliary tree
solitary liver cysts
Most common type of choledochal cysts
cystic dilatation of the CBD
Choledochal cysts usually lie in anterior location adjacent to the _____
gallbladder
Most common vascular tumor
infantile hemangioendothelioma
echogenic masses within the fetal gallbladder that may or may not demonstrate posterior shadowing; often resolve as a result of postnatal hydration or because of changes in bile metabolism
gallstones
There is a significant correlation between perimeter measurement of the spleen and ______
fetal hemoglobin defecit
Asplenia and polysplenia associated with significant:
congenital heart disease
Most common type of esophageal atresia
proximal esophageal pouch
unequal partitioning of the foregut
esophageal atresia
Most common atresia
anorectal
_____ and stress of _____ may result in absence of stomach fluid
oligohydramnios
nonimmune hydrops
caused by errors of GI lumen recanalization or errors in development of normal inpouching of longitudinal folds
duplication of stomach and bowel
obstruction caused by bowel twisting upon its blood supply
midgut volvulus
In volvulus the bowel twists around the _____
superior mesenteric artery
usually diagnosed within first few days of life; infant may present with distention or obstruction, and biliary vomiting
volvulus
fluid filled proximal duodenum with an arrowhead twist at point of descending or transverse duodenal obstruction; mild polyhydramnios; echogenic mass under fetal liver; slightly dilated bowel loops
volvulus
the gold standard for midgut volvulus is:
upper GI
failure of duodenum to change from a solid cord of tissue during development to a tube
duodenal atresia
Majority of duodenal atresias occur distal to:
ampulla of Vater
formed by pancreatic and common bile duct
hepatopancreatic ampulla
major landmark marking foregut to midgut transition
hepatopancreatic ampulla
occur high in abdomen; demonstrate multiple cystic structures with associated hydramnios
venjunoileal or ileal atresia or stensos
most common sites of involvement in venjunoilieal or ileal atresia or stenosis
proximal jejunum and distal ileum
known as apple peel or christmas tree atresia
extensive small bowel atresia
fluid filling stomach and duodenum at site of obstruction
“double bubble” sign
Duodenal atresia is most commonly associated with _____
trisomy 21
third most common bowel obstruction
meconium ileus
Meconium ileus is most often owing to ______
cystic fibrosis
occurs when the meconium becomes thickened and congested in the ileum
meconium ileus
dysfunction of the exocrine and mucus-producing glands
cystic fibrosis
small bowel obstruction of distal ileus; increased stickiness and and thickness of meconium
meconium impaction
Meconium peritonitis may result from ______ and _____
meconium ileus
cystic fibrosis
Meconium peritonitis occurs following:
rupture of bowel
Meconium peritonitis is usually seen within ___ days of rupture
8
functional disorder of distal colon that results in perpetually contracted or tonic bowel; colon does not relax because of neuroenteric ganglion cells in mucosal layer of bowel
large bowel obstruction
Descending colon measurement greater than __ mm in preterm fetus is abnormal
20
The fetal rectosigmoid colon can reach __-__ cm near term
2
3
Antenatal indication of Hischsprung
focal bowel dilatation proximal to obstruction
most common echogenic fetal mass found in abdomen
echogenic bowel
echogenic nonshadowing mass in lower abdomen and pelvis
collapsed small bowel
cystic or solid appearing structures; formed by an inner epithelium of a respiratory or intestinal type and a two layer smooth muscle wall
enteric inclusion cysts
dialysate of maternal serum
amniotic fluid
essential for maintenance of an even fetal temperature and biochemical homeostasis; presence allows fetal movement and growth
amniotic fluid
AFV 12 weeks
60 mL
The AFV increases __-__ mL until week 16
20-25
The AFV increases to __-__ mL until week 20
50-100
Fetal urine production begins at __ weeks
12
In the late third trimester, fetal urine production is ___ mL a day.
450
decreased fluid surrounding fetus
oligohydramnios
The umbilical cord consists of one _____ and two ______
umbilical vein
umbilical arteries
Measure the ______ in a true axial plane of the abdomen, demonstrating the transverse spine, left-sided stomach, and umbilical vein entering into left portal vein.
abdominal circumference
Measurements are made along the ____ perimeter of the abdomen
outer
Echoes within the stomach can be associated with ______
swallowed blood
By week ___, the small bowel should not be herniated within the base of the umbilical cord.
12
An _____ has a covering, whereas the ______ demonstrates free-floating bowel within the amniotic fluid
omphalocele
gastroshisis
The internal structure of the fetal kidneys are not reliably assessed before __ to __ weeks
14-16
Polyhydramnios is common with _____
GI malformation
Oligohydramnios is common with ______
renal malformation
______ is the twisting of bowel around the blood supply
Midgut volvulus
The characteristic finding of duodenal atresias on both the radiograph and the prenatal sonogram is called the _____ sign
double bubble
The ______ presents as a dilated, echogenic mass or structure on sonographic examination
meconium ileus
The fetal organ that is usually not seen well is the second trimester is the:
pancreas
Left parasagittal views of the fetal abdomen demonstrate the:
stomach and left kidney
The umbilical vein can be followed in a sagittal view from the anterior abdominal wall into the:
liver’s left portal vein
The allantois is:
a. involved in early placental maturation
b. involved in early blood production
c. involved in the production of Wharton jelly
d. a permanent structure
b
After birth, the ductus venosus closes and becomes the:
ligamentum venosum
Fetuses of diabetic mothers often display:
increase abdominal circumference
A correct AC measure includes the:
soft tissue surrounding the ribs/spine
The spleen is part of the:
lymphatic system
In a fetus, the spleen in similar in echogenicity to the:
kidney
Herniation of the midgut resolves by week:
12
Complete situs inversus means the:
cardiac apex is on the right and liver on left
Duodenal atresia involves a fluid-filled stomach and duodenum at the site of obstruction, which demonstrates a(n):
“double-bubble” image
The descending colon wall-to-wall diameter measurement varies with fetal gestational age, but should not measure greater than __ in a preterm fetus
2 cm
Mean fluid volume of amniotic fluid in a 20 week is:
500 mL
Oligohydramnios is common with:
renal anomalies
Single umbilical artery is usually insignificant, but is mostly assocaited with all except:
a. gastrointestinal tract anomalies
b. renal and cardiac abnormalities
c. increased incidence of trisomy
d. pulmonary anomalies
d
Gastroschisis is a wall defect that typically occurs ____ the umbilical cord insertion.
to the right of
Ultrasound displays the fetal liver echotexture as:
homogenous
Fetal abdominal organs have attained their normal adult position and structure in the early ____ trimester.
second
The presence of intact skin surface covering vertebral bodies is helpful to rul out ______
myelomeningocele
The fetal abdominal wall displays an outer ___genic skin line and deeper, 1- to 3- mm _____echoic muscular layer.
echo
hypo
A two-vessel cord is most common in a ____ pregnancy.
twin
An abdominal circumference should be obtained at the level of the junction of the umbilical vein, _____, and fetal stomach
portal vein
Absence of the fetal gallbladder may be associated with biliary ____
atresia
Filling and emptying of the stomach occur causing absent stomach images, which requires ____ by a sonographer.
follow up
Midgut herniation is seen on an early fetus at the ______ portion of the embryo
ventral
Duodenal atresia is the failure of the duodenum to change from a solid _____ of tissue during development to a _____.
cord
tube
A _____ is an obstruction caused by the bowel twisting upon its blood suplly
volvulus
Meconium ileus is most often owing to ______
cystic fibrosis
The umbilical cord consists of ___ umbilical vein and ____ umbilical arteries
1
2
Echogenic bowel can be assocaited with swallowed _______
blood or vernix
An omphalocele has a membrane whereas gastrochisis doesn ot.
membrane
Midgut volvulus is usually diagnosed in the first days of life; the infant typically presents with ______
bilious vomiting
The internal structures of the fetal kidneys are not reliably assessed before _____ weeks
14-16
Esophageal maldevelopment is most related to the ____ gender.
male
An echogenic mass within the fetal gallbladder may be related to ____ or ____
sludge
gallstones
Diffuse liver calcifications occur in fetuses with intrauterine ____, especially those caused by pathogens responsible for _____ infections
infections
TORCH
Oligohydramnios and the stress of nonimmune hydrops may result in the physiologic absence of _____ fluid.
stomach
The most common fetal bowel obstructions
midgut volvulus
duodenal atresia
meconium ileus
Echogenic bowel is associated with all of the following except:
A. Fetal demise
B. Cytomegalovirus
C. Growth restriction
D. Beckwith Weidemann syndrome
D
Normal physiological bowel herniating normally resolves by:
12 weeks
Which of the following is often associated with duodenal atresia?
A. Trisomy 21
B. Trisomy 18
C. Trisomy 13
D. Triploidy
A
An excessive amount of amniotic fluid is termed:
Polyhedramnios
The most common abnormality of the liver is:
Hepatomegaly
Which of the following is associated with Echogenic bowel?
A. Fetal anemia
B. Cystic fibrosis
C. Radial ray syndrome
D. Portal hypertension
B
The stomach should be visualized by:
14 weeks
An abnormal connection between the duodenum and the trachea is termed:
Tracheoesophageal fistula
The congenital absence of part of the esophagus is termed:
Esophageal atresia
The double bubble sign is indicative of:
Duodenal atresia
Which of the following lab values would be significant in detection of an abdominal wall defect?
A. MSAFP
B. HcG
C. Maternal serum amylase
D. Estradiol
A
What is an inherited disorder in which mucus secreting organs such as the lungs, pancreas, and digestive organs produce thick and sticky secretions instead of normal secretions?
Cystic fibrosis
The fetal gut develops at the end of the fifth menstrual week and can be divided into allof the following except:
A. Midgut
B. Hindgut
C. Central gut
D. Foregut
C
Which of the following best describes a choledochal cyst?
A. Cystic dilation of the common bile duct
B. Herniation of the umbilical contents into the umbilical cord
C. Congenital absence of the cystic duct
D. Inflammation of the biliary tree due to obstruction
A
The congenital maldevelopment of the rectum and absence of anal opening in termed:
Anorectal atresia
Fetal mechoium typically consist of all of the following except:
A. Skin
B. Hair
C. Bile
D. Blood
D
The majority of amniotic fluid is composed of:
Fetal urine
What is the most common fetal abnormality noted during an obstetric sonogram?
Hydronephrosis