359 - Ch 61 Fetal Thorax; Ch 62 Fetal Anterior Abdominal Wall
Sono signs of omphalocele:
-central abdominal wall defect w/ herniation into base of umbilical cord -evisceration of bowel -combination of liver and bowel
In the normal fetus, the diaphragm should appear as:
-curvilinear hypoechoic structure -coursing anteriorly to posteriorly
When a cystic or solid lung mass is identified in a fetus, the sonographer should attempt to:
-determine number and sizes of cystic structures -check for presence or absence of mediastinal shift -identify and assess the size of lungs -look for fetal hydrops -exclude cardiac masses -search for other fetal anomalies
Thoracic cavity masses have what detrimental effects on lung development?
-heart & mediastinal structures displaced -lung may be compressed and destroyed
What are the sonographic features of a left congenital hernia?
-intrathoracic stomach -displaced cardiac apex -cardiomediastinal shift -intrathoracic liver and/or intestine -small left lung -small left ventricle of heart
Normal sono characteristics of of the thoracic cavity:
-ribs form lateral margins -clavicles form upper margins -diaphragm forms lower margin -lungs serve as lateral borders for heart & lie superior to the diaphragm
Sono appearance of gastroschisis
-right paraumbilical defect of abdominal wall -free-floating herniated small bowel
Lung masses are:
-separate from the heart -located above the level of the diaphragm -may be cystic, solid, complex
How do cystic lung masses appear sonographically?
-small circumscribed masses -without evidence of mediastinal shift
These methods are used to determine the presence of pulmonary hypoplasia:
-thoracic measurements -various lung measurements (estimation of lung volume) -doppler studies of pulmonary arteries -assessment of fetal breathing activity
CCAM Type II lesions measure less than ___
1 cm
The heart should fill ___ of the thoracic cavity
1/3
At what week do intestines return to the abdominal cavity?
12th
CCAM Type 1 lesions measure more than ___ and up to ____
2 cm; 10 cm
Size of gastroschisis defect:
2-4 cm
Fetal breathing becomes most prominent in the ______ trimesters
2nd and 3rd
Chromosomal anomalies occur in ____ percent of omphaloceles
35-60
Normal cardiac axis is ____
45 degrees
By the end of the ____ week of development, the embryo is a flat disk consisting of 3 layers
5th
In the ____ week, folding helps the embryo transform itself into a cylindrical shape
6th
What is the prognosis for pulmonary hypoplasia?
80% of affected die after birth
Umbilication hernia of the bowel occurs during the ____ week of development
8th
T/F Cord insertion is normal with an omphalocele
False
T/F Gastroschisis has a membrane
False
T/F The abdominal cavity grows faster than the midgut at around the 8th week of development
False
T/F extra lung tissue from a pulmonary sequestration is functional
False
T/F CCAM lesions are usually bilateral
False - unilateral
T/F CCAM usually affects all lobes
False - usually only one lobe
T/F Cystic lung masses are small isolated lesions
False - vary from small isolated lesions to large cystic masses
T/F A pulmonary sequestration rarely occurs below the diaphragm
True
T/F CCAM lesions may involve one or more lobes, or the entire lung, or be bilateral
True
T/F Cloacal exstrophy is rare and more complex than bladder exstrophy
True
T/F Folding of the embryo is critical in the process of closing the abdominal wall
True
T/F Insertion of umbilical cord is normal in fetuses with gastroschisis
True
T/F Most cases of beckwith-wiedemann syndrome are sporadic
True
T/F Omphaloceles often occur with chromosomal abnormalities
True
T/F Pulmonary sequestration is normal intra-abdominal anatomy
True
T/F Simple cystic lung masses may be surgically removed after delivery
True
T/F Stomach may be involved in an omphalocele
True
T/F Thorax circumference excludes the skin and subcutaneous tissues
True
Which type of CCAM is macrocystic, large, and replaces normal lung tissue?
Type I
Which type of CCAM is macrocystic with a microcystic component and consists of small cysts?
Type II
Which type of CCAM appears as echo-dense masses of the entire lung lobe?
Type III
Which type of CCAM is characterized as bulky, large and noncystic?
Type III
What is the single most important determinant for fetal viability?
adequacy of pulmonary development
A rare group of disorders having in common the coexistence of omphalocele, macroglossia and visceromegaly
beckwith-wiedemann syndrome
___________________ is characterized by a defect in the lower abdominal wall and anterior wall of the urinary bladder
bladder exstrophy
What is the most common lung cyst?
bronchogenic cyst
In the normal fetus, the stomach and liver should be identified ________ to diaphragm
caudal
In the normal fetus, lungs and heart should be positioned ____________
cephalad
This condition results in exstrophy of the bladder in which two hemibladders are separated by the intestine
cloacal exstrophy
Multicystic mass within the lung consisting of primitive lung tissue and abnormal bronchial structures
congenital cystic adenomatoid malformation (CCAM)
Herniation of abdominal viscera into chest that results from congenital defect in fetal diaphrgam
congenital diaphragmatic hernia
As the embryo folds at the _________ end, the base of the yolk sac is partially incorporated as the foregut
cranial
Echo-free masses that replace normal lung parenchyma
cystic lung masses
Pulmonary hypoplasia is caused by:
decrease in number of lung cells, airways and alveoli
How do solid lung masses appear sonographically?
echo-dense masses in lung tissue
How does pleural effusion appear sonographically?
echo-free peripheral masses on one or both sides of fetal heart
How does a pulmonary sequestration appear on US?
echogenic solid mass resembling lung tissue
By the end of the 5th week of development, the embryo consists of what 3 layers?
ectoderm mesoderm endoderm
Extra pulmonary connected to inferior border or the lung within its own pleural sac
extralobar
On US, the diaphragm can be seen between the _______ and the ______
fetal liver; lungs
An opening in the layers of the abdominal wall with evisceration of small bowel
gastroschisis
Periumbilical defect nearly always located to the right of the umbilicus
gastroschisis
What are the 3 most common types of abdominal wall defects?
gastroschisis omphalocele umbilical hernia
How do the fetal lungs appear sonographically?
homogeneous w/ moderate echogenicity
Pulmonary sequestration is associated with:
hydrops polyhydramnios diaphragmatic hernia GI anomalies
Fetal respiration is stimulated by:
increased sugar decreased smoking
Extra pulmonary tissue present within the pleural lung sac
intralobar
What is the first sign of a left congenital hernia?
intrathoracic stomach
CCAM Type III:
large, bulky, noncystic lesions producing mediastinal shift; poor prognosis
A congenital diaphragmatic hernia is usually found on the _______ side of the diaphragm
left
The apex of the fetal heart should be directed toward the ______
left
In a congenital diaphragmatic hernia, _____________ enter the chest through an opening
left-sided organs
Compression of ________________ may cause pulmonary hypoplasia
lung parenchyma
The central portion of the thorax is occupied by the ___________
mediastinum
The majority of the heart is positioned in the ________
midline
CCAM Type II:
multiple small cysts, <1 cm in diameter, echogenic; high incidence of other congenital anomalies (renal, GI)
When bowel loops fail to return to the abdomen by the 12th weeks, ______________ occurs
omphalocele
Bladder exstrophy is accompanied by:
omphalocele inguinal hernia undescended testes anal problems
Pulomary hypoplasia results in a decrease in _______ and ________
organ size; weight
Which pathology is considered when fetus presents with a large omphalocele, diaphragmatic hernia, ectopia cordis and other heart defects?
pentalogy of Cantrell
A membrane consisting of the ___________ and _______________ forms an omphalocele
peritoneum; amnion
The foregut later develops into:
pharynx lower respiratory system esophagus stomach duodenum liver pancreas GB biliary duct system
Accumulation of fluid within pleural cavity that may appear as isolated lesion or secondary to multiple fetal anomalies
pleural effusion (hydrothorax)
In CCAM Type III, _______________ may occur secondary to esophageal compression
polyhydramnios
Associated _____________ and _________ with CCAM have a poor prognosis
polyhydramnios; anasarca
Hernia differs from omphalocele in that:
protruding mass is covered by subcutaneous tissue and skin
________________ is a major reason why retuses younger than 24 weeks are generally considered nonviable
pulmonary immaturity
Supernumerary lobe of the lung, separated from normal tracheobronchial tree
pulmonary sequestration
Fetal breathing movements are documented if ________________________ is demonstrated
seesaw movements of fetal chest or abdomen
CCAM Type I:
single or multiple large cysts 2 cm in diameter; good prognosis after resection of affected lung
The midgut develops into:
small intesting cecum vermiform appendix ascending colon part of transverse colon
The thorax is normally slightly __________ than the abdominal cavity
smaller
The diaphragm may be observed on US as a:
smooth hypoechoic muscular margin
Thorax circumference measurements are made in the __________ plane at the level of the ____________
transverse; 4ch heart view
This forms when intestines return normally to the abdominal cavity and herniate either prenatally or postnatally through the umbilicus
umbilical hernia
Severity of pulmonary hypoplasia depends on ________________________ and ___________________
when it occurred during pregnancy; it's severity and duration
Where are bronchogenic cysts usually located?
within the mediastinum or lung
Growth of the neural tube causes the embryo to fold at the caudal end, incorporating part of the __________ as the hindgut
yolk sac
