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