Chapter 26: Sonographic Assessment of the Fetal Chest Flashcards
From a volume dataset, static 3D images can display height, width, and depth of anatomy (three dimensions) from any orthogonal plane
3D imaging
Generalized edema in the subcuteaneous tissue
Anasarca
complete absence of a body part
aplasia
solitary cyst within the lung
bronchogenic cyst
an enlarged heart
cardiomegaly
an inflammation of the fetal membranes (amnion/chorion) caused by infection
chorioamnionitis
Birth defect of the diaphragm that allows the abdominal contents to enter the chest
congenital diaphragmatic hernia
replacement of normal lung by nonfunctioning cystic lung tissue
congenital multicystic adenomatoid malformation
Half-fourier acquisition single-shot turbo spine-echo; a fast spin method to obtain the MRI dataset.
HASTE
benign mass made up of blood vessels
hemangioma
accumulation of fluid in the fetal tissues, peritoneum, and pleural cavities caused by either immune or nonimmune factors
hydrops
areas of high intensity or increased brightness on the MRI image; equivalent to hyperechogenic
hyperintense
Areas of low intensity or increased brightness on the MRI image; equivalent to hypoechogenic
hypointense
underdevelopment or incomplete development of a body part
hypoplasia
fetal weight below the 10th percentile for gestational age
IUGR
area lying between the lungs, which contains the heart, aorta, esophagus, trachea, and thymus
mediastinum
genetic disorder causing extremely fragile bones
osteogenesis imperfecta
This group of findings, also called Potter syndrome, or oligohydramnios sequence, includes renal agenesis, obstructive processes, and acquired or inherited cystic disease
Potter sequence
incomplete development of the lung tissue
pulmonary hypoplasia
noncommunicating lung tissue that lacks pulmonary blood supply
pulmonary sequestration
semiautomated process to calculate volume using a 3D dataset
VOCAL
single large cyst, usually 3-7 cm but at least 2 cm; trabeculated wall with smaller cystic outpouchings; usually unilateral; may involve a lung lobe or part of a lung lobe; single large cyst with smaller cystic outpouchings visualized superior to the diaphragm in the fetal lung; can have echogenic areas within the cyst
Type 1 Cystic Adenomatoid Malformation
mass made up of multiple similar sized cysts, 1.5 cm in diameter; usually unilateral; may involve a lung lobe or part of a lung lobe; multiple similar sized cysts seen in the fetal lung replacing normal lung parenchyma
Type II Cystic Adenomatoid Malformation
Multiple small cysts (0.5-5mm); cysts too small to be resolved sonographically appear a single solid echogenic mass in the fetal lung
Type III Cystic Adenomatoid malformation
sonographic appearance of pulmonary sequestration
spherical mass; homogenous; echogenic; midline shift; vascular supply from aorta
Intrathoracic masses that compress the developing lung that can cause pulmonary hypoplasia
pleural effusion
pulmonary cyst
teratoma
meningocele
hemangioma
Abdominal masses that prevents downward displacement of the diaphragm or compresses developing lung that can cause pulmonary hypoplasia
ascites
renal mass
diaphragmatic hernia and its contents
Oligohydramnios with a lack of transmitted fluid pulsation on the chest wall that can cause pulmonary hypoplasia
bilateral renal agenesis or obstruction
bilateral ureteral obstruction
bladder outlet obstruction, usually urethral atresia
prolonged rupture of the membranes
small thorax as part of a skeletal dysplasia that can cause pulmonary hypoplasia
thanatophoric dwarfism
jeune syndrome
ellis-van creveld syndrome
hypophosphatasia
celidocranial dysotosis
metatropic dwarfism
campomelic dwarfism
causes of fetal immune hydrops
fetal anemia
Rh incompatability
Sonographic features of immune hydrops
hydrops fetalis
causes of nonimmune fetal hydrops
heart arrythmias/malformations
intrauterine infection
chromsomal abnormalities
masses causing venous obstruction
blood disorders
renal anomalies
maternal disease
sonographic features of nonimmune fetal hydrops
anasarca
pleural effusion
ascites
splenomegaly
thick placenta
polycystic kidneys
hydraps fetalis
sonographic findings of congenital diaphragmatic hernia
stomach, bowel, or other abdominal organs within the chest
peristalsis of structures within the chest
small abdominal biometry
descension and ascension of organs with fetal breathing
pleural effusion
polyhydramnios
The thorax is surrounded by the ____ and ____
spine
ribs
The thorax is separated from the abdominal cavity by the _____
diaphragm
The bony thorax consists of:
clavicles
ribs
scapulae
vertebral bodies
sternum
The thorax surrounds:
lungs
heart
mediastinum
Ossification of the clavicles occurs as early as:
8 weeks
ossification of the scapulae begins at:
10 weeks
Ossificiation of the sternum occurs between:
21 and 27 weeks
bright echoes at junction of fetal neck and thorax
clavicles
echogenic bands projecting in a fanlike pattern from the spine
ribs
echogenic, external to ribs, surrounded by hypoechoic musculature, sonographic appearance of Y or V shape
scapula
The muscles of the chest wall are:
hypoechoic and thin
TC measurements should be measured from ____ edge to ____ edge
outer
outer
TC measurements should be taken in a true transverse view:
just above the diaphragm at level of fetal heart
Significant decrease in lung volume is indicative of:
pulmonary hypoplasia
Pulmonary hypoplasia should considered if the heart appears to occupy more than ___ of the thorax
1/3
stages of development of the lungs
embryonic
pseudoglandular
canalicular
terminal saccular
alveolar
start development as diverticulum extending from tracheal bud; develop into two outpouchings, primary bronchial buds grow laterally into what will be the pleural cavity; buds join with primitive trachea to form the bronchi
embryonic phase of lung development
bronchi divide into secondary bronchi forming the lobar, segmental and intersegmental branches
pseudoglandular phase of lung development
All the segmental branches form between the ___ and ____ week
8
9
16th to 28th week; vascularization and teminal bronchioles increase in size; respiration becomes possible during 24th week because of development of terminal saccules
canalicular period of lung development
Respiration becomes possible during the:
24th week
26 weeks to birth; continued development of saccules; increase in ability of lung to perform gas exchange
terminal saccular period
overlaps terminal saccular period; 32 weeks to birth; surfactant production increases; branching of airways continues; blood-gas barrier thins
alveolar period
The lungs are separated by abdominal organs by the _____
diaphragm
Lung normal sonographic appearance
symmetrically, homogenous echotexture
Early in gestation, lung echogenicity is equal to or slightly less than the _____, as gestation progresses, echogenicity increases.
liver
gold standard to assess lung maturity
amniocentesis
use of a 3D dataset to obtain lung volumes
VOCAL
Low lung volume increases fetal risk of:
pulmonary hypoplasia
The diaphragm completes at end of week 8 with fusion of:
septum transversum
pleuroperitoneal membranes
dorsal mesentary of esophagus
muscular ingrowth from lateral body walls
At ___ days, the septum transversum close to caudal end of the embryo
24
At ___ days, the diaphragm is located mid embryo
52
thin, hypoechoic, dome shaped muscular band separating abdominal from thoracic cavity
diaphragm
The ________ contributes to formation of the thymus.
third pharyngeal pouch
The ____ descends from the superior mediastinum to its final located posterior to sternum.
thymus
The thymus is located posterior to _____ at the level of the great vessels of heart, and anterior to _____ and _____
sternum
aorta
pulmonary artery
located in the fetal neck anterior to trachea at level of third to sixth cervical vertebrae
the larynx
The larynx is best appreciated in the _______ view.
longitudinal coronal
accumulation of pleural fluid in the fetal lungs
pleural effusion
Pleural effusion may be associted with:
hydrops
congenital cardiac anomalies
chromsomal anomalies
polydactyl
Pleural effusion comprises ___% of all intrathoracic abnormalities
50
Intrathoracic masses
predominant cystic masses
multicystic adenomatoid malformation
aortic aneurysm
pulmonary sequestration
congenital lobar emphysema
neurenteric cyst
bronchial atresia
teratoma
Bronchogenic cysts may be ______ or _____
unilocular
multilocular
Result from abnormal budding of the ventral diverticulum of the primitive foregut
bronchogenic cyst
Lined by epithelium, and may contain cartilage, muscle, or mucus glands
bronchogenic cysts
Bronchogenic cysts may be found within ______ or ______
lung parenchyma
mediastinum
Bronchogenic cysts often communicate directly with the ______ or _____
trachea
main stem bronchi
excluding diaphragmatic hernias, most frequently identified mass in fetal chest
congenital cystic adenomatoid malformations
CCAM accounts for __% of lung malformations
25
CCAM is usually found in the _____ lobe of the lung
upper
adenomatoid increase in terminal respiratory elements leading to development of a pathologic mass consisting of multiple cysts of different sizes
CCAM
There are __ forms of CCAM
3
CCAM type ___ consists of a single cyst or multiple large cysts measuring 2-10 cm in diameter; trabeculated wall and smaller cystic outpouchings; broad, fibrous septa and mucin-producing cells may be responsible for areas of echogenicity
I
CCAM type ___ consists of a mass effect, made up of multiple, uniform-sized cysts 0.5 to 2 cm in diameter; cysts resemble bronchioles
II
CCAM type ___ consists of multiple microscopic cysts measuring between 0.5 and 5mm; present numerous reflecting surfaces; cannot be resolved individually, appear as a single, solid homogenously echogenic mass
III
CCAM is associated with _____ and _____ anomalies.
cardiac
gastrointestinal
Anomalies occur more often with type __ CCAM
II
Because of compression on lungs, fetuses with CCAM may also present witH:
fetal hydrops
ascites
polyhydramnios
Fetuses with greater than normal thoracic diameter and an inversion of the diaphragm have indications of ____
CCAM
Type ____ CCAM has a poor prognosis
III
____% of fetuses with CCAM will be born with respiratory distress
80
unilateral pulmonary mass with one or more large cysts
Type I CCAM
an echogenic mass containing small cysts
Type II CCAM
homogenous echogenic mass
Type III CCAM
Color Doppler arterial supply is via the _______ vessels for CCAM
pulmonary
____ has a higher accuracy for classification of CCAM
MRI
Differential diagnosis for type I and II CCAM
cystic lung and mediastinal masses
pleural and pericardial effusions
Differential diagnosis for type III CCAM
pulmonary sequestration
rhabdomyoma
mediastinal teratoma
herniated abdominal contents
also known as bronchopulmonary sequestration
pulmonary sequestration
solid, nonfunctioning mass of lung tisse contained within the pleural sac that lacks communication with the tracheobronchial tree and has a systemic arterial blood supply
pulmonary sequestration
Pulmonary sequestration accounts for ___% of lung lesions
pulmonary sequestration
The ______ type pulmonary sequestration can be above or below the diaphragm and has its own pleural sac and systemic venous drainage
extralobar
spherical, homogenous, highly echogenic, often found at lung base or just inferior to diaphragm, abnormal vascular supplies arising from thoracic or abdominal aorta
intralobar pulmonary sequestration
herniation of meninges and brain through a defect in the calvarium
cephalocele
predominantly cystic masses; may or may not contain echogenic brain or spinal cord
myelomeningoceles
often associated with fetal hydrops; increased soft tissue thickness; forms halo pattern around neck, thorax, abdomen
fetal edema
presence of excessive abnormal skin or soft tissue in nuchal area is associated with:
trisomy 21
If the nuchal area thickness is __ mm or greater between 14 and 18 weeks it can be associated with trisomy 21
5
If the nuchal area thickness is __ mm or greater between 19 and 24 weeks it can be associated with trisomy 21
6
benign abnormalities of lymphatic organ; result of failure of development of normal lymphatic venous communication; most common abnormality seen in the first trimester
cystic hygromas
___% of cystic hygromas develop in the posterolateral neck
80
may be associated with cardiac dilatation because of presence of arteriovenous shunting and increased blood return to the heart
Large hemangiomas
webbed neck; most common abnormal fetal karyotype with cystic hygroma
Turner syndrome
mixed with cystic and solid components; may increase in size during pregnancy and become more echogenic or solid in appearance
teratoma
benign neoplastic overgrowth of normal cellular elements of an affected area; usually arise within a rib; may have disproportionately large intrathoracic component capable of displacing the fetal heart and causing respiratory insufficiency
hamartomas
abnormal or lack of development of lung; associated with oligohydramnios
pulmonary hypoplasia
______ syndrome includes renal conditions: agenesis, obstructive processes, acquired or inherited cystic disease
Potter
small chest cavity in relation to larger abdominal cavity; heart that occupies more than 1/3 of the fetal chest; TC/AC ratio below 0.77
lung hypoplasia
Normal TC/AC ratio
0.89
extrapericardial and intrapericardial teratoma; lymphangioma; thymic cyst; mediastinal meningocele
mediastinal masses
can be caused by compression on esophagus by a mass
polyhydramnios
also known as hydrothorax
pleural effusion
milky fluid consisting of lymph and fat; anechoic, seroous
chylous
accumulation of lymph within chest
chylothorax
Chylothorax is more common in _____ and most often located on the ____ side
male
right
known as eryhtroblastosis
immune fetal hydrops
occurs in a fetus whose mother has been sensitized
immune fetal hydrops
Immune fetal hydrops is usually determined through ______ or _______
amniocentesis
cordocentesis
condition resulting from a variety of severe fetal diseases; not associated with incompatability of fetal maternal blood; usually fatal; occurs in over half of fetuses with chromosomal abnormalities
nonimmune fetal hydrops
polyhydramnios is a warning sign of:
fetal distress
defect of the diaphragm that allows contents of abdomen to migrate into the thorax
congenital diaphragmatic hernia
The origin of congenital diaphragmatic hernia is:
flawed formation or fusion of diaphragm
posterolateral herniation through foramen of Bockdalek; accounts for over 90% of herniations; usually on the left side
congenital diaphragmatic hernia
restrosternal, anteromedial herniation through foramen of Morgagni
congenital diaphragmatic hernia
Protrusion of bowel through diaphragm
eventration
smaller than normal AC measurement; breathing-abdominal organs may descend on normal side and paradoxically ascend on affected side; polyhydramnios, pleural effusions
congenital diaphragmatic hernia
different diagnoses congenital diaphragmatic hernia
CCAM
pulmonary sequestration
bronchogenic cyst
teratomas
neurenteric cysts
bronchial atresia
Overall mortality of congenital diaphragmatic hernia is __-__%
50
80
Surgical intervention of congenital diaphragmatic hernia by ___ weeks improves prognosis
24
Obtain thoracic measurements from a true transverse view just above the diaphragm at the level of the:
fetal heart
Sonography is not reliable to indicate fetal lung maturity; _____ remains the gold standard for this assessment
amniocentesis
The _____ is located at the level of the great vessel of the heart, anterior to the aorta and pulmonary artery
thymus
_____ is the most frequently found mass within the fetal chest
CCAM
To differentiate pulmonary sequestration from CCAM, use:
color Doppler to trace the origin of the feeder vessel
______ is usually a secondary condition related to oligohydramnios found within renal anomalies
Pulmonary hypoplasia
_______ has the same sonographic appearance regardless of whether it is caused by an immune or nonimmune condition
fetal hydrops
The ____ enlarges with immune fetal hydrops and infections
spleen
The fetal chest should be evaluated for all except:
a. L 1-5
b. heart
c. diaphragm
d. bony symmetry
a
Routine observation of fetal breathing movements in the ____ trimester(s) should be included in the fetal examination.
second and third
The thoracic inlet is at the:
base of the neck, level of the clavicles
The fetal heart lies with the apex oriented toward the:
spleen
A break in the skin surface directly over the spine is associated with:
myelomeningocele
Thoracic chest measurements (outer edge to outer edge) are obtained from a true transverse view at the level of the:
fetal heart
If the fetal heart (in transverse view) occupies more than 1/3 of the thorax, ______ should be considered:
pulmonary hypoplasia
Fetal lung development begins in what week?
fourth
Respiration becomes possible during the _____ week because of the development of terminal saccules.
24th
Fetal lung volume can be estimated by all except:
a. MRI
b. VOCAL
c. 3D data set
d. 2D coronal
d
Successfully locating the oropharnyx and laryngeal pharynx is accomplished with a:
longitudinal view through the upper neck and fluid-filled pharynx
Lung masses include all except:
a. CCAM
b. aortic aneurysm
c. teratoma
d. pulmonary atresia
d
CCAM typically appears as all except:
a. a bilateral large predominantly cystic mass of the lower lobes
b. a unilateral pulmonary mass with one or more large cysts
c. an echogenic mass containing small cysts
d. a homogeneous echogenic mass
a
The presence of abnormal and excessive skin or soft tissue in the nuchal area is well known and common clinical finding in many newborns with Trisomy 21 and is suspect if the nuchal fold measures:
6 mm or greater 19-24 weeks
Fetal posterolateral neck thickening may be caused by all except:
a. absent clavicles
b. failure of the lymphatic channels to communicate
c. nuchal skin thickening
d. Turner syndrome
a
The most accurate term for a collection of lymph within the chest is termed:
chylothorax
Nonimmune fetal hydrops is related to:
severe anemia
The AC measurement in a fetus with CDH is _____ than normal.
smaller
The correct area to obtain a thoracic measurement is from a true transverse view just above the ______ at the level of the _____
diaphragm
fetal heart
_______ is the gold standard for indication of fetal lung maturity
amniocentesis
The ______ is located at the level of the great vessel of the heart, anterior to the aorta and pulmonary artery.
thymus
The typical scapula has a sonographic appearance of a ____ or _____ shape, depending on the angle of insonation.
Y
V
The muscles of the chest wall are ______ and thin
hypoechoic
The lungs are separated from these abdominal organs by the ______
diaphragm
______ remains the gold standard in assessing lung maturity.
Amniocentesis
The fetal diaphragm is seen as a thin, hypoechoic, dome-shaped muscular band separating the _____ cavities from echogenic _____ tissue.
abdominal
lung
Pleural effusions are an accumulation of ______ fluid in the fetal lungs.
pleural
To differentiate pulmonary sequestration from CCAM, use color Doppler to trace the origin of the _______
pulmonary artery
Both fetal edema and cystic hygroma have an increased connection with ______ abnormalities
karyotype
Cystic hygromas are thought to be a result of a failure in the development of normal ______ venous communication.
lymphatic
Compression on the esophagus by a mass could lead to ________ because of GI tract obstruction.
polyhydramnios
Mass compression on the vena cava may compromise blood return to the fetal heart and lead to the development of _____
fetal hydrops
The thymus is located at the level of the great vessel of the heart, ______ to the aorta and pulmonary artery.
anterior
The ______ enlarges with immune fetal hydrops and infections.
abdomen
______ is the most frequently found mass within the fetal chest.
CCAM
Imaging the diaphragm can help differentiate cystic intrathoracic masses of pulmonary origin from those that are of ______ origin.
extrathoracic
