Ch. 60 The Fetal Thorax

Question 1

what is the most important determinant for fetal viability?

Answer 1

pulmonary development

Question 2

at birth fluid in the lungs is expelled through 3 routes. what are these routes?

Answer 2

1. mouth and nose
2. pulmonary capillaries
3. lymphatics and pulmonary vessels

Question 3

what 3 planes is the thorax examined in?

Answer 3

transverse, coronal, parasagittal

Question 4

a fetus with a narrow chest diameter may have what?

Answer 4

asphyxiating thoracic dystrophy

Question 5

the apex of the heart should be directed towards ___________ at an axis that is _____ degrees from midline

Answer 5

left chest wall

45

Question 6

the base of the heart lies _______ to the diaphragm

Answer 6

horizontal

Question 7

why is the location of the heart important?

Answer 7

to indicate presence of chest mass, pleural effusion, or cardiac malformation

Question 8

when will fetal breathing become more prominent?

Answer 8

second and third trimesters

Question 9

where can color doppler detect fetal breathing?

Answer 9

through the nostrils

Question 10

4 reasons the lungs will not develop properly

Answer 10

1. oligohydramnios
2. small chest cavity
3. balance between tracheal and airway pressure and fluid volume is inadequate
4. fetus unable to practice breathing movements

Question 11

what causes pulmonary hypoplasia?

Answer 11

decrease in lung cells, airways, and alveoli resulting in decreased organ size and weight

Question 12

occurs from prolonged oligohydramnios or is secondary to a small thoracic cavity

Answer 12

pulmonary hypoplasia

Question 13

4 masses that cause pulmonary hypoplasia

Answer 13

1. pleural effusion
2. diaphragmatic hernia
3. cystic adenomatoid malformation
4. bronchopulmonary sequestration

Question 14

most common lung cyst detected prenatally

Answer 14

bronchogenic cyst

Question 15

sonographic appearance of bronchogenic cyst

Answer 15

small circumscribed mass without mediastinal shift or heart failure

Question 16

fluid within the pleural cavity that appears as an isolated lesion is called what?

Answer 16

pleural effusion or hydrothorax

Question 17

sonographic appearance of pleural effusion

Answer 17

echo-free peripheral masses on one or both sides of fetal lung

Question 18

compression of lung may cause what?

Answer 18

pulmonary hypoplasia (which leads to life-threatening consequences for neonate)

Question 19

what is pulmonary sequestrian?

Answer 19

supernumerary lobe of lung separated from the normal tracheobronchial tree

Question 20

sonographic appearance of pulmonary sequestrian

Answer 20

echo-dense solid mass resembling lung tissue

Question 21

extralobar defects occur on the _____ side and are _______ or _______ shaped

Answer 21

left
cone
triangular

Question 22

intralobar lesions are _____ shaped

Answer 22

spherical

Question 23

what is congenital cystic adenomatoid malformation

Answer 23

multicystic mass within the lung consisting of primitive lung tissue and abnormal bronchial structures

Question 24

what is the first form of cystic adenomatoid malformation?

Answer 24

CCAM type I: one or more large cysts replace normal lung tissue

Question 25

what is the second form of cystic adenomatoid malformation?

Answer 25

CCAM type II: lesions consist of multiple small cysts

Question 26

what is the third form of cystic adenomatoid malformation?

Answer 26

CCAM type III: bulky, large, noncystic lesions appearing echo-dense

Question 27

what 6 sonographic findings should you attempt when you find a lung mass

Answer 27

Determine number and size of cystic structures Check for presence or absence of a mediastinal shift Identify and assess lung size Look for fetal hydrops Exclude cardiac masses Search for other fetal anomalies

Question 28

what is congenital bronchial atresia

Answer 28

rare pulmonary anomaly that results from obliteration of a segment of the bronchial lumen

Question 29

where is congenital bronchial atresia commonly found?

Answer 29

left upper lobe

Question 30

when does the diaphragm form

Answer 30

between 6th and 14th week

Question 31

the fusion of what 4 structures causes the diaphragm to form

Answer 31

1. septum transversum 2. pleuroperitoneal membranes 3. dorsal mesentery of esophagus 4. body wall

Question 32

congenital diaphragmatic hernia is

Answer 32

a herniation of the abdominal viscera into the chest that results from a congenital defect in the fetal diaphragm

Question 33

the most common type of diaphragmatic defect occurs through

Answer 33

the foramen of Bochdalek posteriorly and laterally

Question 34

if a diaphragmatic hernia occurs anteriorly and medially it goes through

Answer 34

the foramen of Morgagni and may communicate with the pericardial sac

Question 35

prognosis for fetus is poor with diaphragmatic hernia is (4)

Answer 35

1. hernia is detected before birth 2. stomach is found in chest 3. left heart is underdeveloped 4. congenital heart disease is present

Question 36

6 associated abnormalities of diaphragmatic hernia

Answer 36

1. cardiac malformations 2. CNS malformations 3. renal anomalies 4. vertebral defects 5. pulmonary hypoplasia/ face clefts 6. chromosomal abnormalities

Question 37

what is the mortality rate for diaphragmatic hernia and why?

Answer 37

75% because of increased frequency of coexisting anomalies