Module 7 : Fetal Chest Pathology Flashcards
contents of the chest
- lung
- heart
- muscle and diaphragm
- trachea
- esophagus
- ribs
what is the diaphragm
- hypo echoic liner structure between lungs and abdomen
- easier to see in later gestations
- note shape and continuity
- usually visualized on parasagittal scans
why is the diaphragm hypo echoic
- lung tissue is filled with fluid and collapsed so diaphragm appears hypo echoic
fetal lungs
- homogenous
- echogenicity compared to liver can be
+ isoechoic
+ hyperechoic
fetal heart position and chamber
- 4 chambers
- occupies 1/3 of the fetal chest
- apex points to the left with axis about 45º
9 lung pathology
- pulmonary hypoplasia
- congenital cystic adenomatoid malformation (CCAM)
- congenital pulmonary airway malformation (CPAM)
- pulmonary sequestration
- bronchogenic cyst
- diaphragmatic hernia
- pleural effusions
- tracheal atresia
- esophageal atresia
pulmonary hypoplasia
- when one or both lungs are underdeveloped
- can be lethal
- fetuses < 24 weeks are not considered viable due to pulmonary immaturity
causes of pulmonary hypoplasia at term
- restricted chest cage \+ some skeletal dysplasia - decreased amniotic fluid - chest masses - pleural effusion
what is the most frequent cause of pulmonary hypoplasia
- due to lack of fluid
+ PROM = premature rupture of membranes
+ GU anomalies = genitourinary
amniotic fluid things
- produced by membranes until fetal kidney begin to produce urine
- fetus swallows amniotic fluid
- fluid goes through the GI track absorbed by the GI track excreted by the kidneys as urine fetus urinates back into the amniotic cavity
cause of polyhydramnious and oligohydramnios
- poly= any high GI obstruction/swallowing deficits
- oligo = any bilateral GU obstruction/renal agenisis
thoracic/ chest circumference
- method to predict pulmonary hypoplasia
- transverse chest circumference at level of 4 chamber heat
- measure outer to outer
+ except in cases of skin edema/hydrops
congenital cystic adenomatoid malformation CCAM
- now called CPAM \+ congenital pulmonary airway malformation - three classifications \+ type I, type II, type III - type of hamartoma (1 lobe effected) - communicates with tracheobronchial tee - large may see mediastinal shift -
what is CPAM associated with
- hydrops
- pulmonary hypoplasia
- polyhydramnious
type I CPAM
- macrocystic
- > 2cm
type II CPAM
- macro and microcystic
+ < 1.5cm
type III CPAM
- microcystic
- monographically hyperechoic
prognosis and treatment of CPAM
- depends on mediastinal shift and hydrops
- may regress or disappear on its own
- no intervention is performed unless hydrops is noted
- may drain cyst or surgically resect the mass
DDX of CPAM
- sequestration
- bronchogenic cysts
- CDH = congenital diaphragmatic hernia
pulmonary sequestration characteristics
- a mass of ectopic pulmonary tissue covered by its own pleura
- no communication of this tissue with bronchial tree
- ectopic ARTERIAL supply
+ off descending aorta - venous to systemic system not pulmonary veins
- usually left lung base
sonographic appearance of pulmonary sequestration
- uniform hyperechoic mass
- associated with hydrops and polyhydramnios
- look for FEEDING ARTERY OFF THE AORTA
- prognosis is good unless associate with hydrops
- often resolve on their own
DDX of pulmonary sequestration
CCAM III
bronchogenic cysts characteristics
- cyst in lung lined with bronchial epithelium
what is bronchogenic cysts associated with
- associated with foregut anomalies
+ TE fistula
+ lung sequestration
sonographic appearance of bronchogenic cysts
- uni/multilocular cyst
- mediastinal shift
DDX of bronchogenic cysts
CPAM I
* cannot differentiate between the two
diaphragmatic hernia characteristics
- a defect in the diaphragm which allows abdominal contents to herniate up into the chest \+ intestines \+ stomach \+ liver - causes pulmonary hypoplasia
two major types of diaphragmatic hernias
- foramen of bochdalek
- foramen of maorgagni
foramen of bochdalek
- posterior lateral defect
- MORE COMMON OF LEFT
foramen of bochdalek - left hernia
- may see stomach or intestines in chest
- lung with absence of diaphragm + mediastinal shift
foramen of bochdalek - right hernia
- may see liver in chest
- difficult to recognize liver from lung
- may not appreciate mediastinal shift
- leads to pulmonary hypoplasia
foramen of morgangi
- partial or complete absence of the central diaphragm
- usually liver herniated
+ may see portal flow in chest - MEDIASTINAL SHIFT EVEN THOUGH HEART IS STILL ON LEFT SIDE THE AXIS WILL BE SHIFTED
CDH on sonography
- mediastinal shift \+ KEY SONGRAPHIC SIGN - cystic component in fetal chest \+ difficult to catch \+ only if fetus has recently swalloed - diaphragm no intact on sagittal scans - stomach not seen in abdomen
what is eventuation of the diaphragm
- lacks muscle therefore the abdominal contents push into chest area
- may causes pulmonary hypoplasia
what are pleural effusions
- any amount of pleural fluid is abnormal in any gestations
- if large can cause pulmonary hypoplasia
- appear as sonolucent fluid collection
- may displace lung toward midline
2 types of pearl effusions
- serous
- chylous
serous pleural effusion
- sign of hydrops
- associated with downs and turners
chylous pleural effusion
- lymphatic fluid
sonographic appearance of pleural effusion
- cystic collection above the diaphragm
- unilateral = may cause mediastinal shift
- may invert diaphragm
treatment of pleural effusions
- hydrothorax and chylothorax
+ thoracentisis
+ shunt fluid into abdomen or amniotic cavity
+ may resolve on their own
what is tracheal atresia
- congenitally non patent airway
- tiny amount of fluid is produced in fetal lungs and cannot get out
sonographic appearance of tracheal atresia
- bilaterally enlarged lungs with distended airways
- flat diaphragms
- ascites and polyhydramnios
what is esophageal atresiA
- congenitally non patent esophagus
- often associated with TE fistula
- associated with Down syndrome and VACTERL
sonographic appearance of esophageal atresia
- no stomach bubble
- cystic structure in neck (disappears)
- may note polyhydramnious
4 chest wall shape abnormalities
- narrow
- long
- bell shaped
- dwarfism (skeletal dysplasia)
- may cause pulmonary hypoplasia
what is ectopia cords
- anterior chest wall fusion defect
- heart outside of cavity
the pentology of cantrell
- sternum defects
- anterior diaphragm defects
- pericardium defects
- ectopia cordis with heart defects
- omphalocele
