M7: Fetal Chest Pathology Flashcards
How does the diagram appear on US
Hypoechoic linear structure b/w the lungs and abdomen
Why is the diaphragm hypo?
There’s no air in the lungs, and some fluid
When is the diaphragm easiest to see
Is what view?
Later gestation
Parasagittal scans
Echogenicity of fetal lung tissue
Echgenicity compared to liver
Homogenous
Isoechoic
Hyperechoic
What do we assess when scanning the heart (in general)
4 chambers
That it occupies 1/3 of the fetal chest
Apex points to the left w/ axis at about 45 degrees
What must you always do when scanning the heart
Zoom and sector down
What is pulmonary hypoplasia
Can it be lethal
When one or both lungs are underdeveloped
Yes
Fetuses under how many weeks are not considered viable w/ pulmonary hypoplasia
24
Which drugs given in utereo can help w/ the exchange of 02
Steroids
Possible causes of pulmonary hypoplasia
Restricted chest cage w/ skeletal dysphasia
Decrease amniotic fluid
Chest masses
Pleural
Most common cause of pulmonary hypoplasia
Lack of fluid, causes by PROM and genitourinary anomalies
US methods to predict pulmonary hypoplasia
- measure (outer to outer) the TRX chest circumference at the level of the 4CH view
When would you not measure outer-outer when doing a chest circumference measurement
If the fetus has Edema/hydrops
What is CCAM/CPAM
Congenital cystic adenomatoid malformation / congenital pulmonary airway malformation
It’s a type of hamartoma that usually effects 1 lobe of the lung and communicates w/ the tracheobronchial tree
3 classifications of CPAM
Type 1, 2, and 3
CPAM is associated with which conditions
Hydrops
Pulmonary hypoplasia
Polyhydramnious
If the CPAM is large what might it cause
Mediastinal shift
What is a hamartoma
Overgrowth of tissue
Describe type 1 CPAM
Macrocystic w/ cysts >2cm
Describe type 2 CPAM
Macro and microcystic, cysts are smaller than 1.5 cm
Describe type 3 CPAM
Microcystic, will see multiple interfaces and lungs will be echogenic
The heart will also be very displaced
Prognosis for CPAM
-Depends on mediastinal shift and hydrops
Can CPAM disappear on its own
Yes
Is intervention usually need for CPAM
No, unless hydrops in seen
But cysts may be drained or masses may be surgically resected
DDX for CPAM
Sequestration
Bronchogenic cyst
Congenital diaphragmatic hernia (CDH)
What is pulmonary squestation
A mass of ectopic pulmonary tissue, covered by its own pleura
Does pulmonary squestation tissue communicate w/ the bronchial tree
No
Where does pulmonary squestation get its blood supply
An ectopic arterial supply that branches off the descending AO
Venous drainage is to the systemic system, not the pulmonary veins
Does pulmonary squestation occur more commonly in the L or R lung
Left
US appearance of pulmonary squestation
Uniform hyperechoic mass
Look for artery feeding off the AO
pulmonary squestation is associated w/ which conditions
Hydrops and polyhydramnious, secondary to the mass effect
Prognosis for pulmonary squestation
Good unless associated w/ hydrops
Does pulmonary squestation often resolve on it own
Yes
Ddx for pulmonary squestation
CPAM III
What’s the mass effect w/ pulmonary squestation
Mass pushing on the heart and mediastinum
How can you differentiate b/w pulmonary squestation and CPAM on US
pulmonary squestation will have the branch feeding off the artery
What is a bronchogenic cyst
A cyst in the lung, lined w/ bronchial epithelium
Bronchogenic cysts are associated w/ what anomalies
TE fistula
Lung sequestration
US appearance of Bronchogenic cysts
Uni/multiocular cyst
Mediastinal shift
DDX for Bronchogenic cysts
CPAM type 1
Describe a diaphragmatic hernia
2 types
A defect in the diaphragm that allows the abdo contents to herniate up into the chest
- foramen of bochdalek
- foramen of maorgagni
Which structures can herniate into the chest
Intestines
Stomach
Liver
Which side do diaphragmatic hernias usually occur
Left
prognosis for diaphragmatic hernia
good if theres no other anomalies
describe a foramen of bochdalek hernia
- posterolateral defect in the diaphragm, more commonly on the L side
- can be a hole in the diaphragm, or it can be intact but weak
what may you see w/ a left foramen of bochdalek hernia
- stomach or intestines in chest (look for parastalsis)
- lung w/ absence of diaphragm + mediastinal shift
what may you see w/ a right foramen of bochdalek hernia
- liver in chest which is hard to tell apart from the lungs (use colour)
- may not see mediastinal shift as much
a mediastinal shift is always to what side
right
describe a foramen of morgagni hernia
it usually involves which organ
-partial or complete absence of central diaphragm (think midline b/c of gag reflex)
liver
is there a mediastinal shift w/ a foramen of morgagni hernia
yes, but heart is still on L side
which type of diaphragmatic hernia is more common
bochdalek
key US sign of CDH
other signs
mediastinal shift
cystic components in fetal chest
diaphragm not intact on SAG scan
stomach not seen in the abdo
what is the cystic component in the fetal chest w/ CDH
is it hard to see
the stomach, or bowel
yes, can only see if fetus has been swallowing
what does CDH cause
pulmonary hypoplasia
is pleural fluid in the lungs always abnormal
what can happen if its a large collection
yes,
can cause pulmonary hypoplasia
define hydrops
fluid in 2 body cavities, or fluid in 1 cavity w/ edema
2 types of pleural effusion
describe them
serous:
a sign of hydrops
associated w/ down and turners
hypoechoic
chylous:
collection of lymphatic fluid (appears white)
maybe associated w/ polyhydramnios
both may displace lungs towards midline
US appearance of pleural effusion
- cystic collection above the diaphragm
- unilateral
- possible mediastinal shift
- may invert diaphragm
Tx for pleural effusion
when is this done
hydrothorax and chylothorax:
- thoracentesis
- shunt fluid into abdo or amniotic cavity
- no treatment, may resolve on its own
treatment is done if the fetus is compromised
describe a tracheal atresia
US appearance
congenitally non-patent airway
Enlarged lungs and airways
flat diaphragm
ascites w/ polyhydramnios
is a sm amount of amniotic fluid naturally produced in the fetal lungs
yes
describe an esophageal atresia
US appearance
congenitally absence of a segment of the esophagus
small or no stomach bubble - depends on if a TE fistula is present
cystic strucutre in neck that disappears
polyhydramnios
fetal vomiting
esophageal atresia is associted w/ which conditions
TE fistula
down syndrome
VACTERL
heart defects
list some chest wall shape abnormalities
what can they cause
narrow
long
bell shaped
dwarfism
pulmonary hypoplasia
describe ectopia cordis
an anterior chest wall fusion defect that causes the heart will be outside the chest cavity
describe the pentalogy of centrell
5 defects involved: SOAPE
sternum anterior diaphragm pericardium ectopia cordis w/ heart defects omphalocele
