Fetal Chest Normal And Pathology Flashcards
What is the diaphragm?
Hypoechoic linear structure between lungs and abdomen
When is it easier to see the diaphragm?
Later gestations
How is diaphragm usually visualized?
On Parasagittal scans
What does the fetal lungs look like on U/S?
In terms of echotexture
Homogenous
Fetal lungs are usually compared to what for echogenicity? What do we look for?
- Liver
- Isoechoic and hyperechoic
What are requiremets of fetal lung needed for development? 3
- Adequate space for growth
- Fetal breathing movements
- Fluid within lungs to distend developing airways Adequate amniotic fluid volume
How much of the fetal chest does the fetal heart take up?
1/3
Where is the fetal heart located in relation of the fetal body?
Left of mediastinum and sits in the space in the chest between the lungs that contains the heart and other important structures
How does the apex of the heart tilt/ point?
Apex points to the left with axis about 45 degrees
What are some examples of lung pathology?9
- Pulmonary hypoplasia
- Congenital cystic adenmatoid malformation
- Congenital pulmonary airway malformation
- Pulmonary sequestration
- Bronchogenic cyst
- Diaphragmatic hernia
- Pleural effusion
- Esophageal atresia
- Tracheal atresia
What is pulmonary hypoplasia?
When one or both lungs are underdeveloped
In terms of pulmonary hypoplasia, fetus under which range are not considered viable due to pulmonary immaturity ? (weeks)
<24
At term pulmonary hypoplasia is caused by what?4
- Restricted chest circumference/ rib cage (some restricted chest restriction)
- Chest masses
- Pleural effusion
- Decreased amniotic fluid (oligiohydramnios)
Most frequent cause of pulmonary hypoplasia is what?2
Lack of amniotic fluid caused by
1. PROM - premature rupture of membranes
2. GU anomalies (genitourinary)
Amniotic fluid is produced by membranes until when?
Fetal kidneys begin to produce urine
What is the pathway of amniotic fluid for baby?5
- Fetus swallows amniotic fluid
- Fluid goes through GI tract
- Absorbed by the GI tract
- Exerted by kidneys as urine
- Fetus urinates back into the amniotic cavity
Amniotic fluid is produced in a small amount by what?4
- Fetal lungs
- Fetal skin
- Nose
- Mouth
Any high GI obstruction/ swallowing deficits causes what?
Polyhydraminos
Any bilateral GU obstruction/ renal agenesis, causes what?
Oligiohydramnios
What is the method to predict pulmonary hypoplasia sonograpically?2
- Transverse chest circumference at level of 4CH heart view
- Measure outer to outer (except in cases of skin edema/ hydrops)
Congenital cystic adenomtoid malformation is now called what?
- CPAM
- Congenital pulmonary airway malformation
What is the three classifications of CPAM?
- Type 1
- Type 2
- Type 3
CPAM is a type of what disorder? Which lobe is affected?2
- Hamartoma
- Usually 1 lobe affected (95% unilateral)
CPAM malformation communicates with what?
Tracheobronchial tree
Large CPAM can result in what?
Mediastinal shift
What happens with the mediastinal shift with a large CPAM?
Heart position deviates, compressing lungs and great vessels
CPAM is associated with what? 3
- Hydrops
- Pulmonary hypoplasia
- Polyhydraminos
What does CPAM type 1 look like? 4 ( size, appearance, amount, contents)
- Macrocystic
- Single or multiple
- Will appear as large, anechoic cystic spaces
- > 2cm
What does CPAM 2look like?3 (contents, size, echogenicity)
- Macro and micro cystic
- Mixed echogenicity
- Cysts 0.5 - 2 cm
What is CPAM type 3?
- Microsystems
- Multiple microscopic cysts (0.5-5mm)
- Appears as homogenous hyperechoic masses
What is the prognosis of CPAM?
Depends on mediastinal shift and whether hydrops occurs
Would CPAM have the chance to regress?
Yes it may even disappear on its own
Is any intervention needed for CPAM?
No intervention is performed unless hydrops is noted
What is the way we drain CPAM cysts?
Antenatally or surgically reset the mass postnatally
What is the DDX of CPAM? 3
- Pulmonary sequestration
- Bronchogenic cyst
- CDH (Congenital diaphragmatic hernia)
What is pulmonary sequestration?
A mass of ectopic pulmonary tissue, covered by its own pleura
What is communication like for pulmonary sequestration?
There is no communication
In terms of pulmonary sequestration, what is the arterial supply like?
Ectopic arterial supply
What is the flow of blood in the venous system for pulmonary sequestration? Where is it generally based?
- Venous to systemic system not pulmonary veins
- 80% in left lung base
What is the sonographic appearance of pulmonary sequestration? What is it assocaited with? 2
- Uniform hyperechoic mass
- Associated with hydrops and polyhydraminos secondary to mass effect
When doing a sonographic investigation for pulmonary sequestration, what should we look for?
Feeding artery, off the aorta
What is the prognosis for pulmonary sequestration?
Good unless associated with hydrops, usually resolve on their own
What is a Bronchogenic cyst?
A cyst in the lung, lined with bronchial epithelium
Bronchogenic cyst results from what?
An abnormal budding of the foregut
What is Bronchogenic cysts associated with? 3
Forgot anomalies such as
1. TE fistulas
2. Esophageal duplications
3. Lung sequestration
What is the sonographic appearance of bronchitis cysts? 2
- Uni/multiocular cysts
- Mediastinal shift
What is a diaphragmatic hernia?
A defect in the diaphragm which allows abdominal contents to herniate up to the chest
What are some organs affected by diaphragmatic hernias? 3
- Intestines
- Stomachs
- Liver