Fetal Chest Flashcards
Ossification of clavicles occur during what week?
Scapula?
Sternum?
Clavicles: 8 weeks
Scapula: 10 weeks
Sternum: 21-27 weeks
When may the soft tissues in the chest appear thickened?
- Fetal edema
- Fat deposits due to a diabetic mother
What can thoracic circumference help rule out?
Pulmonary hypoplasia
At what level in a TRV view is a thoracic circumference measured?
Level of the heart just above the diaphragm
T or F? All TC/AC ratios that are low are due to pulmonary hypoplasia
FALSE: A small TC could just be a small thorax and be completely normal
How much of the thorax should the heart take up?
1/3 - at the level of the AV valves
In what possible situations may the heart take up more than 1/3rd of the thorax?
- Pulmonary Hypoplasia
- Cardiomegaly
What do the primary bronchial buds grow into?
The pleural cavity
In what week does the bronchi form?
5th
When does respiration become possible?
24th week
What structure aids in respiration?
Terminal saccules
What is the lung echogenicity early in gestation compared to later?
Equal or less than the liver earlier and becomes brighter with increasing gestation
T or F? Sonography is a good tool to assess lung maturity
FALSE
Is the thymus located anterior or posterior to the Ao and PA?
Anterior
When is assessing the thymus useful?
When predicting IUGR and chorioamnionitis
At what vertebral level is the larynx located?
C3-6
What may be suspected in the presence of a persistently fluid filled trachea?
Laryngeal atresia or stenosis
T or F? Bronchogenic cysts communicate directly with trachea or main stem bronchi
TRUE
What may fetuses present with in cases of CCAM?
Hydrops
Ascites
Polyhydramnios
Sonographic features of the types of CCAM?
Type I - pulmonary mass with one or more large cysts (2-10cm)
Type II - echogenic mass with small cysts (0.5 - 2cm)
Type III - Homogenous echogenic mass
How can you tell a CCAM apart from pulmonary sequestration or diaphragmatic hernia?
Colour - CCAM presents vascularity
T or F? Pulmonary sequestration communicates with the tracheobronchial tree
FALSE: It is a piece of non-functioning lung tissue
T or F? Pulmonary sequestration is more common in females
FALSE
Do patients with intralobar or extralobar pulmonary sequestration have a better prognosis?
Extralobar
In CCAM, where does its blood supply come from?
Pulmonary artery
What is immune fetal hydrops also called?
Erythroblastosis fetalis
What may cause immune fetal hydrops?
- Rh incompatibility
- Anemia
What form of hydrops is most lethal?
Non-immune
What may cause non-immune hydrops?
- TORCH infections
- Heart arrythmias
- Chromosomal abnormalities: Turner syndrome, Trisomies 18 and 21
Sonographic findings of non-immune hydrops?
- Skin thickening
- Pleural and pericardial effusion
- Ascites
- Hepatomegaly
- Splenomegaly
What does CDH stand for?
Congenital Diaphragmatic Hernia
What is the postero-lateral CDH called?
Foramen of bochdalek and is the most common
On what side are CDH usually occur?
Left
What is the term for bowel protruding from the abdomen into the diaphragm?
Eventration
What is antero-medial herniation called?
Foramen of margagni
Why are left sided hernias more common?
Because the liver protects the right side and prevents herniation
What can result in a good prognosis of CDH?
If surgical intervention is done before lung development completes (24 weeks)
In what week does the bronchi form?
5th week
What comprises half of all intra-thoracic abnormalities noted on fetal examinations?
Pleural Effusion
In what trimester does CCAM begin to develop? When will it be seen on ultrasound?
First but won’t be seen on ultrasound until the second
T or F? Serial examinations have demonstrated a significant decrease or the spontaneous resolution of CCAMs antenatally
True
Why is it important to evaluate the post skin surface?
Look for breaks in the skin –> myelomeningocele
