PU Fetal Anomaly Detection 3

Question 1

What is the most common cause of ventriculomegaly detected on prenatal ultrasound?

Accepted Answer

Aqueductal stenosis

Answer

Aqueductal stenosis, which obstructs CSF flow between the third and fourth ventricles, is the most common cause of isolated congenital ventriculomegaly.

Question 2

At what atrial width measurement is ventriculomegaly diagnosed?

Accepted Answer

Greater than 10 mm

Answer

Ventriculomegaly is diagnosed when the atrium of the lateral ventricle measures greater than 10 mm; measurements between 10–15 mm are mild and above 15 mm are severe.

Question 3

Which cardiac abnormality is most commonly detected on the four-chamber view of the fetal heart?

Accepted Answer

Hypoplastic left heart syndrome

Answer

Hypoplastic left heart syndrome causes marked asymmetry of the cardiac chambers, making it the most commonly detected cardiac defect on the four-chamber view.

Question 4

What does an echogenic intracardiac focus (EIF) represent on ultrasound?

Accepted Answer

A calcification in the papillary muscle, a soft marker for aneuploidy

Answer

An EIF is a bright spot in the fetal heart representing a calcification of the papillary muscle and is considered a soft marker for chromosomal abnormalities, particularly Trisomy 21.

Question 5

What is the significance of bilateral renal pyelectasis on a second-trimester scan?

Accepted Answer

It is a soft marker for Down syndrome and warrants follow-up

Answer

Bilateral renal pyelectasis (mild pelviectasis ≥4 mm AP) is a soft marker for Down syndrome and warrants follow-up to assess for persistent hydronephrosis.

PU - Pregnancy Ultrasound Certification Practice Test

PU - Pregnancy Ultrasound Certification Practice Test

PU Fetal Anomaly Detection 3