PU Doppler Ultrasound in Pregnancy

Question 1

What does absent end-diastolic flow (AEDF) in the umbilical artery indicate?

Accepted Answer

Severely elevated placental resistance with high risk of fetal compromise

Answer

Absent end-diastolic flow in the umbilical artery indicates markedly elevated placental vascular resistance and is associated with severe fetal compromise and increased perinatal mortality.

Question 2

What is the S/D ratio in umbilical artery Doppler?

Accepted Answer

The ratio of peak systolic to end-diastolic velocity

Answer

The S/D ratio (systolic-to-diastolic ratio) compares peak systolic velocity to end-diastolic velocity in the umbilical artery and reflects placental vascular resistance.

Question 3

Reversed end-diastolic flow (REDF) in the umbilical artery is associated with what outcome?

Accepted Answer

Imminent fetal deterioration requiring urgent delivery consideration

Answer

REDF in the umbilical artery indicates critical placental resistance with reverse flow during diastole and is associated with very high perinatal morbidity and mortality, often requiring urgent delivery.

Question 4

Which Doppler waveform is used to assess fetal cerebral blood flow?

Accepted Answer

Middle cerebral artery (MCA)

Answer

The middle cerebral artery is the standard vessel used to assess fetal cerebral blood flow, particularly for detecting brain-sparing in IUGR and anemia.

Question 5

What is the brain-sparing effect in Doppler assessment?

Accepted Answer

Increased MCA flow with decreased umbilical artery flow indicating redistribution to protect the brain

Answer

Brain-sparing refers to vasodilation of the middle cerebral artery with reduced resistance, allowing more blood to reach the fetal brain when placental insufficiency is present.

PU - Pregnancy Ultrasound Certification Practice Test

PU - Pregnancy Ultrasound Certification Practice Test

PU Doppler Ultrasound in Pregnancy