FE Doppler Assessment Flashcards

Which Doppler mode provides quantitative velocity measurements essential for fetal cardiac assessment?

Answer: Pulsed-wave Doppler

Pulsed-wave Doppler provides quantitative velocity measurements at a specific sample volume location, essential for fetal cardiac hemodynamic assessment.

The Doppler angle of insonation should ideally be less than how many degrees for accurate velocity measurement?

Answer: 60 degrees

A Doppler insonation angle less than 60 degrees is required for acceptable velocity accuracy, with angles below 20 degrees being ideal.

Which Doppler waveform parameter reflects downstream vascular resistance?

Answer: Resistance index (RI)

The resistance index (RI = [peak systolic – end diastolic] / peak systolic) reflects downstream vascular resistance independent of absolute velocity.

In which fetal vessel is Doppler assessment used to predict the risk of fetal chromosomal aneurysm in the first trimester?

Answer: Ductus venosus

Abnormal ductus venosus Doppler (absent or reversed a-wave) in the first trimester is associated with increased risk of chromosomal abnormalities and cardiac defects.

Color Doppler aliasing in fetal echocardiography indicates:

Answer: Flow velocity exceeding the Nyquist limit

Color Doppler aliasing occurs when flow velocity exceeds the Nyquist limit of the pulse repetition frequency, causing color wrapping.

Which Doppler finding is characteristic of pulmonary stenosis in the fetus?

Answer: Increased pulmonary artery peak velocity with turbulence

Pulmonary stenosis produces a high-velocity, turbulent jet across the pulmonary valve with elevated peak systolic velocity on pulsed-wave Doppler.