FE FE Doppler Assessment 2 ā Questions and Answers
Question 1: Which parameter is derived from the aortic isthmus Doppler and used to assess fetal cardiac reserve?
- Peak systolic velocity
- Pulsatility index (PI)
- Isthmus flow index (IFI) (Correct answer)
- Resistance index (RI)
Correct answer: Isthmus flow index (IFI)
The isthmus flow index (IFI) is calculated from the aortic isthmus and reflects the balance between cerebral and placental vascular resistances.
Question 2: Reversed diastolic flow in the aortic isthmus indicates:
- Normal fetal circulation
- Mild growth restriction without compromise
- Severe hemodynamic compromise with cerebro-placental pressure reversal (Correct answer)
- Structural aortic anomaly
Correct answer: Severe hemodynamic compromise with cerebro-placental pressure reversal
Reversed diastolic flow in the aortic isthmus reflects severe hemodynamic compromise where descending aortic pressure exceeds aortic isthmus pressure throughout diastole.
Question 3: Tricuspid regurgitation velocity on Doppler can be used to estimate:
- Systemic arterial pressure
- Right ventricular systolic pressure (Correct answer)
- Left ventricular end-diastolic pressure
- Pulmonary capillary wedge pressure
Correct answer: Right ventricular systolic pressure
Using the modified Bernoulli equation (4vĀ²), tricuspid regurgitation jet velocity estimates the right ventricular-to-right atrial pressure gradient.
Question 4: Which Doppler finding supports a diagnosis of fetal coarctation of the aorta?
- Increased left ventricular outflow velocity
- Discordant ventricular sizes with right heart dominance and aortic arch hypoplasia (Correct answer)
- Elevated pulmonary vein Doppler PI
- Reduced right ventricular outflow velocity
Correct answer: Discordant ventricular sizes with right heart dominance and aortic arch hypoplasia
Coarctation is suspected when there is right heart dominance, a hypoplastic aortic arch, and discordant ventricular sizes with left heart hypoplasia.
Question 5: Pulmonary venous Doppler shows which pattern in the normal fetus?
- Monophasic systolic flow
- Biphasic flow with systolic and diastolic peaks (Correct answer)
- Continuous non-pulsatile flow
- Reversed flow during atrial contraction
Correct answer: Biphasic flow with systolic and diastolic peaks
Normal fetal pulmonary veins show biphasic forward flow with systolic (S) and diastolic (D) peaks, similar to postnatal patterns.
Question 6: Which Doppler finding in the hepatic veins suggests elevated central venous pressure in the fetus?
- Increased S-wave
- Absent or reversed a-wave (Correct answer)
- Increased D-wave dominance
- Continuous forward flow
Correct answer: Absent or reversed a-wave
An absent or reversed a-wave in hepatic venous Doppler reflects elevated right atrial pressure transmitted during atrial contraction.
FE FE Doppler Assessment 2
Which parameter is derived from the aortic isthmus Doppler and used to assess fetal cardiac reserve?