FE Imaging Techniques & Protocols 3 — Questions and Answers
Question 1: Which scan plane in fetal echocardiography demonstrates both great arteries crossing each other in their normal relationship?
- Four-chamber view
- Three-vessel and trachea (3VT) view
- Short-axis view at the great vessel level (Correct answer)
- Bicaval view
Correct answer: Short-axis view at the great vessel level
The short-axis view at the level of the great vessels shows the pulmonary artery wrapping around the circular aortic root, demonstrating their normal crossing relationship.
Question 2: In the three-vessel and trachea (3VT) view, the normal left-to-right arrangement of structures from the fetal perspective is:
- Pulmonary artery, aorta, superior vena cava (Correct answer)
- Aorta, pulmonary artery, superior vena cava
- Superior vena cava, aorta, pulmonary artery
- Superior vena cava, pulmonary artery, aorta
Correct answer: Pulmonary artery, aorta, superior vena cava
In the standard 3VT view, from the fetal left to right the order is pulmonary artery (largest), aorta, then superior vena cava (smallest).
Question 3: Which imaging artifact can mimic a ventricular septal defect (VSD) on 2D echocardiography?
- Ring-down artifact
- Dropout artifact due to beam parallel to the septum (Correct answer)
- Reverberation artifact
- Mirror-image artifact
Correct answer: Dropout artifact due to beam parallel to the septum
Dropout artifact occurs when the ultrasound beam strikes a tissue interface at a perpendicular angle, causing apparent absence of the septum and mimicking a VSD.
Question 4: Tissue Doppler imaging (TDI) in fetal echocardiography primarily measures:
- Blood flow velocities through cardiac valves
- Myocardial wall motion velocities (Correct answer)
- Chamber pressures derived from flow gradients
- Pericardial effusion volume
Correct answer: Myocardial wall motion velocities
TDI uses low-velocity, high-amplitude Doppler shifts to quantify myocardial wall motion velocities rather than blood flow.
Question 5: When should harmonic imaging be preferred over fundamental imaging in fetal echocardiography?
- When the fetus is in an optimal anterior position
- In patients with technically difficult windows, such as posterior placenta or increased BMI (Correct answer)
- Exclusively for color Doppler studies
- Only after 28 weeks of gestation
Correct answer: In patients with technically difficult windows, such as posterior placenta or increased BMI
Harmonic imaging improves endocardial border definition and reduces clutter in technically challenging patients by using second-harmonic frequencies.
Question 6: The normal peak systolic velocity in the fetal middle cerebral artery (MCA) is used in conjunction with fetal echocardiography to assess for:
- Pulmonary hypertension
- Fetal anemia and high-output cardiac states (Correct answer)
- Coarctation of the aorta
- Tricuspid regurgitation severity
Correct answer: Fetal anemia and high-output cardiac states
Elevated MCA peak systolic velocity (>1.5 MoM) indicates fetal anemia, which causes increased cardiac output detectable on echocardiography.
Question 7: Which view best demonstrates the relationship of the inferior vena cava and hepatic veins entering the right atrium?
- Apical four-chamber view
- Subcostal four-chamber view
- Bicaval sagittal view (Correct answer)
- Ductal arch view
Correct answer: Bicaval sagittal view
The bicaval sagittal view displays both the superior and inferior vena cava draining into the right atrium, including hepatic venous confluence.
FE Imaging Techniques & Protocols 3
Which scan plane in fetal echocardiography demonstrates both great arteries crossing each other in their normal relationship?