Echocardiogram Echocardiograms Echocardiographic Techniques 2 — Questions and Answers
Question 1: Which Doppler modality provides the highest temporal resolution for measuring high-velocity jets such as aortic stenosis?
- Color flow Doppler
- Continuous wave Doppler (Correct answer)
- Pulsed wave Doppler
- Tissue Doppler imaging
Correct answer: Continuous wave Doppler
Continuous wave Doppler has no range ambiguity limit and can measure high velocities accurately, making it ideal for aortic stenosis jets.
Question 2: When performing a subcostal four-chamber view, the transducer is placed:
- At the left sternal border in the fourth intercostal space
- Below the xiphoid process with the marker toward the patient's left (Correct answer)
- At the apex with the marker pointing to the left shoulder
- In the suprasternal notch angled inferiorly
Correct answer: Below the xiphoid process with the marker toward the patient's left
The subcostal four-chamber view is obtained by placing the transducer below the xiphoid and angling the beam superiorly toward the heart.
Question 3: Harmonic imaging improves image quality primarily by:
- Increasing the transmitted frequency
- Reducing frame rate to improve penetration
- Suppressing near-field artifact and improving signal-to-noise ratio (Correct answer)
- Widening the scan sector to capture more anatomy
Correct answer: Suppressing near-field artifact and improving signal-to-noise ratio
Tissue harmonic imaging uses second-harmonic frequencies generated within tissue, reducing near-field clutter and side-lobe artifacts.
Question 4: The Nyquist limit in pulsed wave Doppler is defined as:
- The maximum depth at which flow can be detected
- Half the pulse repetition frequency (Correct answer)
- The maximum frame rate divided by sector width
- The minimum detectable velocity at a given gain setting
Correct answer: Half the pulse repetition frequency
The Nyquist limit equals PRF/2; velocities exceeding this cause aliasing in pulsed wave Doppler.
Question 5: In M-mode echocardiography, the E-point septal separation (EPSS) is most useful for estimating:
- Mitral valve area by planimetry
- Left ventricular systolic function (Correct answer)
- Right ventricular pressure
- Aortic valve calcification severity
Correct answer: Left ventricular systolic function
An elevated EPSS (>7 mm) indicates reduced left ventricular ejection fraction due to decreased anterior mitral leaflet excursion.
Question 6: When color Doppler aliasing occurs, the most appropriate first adjustment is to:
- Decrease depth to improve frame rate
- Increase the color Nyquist limit (velocity scale) (Correct answer)
- Switch to M-mode to eliminate aliasing
- Reduce gain to suppress the color signal
Correct answer: Increase the color Nyquist limit (velocity scale)
Increasing the Nyquist limit raises the velocity range, reducing aliasing when flow velocities exceed the current scale.
Question 7: The apical two-chamber view visualizes which cardiac structures?
- Left ventricle, mitral valve, left atrium, and aortic valve
- Left ventricle, mitral valve, and left atrium only (Correct answer)
- Right ventricle, tricuspid valve, and right atrium
- Both ventricles and both atrioventricular valves simultaneously
Correct answer: Left ventricle, mitral valve, and left atrium only
The apical two-chamber view displays the left ventricle, mitral valve, and left atrium without showing the right-sided structures.
Echocardiogram Echocardiograms Echocardiographic Techniques 2
Which Doppler modality provides the highest temporal resolution for measuring high-velocity jets such as aortic stenosis?