Which of the following statements correctly describes power Doppler?
A. Demonstrates mean flow velocities ofany RBC in the sample
B. Offers highest temporal resolution of all ultrasound imaging techniques
C. Color is assigned to the shift based on the NUMBER of moving RBCs
D. Color is assigned to the shift based on the VELOCITY of moving RBCs
C. Color is assigned to the shift based on the NUMBER of moving RBCs
If the PSV is 3 m/s, what is the peak pressure gradient?
A. 9 mmHg
B. 36 mmHg
C. 27 mmHg
D. 18 mmHg
B. 36 mmHg
Bernoulli’s equation: pressure gradient = 4 x velocity^2
Which of the following correctly describes a limitation of the fast Fourier transformer?
A. cannot process a frequency shift less than 1/2 the PRF
B. requires a min. of 2 samples per cycles to process and produce a Doppler tracing
C. cannot process more than 2 samples per cycle
D. cannot process a frequency shift less than 1/2 the transducer frequency
B. requires a min. of 2 samples per cycles to process and produce a Doppler tracing
**also cannot process frequency shift 2x greater than 1/2 PRF (Nyquist limit)
Increasing the amount of pulses in a color packet will…
A. Increase color priority
B. increase frame time
c. decrease color sensitivity
d. increase frame rate
B. increase frame time
**also increases color sensitivity
Which of the following is a limitation of Analog Doppler?
A. unable to detect post stenotic turbulence and spectral broadening
B. overestimates high velocities and underestimates low velocities
C. cannot detect flow velocities less than 60 cm/s
D. cannot detect flow velocities over 300 cm/s
A. unable to detect post stenotic turbulence and spectral broadening
** also overestimates low velocities and underestimates high velocities
