Which of the following is a method for overcoming aliasing?

1. Proximal to, at, and distal to a stenosis, which of the following must remain constant?

 

a. velocity

b. pressure

c. resistance

d. volumetric flow rate

2. The greater the impedance difference between two structures, the greater the:

a. refraction

b. reflection

c. attenuation

d. transmission

3. Which Doppler angle yields the greatest Doppler shift?

a. 0 degrees

b. 10 degrees

c. 45 degrees

d. 60 degrees

4. Increasing the transducer frequency will:

a. decrease contrast resolution

b. increase the penetration depth

c. increase the amount of attenuation

d. decrease sensitivity to Doppler shifts

5. Image quality is improved by:

a. decreasing the output

b. decreasing the frame rate

c. increasing the beam width

d. shortening the pulse length

6. What is the purpose of the damping material in the transducer assembly?

a. increase in sensitivity

b. reduction in pulse duration

c. improvement in sound transmission into the body

d. diminishment of reflections at the transducer surface

7. Which of the following instruments generates the pulse of sound?

a. pulser

b. transducer

c. beam former

d. master synchronizer

8. Firing delays found in array systems are determined by the:

a. receiver

b. transducer

c. beam former

d. master synchronizer

9. The speed at which a wave travels through a medium is determined by the:

a. distance from the sound source

b. stiffness and density of the medium

c. resistance and impedance of the medium

d. amplitude and intensity of the sound beam

10. Which of the following is a method for overcoming aliasing?

a. shift the baseline

b. increase imaging depth

c. decrease the Doppler angle

d. increase the operating frequency

11. Brightening of echoes in the focal zone is a result of:

a. acoustic speckle

b. slice thickness artifact

c. horizontal enhancement

d. propagation speed error

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