Pulse-Echo Instrumentation Part 4

When you select harmonic imaging, which artifact is less likely to be observed?

• Refraction

• Shadowing

• Ring-down

• Grating lobes

When you select spatial compound imaging, which artifact is less likely to be observed?

• Refraction

• Shadowing

• Enhancement

• Acoustic speckle

• All of the above

The salt-pepper appearance you observe in this ultrasound mage is a result of

• Acoustic speckle

• Compound imaging

• Harmonic imaging

• Electromagnetic interference

This image exhibits banding. This is a result of:

• Dead transducer element

• Incorrect TGC

• Incorrect master gain

• Incorrect focal zone position

What imaging artifact is much worse on the left phantom image compared to the right phantom image?

• Reverberation

• Volume averaging

• Range ambiguity

• Multipath reflections

What type of transducer will improve the artifact demonstrated?

• Linear array

• 1.5D or multirow array

• Mechanical 3D

• Phased array

This image was obtained with a linear array transducer that employs phasing to steer the beam. What artifact do the arrows point to?

• Grating lobes

• Reverberation

• Mirror-image

• Slice-thickness

What can be done to reduce the presence of the artifact seen in the previous question?

• Reduce or eliminate beam steering

• Change the angle of incidence

• Use dynamic aperture

• Increase the number of rows of elements in z-axis

Complete destructive interference of echo reflections will affect the display in the following way:

• By creating bright white pixels

• By creating black pixels

• By creating dark gray pixels

• By creating light gray pixels

You are observing a sonographic artifact based on the interference patterns of scattered echoes. What artifact are you using?

• Mirror

• Grating lobe

• Acoustic speckle

• Comet-tail