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WorksheetsChapter 21 3/3
Total questions: 66
Worksheet time: 33mins
What is a consequence of edge shadowing in ultrasound imaging?
It prevents visualization of true anatomy
It improves image resolution
It enhances color Doppler signals
It helps identify vascular structures
What is the difference between Shadow and Edge Shadow artifact?
Shadowing and edge shadowing are both caused by attenuation of the beam equally throughout all tissues
Edge shadowing is caused by increased absorption at the surface of fluid-filled structures
Edge shadowing is caused by reflection from strong acoustic interfaces
Edge shadowing is caused by the shape of the structure, not by attenuation
What does enhancement appear as in an ultrasound image?
A hypoechoic region beneath highly attenuating tissue
A shadow below dense structures
A hyperechoic region beneath tissue with abnormally low attenuation
A region of no echoes beneath a cyst
Which of the following best describes the relationship between enhancement and shadowing?
They are the same phenomenon
Enhancement is the opposite of shadowing
Both are caused by high attenuation
They only occur with cystic structures
How can enhancement assist in clinical diagnosis?
It may provide valuable diagnostic information that helps characterize tissue
It always obscures pathological features
It helps eliminate artifacts
It speeds up the imaging process
Is enhancement related to the speed at which sound travels through a medium?
Yes, it directly correlates
Partially, depending on the density
No, it is entirely unrelated
Only in soft tissue
What incorrect assumption does enhancement relate to in ultrasound imaging?
That the intensity of a reflection is solely related to the characteristics of the tissue
That the reflection angle affects intensity
That echoes occur only from strong reflectors
That sound speed influences echo brightness
What is a key characteristic of enhancement in ultrasound imaging?
Hypoechoic appearance
Hyperechoic appearance (same as foreground tissue)
Anechoic shadowing
Increased attenuation
What causes enhancement artifacts in ultrasound?
Excessive reflection
Strong refraction
Too little attenuation
Over-gained image settings
Where is enhancement typically located in an ultrasound image?
Above structures with high attenuation
At the skin surface
Next to structures with high impedance
Beneath structures with low attenuation
What is focal enhancement in ultrasound imaging also known as?
TGC artifact
Lateral artifact
Focal banding
Reverberation
Where is focal enhancement most prominent in the ultrasound image?
Near the transducer
At the region of the focus
At the far field
Throughout the entire depth
How does focal enhancement typically appear in an image?
As a horizontal band of hyperechoic tissue
As a vertical line of shadowing
As a region of anechoic dropout
As a misalignment of structures
What incorrect assumption does focal enhancement relate to?
That the sound travels in a straight line
That the speed of sound in tissue is constant
That the intensity of a reflection is related to tissue characteristics
That echoes return directly to the transducer
Which artifact has the appearance similar to an incorrect TGC setting?
Shadowing
Reverberation
Focal enhancement
Comet tail
What is a characteristic of focal enhancement in ultrasound imaging?
A hypoechoic area near the surface
A shadowing region behind bone
A hyperechoic side-to-side region
A region with no echoes
What causes focal enhancement in ultrasound imaging?
Attenuation due to dense tissue
Reverberation artifact
Increased intensity at the focus
Weak transducer signal
What causes a mirror image artifact in ultrasound imaging?
Refraction of sound at a tissue boundary
Sound absorption by a dense object
Reflection off a strong reflector that redirects sound toward a second structure
Scattering of sound by small particles
Where is the mirror image artifact typically located in relation to the real structure?
At the same depth as the real structure
Deeper than the real structure
Shallower than the real structure
It appears lateral to the real structure
Which of the following ultrasound modalities can show mirror image artifacts?
Gray scale imaging only
Both gray scale and color Doppler imaging
Only M-mode imaging
Only power Doppler imaging
What ultrasound assumptions are violated by the mirror image artifact?
Sound is reflected only once
Sound is absorbed completely by soft tissue
Sound travels in a straight line and directly to a reflector and back
Sound intensity does not vary with depth
In color Doppler imaging, which vessel is real when a mirror artifact is present?
The shallower vessel
The deeper vessel
Both are real
Neither is real
What is a key characteristic of a mirror artifact in ultrasound imaging?
It appears shallower than the true reflector
It appears as a second copy of a true reflector
It is always located laterally from the true reflector
It enhances the resolution of the image
Where does the mirror artifact typically appear in relation to the true reflector?
Deeper than the true reflector
At the same depth as the transducer
Shallower than the true reflector
Lateral to the true reflector
Which structure must lie on a straight line between the transducer and the artifact in mirror artifacts?
A hypoechoic lesion
A bright reflector (the mirror)
A shadowing object
The true reflector
26. The distances between the true reflector and the artifact in mirror artifacts are:
Equal
Greater
Lesser
Unrelated
The artifact is always closer to the mirror
The artifact is always closer to the mirror
They are equal distances from the mirror
The artifact is always farther from the mirror
There is no predictable relationship
What is Crosstalk artifact in ultrasound imaging?
A type of reverberation artifact
A lateral resolution error
A type of mirror image artifact that appears on spectral Doppler display
An artifact caused by poor gain settings
What causes a speed error artifact in ultrasound imaging?
Incorrect transducer frequency
Improper gain settings
A sound wave propagates through a medium at a speed other than soft tissue
High thermal index levels
What is the speed of sound assumed in soft tissue for ultrasound imaging?
1,000 m/s
1,540 m/s
2,000 m/s
1,200 m/s
What is another name for speed error artifact?
Reverberation artifact
Shadowing artifact
Range error artifact
Side lobe artifact
What is the visual result of a speed error artifact on the ultrasound image?
Structures appear brighter than normal
Reflectors appear at incorrect depths
Reflectors appear twice
There are no changes on the image
What happens when the medium's speed is slower than that in soft tissue?
Sound travels faster than the system expects
Sound travels slower than the system expects
Sound travels at the same speed as expected
Sound does not return to the transducer
How does the ultrasound system interpret the go-return time when the speed of sound is slower than expected?
The system thinks the reflectors are farther from the transducer
The system places reflectors too close to the transducer
The system ignores the returned pulses
The system assumes the medium is solid
What artifact results from a slower speed of sound in the medium?
Shadowing artifact
Reflectors placed too deep
Lateral resolution artifact
Comet tail artifact
What is the impact on measured distances when the speed of sound is slower than expected?
Distances are underestimated
Distances are overestimated
Distances remain unchanged
Distances are not measurable
What happens when the medium's speed is faster than that in soft tissue?
Sound travels slower than expected
Pulses return with a delay
Sound travels faster than the ultrasound system expects
There is no change in pulse return timing
What is the effect of a fast go-return time on the ultrasound image?
Reflectors are located too shallow on the image
Reflectors appear deeper on the image
Reflectors are not displayed
The image contrast is enhanced
How does the system interpret the location of reflectors when sound travels faster than expected?
The system assumes the reflectors are closer to the transducer
The system places reflectors deeper than they are
Reflectors are considered noise
No reflectors are displayed
What error occurs in distance measurement when sound travels faster in the medium?
Distances are overestimated
Distances are underestimated
Distances remain accurate
Distances fluctuate randomly
What is another name for propagation speed errors in ultrasound imaging?
Doppler artifact
Reverberation artifact
Range error artifact
Mirror artifact
Which of the following is TRUE about propagation speed error artifacts?
They always appear at the correct depth
They do not affect the number of reflectors seen
They cause reflectors to appear at improper depths
They result in complete loss of reflectors
What visual effect does propagation speed error typically create?
Shadowing
Enhancement
Step-off appearance
Twinkling artifact
What remains correct in a propagation speed error artifact?
Number of reflectors
Depth of reflectors
Position of reflectors
Shape of the reflectors
If two pins are 100mm apart but appear 90mm apart on the display, and two other pins are 50mm apart, how will they appear on the display?
50mm
48mm
45mm
40mm
An ultrasound system underestimates the distance between two pins. What does this indicate?
The sound is traveling faster than that of soft tissue.
The system is overestimating the actual distance.
The gain setting is too high.
The transducer frequency is too low.
What is a lobe artifact in ultrasound imaging?
A shadow behind a dense object
A result of insufficient gain settings
An artifact that appears when sound energy is transmitted in a direction other than along the beam’s main axis
A misalignment of the Doppler angle
What effect do lobe artifacts have on image quality?
They improve axial resolution
They degrade lateral resolution
They enhance color Doppler sensitivity
They eliminate mirror artifacts
Which type of transducer creates side lobes?
Array transducer
Mechanical sector transducer
Single crystal transducer
Annular array transducer
Which type of transducer creates grating lobes?
Array transducer
Single crystal transducer
Mechanical transducer
Annular transducer
Why do lobe artifacts usually not generate reflections?
They are too deep to return echoes.
They only occur in M-mode imaging.
They are generally weaker than the main beam.
They are absorbed by soft tissue.
When can a lobe artifact generate a reflection?
When scanning superficial tissues.
When a strong reflector lies in the path of the lobe.
Only during Doppler imaging.
When gain is set too low.
How can real anatomy be differentiated from an artifact in ultrasound imaging?
By increasing output power.
Real anatomy will appear in all imaging views.
Artifacts will always appear brighter.
Real anatomy creates shadowing.
What assumption related to lobe artifacts is considered invalid?
That all tissues reflect ultrasound equally.
That reflections arise only from structures located along the beam’s main axis.
That lateral resolution is always sufficient.
That all echoes come from superficial depths.
What is a key characteristic of a lobe artifact in ultrasound imaging?
It always appears deeper than the true reflector
It only appears during Doppler imaging
It is a second copy of the true reflector
It is caused by mirror reflection across a bright structure
Where is the lobe artifact located in relation to the true reflector?
Above and deeper than the true reflector
Side-by-side at the same depth
Closer to the transducer and to the right
Farther from the transducer and to the left
What is the process called where each PZT element is divided into smaller pieces to reduce grating lobes?
Apodization
Subdicing
Refraction
Attenuation
What is the term for applying different voltages to subdiced elements to further reduce grating lobes?
Subdicing
Apodization
Modulation
Diffusion
How are elements near the center of the beam excited during apodization?
With lower voltages
With higher voltages
With the same voltages as the edges
They are not excited at all
How are the outermost elements excited in apodization?
With higher voltages
With equal voltages
With lower voltages
They are not excited
What is refraction in ultrasound imaging?
Reflection of sound back to the transducer
Scattering of sound in all directions
Absorption of sound by tissue
Change in direction of sound during transmission
Under what conditions does refraction occur?
When sound strikes a boundary perpendicularly
When media on either side have identical propagation speeds
When sound strikes a boundary obliquely and the media have different propagation speeds
When there is no difference in tissue density
Which resolution is degraded due to refraction?
Axial resolution
Temporal resolution
Contrast resolution
Lateral resolution
Refraction is related to the violation of which ultrasound assumption?
Sound travels in soft tissue at 1540 m/s
Sound reflects at 90 degrees incidence
Sound travels in a straight line
The transducer is the only sound source
What is a characteristic of a refraction artifact in ultrasound imaging?
A copy of the reflector appears deeper than the original
The artifact appears in front of the true reflector
A second copy of the reflector is seen
The artifact appears at a different frequency
Where is the artifact located in relation to the true reflector in refraction artifact?
Above and behind the true reflector
Side-by-side at the same depth
At a different angle but same depth
Directly beneath the true reflector
