Artifacts Registry Review Flashcards
___ appears when the beam dimension is greater than the reflector size
refraction
axial resolution
slice thickness
propagation speed error
slice thickness
Occurs when a sound wave strikes a boundary obliquely and the media on either side of the boundary have different propagation speed
slice thickness
mirror image
shadow
refration
refraction
_ artifact appear when sound energy is transmitted in a direction other thatn along the beam’s main axis
mirror image
speed error
refraction
slice thickness
lobes
lobes
is created when closely spaced reverberations merge
reverberation
comet tail
shadow
side lobes
comet tail
A second copy of true reflector appears deeper that the true reflector
shadow
reverberation
mirror image
crosstalk
mirror image
Also known as ring down artifact?
reverberation
comet tail
shadow
enhancement
comet tail
Appears as hypoechoic or anechoic region extending downward from a strong attenuating medium
enhancement
comet tail
reverbertation
edge shadow
shadow
shadow
Artifact appears as a hyperechoic region beneath tissues with abnormally low attenuation
shadow
reverbertation
edge shadow
mirror image
enhancement
enhancement
Artifact is created weehn a long pulse strikes two closely spaced structures, where one in front of the other, or parallel to the main axis of the ultrasound beam
Axial resolution
Lateral resolution
Elevational resolution
Axial resolution
Artifact is related to the dimension of the beam perpendicular to the imaging plane.
slice thickness
refraction
lateral resolution
axial resolution
slice thickness
Artifact is created when sound pulses glance off a second structure on the way to or from the primary reflector.
multipath
lateral resolution
Axial resolution
refraction
multipath
Artifact occurs when a sound pulse changes direction during transmission
slice thickness
refraction
reflection
beam bending
refraction
Artifact occurs when the beam is wider than the distance between two reflectors that are located side by side or perpendicular to the beam.
Axial resolution
Lateral resolution
Elevational resolution
Multipath
Lateral resolution
Artifart appears as multiple, equally spaced echoes caused by bouncing of the sound wave between two strong reflectors positioned parallel to the ultrasound beam
shadow
comet tail
reveberation
enhancement
reveberation
Edge shadow is also called?
shadowing by refraction
shadowing by bending
shadowing by Guicci
shadowing by refraction
Grating lobes can be further reduced by a process called?
subdicing
apodization
oxidization
revolation
apodization
Imaging plane is very thin? T or F
T
F
T
In a Refraction artifact where is the second copy of the reflector?
side by side
below
above
side by side
In which a side to side region of an image appears brighter than tissues at other depths
mirror image
side lobes
reverberation
focal enhancement
focal enhancement
Is a special form of shadowing that appears as a hypoechoic region extending along the edge of a curved reflector
enhancement
shadow
edge shadow
reverbertation
edge shadow
Is created when a sound wave propagates through a medium at a speed other thann soft tissue 1.54km/s
mirror image
speed error
grating lobes
side lobes
speed error
Is temporal resolution better with high or low frame rates
high
low
high
Is created when sound reflects off a strong reflector, and is redirected toward a second structure.
refraction
mirror image
reverberation
forcal enhancement
mirror image
Lobe artifacts have different names based on?
Angle
Transducer
Positioning
Focus
Transducer
Reflected freq- transmitted freq =
Doppler shift
Doppler positive
negative doppler
Doppler shift
Side lobes are created by what type of transducer?
Linear
Curved Array
Mechanical
Annular
Mechanical
Solid hyperechoic line directed downward artifact
shadow
enhancement
reverberation
comet tail
comet tail
Six assumptions of imaging systems. Sound travels in a straight line? T or F
T
F
T
The motorcyle approaches and the sound gets louder. What is this called?
negative doppler shift
positive doppler shift
neutral shift
positive doppler shift
Positive shift is when the blood is moving ___ transducer
toward
away
no change
toward
The % of the true velocity that is measured depends on the _____ of the angle between the sound beam and direction of motion
2
velocity
cosine
speed
cosine
Negative shift is when the sound is moving ___ the transducer
away
toward
no change
away
Is defined by a magnitude and a direction
speed
velocity
distance
direction
velocity
What changes when the sound source and the reveiver move closer together or farther apart?
power
intensity
harmonics
frequency
frequency
Which artifact resemble a ladder or venetian blind?
comet tail
reverberation
shadow
acoustic enhancement
reverberation
Is purely a magnitude, indcates the distance that a red blood cell moves in one sec
velocity
speed
amplitude
speed
Sound travels in soft tissue at exactly 1,540m/sec T or F
T
F
T
Which of the following create on reflection on the image from two closely spaced reflectors
Axial
Lateral
Elevational
Axial
Which of the below does Doppler frequency indicate?
velocity
speed
amplitude
distance
velocity
What are lobe artifacts called when using an array probe
side lobes
grating lobes
subdicing
apodization
grating lobes
If the transducer’s frequency doubles the Doppler shift will ?
remain the same
double
halve
double
T or F: You have to turn on the Doppler equation for it to work?
T
F
F
What resolution is determined by the thickness of the imaging plane
Elevational
Axial
Lateral
Longitudinal
Elevational
T or F. In a lobe artifact the second copy of the true reflector are located side by side
T
F
T
What is the standard cosine angle we use in clinical practice? We use this number since we cannot achieve 0 or 180?
0
50
60
75
60
The stregth of a reflection is related to the characteristics of the tissue creating the reflection? T or F
T
F
T
Is this the doppler equation?
2x velocity of blood x tx freq x transducer freq x cos/prop speed
YES
NO
No answer text provided.
NO
The ___ axis represents Doppler shift or velocity
X
Y
Z
M
Y
T or F: The slower the velocity the greater the Doppler frequency
T
F
F
What is another name for Doppler shift?
Doppler Dan
Doppler harmonics
Doppler frequency
Doppler frequency
The reflected frequency is ___ than the tranasmitted frequency to create positive shift
higher
lower
same
higher
In Doppler if we have a 90 degree to the vessel the image will be black with a ___doppler shift
10
100
180
0
0
T or F: Doppler shifts are created when transmitted sound wave strike moving red blood cells.
T
F
T
What does the 2 in the Doppler equation represent?
two different frequency
two doppler shifts
two different images produced
two doppler shifts
What is the process to reduce grating lobes artifact?
subdicing
slicing
dicing
angle correction
subdicing
The ability to precisely postition a moving structure is called?
Axial resolution
Lateral resolution
Temporal resolution
Speckle
Temporal resolution
The process of extracting the low Doppler freq from the transducers carrier frequency is called?
compression
compensating
demodulation
amplification
demodulation
When an angle exists between the direction of flow and the sound beam, the measured velocity is ___ than the true velocity?
less
more
same
entire
less
Which resolution is related to the overall detail in an image
Temporal
Spatial
Axial
Lateral
Spatial
When the velocity is halved, the Doppler shift is ?
doubled
halved
remains the same
halved
Doppler shift is directly related to the ___ of the transmitted sound
period
speed
velocity
frequency
frequency
When the blood cells are moving parallel to the sound beam, the _____ velocity is measured?
10%
50%
100%
150%
100%
Which artifact appears as a step off, as if structures are split or cut
speed error
mirror image
crosstalk
side lobes
speed error
Motion between the sound source and the receiver creates a __ change
power
frequency
intensity
pressure
frequency
Measured velocity = true velocity x ____
cosine 0
speed
harmonics
frequency
cosine 0
The ___ axis of a Doppler spectrum represents time?
X
Y
Z
M
No answer text provided.
X
Doppler shift is ___ related to the velocity of blood cells
directly
indirectly
not related
directly
Units for speed?
cm2
Length
cm/per sec
distance
cm/per sec
What artifact would you normally see behind a simple cyst
shadow
no change
enhancement
enhancement
Which of the two may display a small reflector as a wide line?
Axial
Lateral
Lateral
