Chapter 2 Review Flashcards
What is the basic concept of ultrasound?
detect structures and measure distance
adjusts or amplifies the brightness of all of the pixels on the system monitor
overall gain
Is overall gain a pre or post processing function?
post
This control is used when the overall appearance of the image is too bright or too dark
overall gain
When adjusting the overall gain, a high setting introduces “noise” which decreases the _____ and _____ resolution.
contrast
spatial
As sound travels through tissue, there is a waveform amplitude reduction because of _______
attenuation
3 reasons for reduction in ultrasound energy through a tissue
absorption
scattering
reflection
Attenuation from lowest to highest .
water, fluid, fat, soft tissue, muscle, bone, and air
time gain compensation is also called
depth gain compensation
allows the adjustment of darker or brighter areas
TGC
the separation of structures perpendicular to the transmit beeam
lateral resolution
Lateral resolution is highest within ______
focal zone
If using multiple zones, you may see a decrease in _____
frame rate
The operating frequency relates directly to _______
thickness of the piezoelectric element
In ______ imaging, higher frequencies increase both aliasing and scatter artifacts
Doppler
allows adjustment of the amount of anatomy displayed in the image
image depth
the number of lines used in an image
line density
Narrowing sector width _____ frame rate
increases
Narrowing sector width, _____ lateral resolution
increases
the range of grays displayed in the B-mode image, M-mode tracing, or spectral Doppler tracing
Dynamic range
tint overlay to increase structure visualization
tint/colorize
temporal averaging of multiple sequential ultrasound images or frames
persistence/frame averaging
determines the number of frames used to create the final image
persistence
helps decrease the noise within an image because of the averaging of the data across multiple frames
persistence
What resolution decreases with persistence?
temporal
Increasing persistence, _____ frames
decreases
changes the gray assignment of each pixel based on the received ultrasound signal to increase image contrast
maps/curves
adjusts the brightness of the grays rather than the number of displayed shades
maps/curves
allows for manual adjustment of the acoustic output of the transducer per unit of time
transmit power
an indicator of the potential damage to tissue with the passing wave
mechanical index
displays the thermal index in bone
TIB
the soft-tissue thermal index
TIS
the cranial thermal index
TIC
allows the ultrasound system to use two signals to help create the image
tissue harmonic imaging
uses multiple, averaged transmit beams at different angles and frequencies to increase image detail
compound imaging
_____ angle of incidence creates the optimal reflection
90 degree
Compound imaging ______ axial, lateral, and contrast resolution.
increases
allows visualization of anatomy posterior to a strongly reflecting structure
compound imaging
provide a graphic display of structure in relation to time
M-mode (motion mode)
adjusts the scrolling speed or time of the M-mode
sweep speed
involves the addition of color over the grayscale ultrasound image to indicate movement
color flow imaging
The color above Color flow imaging bar represents:
color flow toward the transducer or positive Doppler shifts
The color below Color flow imaging bar represents:
flow away from the transducer or negative Doppler shifts
BART
blue away
red toward
The color white commonly represents:
increase in blood velocity
Darker colors represent:
slower velocities
green colors represent:
flow disturbances
Mixture of colors represents:
turbulence
ROI should have an angle of incidence of less than ____ degrees
60
Color shadings become darker as the angle of insonation approaches __ degrees
90
Optimal ROI
longer ROI
The wider the gate, the ____ scan lines are required.
more
Increasing or decreasing the scale adjust the ____.
PRF
allows adjustment of the displayed flow to accomodate the vessel flow type and to show true aliasing
PRF
adjusts the spatial averaging for flow between color frames
smooth
adjusts the range of flow velocities displayed above and below the baseline through the movement of the baseline up or down
baseline
to detect slow flow, _____ the persistence
increase
Increased persistence _____ temporal resistance
decreases
allows ability to select a processing curve that assigns the velocity or variance range with color Doppler
Maps
allow ability to display an image with more 2D information, a balance between color and gray scale, or prioritize the color
color priority
adjusts the amount of color or grayscale information each image pixel contains
color priority
reverses the color display
invert
calculates the amplitude within the ROI instead of the mean Doppler frequency shift
Power Doppler
The power Doppler scale calculation includes the ____, ____, and _____ of the signal
intensity
power
amplitude
hybrid of color and power Doppler imaging
directional color Doppler
displays both the power magnitude or amplitude of the power Doppler and the direction of the flow velocity using a small ROI
directional color Doppler
the signal brightness indicates the magnitude of the flow power
directional color Doppler
bright signals = ____ power
strong
allows identification of the direction of blood flow and detect flow disturbances
quantitative Doppler
allows measurement of the speed or velocity of the flow
Spectral doppler
allows adjustment of the displayed velocity range on the spectral tracing
PRF/scale
Lowering the scale allows for measurement of _____ flow
slower
Optimal PRF
spectral tracing filling about 2/3 of the spectral window without the waveform touching the top or bottom
controls the displayed amplitude as brightness of the spectral waveform
spectral gain
moves the Doppler baseline up or down
baseline
allows the display of the spectral waveform either above or below the baseline
invert
allows adjustment of the amount of flow sampled while creating the spectral tracing
sample volume size
allows placement of teh sample depth within the central vessel
range gate
adjusts the spectral Doppler D-line
steer
tells the equipment the position of teh vessel in relation to the sample volume and D-line
angle
the optimal angle - __ degrees
0
reduces the amount of noise and clutter by suppressing the lower level signals that are the result of tissue and vessel wall motion
filter/reject
allows automatic measurements of the spectral Doppler waveform allowing for the simultaneous performance of multiple calculations
automatic waveform measurements
The first step in obtaining a 3D image:
optimization of the 2D image
90 degree angle of incidence a mirrorlike specular reflection
reflection
larger reflector than the wavelength of the transmitted beam
specular reflector
smaller reflector than the wavelength of the transmitted beam
nonspecular reflector
artifact that occurs when a structure is a strong reflector; areas devoid of echoes located deep to the anatomy
posterior acoustic shadowing
presence of two strongly reflecting structures along the beam path often results in the appearance of multiple, hyperechoic linear lines within the tissue
reverberation
occurs if two different conditions are met: a non-perpendicular, or oblique angle of incidence, and a difference in propagation speeds between the two media
refraction
a change in direction of the transmitted beam at the interface
refraction
sound transmits into the tissue at the same angle with no change in direction at the interface
perpendicular incidence
unequal propagation speeds, transmitted sound changes direction
oblique incidence
If the propagation speed of the second medium is greater than 1540 m/s, the angle of the transmitted angle will be ______ than the incident angle.
greater
The ultrasound system calculates the travel distance of the transmitted and received sound wave based on:
sent and return time of the waveform
It takes __ us for sound to reach a depth of 1 cm.
13
occurs when a structure lies between the transducer and a curved or angled strong reflector
mirror image
the system places the echoes deep or lateral to the strong reflector, with an inverted appearance and shifts the artifact in the opposite direction from the original structure
mirror image artifact
Extra beams, located adjacent to the central beam, create echoes in an incorrect location
grating lobes
The appearance of a hazy artifact, because of anatomy laterally located outside of the beam
slice thickness or beam width artifact
evaluation of a cystic structure results in the creation of an area deep into the targeted anatomy appearing brighter than adjacent tissue
posterior acoustic enhancement
The display of either the spectral tracing or color image that exceeds the selected PRF or scale
aliasing
the same axial or depth interaction of a vessel overlying a strong reflector
mirror artifact
appearance of duplication of flow deep to the reflectors
mirror artifact
extension of color outside of the vessel wall
color bleed/blooming
vessels show flow reversal in both the color and spectral modes
color flow reversal
movement of the transducer or targeted anatomy
color flash
_____ and _____ increase or decrease the brightness of the entire B-mode image or tracing.
overall
spectral
____ allows adjustment of image brightness changes caused by absorption of the ultrasound beam by tissue
TGC
The _____ is the narrowest portion of the transmit beam and should be placed at or deep into the imaged anatomy.
focal zone
______ in both 2D and color modes determines the temporal averaging of each pixel
persistence
______ adjusts the acoustic output of the transducer
Transmit power
_____ uses tissue-generated, received signals that are an even multiple of the transmit signal.
Tissue harmonics imaging
______ uses multiple angles to reduce image artifacts, increase image detail, and visualize structures deep to anatomy and pathology.
Compound imaging
_____ provides a graphic display of motion in the fetal heart
M-mode
_____ adjusts the number of M-mode or spectral cycles to include in the tracings.
Sweep speed
______ allows adjustment of the color pixels displayed within the ROI.
Color Doppler gain
Both color and spectral Doppler require an angle of incidence between __ and __ degrees
0
60
The reduction of Doppler aliasing is through adjustment of the _____ or the ______
PRF (scale)
baseline
_______ uses amplitude to create a color overlay of blood flow.
color power Doppler
Artifacts appearing parallel to the transmitted beam include:
reverberation
mirror
propagation speed
acoustic shadowing
enhancement
Artifacts appearing lateral to the iamged anatomy and central beam
beam width
mirror image
slice thickness
grating/side lobe
refraction
_____ is a Doppler artifact seen in both color and spectral modes.
Aliasing
Overall gain adjusts or amplifies the _____ of all the pixels on the system monitor
brightness
As sound travels through tissue, there is a waveform amplitude _____ because of attenuation.
reduction
TGC allows the adjustment of image by changing areas to:
darker or brighter
A single focal zone carat should be positioned:
at or just deep to the imaged structure
The best B-mode image uses:
a. the lowest frequency that provides an adequate amount of penetration
b. high resolution with a high frame rate
c. the highest frequency that provides an adequate amount of penetration
d. low frequency without aliasing
c
A higher dynamic ranged is best utilized with:
a. the uterus
b. ovarian varicosities
c. fetal heart imaging
d. the aorta
a
Narrowing sector width _____ frame rate.
increases
Low persistence improves resolution of:
a. ovarian masses
b. the fetal heart
c. breast masses
d. uterine masses
b
The map feature adjusts ____ of the grays in an image.
brightness
Which is not an indicator of thermal index?
a. TIB
b. TIC
c. TIS
d. TIA
d
Tissue harmonic imaging offers improved image by decreasing all except:
a. side lobes
b. reverberation
c. speckle
d. contrast
d
This feature uses multiple, averaged transmit beams at different angles and frequencies to increase image detail.
Compound imaging
Sweep speed adjusts the M-mode scrolling speed or:
time
Turbulent flow patterns are often associated with:
a. normal pathology
b. red coloring
c. pathologies
d. blue coloring
c
The optimal angle to sample with color flow is:
30 to 60 degrees
On a color bar indicator, the black area represents;
range of flow velocities displayed above and below the baseline
What will aid in detecting slow vascular flow?
a. Pressing “maps” control
b. Decreasing persistence
c. increasing persistence
d. decreasing color priority
c
This type of artifact occurs when a structure is a strong reflector, such as fetal bony structures, or when a tissue reflects most or all of the transmitted beam.
posterior acoustic shadowing
Movement of the transducer or targeted anatomy results in an artifact called:
color flash
Evaluation of a cystic structure results in the creation of an area deep into the targeted anatomy appearing:
brighter than the adjacent tissue
“Slide pots” is another name for _____
potentiometer
The control _____ is used when the overall appearance of the image is too bright or too dark.
overall gain
Dynamic range or DR is simply the range of _____ displayed in the B-mode image.
grays
Adding ____ or _____ to an image has the potential to increase structure visualization over black and white coloring.
tint
colorize
Increasing persistence _____ the frame rate.
slows
The mechanical index is an indicator of the _______ to tissue with the passing wave.
potential damage
The M-mode or motion mode tracings provide a graphic display of structures in relation to _____.
time
If color appears outside of the vessel when using color Doppler gain, it indicated a ____ gain level.
high
Optimally, the ROI should be no larger than necessary because of the _____ frame rates often associated with a larger color box.
decreases
From a frame rate perspective, it is better to have a ____ ROI than a ____ ROI.
long
wide
Changing the “smooth” function adjusts the ______ averaging for flow between color frames.
spatial
The ____ selection reverses the color display.
invert
Power Doppler is an alternate method for assessing ____-flow velocities
low
The _____ function reduces the amount of noise and clutter by suppressing the lower-level signals that are the result of tissue and vessel wall motion.
filter
The first step in obtaining a quality 3D data set is the optimization of the ___ image.
2D
Extra beams, located adjacent to the central beam, called ______ create echoes in an incorrect location.
grating/side lobes
____-mode provides a graphic display of motion in the fetal heart
M
An image produced with misregistration of sound waves occurs when a structure lies between the transducer and a curved or with an angled strong reflector. It is called _____ or _____.
mirror image
ghost image
Color power Doppler uses amplitude to create a color _____ of blood flow.
overlay
The reduction of Doppler aliasing is through adjustment of the _____ or baseline.
PRF
