URR part 2 Flashcards
Non specular reflector increases with increasing ______
frequency
______ relies on Rayleigh scattering from red blood cells to demonstrate the flow on the image
Doppler imaging
System sensitivity should be ______ for all types of Doppler imaging.
increased
Although higher frequency transducers result in greater amounts of ______, penetration of the beam must still be adequate to properly demonstrate flow in deeper structures
Rayleigh scattering
Time of flight or go-return time refers to the time sound travels to and from the transducer
range equation
total time for the pulse to reach a reflector and return to the transducer
range equation
used to calculate distance to the transducer
range equation
US system uses this reflector information to locate pixel placement on the screen
range equation
d = c x 1/2
range equation
in soft tissue, every 13 us of time of flight, the reflector is 1 cm deeper
13 us rule
Cosine of 0 degrees=
1
cosine of 60 degrees =
0.5
cosine of 90 degrees =
0
A CW probe is not limited by the ____ and _____ because the beam is not pulsed
PRF
Nyquist limit
What is the primary factor that determines the resistance characteristics of the arterial signal displayed by PW Doppler?
part it is supplying
Which of the following is a limitation of Analog Doppler?
a. cannot detect flow velocities over 300 cm/s
b. cannot detect flow velocities less than 60 cm/s
c. overestimates high velocities and underestimates low velocities
d. unable to detect post stenotic turbulence and spectral broadening
d
Which of the following will improve a color Doppler image by averaging previous frames to create a new image?
a. sensitivity
b. gain
c. priority
d. persistence
d
If the peak systolic velocity is 3 m/s, what is the peak pressure gradient?
36 mm/Hg
Bernoulli equation
pressure gradient = 4(velocity) squared
When evaluating a focal stenosis of an artery, where should you place the cursor to obtain the highest velocity related to the stenosis?
at the narrowest point in the vessel or immediately distal to the focal point of the stenosis
occurs with slow moving bloow flow and the reflections from the congregated red blood cells
Rouleaux formation
Blood flow at a focal stenosis will demonstrate:
increased resistance
How is the PRP reduced in Doppler imaging?
decreasing imaging depth
Decreased imaging depth = _______ PRP
decreased
number of pulses emitted per second
pulse repetition frequency
PRF is determined by:
the source of the sound
Pulser PRF =
5 kHz
US PRF =
5 kHz
Technologist adjusts the PRF in 2D imaging by using the ______
depth control
Technologist adjusts the PRF in Doppler imaging by using the ______
velocity scale control
PRF is ______ related to imaging depth
inversely
PRF is the reciprocal of ____
PRP
As PRF increases, PRP ______
decreases
Average diagnostic PRF US
1-10 kHz
An increase in imaging depth leads to ______ PRF with a _____ in duty factor
decrease
decrease
The number of pulses per second decreases so that they acn:
travel deeper into the body
time from start of transmission of one pulse to the start of transmission of the next pulse
PRP
In Doppler imaging, this is described as the time from pulse transmission to the time of the Doppler sample displaying the first shift
PRP
Technologist can adjust PRP with the _____
depth control
PRP is the reciprocal of ____
PRF
As PRP increases, PRF _____
decreases
Deeper imaging requires a long time between pulses = ______ PRF
increase
average PRP diagnostic US
100 us - 1ms
Transmission time + receive time =
PRP
also known as field of view
sector angle
The greater the number of scan line per sector degree, the better the _____
spatial resolution
Increasing the sector angle _____ frame rate because fewer pulses are required to produce the small field of view
increases
Decreasing the sector angle improves _______
temporal resolution
in a sector image, the number of scan line per degree of the sector
line density
In a rectangular image, the number of scan lines per cm
line density
Increasing line density _____ the number of pulses per frame
increases
Increasing the line density imroves ______ resolution
spatial
Increasing the line density _____ frame rate
decreases
Increasing the line density, ____ temporal resolution
degrades
If the sector angle contains 100 scan lines and you decrease the sector to 1/2 the size, the new sector angle will contain ___ scan lines
50
If the sector angle contains 100 scan lines and you increase the sector to 2x the size, the new sector angle will contain ____ scan lines
200
Smaller sectors have ____ line density, _____ frame rate, and _____ temporal resolution
lower
increase
better
Increasing line density will improve _____ resolution with most lateral sides of the sector image
detail
refers to decreasing line density within the us system fill in the “gaps” between the fewer lines with averaged information
fill-in interpolation
Fill-in interpolation improves _____ resolution
spatial
range of highest to lowest frequencies in each pulse
bandwidth
Presence of backing/damping layer reduces the number of cycles in a pulse and _____ the bandwidth
broadens
Longer pulses result in ____ bandwidth
narrower
Narrow bandwidth leads to an increase in the Q factor and spatial pulse length =
poor image quality
_____ bandwidth decreases Q factor and improves image quality
Broad
also known as damping factor
Q factor
unitless number that represents the amount of damping applied
Q factor
Ratio of the transducer frequency and the frequencies in the bandwidth
Q factor
Q factor is _____ related to transducer frequency
directly
Higher frequencies have ____ QF
higher
Resolution improves with ____ QF
lower
Imaging transducer have ____ QF
low
Doppler transducers have ____ QF
high
Therapeutic transducers have ___ QF
high
Amount (%) of time pulse transmission is occurring related to time of transmission and receiving pulses
duty factor
The technologist can adjust duty factor with the _____
depth control
Increased imaging depth equals ___ DF
decreased
Decreased PRF and PD lead to _____ DF
decreased
Increased PRP will _____ the duty factor
decrease
(PD x PRP) x 100%
Duty factor
Pulse US DF average
0.1 %
Continuous DF average
q100%
The higher the Df, the greater the risk of ______
bioeffects
increases efficiency of sound transmission in and out of the body
matching layer
usually made of plastic and protects the elemtents
matching layer
Thickness of the matching layer measures ____ wavelength of the sound in the matching layer materal
1/4
Which of the following correctly describes how the elements of a sequential linear transducer are excited?
a. in a specific order that does not change
b. varies with transmitted frequency of the transducer
c. varies with exam preset selection on the system
d. elements are excited left to right with a 0.01 ms between each voltage spike
a
Which of the following can be used to improve beam penetration on cases of high body mass index?
a. higher frequency transducer
b. activate harmonic imaging
c. increase transmit power
d. deactivate coded excitation
c
When switching to a higher frequency transducer during an ultrasound exam, what other setting will need to be adjusted to maintain quality images?
far field gain
Increasing ____ will increase the ability of the system to display fine details on the image.
pixel density
______ refers to the process of programming the receiving elements to use the higher frequency reflections for more superficial structures and lower frequency reflections for deeper structures
dynamic frequency tuning
B-mode display is termed:
brightness mode
Which of the following will be negatively affected by spatial compounding?
a. signal to noise ratio
b. spatial resolution
c. temporal resolution
d. speckle reduction
c
Changing the sweep speed on m-mode will change what characteristic of the display?
x-axis
As the pulse repetition period decreases, _____
a. the imaging depth decreases
b. the imaging depth increases
c. amplitude increases
d. the pulse repetition frequency decreases
a
Which of the following will allow for the display of the most shades of gray on the image?
a. small pixel size with 16 bits/pixel
b. large pixel size with 24 bits/pixel
c. large pixel size with 8 bits/pixel
d. small pixel size with 8 bits/pixel
b
Which of the following is a primary factor in determining the frame rate of an ultrasound system?
a. propagation speed in tissue
b. transducer frequency
c. output power
d. axial resolution
a
Which of the following is related to an increase in the spatial pulse length of an US beam produced by the transducer?
a. decrease in probe frequency
b. remove a focal zone
c. decreased imaging depth
d. increased beam width
a
Activation of B-color is used to improve:
contrast resolution
Harmonic frequencies are generated:
as the sound wave travels through the medium
Increasing the image size, while increasing the number of pixels in the real-time image indicates:
write magnification
If the output power setting is at 100% and this indicates 0dB, decreasing the power by:
6 dB will decrease the power output to 25% of the original power
While scanning the thyroid, you select three focal zones for the image, 1cm, 2cm, and 3cm depth. Which focal zone will demonstrate the highest beam intensity?
1cm
If you increase the sector angle from 45 to 90 degrees and reduce the line density by 50%, what happens to the frame rate?
unchanged
Which of the following will not affect the signal to noise ratio on a 2D image?
a. temporal compounding
b. frequency compounding
c. harmonic imaging
d. spatial compounding
a
You are scanning at a depth of 5cm using a 3MHz transducer and switch to a 5 MHz transducer without changing the depth setting. Which transducer has the greatest pulse repetition frequency?
the have the same PRF
What part of the ultrasound system is responsible for changing the PRF with changes in imaging depth>
pulser
Which of the following is true regarding signal-to-noise ratio?
a. a low signal-to-noise ratio image is preferred for 2D imaging
b. the signal to noise ratio is increased by increasing the overall gain
c. noise is helpful in producing an accurate image
d. a high signal to noise ratio image is preferred over a low signal to noise ratio image
d
Which statement correctly describes the Q factor?
a. a lower Q factor is associated with a longer spatial pulse length
b. a short spatial pulse length is associated with a high numerical value for axial resolution
c. the higher the Q factor, the better the axial resolution
d. better axial resolution is seen with shorter spatial pulse lengths and low Q factor
d
Increasing the edge enhancement setting will:
a. produce a smoother image
b. increase image contrast
c. amplify reflections on the edges of the image
d. improve contrast resolution
b
What system control should be turned off when attempting to demonstrate posterior shadowing from a suspected renal or biliary stone?
spatial compounding
The gray scale map is adjusted to a new map just prior to freezing the image. This is an example of:
applying preprocessing
If the entire image is too bright, what console adjustment should you make first?
decrease the output power
Which of the following describes the preferred placement of the focal zone on standard imaging?
a. just below the area of interest on the image
b. approximately 3 cm from the face of the transducer
c. just above the area of interest on the image
d. approximately 1cm from the bottom of the image sector
a
_____ improves penetration and axial resolution/.
coded excitation
Which of the following will improve lateral resolution at all depths on the image?
a. decrease probe frequency
b. dynamic receive focusing
c. use >3 focal zones
d. dynamic transmit focusing
b
The cine function on the ultrasound system:
a. is performed by the pulser
b. is used to improve temporal resolution
c. is a type of postprocessing
d. is only available on a phased array
c
Which of the following will require the highest levels of time gain compensation?
a. 10 MHz near field
b. 10 MHz far field
c. 5 MHz near field
d. 5 MHz far field
b
Which of the following relies on the non-linear behavior of sound waves?
a. harmonic imaging
b. CW Doppler
c. dynamic frequency tuning
d. compound imaging
a
What is the best way to reduce slice thickness artifact that is causing false echoes in a superficial structure?
use a standoff pad
Which of the following digital displays will be most effective at demonstrating subtle differences on the gray scale image?
a. 100,000 pixels, 10 bits/pixel
b. 10,000 pixels, 10 bits/pixel
c. 10 pixels, 100,000 bits/pixel
d. 200,000 pixels, 1 bit/pixel
a
Spatial averaging is used to:
reduce noise display and signal dropout
Which of the following would brighten the image without affecting beam intensity?
a. increase the amplitude of reflected sound
b. decrease monitor brightness
c. decrease rejection
d. increase the amplitude of transmitted sound
a
Which of the following is an advantage of frequency compounding over spatial compounding?
a. frequency compounding does not affect temporal resolution, while spatial compounding degrades temporal resolution
b. frequency compounding improve the signal to noise ratio, while spatial compounding increases reflection amplitude with no effect on the signal to noise ratio
c. frequency compounding does not affect beam intensity, while spatial compounding increases beam intensity and risk of bioeffects
d. frequency compounding reduces speckle and clutter artifacts, while spatial compounding only reduces posterior shadowing and enhancement
a
Which of the following correctly describes apodization?
a. it is a postprocessing function that adjusts temporal resolution
b. it is used to remove the high frequency reflections outside the bandwidth
c. it is a postprocessing function that adjusts contrast resolution
d. it is performed by maximizing the voltage of the central elements and reducing the voltage to the outer elements
d
Increasing overall gain will:
a. increase the patient exposure to ultrasound
b. produce a diagnostic image in most cases
c. increase the signal to noise ratio
d. increase the amplitude of all of the reflectors on the image
d
Increasing ______ will improve detail resolution the most on lateral sides of the iamge.
line density
_____ increases with increasing the overall gain.
brightness of the iamge
Vessel wall thickness and plaque morphology are best evaluated in 2D when the beam is at what incident angle to the vessel?
90 degrees
Which of the following statements is true regarding pulse inversion imaging?
a. increases destruction of contrast material microbubbles
b. used to improve color Doppler display in deep structures
c. reduces frame rate compared to standard 2D imaging
d. improves temporal resolution
c
Your department recently upgraded the display monitors from a 512 x 512 matrix to a 1024 x 1024 matric. How will this affect the image displayed?
improved contrast resolution
If the ultrasound image is too black and white, which of the following will add more levels of grey to the image?
a. increase threshold levels
b. decrease rejection levels
c. reduce the dynamic range
d. decrease compression
b
Which of the following describes the effect on the frame rate when changing from duplex to triplex imaging?
a. increased
b. decreased
c. no change to frame rate when PW Doppler is active
d. no change to the frame rate when color Doppler is active
b
Which of the following causes range ambiguity artifact?
a. element damage
b. refraction
c. electrical interference
d. high PRF
d
Which of the following should be activated to create a smoother appearance to the image?
a. frequency fusion
b. compression
c. spatial compounding
d. persistence
d
A disadvantage of increasing edge enhancement is:
amplifies echoes related to noise and speckle
What optimization technique creates an image by combining multiple images created at different frequencies?
frequency compounding
Read magnification is performed _____, while write magnification is performed ____.
a. with single element transducers, with transducer arrays
b. using static images, during real time scanning
c. during real time scanning, using static images
d. with transducer arrays, with single element transducers
b
Pulse inversion imaging improves ______ while degrading ______.
spatial resolution
temporal resolution
Which of the following console adjustments will improve the temporal resolution on the image?
a. turning off the zoom function
b. turning on harmonic imaging
c. adding another focal zone
d. decreasing imaging depth
d
Increasing the number of bits assigned to a pixel will:
allow for the display of more shades of grey
As the transducer frequency increases, the spatial pulse length ______
decreases
Frame rates can be improved by the use of what signal processing technique?
parallel processing
The first step in any contrast exam is to:
a. turn on spatial compounding
b. optimize the 2D image
c. set the MI setting to 1.0
d. set the focal zone to just below the area of interest
b
In read magnification, image size and ______ increases. In write magnification, image size and _____ increases.
pixel size
number of pixels
Which of the following system adjustments can be used to help demonstrate the presence of posterior shadowing seen with gallstones?
a. decrease dynamic range
b. decrease transducer frequency
c. increasing compression setting
d. decrease the monitor contrast
a
When scanning in 2D, you can adjust the PRF by changing the _____. When performing a PW Doppler evaluation, you can adjust the PRF by changing the ______.
imaging depth
velocity scale
Even and odd harmonics are created by:
non-linear sound wave propagation
Changing the depth on the image used for an m-mode tracing will change what characteristic of the display?
y-axis
In order to improve spatial resolution and the signal to noise ratio, ______ uses frequency modulation to manipulate the transmitted beam.
coded excitation
Which of the following console controls will have NO effect on the dynamic range?
a. suppression
b. rejection
c. output power
d. compression
c
Which of the following console controls will adjust the pulse duration?
a. output power
b. imaging depth
c. adding a focal zone
d. none of the above
d
When you change the PRF, this adjusts _____
the number of pulses emitted per second
What is the best way to visualize a suspected mass that is isoechoic to surrounding tissues?
minimize the dynamic range to 60-65 dB
If the output power setting is at 50% and this indicates 0 dB, increasing the power by:
a. 3dB will increase the power output by a factor of 10
b. 6dB will increase the power output by a factor of 2
c. 6dB will increase the power output by a factor of 6
d. 3dB will increase the pwoer output by a factor of 2
d
When scanning using harmonic imaging, the second harmonic frequency is 10 MHz. What is the fundamental frequency?
5MHz
Which of the following describes the best placement for the focal zone when imaging a patient with a high body mass index?
a. use 3 focal zones clustered together at the level of the area of interest
b. single focal zone positioned at the bottom of the image
c. use 2 focal zones clustered together at the level of the area of interest
d. single focal zone positioned just above the level of the area of interest
b
Dynamic focusing refers to:
using the time of flight of pulses to improve resolution
Changing the dynamic range from 50 dB to 75dB will:
increases the number of shades of grey displayed
Applying transducer compression will:
increase sound penetration
What can be used to alter the displayed brightness of the image after it has been stored in the memory?
postprocessing
The _____ is defined as the time it takes for one pulse to occur
pulse duration
Which of the following characteristics of an LCD monitor determines the spatial resolution of the 2D imaging?
a. speed of the digital to analog converter
b. size of the patient
c. number of voxels
d. number of pixels
d
The pulse repetition period in 2D imaging is determined by:
imaging depth
_____ refers to the process of steering the scan lines in multiple views to evaluate tissues with several pulses with varied incident angles
spatial compounding
A system that performs parallel processing will demonstrate:
increased frame rates with reduced lateral resolution
Activating a zoom magnification while imaging a superifical structure is most helpful for reducing what acoustic artifact?
range ambiguity artifact
Increasing the rejection or suppression setting can be used to:
increase the contrast of the image to produce a more black and white image
Which of the following will improve the signal to noise ratio of the image?
a. increasing image depth
b. reducing frequency
c. increasing output power
d. turning on harmonic imaging
increasing output power
Which of the following will improve the signal to noise ratio of the image?
a. reducing rejection
b. increasing overall gain
c. increasing transducer frequency
d. increasing output power
d
Which of the following will increase the spatial pulse length?
a. decrease transducer frequency
b. increase output power
c. decrease output power
d. increase transducer frequency
a
A larger bandwidth leads to:
a. increased spatial pulse length
b. improved axial resolution
c. improved temporal resolution
d. degraded temporal resolution
b
Which of the following correctly describes a difference between read and write magnification?
a. read magnification displays a selected portion of the original image from data stored in the system. Write magnification allows the selection of a region of the image to display and the US system rescans the area to produce a new image
b. read magnification is a pre-processing function. Write magnification is a post-processing function
c. write magnification displays a selected portion of the original image from data stored in the system. Read magnification allows the selection of a region of the image to display and the US system rescans the area to produce a new image.
d. Read magnification offered improved spatial and temporal resolution. Write magnification has no effect on resolution
a
Which of the following sound wave characteristics is adjustable by the Sonographer?
a. propagation speed of the element
b. intensity
c. wavelength
d. period
b
The _____ of a wave multipled by the number of cycles in the pulse will calculate the pulse duration
period
The imaging depth is increased and temporal resolution is degraded. Which of the following console adjustments can improve the temporal resolution?
a. add a focal zone
b. reduce the sector size
c. increase persistence
d. increase the line density
b
Which system control will simultaneously enhance far field echoes and diminish near field echoes?
time gain compensation
What is the difference between spatial compounding and persistence?
The imaging angle is varied between frame with spatial compounding, while persistence averages data obtained from frames obtained at the same angle
Clutter artifact in the near field is obscuring essential anatomy. Which system setting should be activated to improve the near field image?
harmonic imaging
Harmonic imaging leads to:
a. improved axial resolution but degraded lateral resolution
b. increased side lobe production
c. decreased image clutter
d. decreased signal to noise ratio
c
While imaging the thyroid, you increase the number of focal zones from one to three. How will this affect the image?
degraded temporal resolution
Which of the following correctly lists how to estimate the volume of a structure on 2D imaging?
a. length x width x height x 100%
b. length x width x height x 0.523
c. length x width x height
d. length x width x 0.523
b
Which of the following system controls is used to improve signal to noise ratio and reduce specular reflection type artifacts?
a. transmit gain
b. compound imaging
c. output power
d. receiver gain
b
How is focusing performed using the reflected portion of the beam?
varying the number of PE elements used to receive the reflected echoes
If each image requires 50 acoustic pulses and your system displays 30 images per second, what is the PRF?
1500 Hz
Which of the following is NOT adjustable by the Sonographer?
a. compression
b. demodulation/detection
c. compensation
d. amplification
b
Reducing or eliminating posterior shadowing and enhancement is a disadvantage of:
spatial compounding
______ increases the strength of all of the reflected signals, regardless of the reflector depth.
overall gain
Which of the following will not change with an increase in gain settings?
a. number of echoes displayed
b. reflection amplitude
c. signal to noise ratio
d. brightness of the image
c
How many shade of grey will a 6 bit system display?
64
What portion of the TGC curve is the deepest region attenuation compensation can occur?
knee
The ultrasound image is usually created using all of the reflected frequencies in a pulse. When using ______ the reflected frequencies are divided into smaller sections and each of the sections is used to create an image.
frequency compounding
Which of the following is recommended for 2D imaging patients with high body mass index?
a. increase dynamic range
b. deactivate harmonic imaging
c. deactivate coded excitation
d. activate parallel processing
b
While scanning, you decide to increase the image contrast. What console control will be adjusted?
increase rejection
What system component determines the initial amplitude of the ultrasound wave?
the transducer
What system control should be turnedd off when attempting to demonstrate posterior enhancement from a suspected cyst?
spatial compounding
If the entire image is too bright, what is the best way to adjust the image to the appropriate brightness level?
adjust the power output
Activating harmonic imaging will result in:
a. increased beam diameter
b. improved contrast resolution
c. increased production of grating lobes
d. degraded lateral resolution
b
Which of the following system controls is used mainly in cardiac imaging to correct for dropout on the sides of the images?
a. lateral gain
b. post-processing
c. 3D image rendering
d. 2D priority
a
B-color can be helpful in the evaluation of:
a. anechoic fluid/cysts
b. high velocity blood flow
c. subtle differences in tissues
d. low velocity blood flow
c
In B-mode imaging, the x-axis indicates _____ and the z-axis indicates ______
reflector depth
reflector brightness
If you increase the sector angle from 45 to 90 degrees and no other console changes are made, what happens to the frame rate?
it is reduced to 1/2 the original frame rate
If beam intensity decreases from 10mW/cm^2 to a level of 2.5 mW/cm^2, the output power was adjusted by:
-6dB
The spatial resolution on a CRT monitor is directly related to:
the number of lines per frame
If the lines per frame increases and the depth remains the same, what other system parameter must change for sound wave production?
PRF
For an US system to produce a real time flicker free image the minimum frame rate required is _____
15 Hz
What console setting can be changed to adjust the propagation speed of the transmitted wave?
none, propagation speed is determined by medium only
Decreasing the PRP leads to:
a. a decrease in the maximum depth that can be imaged
b. improved spatial resolution
c. improved elevational resolution
d. an increase in the maximum depth that can be imaged
a
The more bits per pixel, the _____ shades of grey on the image and ______ improves.
more
contrast resolution
If the time to produce a single image frame increases, how will temporal resolution be affected?
degrades
Assuming line density is constant at two lines per degree and you change from a 45 degree sector to a 90 degree sector, how many lines will now be produced?
180
Which of the following correctly describes dynamic receive focusing?
a. it is a function of the pulser
b. allows focusing at multiple depths on the image
c. can only be performed in single element transducers
d. adjusted by Sonographer by adding or removing focal zones
b
Which of the pulses produced from a 7 MHz transducer would have the best lateral and axial resolution?
a. 8 mm beam diameter, 2 pulses per cycle
b. 8 mm beam diameter, 8 pulses per cycle
c. 2 mm beam diameter, 8 pulses per cycle
d. 2 mm beam diameter, 3 pulses per cycle
d
What is the contrast resolution for a system with a 4 bit memory and 32dB dynamic range?
2 dB/shade
Fill-in interpolation will:
a. improve spatial resolution
b. improve elevational resolution
c. reduce contrast resolution
d. reduce temporal resolution
a
If two calcifications are located side by side in the liver with a 3mm distance between them and the beam width is 6mm, how will the structures appear on the image?
as a single elongated horizontal reflection
Increasing the pulse repetition frequency improves:
a. the pulse duration
b. spatial pulse length
c. temporal resolution
d. the PRP
c
A 4 bit memory will demonstrate ____ shades of grey.
16
As transducer frequency increases:
a. lateral resolution will improve, but axial resolution will be degraded
b. lateral resolution will be degraded, but axial resolution will improve
c. axial and lateral resolution will improve
d. axial and lateral resolution will be degraded
c
Some US systems allow you to adjust the beam thickness or slice thickness. Decreasing the slice thickness will primarily improve ______ resolution
elevational
The imaging PRF is set to a level of 14 kHz. This can also be written as _____Hz
14,000
Curved PE elements and acoustic lenses will improve which two types of resolution?
elevational
lateral
____ resolution is defined as the ability of an ultrasound system to differentiate structures on an image based on variations in the brightness of the echo/pixel
contrast
Increasing the sector size increases:
the number of pulses per image
If the dynamic range is 64 dB and there are 32 shades of grey, what is the contrast resolution?
2 dB/shade
Focusing of the transmitted and received beam occurs in the:
beam former
To maximize reflections from a specular reflector, the sonographer should manipulate the transducer until the ultrasound beam strikes the specular interface at precisely:
90 degrees
Mispositioned focal zones can lead to excessive _____
volume averaging artifact
Which of the following system functions converts the received signal from radiofrequency form to amplitude form?
a. compression
b. bandpass filtering
c. demodulation/detection
d. coded excitation
c
You are using a 5 Mhz transducer to perform pulsed wave Doppler on the carotid arteries. You change to a 7.5 MHz continous wave Doppler transducer to evaluate blood flow. How will this affect the propagation speed in the soft tissue of the neck?
remains constant
Which system component converts the scan line data into image format for display?
image processor
Which of the following acronyms refers to the standard image file storage format used in medical facilities in the United States?
a. MPEG
b. DICOM
c. AVI
d. JPEG
b
______ is defined as the ratio of particle pressure to particle velocity at a given point within the US beam
impedance
When sound hits a boundary between two media of the same propagation speed at oblique incidence:
a. at least 50% reflection occurs
b. no refraction will occur
c. 100% reflection occurs
d. the entire beam will be refracted causing multiple refraction artifacts
b
As more reflections occur with reverberation, they each become ______ and are placed _______on the image
weaker
deeper
Greater than 90% of the US beam will be reflected at an interface between:
a. muscle and fat
b. fat and liver
c. gas and tissue
d. peritoneum and muscle
c
Which of the following is a function of the pulser used to increase the signal to noise ratio?
a. temporal compounding
b. coded excitation
c. dynamic receive focusing
d. mechanical index
b
What component of the beam former protects the sensitive circuitry of the amplifier?
transmit/receive switch
There is 100% reflection when the beam strikes an interface at _______
critical angle
Using a high MI setting in contrast imaging will:
a. reduce the signal to noise ratio but decrease exam time
b. improve the signal to noise ratio, but increase exam time
c. cause tissue damage to the patient
d. reduce bubble destruction and exam time
b
Which of the following will result in the artifactual echoes displayed lateral to the reflector?
a. mirror image and clutter artifacts
b. speckle and reverberation artifacts
c. propagation speed error and comet tail artifacts
d. refraction and grating lobe artifacts
d
An area of low pressure and particle density on a pressure wave is referred to as ______
rarefaction
Which of the following is a necessary machine setting when performing a contrast evaluation of the heart?
a. high mechanical index values
b. low mechanical index value
c. harmonic imaging off
d. low PRF color Doppler setting
b
Diffuse reflection:
a. occurs when the beam strikes a large smooth surface
b. occurs when the beam strikes a larger rough surface
c. is also called specular reflection
d. when a structure contains high levels of calcium
b
Time gain compensation is necessary due to:
a. attenuation
b. scatter
c. reflection
d. all of the above
d
______ is the process that is performed in the beam former where the output voltage is varied to decrease the formation of lobe artifacts
apodization
Rayleigh scatterer increases with:
a. high velocity blood flow
b. decreasing depth
c. increasing probe frequency
d. temperature elevation in tissue where US beam passes through
c
Scatter is defined as:
redirection of the sound beam in several directions away from the transducer
Always transport the patient’s IV bag _____ and the urinary catheter bag _______
above the heart
below the bladder
Which of the following correctly describes how to identify an inpatient in a hospital setting?
a. ask the nurse to identify the patient
b. locate the patient chart typically stored at the foot of the bed
c. ask the patient to give their name
d. locate the wrist band with their information printed on it
d
_______ is defined as the bending of waves around a small obstacle and the spreading out of waves past small openings
diffraction
If an ellipse is used to document the circumference of a structure, what unit will be used to report the measurement?
cm
Snell’s law describes what acoustic principle?
refraction
Which of the following will improve signal to noise ratio of the image?
a. use of ultrasound contrast
b. increasing overall gain
c. reducing rejection
d. decreasing output power
a
Which setting should be lowered to the minimum level when beginning to evaluate the patient using the orbital window?
output power
When using virtual beam forming the ultrasound beam is described as:
laser thin
What is the most serious potential complication of a microbubble contrast exam?
respiratory distress
The average attenuation of ultrasound in soft tissue is:
0.5 dB/cm/MHz
If the amplitude of the sound wave doubles, what happens to the beam intensity?
increases by a factor of 4
Which of the following describes the difference between side lobes and grating lobes?
a. grating lobes are seen with curved arrays and side lobes are seen with linear arrays
b. grating lobes are seen with arrays and side lobes are seen with single element probes
c. grating lobes are corrected by subdicing and apodization is used to correct side lobes
d. grating lobes are corrected by apodization and subdicing is used to correct side lobes
b
If 60% of the beam is transmitted, what percent is reflected to the transducer?
40%
On the region of interest in a 3D system, the x-axis represents the _____ and the y-axis represents the ______
width of the box
height of the box
If the reflector dimensions are less than the wavelength of the pulse, _____ occurs
rayleigh scatterer
The speed of sound in tissue is primarily dependent on:
the media in which the sound travels t
Federal regulations require that imaging studies be retained for a period of:
6 years
Which of the following variables has the most significant effect on propagation speed?
a. temperature
b. stiffness
c. density
d. frequency
b
What part of the ultrasound system is responsible for changing the element function back and forth from transmit to receive?
beam former
As a pulse travels through a medium, the amplitude of the pulse _____
decreases
Which of the following sound wave parameters varies as the propagation speed changes in different media?
a. wavelength
b. period
c. PRF
d. frequency
a
What is the best way to determine if a displayed structure is real or an image artifact when scanning?
use multiple imaging windows to evaluate the area
When frequency increases:
a. the wavelength decreases because they are indirectly related
b. the wavelength decreases because they are directly related
c. the wavelength increases because they are indirectly related
d. the wavelength increases because they are directly related
a
Which of the following describes a primary difference between virtual beam forming and traditional pulse echo imaging?
a. virtual beam forming requires only one PE element, which allows for a very lightweight transducer
b. virtual beam forming allows for cordless transducers
c. virtual beam forming does not use transmit focusing like pulse echo imaging
d. virtual beam forming requires only one transducer for all types of ultrasound exams
c
Which of the following artifacts cause the appearance of false echoes beside the actual structure on the image?
a. refraction artifacts and mirror image artifacts
b. lobe artifacts and refraction artifacts
c. speckle artifacts and twinkle artifacts
d. lobe artifacts and mirror image artifacts
b
What leads to the increased propagation speed of sound in the media in which it travels?
increased stiffness
A 7 MHz pulse is attenuated ______ after is passes through 2cm of soft tissue
7dB
A large fatty mass is identified in the liver parenchyma. The diaphragm appears to have an irregular border and is difficult to assess in the area posterior to the mass. Why?
misregistration of anatomy posterior to the mass due to slower speed of sound in fat
Higher duty factors increase the risk of:
a. thermal bioeffects
b. microcavitation
c. heating the transducer above the Curie point
d. electrical shock to the patient
a
Diagnostic ultrasound is described as frequencies greater than:
2MHz
Which of the following describes th ebest way to identify an unconscious patient?
a. verify that the name on the chart matches the name on the order
b. check the hospital wristband on the patient’s arm
c. ask the patient to give you their birthdate
d. ask the patient to give you their medical record number
b
Multiplying density of the tissue by propagation speed in the tissue will provide a value for what tissue characteristic?
acoustic impedance
The range equation is used to determine the:
distance to a reflector
The amount of energy that is transmitted versus reflected at a media boundary depends on which of the following?
a. amount of difference in acoustic impedance
b. output power
c. transducer frequency
d. beam intensity
a
If media 1 has an impedance of 65 rayls and media 2 also has an impedance of 65 rayls, what percentage of the beam will be reflected at their interface?
0%
An area of high pressure and particle density on a pressure wave is referred to as a _______
compression
What system component is responsible for 3D image acquisition and presentation?
image processor
Which of the following best describes ultrasound?
a. a mechanical vibration transmitted through a medium as a transverse wave
b. an electric vibration transmitted through a medium in the form of a wave
c. a thermal wave transmitted through a medium
d. a mechanical vibration transmitted through a medium as a longitudinal wave
d
Which of the following exams would require the storage of a 2-3 second digital clip of the real time image?
a. documentation of needle placement in a thyroid biopsy
b. Color Doppler evaluation of renal perfusion
c. PW Doppler evaluation of venous reflux
d. evaluation of the wall motion of the left ventricle
d
The greatest intensity and amplitude of the second harmonic reflections are located:
a. at the level of the focal zone
b. in the far field
c. within 4 cm of the transducer face
d. in the near field
a
The angle at which total reflection occurs is called the:
critical angle
Which of the following is the most attenuating?
a. full urinary bladder
b. moderately fatty liver
c. 2.5 cm gallstone
d. 2.5 cm renal cyst
c
When the US beam is absorbed by the medium, energy is lost in the form of:
heat
Which law of physics describes the refraction of sound at the boundary between two media with different propagation speeds?
Snell’s law
Which of the following requires heatlh care providers and organizations to develop and follow procedures that ensure the confidentiality and security of protected health information?
a. stark law
b. ALARA principle
c. Health insurance portability and accountability act
d. informed consent
c
If an ellipse is used to document the area of a structure, what unit will be used to report the measurement?
cm squared
Which of the following imaging techniques would be used to best evaluate the volume of an irregular mass?
a. harmonic 2D imaging in at least three imaging planes
b. 3D rendering
c. harmonic 2D imaging in at least two imaging planes
d. elastography
b
Which of the following tissue interfaces will cause the greatest amount of specular reflection?
a. liver parencyma-IVC
b. liver parenchyma- diaphragm
c. rectus abdominis muscle - subcuteaneous fatty tissue
d. renal parenchyma - renal sinue
b
If the amplitude of a wave decreased be one half, the intensity _____
decreases the 1/4 the original intensity
If media 1 has an impedance of 65 rayls and media 2 also has an impedance of 65 rayls, what percentage of the beam will be transmitted at their interface?
100%
Increasing transmit output power will increase the risk of bioeffects and:
a. improve the axial resolution
b. improve the temporal resolution
c. the signal to noise ratio
d. the PRF
c
If there is a focal disruption in perfluorocarbon contrast display in the area of interest at the level of the focal zone, what should be done to improve the image?
a. increase the output power
b. move the focal zone to a more anterior location
c. activate harmonic imaging
d. switch to saline contrast
b
