URR part 3 Flashcards
The location of the ultrasound beam where the diameter is the most narrow is called the:
focus
The Focal Zone is the region around the focus where the beam is:
relatively narrow
_____ has half of its portion located in the Fresnel zone and half of its portion located in the Fraunhofer zone.
focal zone
According to the Doppler equation, for any given velocity, the frequency shift will increase by increasing the:
transmit frequency
Which of the following predicts the onset of turbulent flow?
a. concentration of energy
b. continuity rule
c. aliasing
d. Reynolds numer
d
While evaluating arteries in the body with color Doppler, you are unable to obtain signals from the deeper vessels. What should you do to enhance your ability to demonstrate deep flow?
decrease the ultrasound frequency
Which of the following helps improve the axial resolution in a B-mode image?
a. increase the aperture size
b. increase the bandwidth
c. use focusing with an acoustic lens
d. increase dynamic range
b
Noise arising from small amplitude sound waves intering with each other is called what?
acoustic speckle
What appears as very small amplitude echoes from electrical interference that affects low level echolucent areas?
noise
How many bits are required to display 15 different shades of gray?
4
Line density in a rectangular image is:
the number of scan lines per centimeter
Which of the following will have the greatest improvement of temporal resolution?
a. double the line density and decrease depth by half
b. double the persistence and scan structures more shallow
c. decrease depth from 10 cm to 5 cm and reduce scan lines by half
d. change frequency from 3 MHz to 6 MHz and decrease the line density by half
c
Which of the following is the most appropriate response when a patient refuses an exam?
a. immediately stop the exam and leave
b. convince the patient that the doctor really wants the exam and proceed
c. ignore the patient’s request and continue as planned
d. place restraints and/or sedation and proceed with examination
a
The two most common color mays used in color flow imaging are:
variance and velocity
The velocity scale on the color map is 17 cm/s. If the flow direction is at zero degrees to the sound beam axis, the colors on either end of the bar would represent:
an average velocity of 17 cm/s
You are performing 3D sonography and notice the volume rate is 8 Hz. What does this represent?
number of volumes displayed per second
How many frames must be presented for the human eye to perceive the display without flickering?
30
Which of these is a binary number?
a, 12211221
b. 10000000
c. 98765432
d. 01010102
b
When practicing universal precautions, you should do all of the following except:
a. wash gloves between exams for reuse from one patient to another
b. wash hands immediately after gloves are removed
c. change gloves when moving from one patient to another
d. wear face masks or eye protection whenever there is a possibility of blood splashing into your face
a
When an ultrasound system creates an image in 1/20 of a second, what will be the frame rate?
20 Hz
Which of the following will improve temporal resolution?
a. more pulses per scan line
b. longer time frame
c. longer go-return time
d. low line density
d
Which of the following describes a narrow dynamic range?
a. low contrast
b. low compression
c. bistable
d. low grayscale
c
____ is the number of oscillations per unit of time
the frequency of the sound wave
Sonographic images are usually compressed before sending to PACS in order to:
reduce the time to transmit the image
What is the smallest amount of computer memory?
bit
Which of the following is true regarding write magnification?
a. the ultrasound system scans the anatomy and displays only the original data
b. the image is converted from digital to analog form
c. this is a form of post processing
d. the number of pixels and scan lines increase
d
Which of the following will create fewer pulses?
a. single focus
b. multi-focus
c. high line density
d. backing material
a
Transducers used in therapeutic ultrasound have a:
a. low quality factor
b. high quality factor
c. contain a backing layer
d. have a wide bandwidth
b
Spatial resolution is also known as:
detail resolution
Pixel density is the number of picture elements per:
inch
What is the order in which the signal travels in the ultrasound system?
transducer, receiver, scan converter, display
When you “freeze” the ultrasound image, where is the echo information stored?
scan converter
Selective reception of echoes generated within the body by nonlinear propagation describes:
tissue harmonic imaging
Which artifact is associated with resonance of a gas bubble?
ring down
_____ is a new way of displaying diagnostic information contained in a static or dynamic 3D dataset.
tomographic ultrasound imaging
LATA stands for:
lateral
angular
transverse
azimuthal
3D imaging is sometimes called what?
4D imaging
All of the following are synonyms for main frequency EXCEPT:
a. center
b. resonant
c. primary
d. bandwidth
d
The thickness of the matching layer is:
1/4 the wavelength of the transducer
What is the time needed to make a single image if the frame rate of ultrasound system is 50 Hz?
0.02 seconds
How many frames are created per second using 100 Hz?
100 frames per second
Which of the following is an advantage of coded excitation?
a. penetration
b. improved lateral resolution
c. improved temporal resolution
d. shorter pulse repetition period
a
Which of the following determines the frequency of sound created by a pulse wave transducer?
a. the thickness and speed of the crystals
b. the electrical signal created by the ultrasound system
c. the number of crystals
d. whether the crystals are natural or man-made
a
Which of the following are characteristics of low frequency pulsed wave imaging transducers?
a. thin crystals with lower PZT speeds
b. thin crystals with higher PZT speeds
c. Thick crystals with lower PZT speeds
d. thick crystals with higher PZT speeds
c
A voltage ratio of 1000 to 1 would result in a dynamic range of:
60 dB
The AIUM maximum intensity limit set for a sound beam is:
100 mW/cm squared
Which of the following will reduce blood viscosity?
a. a hematocrit value of 45%
b. decreasing the length of a vessel
c. anemia
d. increasing the diameter of a vessel
c
Which of the following does NOT affect the number of pulses in a single image?
a. the number of scanning lines
b. the maximum scanning depth
c. line density
d. sector size
b
The AIUM maximum intensity limit set for unfocused sound is:
0.1 W/cm squared
Temporal resolution is affected by all of the following EXCEPT:
a. imaging depth
b. the time necessary to create each image
c. the number and size of the pixels in the image
d. pulse inversion
c
Sound will travel slower in:
a. areas where the bulk modulus has a smaller value
b. a linear sound wave behavior
c. regions of refraction
d. regions of compression
a
In order to use contrast enhancing agents, which of the following below is not required?
a. must be a strong reflector of ultrasound
b. must be small enough to pass through arterioles
c. must be metabolically safe
d. must be safe
b
A low mechanical index creates:
a. backscatter
b. strong harmonics
c. resonance
d. non-linear behavior
a
Which of the following is directly related to patient exposure?
a. contrast agents
b. output power
c. receiver gain
d. dynamic range
b
What part of the image is degraded when the image is too bright due to high output power?
lateral and longitudinal resolution
Which of the following is NOT adjustable by the operator?
a. compensation
b. demodulation
c. amplification
d. rejection
e. compression
b
Which of the following will improve the ability to measure the maximum velocity Doppler?
a. increase the PRP
b. eliminating aliasing
c. use a transducer with one crystal
d. decrease the PRF
b
Which of the following is true regarding pulse wave Doppler?
a. can measure very high velocities accurately
b. utilizes two crystals, one to transmit and one to receive
c. NEVER encounters range ambiguity
d. have echoes arising from the entire length of the overlap between the transmit and the receive beams
c
How many bits are required to display 14 different shade of gray?
4
each bit = __ shades of gray
2
So far, there is minimal evidence that cavitation really occurs in diagnostic US. Current data indicates that cavitation can occur in mammals at SPTP intensities exceeding:
3500 W/cm squared
What is the highest output intensity used in ultrasound?
pulsed Doppler
The portion of the TGC curve that compensates for the effects of increasing attenuation that result from increasing path length is called what?
slope
Which of the following does not belong with the group?
a. rejection
b. suppression
c. threshold
d. rectification
d
The process of converting electrical signals within the receiver to a more suitable form for CRT is called what
demodulation
The AIUM maximum intensity limit set for focused sound is:
1 W/cm squared
Unfocused beams are:
a. more likely to cause temperature elevation in tissue
b. only related to temperature elevation in non-living objects
c. less likely to cause temperature elevation in tissue
d. have never been correlated with temperature elevation in tissue
a
The difference between the far gain and the knee on the TGC curve is:
a. far gain indicates the maximum compensation that the receiver can provide and the knee represents the maximum reflections that can be compensated by the ultrasound system
b. far gain indicates the maximum compensation that the switch can provide and the knee represents the maximum reflections that can be compensated by the beam former
c. far gain indicates the maximum compensation that the ultrasound system can provide and the knee represents the maximum reflections that be can compensated by the receiver
d. far gain indicates the maximum compensation that the beam former can provide and the knee represents the maximum reflections that can be compensated by the switch
a
All of the following modes has an x-axis that represents depth EXCEPT:
a. M-mode
b. A-mode
c. B-mode
a
Any exam that causes an elevation in temperature of ____ may be used without reservations
less than 2 degrees celcius
Sound will travel faster in:
a. in areas that are less compressible and with less elasticity
b. regions of compression
c. regions of rarefaction
d. a linear sound wave behavior
b
Which of the following describes the mechanistic approach for study techniques involving biologic effects?
a. correlate exposure and effects
b. acquire/review data from patients or animals
c. identify exposure-response” relationship
d. Theoretical analysis to estimate scope of bioeffects at various exposures
d
Which of the following does not belong with this group?
a. normal
b. shear stresses
c. transient cavitation
d. inertial cavitation
b
Which of the following does not belong in this group?
a. time gain compensation
b. swept gain
c. depth gain compensation
d. receiver gain
d
Which of the following does not belong with the group?
a. high duty factor
b. low pulse repetition frequency
c. short pulse repetition period
d. shallow imaging
b
Which of the following does not belong with this group?
a. suppression
b. compression
c. dynamic range
d. log compression
a
What is the cosine of 0 degrees?
1
The best epidemiological studies are:
a. prospective and designed
b. retrospective and observational
c. retrospective and controlled
d. prospective and randomized
d
A high mechanical index:
a. is low beam strength
b. is created by linear behaviors
c. does not create harmonics
d. is created from the lowest frequency of sound
d
The portion of the TGC curve responsible for indicating the maximum amount of compensation that the receiver can provide is known as what?
far gain
What is the least output intensity used in ultrasound?
gray scale imaging
Focused beams are:
a. have never been correlated with temperature elevation in tissue
b. only related to temperature elevation in nonliving objects
c. less likely because temperature elevation in tissue
d. more likely to cause temperature elevation in tissue
c
All of the following modes have a y-axis mode except:
a. m mode
b. a mode
c. b mode
c
The problem with thermal mechanism is:
a. fetal soft tissue adjacent to vital organs are of great concern
b. fetal soft tissue adjacent to the focal point of the beam are of great concern
c. fetal soft tissue close to the near field beam are of great concern
d. fetal soft tissue adjacent to bone is of great concern
d
The mechanical index is more likely to cause cavitation with:
a. higher pressures and lower frequencies
b. higher pressures and higher frequencies
c. lower pressures and higher frequencies
d. lower pressures and lower frequencies
a
Which of the following does not belong in this group?
a. microstreaming
b. shear stresses
c. highly localized
d. bubbles do not burst
c
Which of the following regulates system and transducer outputs?
a. nuclear regulatory commission
b. the environmental protection agency
c. world health organization
d. the food and drug administration
d
Which of the following is known as the effects of the medium upon a sound wave?
a. Biologic effects
b. acoustic propagation properties
c. mechanical index
d. thermal index
b
Which of the following uses multiple ultrasound pulses to accurately determine red blood cell velocities by Doppler?
a. Fast Fourier transform
b. autocorrelation
c. ensemble length
d. pulse wave Doppler
c
Which of the following has the most effect on color jet size?
a. pulse repetition frequency
b. mechanical index
c. output power
d. Color Doppler gain
d
Sound travels:
a. in a vacuum
b. in a straight line
c. in a sine wave before traveling through tissue
d. in the form of a transverse wave
b
During a Doppler examination, flows in an adjacent artery and vein are measured simultaneously. What will you hear in the right ear cup of your headphone?
a. turbulent flow
b. parabolic flow
c. pulsatile flow
d. venous flow
d
What is the name of the flat flow profile that is seen at the entrance of vessels?
plug flow
Which of the following is seen with continuous wave instrumentation?
a. sample depth can be determined by a range gate
b. transducer frequency matches that of the oscillator
c. very short pulses are used
d. aliasing limits velocity measurements
b
Which of the following transducers can be used to safely scan the patient?
a. betadine infiltration of the matching layer
b. rubber coating on the face of the probe separating from housing
c. pin hole in the rubber coating on the face of the probe
d. bent connector pins at the transducer port
a
During your first exam of the day, you notice a small crack in the face of the transducer. Which of the following describes the correct action to take next?
a. contact service immediately but you can use the transducer with a stand off pad until the new one arrives
b. no action needed unless the piezoelectric elements are exposed
c. no action needed unless the electrical components are exposed
d. contact service immediately and the damaged probe should not be used until it is repaired
d
If a renal artery Doppler exam demonstrates stenosis and stenosis is identified on angiography evaluation, the US results are described as:
true positive
The Centers for Disease control recommend single use sterile ultrasound gel for ultrasound exams performed during which of the following:
a. placement of central venous line
b. scrotal exams
c. venous insufficiency exams
d. 2nd and 3rd trimester OB anatomy exams
a
Which of the following correctly describes the specificity of a testing technique?
a. if a test result is positive, specificity is the probability that the patient actually has the disease
b. the ability of a test to rule out disease when it is not present
c. the ability of a test to detect disease when it is present
d. if the test result is negative, specificity is the probability that the patient does not have the disease
b
Which of the following is true regarding the Curie point of a piezoelectric element?
a. a quartz transducer crystal is heated above the Curie point to initiate the PE effect of the crystal
b. if the active PE crystal is heated to this temperature , the intensity of the beam produced will increase
c. if the active PE crystal is heated to this temperature, the frequency of the crystal will increase
d. If the active PE crystal is heated to this temperature, the element will lose its piezoelectric properties
d
When using a high level disinfectant on an ultrasound transducer, it is important to monitor soak time, rinse time, temperature requirements, ventilation, and ______.
duration of use of solution
Why cant ultrasound probes be thermally sterilized?
if the prove is heated above the Curie point, the piezoelectric properties will be lost.
_______ refers to the ability of a system to detect low-amplitude echoes accurately.
sensitivity
If a renal artery Doppler exam demonstrates normal flow and normal flow is identified on angiography evaluation, the US results are described as:
true negative
What is the proper procedure for removing goggles after performing an ultrasound exam?
remove gloves and grasp the back of the headband and lift up to remove
Transesophageal and transvaginal transducers are considered ______ devices that should be disinfected using ______.
semi-critical
high level disinfectant
Which of the following correctly describes a gold standard test?
a. a type of test that has been used for over 15 years to successfully diagnose disease when it is present
b. an accepted test that is assumed to be able to determine the true disease state of a patient, regardless of positive or negative test findings
c. A type of test that has been used for over 15 years to successfully diagnose rule out disease when it is absent
d. a test that is preferred by most doctors to make a specific diagnosis
b
Which of the following correctly describes the calibration procedure for the ultrasound display monitor?
a. adjust brightness and contrast levels until the first and last block on the color bar blend into the overall screen color
b. adjust brightness and contrast levels until the middle block on the color bar blends into the overall screen color
c. adjust brightness and contrast levels until the first block on the color bar blends into the overall screen color
d. adjust brightness and contrast levels until the last block on the color bar blends into the overall screen color
c
If you set the gain to the lowest level and slowly increase it until an echo is identified on the image, what are you evaluating on the US system?
minimum sensitivity
Which of the following would lead to misregistration of data and incorrectly placed pixels in a deeper than normal location on the image?
a. when less than 75% beam transmission occurs
b. the ultrasound system is calibrated to 1600 m/s as the speed of sound in soft tissue
c. the ultrasound system is calibrated to 1450 m/s as the speed of sound in soft tissue
d. a highly reflective media boundary
c
Which of the following correctly describes the negative predictive value of a testing technique?
a. if the test result is positive, NPV is the probability that the patient actually has the disease
b. the ability of a test to rule out the disease when it is NOT present
c. The ability of a test to detect disease when it IS present
d. If the test result is negative, NPV is the probability that the patient does not have the disease
d
Which of the following statements is correct regarding inspecting a endocavity probe for a potential electrical hazard?
a. The probe head may separate slightly from the housing and it presents no hazard to the patient unless the wiring and internal components are exposed
b. normal use of disinfecting agents can lead to damage of the probe coating which will cause a risk of electrical hazard
c. scratches to the lens of the probe only degrade the image production and are unrelated to electrical hazard
d. bite marks on the rubber coating on the probe are a common finding and present no hazard to the patient
b
Which of the following correctly describes the sensitivity of a testing technique?
a. the ability of a test to detect disease when it is present
b. if the test result is positive, sensitivity is the probability that the patient actually has the disease
c. the ability of a test to rule out disease when it is NOT present
d. if the test result is negative sensitivity is the probability that the patient does not have the disease
a
You notice the cord of the echo transducer is slightly separated from the back of the probe. Which of the following describes the appropriate action to take next?
a. continue scanning as normal. As long as the wiring is unaffected, there is no hazard to you or the patient
b. place a service call for the probe and reschedule all patients until it is repaired
c. Use rubber cement to fill the small gap and resume scanning when it has dried
d. locate some electrical tape and wrap the area until the probe can be replaced
b
Which of the following describes how the ultrasound transducer should be disinfected after performing an ultrasound exam on a patient that has an open would near the area of interest?
a. the probe should be sent to the biomedical department for thermal sterilization
b. an arterial Doppler exam should not be performed on a patient with an open sore or wound
c. The face of the probe and the cord are thoroughly cleaned and soaked in a high level disinfectant
d. the face of the probe and the cord are thoroughly cleaned with a Saniwipe
c
Which of the following describes a normal result for uniformity testing of the ultrasound system?
a. TGC set to produce an image with equal echo amplitude across the screen and then when the TGC function is turned off, the echoes in the far field are reduced in amplitude
b. all images in a randomly selected exam demonstrate a constant mechanical index
c. images taken of the same structure with different probes of the same frequency demonstrate uniform echo amplitude between the compared images
d. all images in a randomly selected exam demonstrate a constant thermal index
a
If you use a tissue phantom that contains a substance with an average propagation speed of 1600 cm/s to evaluate a standard ultrasound system, how will this affect the depth calibration testing?
reflectors will appear more shallow than they are actually located within the phantom
Which of the following statements is true regarding damage to the matching layer of the transducer?
a. it causes an increase in the intensity of the beam and increased exposure to the patient
b. it causes an increased risk of electrical shock to the patient
c. the use of more acoustic gel is required to increase the distance between the probe and the skin surface
d. it is normal for it to develop small boles after extended use
b
Which of the following is seen with continuous wave instrumentation?
a. sample depth can be determine by range gate
b. transducer frequency matches that of the oscillator
c. very short pulses are used
d. aliasing limits velocity measurements
b
Which of the following will not eliminate aliasing?
a. increasing the frequency shift above the Nyquist limit
b. decreasing the sample depth
c. increasing the Nyquist limit above the frequency shift
d. increasing the PRF
a
When a reflector moves towards the transducer, what will happen to the reflected frequency?
b
Which of the following has to be increased in order to see an increase in flow volume?
a. pressure difference
b. resistance
c. vessel length
d. viscosity
a
Adjusting which of the following will have no effect on the measured frequency shift?
a. flow velocity
b. operating frequency
c. amplitude
d. propagation speed
c
What is the point at which Reynolds number predicts turbulence?
2000
In an exercising patient, what is the response to peripheral resistance with arteriolar dilatation?
decreases
If a line density increases from 5 lines to 10 lines and the depth changes from 10 cm to 5 cm what happens to temporal resolution?
unaffected
What does steering your color box degrade?
temporal resolution
Which of the following angles below will have the best Doppler shift?
a. 45
b. 90
c. 160
d. 5
d
A small group of elements are not working in a linear sequential. What type of artifact can you expect to see?
vertical black line
If you have two tranducers, one 5 MHz and one 10 MHz, which one has a true propagation speed?
both transducers
While scanning a patient, what degree of angle should your arm be bent at?
30 degrees
You see a simple cyst while scanning, what type of artifact will you see once you place your probe?
posterior enhancement
Which of the following poses the greatest risk to the patient?
a. output power
b. Pulse wave Doppler
c. temperature elevation of 2 degrees Celcius for 40 hours
d. cracked transducer
d
A high beam strikes a boundary, If the beam reflection is high, which of the following is tee?
a. there is minimum reflection and high transmission
b. there is maximum reflection and low transmission
c. There is minimum reflection and minimum transmission
d. There is maximum reflection and maximum transmission
b
A family member brings in a patient who does not speak English, which of the following is the best acceptable option to translate?
a. a sonographer you work with can translate
b. use a phone app to translate
c. call a hospital interpreter
d. the family member is bilingual and can translate
d
Which transducer has a wide near field and a wide far field?
vector
While using Spectral Doppler imaging, a transducer transmits a 3 MH pulse into the body. The pulse is reflected back to the transducer at 3.999 MHz. The pulse will display where on the screen?
above the baseline
Which is best useful for imaging structures in the dead zone?
a. increasing transmitting frequency
b. acoustic standoff
c. ultrasound gel between the transducer and patient
d. larger footprint
b
The benefit of using pulse wave Doppler over continuous wave Doppler is what?
determines the unlimited depth of the velocity
You are using a PRF of 16 Hz, what is the Nyquist limit?
8 Hz
How do you reduce crosstalk?
decrease spectral gains
If you have multiple focal zones, what does this do to your temporal resolution?
decreases
A high beam strikes a soft tissue- soft tissue boundary. Which of the following is true?
a. there is minimum reflection and high transmission
b. there is maximum reflection and low transmission
c. there is minimum reflection and minimum transmission
d. there is maximum reflection and maximum transmission
a
Coded excitation improves which resolution?
contrast resolution
13 us time of flight =
reflector is 1 cm from the transducer
26 us time of flight =
reflector is 2 cm from the transducer
39 us time of flight =
reflector is 3 cm from transducer
defined as the ratio of particle pressure to particle velocity
impedance
determines the amount of sound wave that is transmitted versus reflected
impedance
directly related to density and propagation speed of the medium
impedance
increased density = _____ impedance
increased
increased propagation speed = ______ density
increased
density of medium x propagation speed =
impedance
Units: Rayls
impedance
The larger the difference in impedance of the two media, the ____ the amount of reflection at their boundary/
greater
If two media have the same propagation speed, but one has greater impedance than the other, the medium with the higher impedance must be more _____
dense
Us gel is used to reduce the change in _____ between the probe and the skin = reduced reflection from skin barrier
impedance
% of US intensity that bounces back when the sound strikes a boundary between two media with different impedance
intensity reflection coefficient
% of US intensity that is transmitted deeper into tissue when the sound strikes a boundary between two media with different impedance
intensity transmission coefficient
IRC + ITC =
100% incident intensity
If IRC increases, ITC ______
decreases
If ITC increases, IRC ______
decreases
waves are uniformly redirected in all directions due to nonspecular reflection
Rayleigh scatter
occurs with tissue interface is smaller in size than the incident beam wavelength
Rayleigh scatter
If frequency doubles, Rayleigh scatter:
increases by the fourth power
Sound waves redirected in all directions from the structure
Rayleigh scatter
Rayleigh scatter leads to increased risk of thermal injury due to _______
temperature elevation
also known as diffuse reflection
backscatter
rough boundaries cause reflected sound to become disorganized and random
backscatter
occurs with large, rough, or irregular tissue interface
backscatter
aids in visualization of tissue boundaries that are not perpendicular to the incident beam
backscatter
requires oblique incidence across two media with different propagation speeds
refraction
oblique beam incidence on a media boundary causes the transmitted beam to bend its path once it enters the second media
refraction
_____ in the second media determines the direction of the bend
speed
If the speed in the second media was lower than the 1st media, the bend will be:
away from incident beam to an angle that is greater than the incident angle
_______ is used to calculate the angles or speeds during refraction
Snell’s law
If the speed of sound is the same in the two different media:
no refraction occurs
If the incident angle equals the transmitted angle=
no refraction occurs
defines the physics of refraction
Snells law
used to determine the angles and speed of the transmitted wave
Snell’s law
spreading out of the beam once it passes through a smaller opening or passes over an obstacle
diffraction
change in beam direction that is not caused by reflection, refraction, or scattering
diffraction
Mechanical focusing (lens) leads to ______ diffraction
increased
two PE crystals, one sends and one receives
continuous wave ultrasound
_______ is determined by the frequency of the voltage applied to the crystal
transmitted frequency
Continuous wave Duty Factor
100%
disadvantage of continuous wave
unable to determine range ambiguity
one PE crystal transmits and receives sound waves
pulsed wave ultrasound
_______ determined by crystal thickness and propagation velocity of the PE material
transducer frequency
The majority of the PE crystal is ______ reflected pulses from pulsed wave ultrasound
receiving
Average duty factor of pulsed wave ultrasound
0.01 %
time of transmission for a single pulse
pulse duration
Pulse duration is determined by:
the sound source
Average Diagnostic pulse duration:
0.3 - 2.0 us
2D imaging typically uses __-__ cycles per pulse
2-3
Doppler imaging typically uses __-__ cycles per pulse
5-30
Increasing frequency _____ pulse duration
shortens
Shorter pulses - better ____ resolution
axial
Decrease pulse duration leads to _____ duty factor and ______ PRF
decreased
increased
of cycles x period
Pulse duration
of cycles/frequency
pulse duration
wavelength x # of cycles in pulse
spatial pulse length
length in mm of pulse from start to finish
spatial pulse length
diagnostis US average SPL
0.1 - 1.0 mm
The _____ the SPL, the better the image quality
shorter
Shorter SPL is seen with ____ frequency waves
higher
Increasing the number of cycles in a pulse will _____ SPL
increase
of pulses emitted per second
pulse repetition frequency
PRF is determined by:
the source of the sound
the number of voltage pulses applied to the transducer each second =
The number of ultrasound pulses emitted per second
Pulser PRF =
US PRF =
5 KHz
5 kHz
The technologist can adjust the PRF in 2D imaging by using the ______
depth control
The technologist can adjust 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
Which of the following beam intensity values is used to assess potential patient exposure?
a. SPTA
b. SATA
c. SPTP
d. SATP
a
Which of the following will increase the duty factor of the pulsed ultrasound probe?
a. decreasing the PRF
b. using PW Doppler
c. Decreasing the image depth
d. increase the power output
c
Preferred levels of axial and lateral resolution will demonstrate:
a. widely different numerical values
b. high numerical values
c. low numerical values
d. the same numberical values
c
When scanning the thyroid, you change from a 5MHz probe to a 10MHz probe. Which of the following statements is true?
a. the 2D imaging depth setting are much more limited in the 5MHz transducer
b. the spatial resolution will improve with the 10MHz transducer
c. there will be decreased attenuation with increased penetration with the 10MHz probe
d. the reflected waves will be more quickly received and processed by the 10MHz probe
b
Which of the following ultrasound techniques has the highest temporal resolution?
a. 2D imaging
b. Color Doppler
c. 3D imaging
d. M-mode
d
Which of the following is an advantage of virtual beam forming (VBF) over traditional pulse echo imaging (PEI)?
a. VBF allows for 5 or more transmit focal zones per image with acceptable temporal resolution
b. VBF produces a lower intensity beam than a traditional PEI system
c. VBF allows for improved lateral resolution without degradation of temporal resolution
d. VBF does not require a Sonographer to operate the transducer
c
Which of the following will improve the lateral resolution on the image?
a. decrease transducer frequency
b. decrease the PRF
c. increase the focal zone number
d. adjust dynamic range
c
The gray scale map is adjusted to a new map just after freezing the image. This is an example of?
a. applying postprocessing
b. adjusting dynamic range
c. applying preprocessing
d. adjusting rejection
a
Which of the following can reduce or eliminate range ambiguity artifact?
a. decreasing the PRF
b. decreasing the imaging depth
c. increasing output power
d. using multiple focal zones
a
If the amplifier power output is 2 times the amplifier power input, what is the value for gain?
3 dB
Which of the following is a function of the signal processor?
a. steering and focusing
b. apodization and aperture
c. filtering and compression
d. amplification and compensation
c
Which of the following describes the type of focusing used in an annular phased array?
a. single focal point that is adjustable by the technologist
b. focusing at multiple levels across all depths of the image
c. fixed focus set by the manufacturer
d. mechanical focusing using curved elements
b
Which of the following parameters will change when the Sonographer decreases the imaging depth?
a. decreased frame rate
b. increased PRF
c. decreased PRF
d. improved elevational resolution
b
Lateral resolution is primarily dependent upon:
beam width
Which of the following techniques is described as a graphic representation of the motion of a structure over time?
a. PW doppler
b. B color
c. M-mode
d. Harmonics
c
Which of the following is an advantage of virtual beam forming (VBF) over traditional pulse echo imaging (PEI)?
a. VBF does not require a Sonographer to operate the transducer
b. VBF allows for simultaneous real-time gray scale, color, and spectral Doppler display
c. VBF allows for 5 or more transmit focal zones per image with acceptable temporal resolution
d. VBF produces a lower intensity beam than a traditional PEI system
b
Which of the following image controls is used to counteract beam attenuation?
a. compression
b. persistence
c. rejection
d. time gain compensation
d
Lateral resolution is best at what location in the beam?
focal point
Which type of image resolution is negatively affected by the placement of multiple focal zones at the area of interest?
temporal
Which of the following instrument controls does the sonographer use to adjust the amplitude of a reflected sound wave?
a. transmit gain
b. rejection
c. swept gain
d. receiver gain
d
Amplification of the received signal occurs in the:
beam former
Which of the following is a type of postprocessing that assigns shades of color, instead of grey, to create the image?
a. Color Doppler
b. Power Doppler
c. Contrast Enhanced ultrasound
d. B color
d
Assuming line density is constant at two lines per degree and you change from a 90 degree sector to a 45 degree sector, how many lines will now be produced?
90
Apodization is a function of the:
beam former
_____ resolution is the ability to resolve two closely spaced structures which lie perpendicular to the sound beam
lateral
If the Sonographer increases the size of the field of view, the frame rate will ______
decrease
Which of the following transducers is capable of electronic beam steering?
a. mechanical
b. linear sequential array
c. curvilinear phased array
d. curvilinear sequential array
c
Edge enhancement, pixel interpolation, persistence, and 3D image acquisition are all types of:
preprocessing
Axial resolution is primarily dependent upon:
pulse duration
Which of the following will improve contrast resolution?
a. decreasing frequency
b. receive focusing
c. using a stand off pad
d. coded excitation
d
Which of the following system controls reduces noise and smooths the image using frame averaging?
a. pixel interpolation
b. persistence
c. compression
d. demodulation
b
Spatial compounding:
a. relies on the non-linear behavior of sound waves
b. decreases the signal to noise ratio on the image
c. can decrease the appearance of useful artifacts such as enhancement and shadowing
d. produces a reflection at double the transmitted intensity
c
What system parameter is defined as the ability to differentiate two separate objects on an image?
resolution
An advantage of virtual beam forming over traditional pulse-echo instrumentation is:
a. no transmit focusing is needed
b. one transducer can be used for all exam types
c. no receive focusing is needed
d. the risk of bioeffects is reduced by 50% or greater
a
The Sonographer can improve the axial resolution by:
a. adjusting the dynamic range
b. adjusting the monitor contrast
c. using a higher frequency transducer
d. increasing the demodulation of the signal
c
Contrast resolution is calculated by dividing the dynamic range by the:
number of shades of grey
Pulse-echo systems use strength and _____ of the received signal to create the gray scale image. Magnitude and ______ of the received signal are used to create the Doppler display.
time of flight
direction
Spatial compounding requires a transducer that can perform:
a. electronic focusing
b. electronic steering
c. dynamic frequency tuning
d. harmonic imaging
b
Which of the following imaging parameters is responsible for the ability to resolve two separate cysts that are side by side in the liver?
a. contrast resolution
b. axial resolution
c. dynamic range
d. lateral resolution
d
Which type of resolution improves the most with a short pulse duration?
a. axial
b. elevational
c. lateral
d. contrast
a
What can be done to improve the visualization of the anterior aortic wall?
a. scan from a more lateral approach
b. decrease the threshold setting
c. center the probe with the ultrasound beam perpendicular to the aortic wall
d. increase the compression
c
The vertical axis on the m-mode display represents the ______
depth of the reflector
When you activate Harmonic imaging and add a focal zone to the field of view, which type of resolution will degrade with these changes?
a. contrast
b. axial
c. temporal
d. lateral
c
Which of the following statements is true regarding decreased frame rate?
a. Color Doppler evaluation requires a low frame rate
b. Decreased frame rates are preferred for real time 2D imaging
c. temporal resolution improves as the frame rate decreases
d. increased line density will lead to a decreased frame rate
d
Which of the following transducers would have the best axial resolution?
a. 4mm element thickness
b. 2mm element diameter
c. 2mm element thickness
d. 4mm element diameter
c
Spatial resolution is:
a. the weakest reflected signal the transducer can receive
b. highest with linear phased arrays
c. another term for slice thickness resolution
d. the minimum reflector separation required to produce separate echoes
d
Which system component improves lateral resolution?
pulser
A gain value of 6dB indicates the output power is ______ greater than the input power to the amplifier.
4
Which of the following is a benefit of activating tissue harmonic imaging?
a. degrades axial resolution in near field
b. improves elevational resolution in far field
c. reduces grating lobe and side lobe artifacts
d. increases beam width with improving lateral resolution
c
Elevational resolution is:
a. the weakest reflected signal the transducer can receive
b. highest with linear phased arrays
c. another term for slice thickness resolution
d. the minimum reflector separation required to produce separate echoes
c
Which of the following can be done to reduce the beam divergence?
a. switch to a lower frequency transducer
b. switch to a higher frequency transducer
c. remove an acoustic lens in front of the PE element
d. deactivate dynamic focusing
b
Increasing the number of bits per pixel in an image memory will improve the:
a. contrast resolution
b. detail resolution
c. temporal resolution
d. elevational resolution
a
What is the best way to increase beam penetration/
a. increase output power
b. decrease operating frequency
c. decrease compression
d. increase rejection
b
______ determines the acoustic power of the transducer
the magnitude of the voltage spike
______ is the predominant factor causing attenuation of the US beam and this can be counteracted by _____
sound absorption, increasing the TGC settings for the far field
Which of the following will improve slice thickness resolution?
a. decrease rejection
b. decreasing transmitted frequency
c. decreasing damping levels
d. adding an external focusing lens
d
The ability to differentiate a hyperechoic hemangioma within the hypoechoic liver tissue is due to what type of image resolution?
contrast resolution
If the pulser PRF is 5kHz, what will the ultrasound PRF be?
5kHz
A 5MHz transducer has a PRF of 6kHz and is being used to produce a wave with a 0.6mm wavelength and 3mm spatial pulse length, What is the axial resolution of this system?
1.5mm
If the sonographer decreases the image depth, how will this affect the pulse repetition frequency?
increase
If more cycles are added to a pulse, which of the following types on resolution is degraded?
a. axial
b. lateral
c. spatial
d. contrast
a
Which of the following machine adjustments will produce a more black and white 2D image?
a. reducing overall gain
b. reducing monitor contrast
c. reducing the compression
d. increasing dynamic range
c
The acoustic power is changed by -3dB. The beam intensity _____.
decreases by half
Virtual beam forming significantly improves all types of resolution compared to pulse echo imaging, except:
axial resolution
As frequency increases, the axial resolution will:
improve
Increasing the frequency improves ______, ______, and _____
axial resolution
lateral resolution
beam width
Reducing the size of the field of view improves ______ resolution/
temporal
Which of the following techniques can improve contrast resolution to aid in the visualization of an isoechoic mass?
a. switch to a lower frequency transducer
b. increase the slice thickness
c. decrease the number of focal zones
d. turn on harmonic imaging
d
Transmit delay or Receive focusing improves _____ resolution.
latearl
As frequency increases, penetration will _____
decrease
Lateral resolution is defined as:
a. the ability to differentiate two reflectors that are moving in a direction that is perpendicular to the US beam
b. the ability to differentiate two reflectors that are perpendicular to the US beam
c. the ability to differentiate two reflectors that are parallel to the US beam
d. the ability to differentiate two reflectors that are moving in a direction that is parallel to the US beam
b
Which of the following correctly describes m-mode?
a. using a higher intensity beam than Doppler ultrasound
b. normally used with a sweep speed of 100 mm/s speed
c. uses a very high sampling rate
d. has better axial resolution than 2D imaging
c
If the amplifier input power is 0.05 mW and the amplifier output power is 5mW, what is the gain?
20dB
When evaluating heavily calcified arteries, what system settings should be increased to improve the demonstration of flow in the vessels?
persistence and sensitivity
Which operator control can be used to adjust the image contrast?
dynamic range
Which of the following transducers would have the best axial resolution?
a. 4mm element diameter
b. 4mm spatial pulse length
c. 2mm spatial pulse length
d. 2mm element diameter
c
If the amplifier power output is 100 times the amplifier power input, what is the value for gain?
20dB
If you are performing an abdominal exam, but inadvertently select the carotid preset on the machine, how will this affect your exam?
a. the phased probe will be activated instead of the linear probe
b. aliasing of all arterial waveforms will occur
c. depth settings will be very superficial causing potential non-visualization of the abdominal structures
d. Color will not be displayed in the abdominal vessels due to high PRF settings
c
Changing the dynamic range from 50dB to 75dB will:
a. make the image more black and white
b. produce spatial broadening on the 2D image
c. improve beam penetration
d. increase the number of shades of gray displayed
d
Some US transducer arrays allow you to reduce the thickness of the beam as an additional type of focusing. What effect will this change have on the image?
a. improved contrast resolution
b. degraded temporal resolution
c. decreased beam attenuation
d. improved elevational resolution
d
Which of the following is an advantage of harmonic imaging?
a. increased lobe artifact
b. increased beam width
c. increasead beam penetration
d. increased signal to noise ratio
d
The spatial pulse length is 4mm. What is the minimum axial resolution?
2mm
How can you adjust the elevation focus to a more superficial location in a 1D array transducer?
a. use a stand off pad
b. scan the breast from a lateral approach
c. there is no way to adjust the elevation focus in a 1D array
d. change the short axis focus setting on the console
a
