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
