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Davies Questions 151-269 > Ultrasound Transducers > Flashcards

Ultrasound Transducers Flashcards

1
Q 
You are using a 5 MHz, 40 mm linear array transducer to image a structure. What is the width of the image ?
A. 20mm
B. 40mm
C. 60mm
D. 80mm
E. 120mm
A

B. 40 mm

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2
Q

You have selected a wide-bandwidth transducer with multiple transmit frequencies to perform a sonographic examination. Which transmit frequency should you select for maximum penetration?
A. 3.0 MHz
B. 3.5 MHz
C. 4.0 MHz
D. 5.0 MHz
E. Penetration is not affected by frequency

A

A. 3.0 MHz

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3
Q 
Which probe would provide the best axial resolution to measure the thickness of a small structure ?
A. 5 MHz linear array transducer 
B. 7 MHz linear array transducer 
C. 10 MHz linear array transducer 
D. 5 MHz curved array transducer 
E. 5 MHz phased array transducer
A

C. 10 MHz linear array transducer

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4
Q

You are performing a sonographic exam with a wide-bandwidth transducer. The advantage you obtain with this transducer compared to a narrow-band transducer is:
A. Decreased acoustic power output
B. Improved axial resolution
C. Improved lateral resolution
D. Improved focusing
E. Wide-bandwidth transducers can be autoclaved

A

B. Improved axial resolution

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5
Q 
Which transducer would provide the longest near-zone length ?
A. 10 MHz, 6mm diameter aperture 
B. 10 MHz, 5mm diameter aperture 
C. 10 MHz, 4mm diameter aperture 
D. 10 MHz, 3mm diameter aperture 
E. 10 MHz, 2mm diameter aperture
A

A. 10 MHz, 6mm diameter aperture

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6
Q 
The location where the sound beam reaches its narrowest diameter is known as the:
A. Fraunhofer zone
B. Beam area
C. Fresnel zone
D. Curie point
E. Focal zone
A

E. Focal zone

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7
Q 
Which of the following transducers creates a rectangular image shape?
A. Linear array
B. Phased array 
C. Annular array 
D. Curved array 
E. B and C only
A

A. Linear array

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8
Q 
The term for a transducer that has an array of a rectangular elements arranged in a straight line is:
A. Annular array 
B. Linear array
C. Curved array
D. Oscillating mechanical transducer 
E. Convex sequenced array
A

B. Linear array

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9
Q 
For a linear array transducer consisting of a single row of elements, what method is most used to focus the beam in the elevational direction?
A. Transmit focusing 
B. Dynamic receive focusing 
C. Aperture focusing
D. Mechanical focusing
E. None of the above
A

D. Mechanical focusing

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10
Q 
What type of transducer could you choose to produce a beam that is symmetric about the beam axis?
A. Annular array 
B. Linear sequenced array
C. Phased array 
D. Curved array 
E. Tightly curved array
A

A. Annular array

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11
Q

The ultrasound system in your lab has a transducer with a small footprint. This kind of transducer has the following disadvantage:
A. It cannot be focused in the elevational direction
B. The field of view in the far field is only one-quarter the diameter of the transducer
C. The near field lateral resolution is poor
D. The Q value is very high
E. Resolution is degraded at large distances

A

E. Resolution is degraded at large distances

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12
Q 
Which of the following will NOT improve axial resolution?
A. Increased damping
B. Increased transducer frequency 
C. Increased bandwidth 
D. Decreased pulse length 
E. Increased focusing
A

E. Increased focusing

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13
Q 
You are reviewing an ultrasound image that has a sector display format that narrows to a point at the transducer surface . What kind of transducer was most likely used to acquire this image?
A. Linear array 
B. Phased array 
C. Curved array 
D. Annular array 
E. Mechanical sector
A

B. Phased array

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14
Q 
Where is the point of maximum intensity in a sound beam?
A. Curie point 
B. Fresnel zone
C. Focal point 
D. Fraunhofer zone
E. F number
A

C. Focal point

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15
Q

What is the main advantage of using a 1.5 D or multirow array transducer?
A. Narrow slice thickness over large part of the scanned volume
B. Increased penetration
C. Improved axial resolution
D. Faster frame rates
E. Smaller footprint

A

A. Narrow slice thickness over large part of the scanned volume

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16
Q

What benefits would you obtain by choosing a transducer having a large diameter compared to one having a smaller diameter?
A. It can focus at great depths
B. It increases frequency
C. It increases the beam diameter in the far field
D. A and C
E. All of the above

A

A. It can focus at great depths

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17
Q 
You are using a linear array transducer with four transmit focal zones. How many pulses are required on each scan line to create this image ?
A. One
B. Two
C. Four
D. Six 
E. Eight
A

C. Four

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18
Q 
What type of transducer has the same measurement for elevational and lateral resolution?
A. Convex linear array 
B. Phased linear array 
C. Annular array 
D. Sequential linear array 
E. Mechanical sector
A

C. Annular array

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19
Q

With a 1D linear array, where in the out-of-plane dimension is the dimension of the sound beam the narrowest?
A. It is at the point of mechanical focusing
B. It is at the point of electronic focusing
C. The beam is the same width throughout the image
D. It is in the far field
E. It is always located at a depth equal to one-half the transducer aperture

A

A. It is at the point of mechanical focusing

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20
Q 
Another name for axial resolution is:
A. Transverse resolution 
B. Azimuthal resolution 
C. Angular resolution 
D. Range resolution 
E. A and C
A

D. Range resolution

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21
Q

Dynamic apodization is a method employed to:
A. Focus the beam at multiple depths on transmit
B. Focus the beam at multiple depths on receive
C. Reduce side lobes
D. Reduce beam width in the z-axis
E. Steer the beam

A

C. Reduce side lobes

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22
Q

Which statement is most accurate regarding resolution with a standard one-dimensional linear array transducer?

A. Axial resolution is the worst measure of resolution with this type of transducer
B. Lateral resolution is the worst measure of resolution with this type of transducer
C. Elevational resolution is the worst measure of resolution with this type of transducer
D. Isotropic spatial resolution is achieved
E. Temporal resolution is the worst measure of resolution with this type of transducer

A

C. Elevational resolution is the worst measure of resolution with this type of transducer

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23
Q

During the course of a sonographic exam , you notice lateral splaying of the echoes in the far field. What can you do to improve the image?
A. Use the maximum acoustic power
B. Use the lowest line density setting
C. Increase the number of transmit focal zones and optimize their location
D. Decrease the scanning depth
E. Increase the sector width

A

C. Increase the number of transmit focal zones and optimize their location

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24
Q

You suspect that a bright spot on the B-mode image is a calcification, but a posterior acoustic shadow is not present. How can you best optimize your system to demonstrate a shadow distal to the calcification?
A. Move the focal zone well below the hyperechoic focus
B. Increase the transducer frequency
C. Increase the acoustic power output
D. Increase the dynamic range
E. Decrease the scan line density

A

B. Increase the transducer frequency

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25
Q

When an electric signal is applied to a piezoelectric element, what happens to the element ?
A. It undergoes temperature fluctuations
B. It expands and contracts
C. It produces an electric signal of the opposite polarity
D. It emits electromagnetic radiation

A

B. It expands and contracts

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26
Q 
You are scanning a phantom containing multiple rows of identical 5mm spherical fluid-filled structures embedded in a tissue-mimicking material. What type of resolution is best evaluated with this phantom ?
A. Axial 
B. Lateral
C. Contrast
D. Elevational 
E. Temporal
A

D. Elevational

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27
Q

Which statement is NOT true regarding lateral resolution?
A. It is equal to beam width
B. It is improved by focusing
C. It is defined as the minimum separation required to resolve two structures perpendicular to the beam axis
D. It is also known as azimuthal resolution
E. It remains constant throughout scanning depth

A

E. It remains constant throughout scanning depth

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28
Q

Which type of transducer should you select to produce the narrowest slice thickness throughout the image plane ?
A. A 1.5D multirow array
B. A phased array with a small footprint
C. A tightly curved curvilinear array
D. A mechanical sector
E. A mechanically rocked 3D transducer

A

A. A 1.5D multirow array

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29
Q

The matching layer between the piezoelectric element and the tissue is designed to :
A. Insulate the patient from the hot element
B. Reduce the vibration of the transducer
C. Reduce the acoustic impedance mismatch between the element and tissue
D. Increase the reflection coefficient at the transducer skin interface
E. Decrease spatial pulse length

A

C. Reduce the acoustic impedance mismatch between the element and tissue

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30
Q

If you choose a lower frequency transducer to image a highly attenuating structure, what tradeoff are you making ?
A. Decreased penetration for increased resolution
B. Decreased beam intensity for longer wavelengths
C. Decreased spatial resolution for improved penetration
D. Increased beam refraction for higher sound speed

A

C. Decreased spatial resolution for improved penetration

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31
Q 
You have been asked to perform an ultrasound study of a structure located about 3 cm below the skin surface. Which transducer frequency range would be most appropriate for this study ?
A. 2-5 MHz 
B. 4-8 MHz 
C. 8-10 MHz 
D. 10-12 MHz 
E. 5 MHz
A

D. 10-12 MHz

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32
Q

Dynamic receive focusing uses:
A. Mechanical means to focus the beam
B. Time delays to excite array elements
C. Variable number of elements to form the transmitted beam
D. Time delays before echo signals from array elements are combined
E. All of the above

A

D. Time delays before echo signals from array elements are combined

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33
Q 
Varying the excitation voltage to each element in the group used to form the ultrasound pulse is called
A. Apodization
B. Dynamic aperture 
C. Interelement isolation
D. Subdicing
E. Recitification
A

A. Apodization

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34
Q

Which of the following describes a phased array transducer?
A. Electronically focused in two dimensions and mechanically steered
B. Electronically focused along the length of the array, mechanically focused along the elevational dimension (width ), and electronically steered
C. Electronically focused along the elevational dimension of the array, mechanically focused along the length of the array , and unsteered

A

B. Electronically focused along the length of the array, mechanically focused along the elevational dimension (width ), and electronically steered

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35
Q 
Resolution of two structures at different depths along the path of the sound beam is termed : 
A. Contrast resolution 
B. Temporal resolution 
C. Axial resolution 
D. Lateral resolution 
E. Azimuthal resolution
A

C. Axial resolution

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36
Q 
Which transducer has the same distance between the scan lines in both the near and far fields ?
A. Convex array 
B. Phased array 
C. Curvilinear array
D. Linear array
E. Mechanical sector
A

D. Linear array

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37
Q 
Which of the following minimizes the degree to which beam width varies with depth? 
A. Apodization 
B. Dynamic aperture 
C. Coprocessing
D. Rectification 
E. Frame averaging (persistence)
A

B. Dynamic aperture

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38
Q 
The sound beam can be focused by all of the following EXCEPT:
A. Acoustic mirror
B. Acoustic lens
C. Curved crystals
D. Matching layer
E. Electronic phasing
A

D. Matching layer

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39
Q 
What type of focusing decreases the frame rate ?
A. Mechanical focusing 
B. Dynamic receive focusing 
C. Dynamic aperture focusing
D. Multiple transmit focusing
A

D. Multiple transmit focusing

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40
Q

For a single transducer to offer multiple frequency selections for scanning, it must have :
A. Large dynamic range
B. Wide bandwidth
C. Multiple rows of elements in the elevational plane
D. Dynamic aperture
E. Electronic steering capability

A

B. Wide bandwidth

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41
Q 
The ability to distinguish between adjacent structures that produce echoes of similar amplitude is termed :
A. Spatial resolution 
B. Axial resolution 
C. Lateral resolution 
D. Temporal resolution 
E. Contrast resolution
A

E. Contrast resolution

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42
Q 
When you increase the scan line density in the B-mode image, you improve :
A. Temporal resolution 
B. Contrast resolution 
C. Slice thickness 
D. Axial resolution 
E. Lateral resolution
A

E. Lateral resolution

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43
Q 
The conversion of an incident pressure wave to an electric signal is the :
A. Curie effect 
B. Piezoelectric effect
C. Doppler effect 
D. Snell effect
A

B. Piezoelectric effect

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44
Q

Electronic focusing in the transmit mode is accomplished using:
A. Curved crystal elements
B. Changeable lens
C. Time delays to excite transducer elements
D. High pulse repetition frequency
E. Receive time delays

A

C. Time delays to excite transducer elements

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45
Q 
What is the purpose of subdicing?
A. To focus the beam upon transmit 
B. To reduce grating lobes
C. To increase transmitted intensity 
D. To alter the transmitted frequency
A

B. To reduce grating lobes

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46
Q 
What transducer component is designed to control ringing of the piezoelectric element?
A. Backing material
B. Electric insulator
C. Matching layer
D. Radio frequency shield
A

A. Backing material

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47
Q

The transducer you are using is an array assembly. What is an advantage of this type of transducer?
A. Transducer arrays produce pure, single-frequency beams
B. Transducer arrays enable mechanical steering
C. Transducer arrays produce very long pulses for improved axial resolution
D. Transducer arrays have greater dynamic range, resulting in more displayed shades of gray
E. Transducer arrays enable electronic focusing and steering

A

E. Transducer arrays enable electronic focusing and steering

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48
Q

What is an advantage of single -crystal or pure-wave crystal transducers?
A. Wide bandwidth
B. Lower frequencies at higher resolution
C. Absence of aliasing with Pulsed Doppler
D. Higher frame rates
E. Greater steering angles

A

A. Wide bandwidth

49
Q 
What type of transducer produced this image?(Pg42)
A. Curved linear array
B. Linear array 
C. Sector
D. Phased array
E. Tightly curved array
A

B. Linear array

50
Q

Increasing the number of transmit focal zones to improve spatial resolution involves the following trade off:
A. Lateral resolution vs. axial resolution
B. Lateral resolution vs. temporal resolution
C. Spatial resolution vs. contrast resolution
D. Contrast resolution vs. frame rate

A

B. Lateral resolution vs. temporal resolution

51
Q 
Which of the following is NOT associated with a low-Q transducer?
A. Wide bandwidth 
B. Multi frequency selection 
C. Long pulse length 
D. Diagnostic pulses-wave ultrasound
A

C. Long pulse length

52
Q 
This image shows a clear distinction between the gray scales of various structure in the fetal brain. The ability to distinguish similar structures with varying gray scales is termed:(pg 43)
A. Axial resolution 
B. Contrast resolution 
C. Lateral resolution 
D. Temporal resolution
A

B. Contrast resolution

53
Q 
If the number of cycles in the transmitted pulsed wave is increased:
A. Axial resolution is degraded 
B. Lateral resolution is degraded 
C. Spatial pulse length becomes shorter 
D. Rate of attenuation is increased
A

A. Axial resolution is degraded

54
Q 
If the frame rate is too slow for adequate temporal resolution, what action could you take to improve frame rate ?
A. Reduce the # of transmit focal zones
B. Increase the scan line density 
C. Increase the scanning depth
D. Decrease the dynamic range
A

A. Reduce the # of transmit focal zones

55
Q 
You have been requested to image a superficial mass and to adjust your equipment to optimize spatial resolution. Spatial resolution consists of :
A. Contrast and temporal resolution 
B. Temporal and axial resolution 
C. Axial and contrast resolution 
D. Contrast and lateral resolution 
E. Lateral and axial resolution
A

E. Lateral and axial resolution

56
Q

What is the purpose of the radiofrequency shield that is placed around the crystal and backing material of the ultrasound probe?
A. It helps to transmit radio waves into the body
B. It aids transmission of the electric signal to the crystal
C. It reduces the incoming electric signal to the crystal
D. It reduces electromagnetic interference

A

D. It reduces electromagnetic interference

57
Q 
The image on the left demonstrates poor lateral resolution compared to the image on the right . How were the system controls adjusted to optimize the image on the right ?
A. Increased dynamic range 
B. Decreased transducer frequency 
C. Changed gray map 
D. Increased line density
A

D. Increased line density

58
Q 
What type of resolution is affected most by pulse duration?
A. Lateral resolution 
B. Contrast resolution 
C. Temporal resolution 
D. Axial resolution
A

D. Axial resolution

59
Q 
With a standard one-dimensional linear array transducer, what type of resolution is affected most by electronic focusing and dynamic aperture?
A. Lateral resolution 
B. Contrast resolution 
C. Temporal resolution 
D. Axial resolution 
E. Elevational resolution
A

A. Lateral resolution

60
Q 
What type of resolution is most affected by the mechanical focus on a linear array transducer 
A. Lateral resolution 
B. Contrast resolution 
C. Temporal resolution 
D. Axial resolution 
E. Elevational resolution
A

E. Elevational resolution

61
Q 
The spectrum of frequencies enmities by a pulsed-wave transducer is known as the :
A. Reynolds number
B. Center frequency 
C. F-number
D. Resonance frequency 
E. Bandwidth
A

E. Bandwidth

62
Q

What is the optimal thickness for the matching layer ?
A. Equal to the thickness of the crystal
B. One-fourth of a wavelength
C. One-half of the pulse length
D. Twice the transducer diameter

A

B. One-fourth of a wavelength

63
Q 
A method for improving frame rates with multi zone electronic focusing is:
A. Apodization 
B. Parallel processing 
C. F-number focusing 
D. Use of low-Q transducers
E. None of the above
A

B. Parallel processing

64
Q

Which of the following best describes the f-number?
A. Focal length divided by the aperture
B. Aperture multiplied by the number of elements in the transducer
C. Number of transducer elements divided by the Fraunhofer zone
D. Beam width 1cm from the transducer surface

A

A. Focal length divided by the aperture

65
Q 
If you wish to use an array transducer that allows you to control transmit focal depth , what type would you select?
A. Linear array 
B. Convex 
C. Phased array 
D. Annular array 
E. Any of the above
A

E. Any of the above

66
Q 
If you wish to acquire a sonogram with the largest possible field of view both in the near field and at depth , what type of transducer would be most preferable?
A. Linear array 
B. Curved array 
C. Phased array 
D. Annular array 
E. Any of the above
A

B. Curved array

67
Q 
A commonly used material in modern transducer elements is:
A. Tungsten powder and epoxy resin
B. Quartz
C. Lead zirconate titanite 
D. Rubber
A

C. Lead zirconate titanite

68
Q 
You are using a linear array transducer to evaluate the thyroid gland. For standard B-mode imaging, this transducer most likely produces pulses of how many cycles ?
A. 1-3 
B. 3-6
C. 6-9
D. 9-12
E. 12-15
A

A. 1-3

69
Q

What is the purpose of applying multiple matching layers to the transducer face?
A. The gel gradually erodes the matching layer , and using multiple layers lengthens the life of the transducer assembly
B. Because the impedance of tissue is quite variable from one pt to the next , multiple matching layers improve the likelihood of providing close impedance to match to each pt
C. Each individual coating of the matching layer contributes to the damping of the sound pulse , which results in improved axial resolution
D. Multiple matching layers result in increased transducer bandwidth

A

D. Multiple matching layers result in increased transducer bandwidth

70
Q 
For a non focused transducer, the region between the transducer element and the point at which the sound beam is narrowest is called the:
A. Far field
B. Fraunhofer zone 
C. Near-zone length
D. Focal distance 
E. Both A and B
A

C. Near-zone length

71
Q 
Axial resolution is determined chiefly by :
A. Beam width
B. Transducer diameter 
C. Pulse duration 
D. Line density 
E. Frame rate
A

C. Pulse duration

72
Q

What is the main advantage of using an intracavitary probe compared to a standard transducer?
A. The intracavitary probe has superior focusing capabilities because of the increased radius of the curved probe face
B. The intracavitary probe uses a lower frequency that provides superior penetration and closer inspection of the pelvic structures
C. The intracavitary probe does not demonstrate side lobes or grating lobes because of the close spacing and curvature of the elements
D. Since the intracavitary probe is closer to the area of interest, a higher frequency transducer can be used, resulting in superior spatial resolution

A

D. Since the intracavitary probe is closer to the area of interest, a higher frequency transducer can be used, resulting in superior spatial resolution

73
Q 
What defines the best axial resolution that can be obtained with a given transducer?
A. Spatial pulse length x2
B. Spatial pulse length x4
C. Spatial pulse length divided by 2
D. Spatial pulse length divided by 4
A

C. Spatial pulse length divided by 2

74
Q 
What term describes the ability of an imaging device to separate closely spaced objects?
A. Resolution 
B. Penetration 
C. Duty factor 
D. Interference
A

A. Resolution

75
Q 
What happens when pressure is applied to a piezoelectric crystal ?
A. It emits an electric signal 
B. It increases temperature 
C. It emits radio waves 
D. It emits photons
A

A. It emits an electric signal

76
Q 
What type of transducer was used to obtain this image?(pg 48)
A. Linear array
B. Sector
C. Phased array 
D. Micro convex
E. Curved array
A

E. Curved array

77
Q

The interpreting physician has asked you to use a stand-off pad to evaluate a superficial mass. What is the main advantage the stand-off pad provides to improve the image?
A. The stand-off pad has an acoustic impedance closer to that of the crystal, which results in improved transmission of sound into the body
B. The stand-off pad has a propagation speed equal to twice that of soft tissue ,which decreased the wavelength of the sound beam
C. The stand-off pad increases the distance between the transducer and the mass, making it more likely that the mass will be located close to the elevational focus on the sound beam

A

C. The stand-off pad increases the distance between the transducer and the mass, making it more likely that the mass will be located close to the elevational focus on the sound beam

78
Q 
What array transducer fires all of the elements for each acoustic scan line, using small time delays to steer the beam?
A. Linear segmental array
B. Convex array 
C. Annular array
D. Linear sequential array 
E. Phased array
A

E. Phased array

79
Q 
The shape corresponding to the image created by a phased array transducer most closely corresponds to which of the following? (Pg49)
A
B
C
D
E
A

D

80
Q 
A linear array will produce which of the following image shapes?
A. A or B
B. B or C
C. C or D
D. D or E
E. A,C, or E
A

E. A,C, or E

81
Q

If you are using a transducer with poor elevational resolution, which of the following problems are you most likely to encounter?
A. Inability to resolve two structures that lie close together and parallel to the path of the beam
B. Inability to resolve two structures that lie close together, perpendicular to the path of the beam, and parallel to the long axis of the transducer
C. Inability to penetrate through dense tissue
D. inability to clearly demonstrates small cystic structures

A

D. inability to clearly demonstrates small cystic structures

82
Q 
What can you do to achieve a higher frame rate?
A. Decrease the number of focal zones 
B. Decrease the line density 
C. Decrease the sector width
D. All of the above
A

D. All of the above

83
Q 
What can you do to improve contrast resolution in the ultrasound image?
A. Increase the sector width
B. Decrease the number of focal zones
C. Use a 2D or matrix array transducer 
D. Use a phased array transducer
A

C. Use a 2D or matrix array transducer

84
Q 
Increasing which of the following will result in improved axial resolution?
A. Pulse duration
B. Pulse length 
C. Frequency 
D. Period
E. Focusing
A

C. Frequency

85
Q 
Which represents the best measure of resolution for modern-day ultrasound scanners? 
A. Contrast 
B. Axial
C. Elevational 
D. Temporal
A

B. Axial

86
Q 
Which of the following transducers produces side lobes or grating lobes?
A. Mechanical sector 
B. Linear sequential array 
C. Phased array
D. Convex array 
E. All of the above
A

E. All of the above

87
Q 
Which transducer type is best suited to vascular imaging?
A. Mechanical sector 
B. Linear array 
C. Phased array 
D. Convex array
A

B. Linear array

88
Q 
Which of the following transducer types is best suited to cardiac imaging?
A. Mechanical sector 
B. Linear array 
C. Phased array 
D. Convex array
A

C. Phased array

89
Q 
Which of the following can NOT be evaluated with a tissue-equivalent phantom?
A. Axial resolution 
B. Lateral resolution 
C. Contrast resolution 
D. Slice thickness 
E. Temporal resolution
A

E. Temporal resolution

90
Q

Increasing the frequency on a multi frequency transducer from 3.5 MHz to 5.0 MHz will:
A. Increase the sound propagation speed
B. Increase the pulse length
C. Increase penetration
D. Decrease the pulse repetition frequency
E. Decrease the wavelength

A

E. Decrease the wavelength

91
Q 
You notice a loss of detail in the lateral dimension of the ultrasound image. What can you do to improve this?
A. Decrease the number of focal zones 
B. Increase the scan line density 
C. Decrease the transducer frequency 
D. Increase the frame averaging
A

B. Increase the scan line density

92
Q 
You are performing an exam on a pt with highly attenuating tissue. Which of the following solutions would be most likely to improve penetration through the tissue?
A. Decrease dynamic range 
B. Decrease near-field TGC
C. Choose a lower frequency transducer 
D. Increase the scan line density
A

C. Choose a lower frequency transducer

93
Q 
This image was obtained with a linear array transducer. The trapezoidal field of view increases the field of view. How is the trapezoidal shape created ? (Pg52)
A. Electronic beam steering 
B. Side lobes 
C. Grating lobes 
D. Mechanically steering the elements
A

A. Electronic beam steering

94
Q

In the image below, how many transmit focal zones are being used? (Pg52)
A. The number of transmit focal zones is not indicated
B. 1
C. 2
D. 3

A

D. 3

95
Q 
What type of transducer was used to take this image? Pg 53)
A. Curved array 
B. Phased array 
C. Linear array 
D. Mechanical sector
A

B. Phased array

96
Q

What best describes the method used to create the triangular-shaped image format in the image above ?
A. Mechanical steering
B. Electronic steering with elements fired in small groups
C. Electronic steering with the most elements fired for each pulse-echo sequence and short time differences steering the beam
D. Curved lens
E. Mirror

A

C. Electronic steering with the most elements fired for each pulse-echo sequence and short time differences steering the beam

97
Q 
You can reduce beam width to improve spatial resolution in the image by which of the following?
A. Focusing 
B. Decrease aperture 
C. Decreasing transducer diameter
D. Decreasing bandwidth
A

A. Focusing

98
Q

Which transducer frequency would have the thinnest crystal?
A. One with a 15 MHz central frequency
B. One with a 10 MHz center frequency
C. One with a 7 MHz center frequency
D. One with a 5 MHz center frequency
E. All would have the same crystal thickness

A

A. One with a 15 MHz central frequency

99
Q 
What component of a pulsed -wave transducer helps to reduce the spatial pulse length and improve axial resolution?
A. Matching layer 
B. Lens 
C. Element 
D. Backing material 
E. Radio frequency shield
A

D. Backing material

100
Q 
Which transducer would have a lower line density in the far field compared to the near field?
A. Linear array 
B. Curved array 
C. Tightly curved array 
D. Phased array 
E. B,C, and D
A

E. B,C, and D

101
Q 
What transducer component reduces reflection at the transducer/skin interface?
A. Matching layer 
B. Lens
C. Element
D. Backing material
A

A. Matching layer

102
Q 
Axial resolution is improved with:
A. Increased bandwidth 
B. Shorter pulse length 
C. Shorter wavelength 
D. B and C
E. All of the above
A

E. All of the above

103
Q

What is a side lobe?
A. Uneven transducer element
B. Accessory pulsed for electronic steering
C. Sound beam emitted from the transducer that travels in a different direction from the main beam

A

C. Sound beam emitted from the transducer that travels in a different direction from the main beam

104
Q

What is the purpose of curving the transducer elements or applying a lens over the elements?
A. To provide focusing on the out-of-plane (elevational) direction
B. To reduce the acoustic impedance mismatch between the crystal and skin
C. To reduce crystal ringing and improve axial resolution
D. To help reduce electronic interference
E. All of the above

A

A. To provide focusing on the out-of-plane (elevational) direction

105
Q 
What advantage is obtained by steering a linear array transducer to create a trapezoidal shape to the display as demonstrated in this image?
(Pg 55)
A. Improved lateral resolution 
B. Improved axial resolution 
C. Improved contrast resolution 
D. Improved elevational resolution 
E. Improved field of view
A

E. Improved field of view

106
Q 
What type of transducer was used to create this image of the uterus ?(pg 56)
A. Linear array 
B. Phased array 
C. Single-element mechanical 
D. Tightly curved array
A

D. Tightly curved array

107
Q

What disadvantage is related to the transducer type (tightly curved array /trans vagina) in the previous question?
A. Axial resolution degrades with depth
B. Lateral resolution degraded with depth
C. Field of view is compromised compared to other transducer types
D. Temporal resolution is compromised compared to other transducer types

A

B. Lateral resolution degraded with depth

108
Q 
What advantage is related to tightly curved array (transvag probe)
A. Axial resolution is improved 
B. Lateral resolution is improved 
C. Field of view is improved 
D. Temporal resolution is improved
A

C. Field of view is improved

109
Q

What best describes the difference between the ultrasound frequencies used for Doppler and for B-mode imaging with a given transducer?
A. The frequency for Doppler is usually lower than for imaging
B. The frequency for Doppler is usually higher than for imaging
C. The transmit pulse for Doppler has a greater bandwidth compared to the bandwidth for imaging
D. The frequency for Doppler and for B-mode imaging must be identical for a given transducer

A

A. The frequency for Doppler is usually lower than for imaging

110
Q

In order to focus a sound beam relatively far away from the transducer, it is advantageous to:
A. Increase the thickness of the element
B. Increase the diameter of the element
C. Decrease the width of the element
D. Decrease the frequency of the element
E. Increase the curvature of the element

A

B. Increase the diameter of the element

111
Q 
Which factor LEAST influences axial resolution?
A. Damping 
B. Beam width 
C. Frequency 
D. Pulse duration 
E. Pulse frequency
A

B. Beam width

112
Q

Spatial pulse length is equal to :
A. The wavelength times the number of cycles in the pulse
B. The wavelength minus the number of cycles in the pulse
C. The wavelength times the axial resolution
D. The wavelength times the beam width

A

A. The wavelength times the number of cycles in the pulse

113
Q 
What is the disadvantage of using multiple transmit focal zones?
A. Decreased lateral resolution 
B. Decreased temporal resolution 
C. Decreased elevational resolution 
D. Decreased axial resolution
A

B. Decreased temporal resolution

114
Q 
What is the advantage of using multiple transmit focal zones?
A. Increased lateral resolution 
B. Increased temporal resolution 
C. Increased elevational resolution 
D. Increased axial resolution
A

A. Increased lateral resolution

115
Q 
What factor LEAST influences lateral resolution?
A. Frequency 
B. Focus depth 
C. Beam width 
D. Transducer diameter 
E. Damping
A

E. Damping

116
Q 
Which transducer will exhibit the LEAST amount of volume averaging?
A. Mechanical single element 
B. 1.5 D or multirow array
C. Linear array 
D. Phased array
A

B. 1.5 D or multirow array

117
Q 
The ability to differentiate between two regions at different depths having similar echogenicity , such as in this liver image with focal fatty infiltration, is termed:pg 58
A. Temporal resolution 
B. Contrast resolution 
C. Axial resolution 
D. Lateral resolution
A

B. Contrast resolution

118
Q 
Imaging frame rate decreases when you:
A. Decrease frequency 
B. Increase dynamic range 
C. Increase frame averaging 
D. Increase sector width
A

D. Increase sector width

119
Q 
The optimal transducer technology for cardiac scanning is:
A. Curved array 
B. Tightly curved array 
C. Linear array 
D. Phased array 
E. Mechanical sector
A

D. Phased array

Davies Questions 151-269 (1 decks)

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