Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

SPI > Penny book > Flashcards

Penny book Flashcards

1
Q

What type of wave is sound

A

Mechanical and longitudinal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

The frequency ranges for ultrasound are

A

20,000 hz or 20KHZ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The speed of sound in soft tissue is

A

1,540 m/s or 1.54 mm/us

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Which of the following transducers fires the elements in groups

A

Linear sequenced array

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The unit for wavelength is

A

mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Enhancement is caused by

A

Passes through a weakly attenuated structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The wavelength in a material having a prop speed of 1.5 mm/us employing a transducer frequency of 5.0 mhz is

A

.3 mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

An u.s transducer converts

A

Mechanical to electrical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Low attenuation to highest

A

Fat, muscle, bone, air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Prop speed lowest to highest

A

air, bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

If the frequency doubles what happens to the wavelength

A

decreases by one half

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What happens to intesnsity if the ampliutude of the signal is halved

A

quartered

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What would be used to decribe the percentage of the time the sound is on

A

Duty factor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

A 3-db gain would indicate a increase in intensity by

A

2 times (doubling of intensity)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Ignoring the effects of attenuation the intensity of the us beam is usually greater of the focal zone because of

A

The smaller beam diameter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Attenuation denotes

A

Weakening of the strength of the beam as it travels. Typically from absorption, reflection, or scattering

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What has the lowest intensity

A

SATA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the definition of the beam uniformity ratio

A

BUR = SP/SA. the spatial peak intensity divided by the spatial average intensity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Continuous wave doppler has a duty factor of

A

100% it is transmitted 100% of the time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

The spatial pulse length is defined as the product of ____ and the number of _____ in a pulse

A

Wavelength and cycles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

With phased array transducers, the transmitted sound beam is steered by

A

Varying the timing of pulses to the individual piezoelectric materials // phased array transducers operate by shocking the element with minute time differences in between

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

If the gain of an amplifier is 18 db, what is the new gain if the power is reduced by half

A

15 db // 18 db - 3db (half) = 15 db

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Which of the following is true regarding SATA/SPTP

A

SPTP is always equal to or greater than SPTA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

If the amplitude of a wave is increased threefold, the power will

A

Increase ninefold // Power is proportional to the amplitude squared.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Ultrasound attenuates an average of _____ db/cm of travel for each megahertz or frequency

A

0.7 db/cm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

If the intensity transmission coefficient is 0.74, the intensity reflection coefficient will be

A

0.26// It has to equal 100

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Acoustic impedance is defined as the product of

A

The speed of sound in tissue and density of tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Rayleigh scattering is an example of

A

A reflector whose size is smaller than the wavelength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Assuming normal incidence, if the medium 2 impedance is equal to medium 1 impedance

A

100% of the intensity will be transmitted because there will be no reflection since they are identical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is the total attenuation of a 3.5 MHz pulse after passing through 2 cm of soft tissue

A

3.5 dB // (0.5 x 3.5) x 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

The thinner the piezoelectric element the

A

The higher the frequency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

The uit for impedance

A

Rayls

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

A sound beam encounters an interface at a 90 degree angle. If the speed of sound in the first tissue is 1540 m.s and the speed of sound in the second tissue is 1450 m/s, which numbers most closely approx. the angle of beam transmission

A

90 degrees

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

ALARA stands for

A

As Low As Reasonably Achievable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

A “dB” describes the

A

Ratio of 2 sound intensities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

The correct equation for snells law

A

sin 0t= (c2/c1) x sin 01 / Describes refraction at an interface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

The attenuation coefficient of sound in soft tissue can be defined by what equation

A

frequency/2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

The intensity transmission coefficient is equal to

A

1 - intensity reflection coefficient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

The rang equation explains

A

Distance to the reflector

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

The typical value for attentuation coefficient for 6 MHz ultrasound in soft tissue is

A

3 db/cm bc it is one half

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What must be known to calculate distance to a reflector

A

Travel time and prop speed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Specular reflections occur when

A

The interface is larger than the wavelength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What is the reflected intensity from a boundary between two materials if the incident intensity is 1mW/cm2 and the impedences are 25 and 75

A

0.25 mW/cm2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

The layer of material within the transducer which has a intermediate impedance between the transducer element and human tissue is know as the

A

Matching layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What relates bandwidth to operating frequency

A

Quality factor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

PZT effect can be best described as

A

Mechanical deformation that results from a high voltage applied to the face of the crystal that in turn generates a pressure wave

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Most commonly found in transducers

A

Lead zirconate titanate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Diffraction refers to

A

Spreading out of the us beam

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Prefered method for sterilizing us transducers is

A

Cold sterilization

49
Q

A transducer with which frequency would have the thickest elements

A

2 MHZ (lowest number)

50
Q

What is best defined as the ability to discriminate between two closely spaced reflectors

A

Spatial resolution

51
Q

What is an effect of focusing

A

Improved lateral resolution

52
Q

Bandwidth is

A

Range of frequencies produced by the transducer

53
Q

What is the technique that permits “virtual palpation” of a lesion to determine the hardness or softness of tissue

A

Elastography

54
Q

The acoustic impedance of the transducers matching layer is

A

Chosen to improve transmission into the body

55
Q

If the amount of damping decreases, the bandwidth

A

Decreases

56
Q

The region where the sound beam diameter is the smallest is referred to as the

A

Focus

57
Q

The near-zone length is determined by

A

Transducer frequency and element diameter

58
Q

A two-element continuous wave transducer is

A

only used for spectral doppler

59
Q

A waves initial intensity is 2 mW/cm2. There is an increase of 10 dB. What is the final intensity

A

20 mW/cm2

60
Q

What best describes a transducer that has multiple elements in a curved shape

A

Curvilinear

61
Q

What is the name of the control that compensates for attenuation related to path length

A

TGCs / compensation is the same as TGC (time gain compensation)

62
Q

The echoes are stored before final display by the

A

Computer memory

63
Q

What portion of the u.s system drives the transducer

A

Pulser

64
Q

What doppler mode uses the amplitude of the doppler shift in order to produce an image demonstrating flow in a vessel

A

Power doppler

65
Q

How many different shades of gray can the human eye discern at one time

A

100

66
Q

Most current u.s systems have ___ shades of gray

A

256

67
Q

How many bits per pixel can be displayed with 4 bits of memory

A

2^4= 16

68
Q

The spatial resolution capabilities of the system are primarily

A

Transducer

69
Q

The echo intensity on a grayscale of 32 shades is represented by the binary number

A

100,000

70
Q

Preprocessing of the info that is fed to the scan converter

A

Determines the assignment of echoes to predetermined gray levels

71
Q

What grayscale systems typically use a means of signal dynamic range reduction

A

Compression / it is the opposite of dynamic range.

72
Q

Area is expressed by what unit

A

cm2

73
Q

If the frequency of a transducer is increased what will decrease

A

Wavelength

74
Q

With tissue harmonic imaging there

A

Decreased artifacts in the near field

75
Q

What is in the range of infrasound

A

15 Hz

76
Q

What is in the range of audible sound

A

18 Khz

77
Q

What can be changed by the operator

A

PRF because you adjust the depth

78
Q

The time is takes for one cycle to occur

A

Period

79
Q

The length of the pulse is the

A

Spatial pulse length

80
Q

Assuming oblique angle of incidence, if the prop speed of medium 1 is greater than the prop speed of medium 2, what will the angle of transmission be?

A

Less than the angle of incidence // Medium 2 is transmission

81
Q

A 5-mHz wave travels through 5 cm of soft tissue. If a 3.5 MHz transducer is selected instead, what happens to the prop speed of a medium

A

No change / Prop speed is only determined by the medium (stiffness and density)

82
Q

The slowest prop speed is found in which medium

A

Air

83
Q

What represents the strength of the beam

A

Intensity

84
Q

What is the unit of pressure amplitude

A

Pascals (pa)

85
Q

Unit of intensity is

A

W/cm2

86
Q

What else changes with a change of amplitude

A

Output power

87
Q

What will increase the acoustic exposure to the patient

A

Increasing output gain

88
Q

What operator control adjusts the intensity of the transmitted pulse

A

Power

89
Q

What happens to the power if the intensity is doubled

A

Doubles / they are directly related

90
Q

The number of pulses that occur in 1 sec is

A

PRF

91
Q

What is along the x-axis on a spectral doppler waveform

A

Time

92
Q

What is the unit for spatial pulse length

A

m

92
Q

What testing device is used to measure acoustic output (intensity) level

A

Hydrophone

93
Q

What is the principle that states sound waves are the result of the interference of many wavelets produced at the face of the transducer

A

Huygens principle

94
Q

When using tissue harmonic imaging, the frequency used is

A

Double the fundamental frequency

95
Q

In B-mode imaging, amplitude is located on what axis of the image

A

z

96
Q

What determines the radial resolution of a system

A

Spatial pulse length

97
Q

The axial resolution can be improved by decreasing the ___ or increasing the ____

A

Number of cycles in a pulse, frequency

98
Q

2 reflectors are 1.3 mm apart in a plane that is parallel to the beam. The spatial pulse length of the transducer is 2.6 mm. The 2 reflectors will

A

Will show up as two dots on the screen

99
Q

In what zone does beam divergence occur

A

Fraunhofer zone (far zone)

100
Q

The larger the aperture,

A

The longer the near zone

101
Q

The ability to resolve two reflectors that lie parallel to the beam is ___ resolution of a system

A

Axial

102
Q

The more focal zones used, the

A

worse the temporal resolution

103
Q

In the most common type of transducers, the slice thickness plane is focused

A

Using a lens

104
Q

If sound travels through a large quantity of water and then encounters a reflector, the reflector will appear to be

A

Too far away / If the prop speed is less than 1.54 mm/us

105
Q

What is the maximum temp increase below which there should be no thermally induced biological effects

A

2 celsius

106
Q

2 sound beams with different frequencies are traveling through soft tissue. Which beam will travel faster

A

Both will travel at the same speed / prop speed and frequency are unrelated

107
Q

A video display that is limited to only black and white, with no other shades of gray is called

A

Bistable

108
Q

The name for the smallest amount of digital storage

A

bit or binary digit

109
Q

In the fresnel zone, the beam

A

the beam area decreases with distance from the transducer

110
Q

Info that travels to the scan converter from the receiver is initially in what format?

A

Analog

111
Q

What is true about color doppler

A

Each pixel can either be grayscale or color, it cannot be both

112
Q

What preserves the pixel density when enlarging the image

A

Write magnification/ it enlarges the image before the image is stored in digital memory

113
Q

Whats the relationship between amplitude and frequency

A

They have no relation

114
Q

Whats the relationship between spatial pulse length and pulse duration

A

Directly related

115
Q

What is true about axial resolution

A

It does not vary with depth

116
Q

If the ____ is increased, the flow increases

A

Pressure differential

117
Q

What law describes the relationshiop between flow and the pressure differential, viscosity, and length

A

Poiseuilles law

118
Q

The most common type of flow found in the body

A

Laminar

SPI (16 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions