physics Flashcards

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1
Q
Compression:
Is a receiver function
Is performed in the pulse
Creates a large DR
All of the above
A

Is a receiver function

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2
Q

Define this term ISPTP

A

Spatial Peak, Temporal Peak

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3
Q

Lateral Resolution does not depend on:

a) Frequency
b) Aperture
c) Phasing
d) Depth
e) Damping

A

Damping

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4
Q

The beam shape for PW is the shape that is created as the pulse of sound sweeps through the medium over time.

A

True

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5
Q

The Motivation for A/D Conversion are all except:

a) Makes the functions of greyscale, memory storage, post-processing easier
b) Allows for the system to store the analog signal
c) Signal exists in numerical representation rather than continuous voltage representation
d) Digital math engines can be applied easily to these numeric values for multiple calculations

A

Allows for the system to store the analog signal

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6
Q

Pulse Duration is defined as:

A

A time measure of how long the transmit pulse lasts

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7
Q

If the colour scale goes from blue at the bottom to red at the top, non-aliased flow towards the transducer will be encoded as:

A

red

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8
Q

The Motivation for A/D Conversion are all except:

A) Makes the functions of greyscale, memory storage, post-processing easier

B) Signal exists in numerical representation rather than continuous voltage representation

C) Allows for the system to store the analog signal

D) Digital math engines can be applied easily to these numeric values for multiple calculations

A

Allows for the system to store the analog signal

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9
Q

The Limit for the thermal index is?

A

ISPTA values BELOW 720W/cm2

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10
Q

Colour Doppler:

a) is a map that displays the mean frequency of the Doppler signal
b) is a map that display the intensity of the Doppler signal
c) is determined by the angle of insonification
d) is used to determine the speed of flow of the Doppler signal

A

is a map that displays the mean frequency of the Doppler signal

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11
Q

How is a colour packet/ensemble formed?

a) repeatedly scanning a single line in the same direction 4-12 times
b) repeatedly displaying a single line in the same direction 4-12 times
c) it is displayed on the spectral tracing
d) none of the above

A

repeatedly scanning a single line in the same direction 4-12 times

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12
Q

The frequency of operation is determined differently for pulsed modes than continuous modes.

A

True

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13
Q

Which of the following is not true regarding a shallower depth of focus:

a) Decreases max transmit power
b) Means the beam is narrower at a shallower depth
c) Means the beam does not much attenuation
d) Increases max transmit power

A

Increased max transmit power

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14
Q

Accuracy is defined as:

a) The percentage of times the test is correct relative to the gold standard
b) The percentage of times the test is correct relative to the comparison test
c) The percentage of times the test is incorrect relative to the gold standard
d) The percentage of times the test is incorrect relative to the comparison test

A

The percentage of times the test is correct relative to the gold standard

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15
Q

The angle of insonification is measured as:

a) Between the line of sight and the direction of the beam
b) Between the beam steering direction and the direction of the flow
c) Between the beam steering direction and the line of sight
d) None of the above

A

Between the BEAM steering direction and the direction of the FLOW

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16
Q

Assume the blood flow is normal/laminar within an interrogating vessel. Why does a Spectral windows exist in Pulsed wave spectral Doppler?

a) Since most the blood is not travelling within the center of the vessel, there is relatively little blood cells demonstrated around the mean velocity
b) Having a spectral window usually indicates that PW Doppler gains are too low. Increasing the PW gains will fix this issue.
c) Since most of the blood traveling through the sample volume is travelling at the same velocity, there is relatively little spread around the mean velocity
d) None of the above apply

A

Since most of the blood traveling through the sample volume is travelling at the same velocity, there is relatively little spread around the mean velocity

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17
Q

A Doppler shift will _______if both the target and observer are moving away from each other faster.

A

increase

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18
Q

Mechanical Stable Cavitation occurs when:

A

microbubbles oscillate and does not lead to collapse

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19
Q

When assessing venous flow with Doppler one is evaluating for:
a) An arrhythmia

b) A stenotic lesion
c) Spontaneous flow
d) a and c
e) a and b

A

Spontaneous flow

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20
Q

What is the greatest limitation of continuous wave operation?

A

range ambiguity

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21
Q

Grayscale maps:

a) More than one of the following

b)Use different schemes to create the images of varying contrast.
`
C) Help to reduce the large amount of DR received by the system

D) Can help and aid in analyzing structures

A

more than one of the following

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22
Q

The category of waves is subcategorized into:

A

mechanical & electromagnetic

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23
Q

A Bioeffect refers

A

undesired biological change to tissue as a result of interaction with the INSONATING BEAM

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24
Q
I-D Phased array is used for:
A) M-Mode
B) A-Mode
C)Doppler
D) 2D imaging
E) All of the above
A

ALL OF THE ABOVE

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25
Q

The Fast Fournier Technique involves:

A) separating a spectrum of amplitudes into components/bins

b) separating a spectrum of red blood cells into compenents/bins
c) separating a spectrum of frequencies into components/bins
d) separating a spectrum

A

separating a spectrum of FREQUENCIES into components/bins

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26
Q

The smallest division of a horizontal display line is called a:

A

pixel

27
Q

What is Colour Priority?

a) When a pixel has both a grayscale signal and a colour signal, this function determines if the colour is displayed or the grayscale is displayed
b) When a pixel has a grayscale signal, this function allows only the colour to be displayed
c) None of the above
d) A and C

A

When a pixel has both a grayscale signal and a colour signal, this function determines if the colour is displayed or the grayscale is displayed

28
Q

Pulsed-Wave Spectral Doppler:
a) Provides information along a specific line or with a specified gate range

b) is a non-scanned modality
c) Does not provide a lateral dimension
d) All of the above

A

Provides information along a specific line or with a specified gate range

29
Q

Assuming no other changes, if the propagation velocity increased by a factor of 1.96, what happens to the Doppler Shift Frequency?

a) Increase in the Doppler shift by a factor of 1.96
b) Decrease in the Doppler Shift by a factor of 1.96
c) a and B
d) Nothing occurs

A

Decrease in the Doppler Shift by a factor of 1.96

30
Q

Locational Artifacts:

a) Results in structures appearing either displaced in the image from its true location
b) Results in the presence of a structure or signal which does not even exist
c) Affects Detail Resolution
d) None of the above
e) All of the above

A

All of the above

31
Q

If the wavelength for a transducer is about 200um, what is the ideal matching layer?

25 um

50um

75um

None of the above

A

50um

32
Q

eneral Purpose Phatoms test for the following except:

a) Dead zone
b) Image Uniformity
c) Flow
d) Focal Zone

A

flow

33
Q

To determine a peak velocity Spectral Doppler must be used.

A

True

34
Q

The pedof transducer is used for:

a) Cardiac studies
b) Ankle-Brachial Indexes
c) Vascular studies
d) A and c
e) All of the above

A

All of the above

35
Q

The Limit for the mechanical index is?

a) ISPPA values above 190W/cm2
b) ISPPA values below 190W/cm2
c) ISPTA values below 190W/cm2
d) None of the above

A

ISPPA values BELOW 190W/cm2

36
Q

Which of the following is an example of a non-scanned modality?

a) M-Mode
b) B-Mode
c) 2D imaging
d) Colour Doppler

A

M-MOde

37
Q

The ability to correctly identify the insonification angle in Doppler is critical for which of the following reasons:

a) The ability to determine flow direction
b) The ability to assess Doppler measurement accuracy
c) The ability to minimize Doppler error sources
d) The ability to assess likelihood of artifact related issues such as spectral broadening
e) All of the above

A

e) All of the above

38
Q

Which of the following are the main five receiver functions?

A
Amplification
Compensation
Compression
Demodulation
Rejection
39
Q

The value of HPRF Doppler is the ability to achieve higher PRFs at a deeper gate depths.

A

TRUE

40
Q

Pulse Repetition Period is defined as:

A time measure of how long the transmit pulse lasts

b) The time between repeating transmit pulses

The number of pulses that occur per time

Percentage of time the system is actively transmitting energy into the patient

None of the above

A

The time between repeating transmit pulses

41
Q

The Sample Volume(Range gate) in Spectral Doppler:

a) Has three dimensions
b) Allows only blood flow within it to be displayed
c) Must be placed within the center of the vessel
d) a and c
e) a, b and c

A

a, b, c

42
Q

Range resolution degrades as:

The pulse frequency increases

Pulse length decreases

The pulse length increases

The amplitude of the wave increases

More than one of the above are true

A

The pulse length increases

43
Q

The Fresnel Zone:

a) Increases with increasing frequency or element size
b) Decreases with decreasing frequency or element size
c) Is not affect by aperture
d) None of the above

A

Increases with increasing frequency or element size

44
Q

Spectral mirroring is evident as a mirrored spectrum in the _____________ direction if strong flow.

a) forward
b) backward
c) upward
d) reverse

A

reverse

45
Q

What are the two major groups of test phantoms?

a) Those that measure the acoustic output of the instrument
b) Those that test the operation of the instrument (anatomic images and flow evaluation performance):
c) Those that measure the operation of the of the phantom
d) a and b

A

A and B

46
Q

The Nyquist limit requires a sampling rate ________ as fast as the highest frequency.

A

twice

47
Q

Lossless Compression:

a) Reduces file size to about ½ its usual size without altering the image
b) Includes file types such as JPEG and TIFF
c) Is identical to lossy compression
d) None of the above

A

Reduces file size to about ½ its usual size without altering the image

48
Q

A sector format is created by:

a) Steering
b) Phasing
c) Mechanically Steering
d) More than one of the above

A

phasing

49
Q

The process by which the piezoelectric efficiency is enhanced by heating and the use of strong magnetic field is called:

Poling

The Curie process

Piezoelectric conversion

Thermal magnetization

Ferroelectric conversion

A

Poling

50
Q

Reverberation is:

a) Is more likely when there is a smaller acoustic impedance mismatch and relatively specular reflection
b) Can occur when the sound is perpendicular to the specular reflecting interface

Incorrect Response
c) Sound bouncing between structures and is very common

d) Often not identified by the person scanning or by the person interpreting the scan.
e) More than one of the above

A

More than one of the above

51
Q

Averaging Based techniques include all of the following except:

a) Spatial/Compound Imaging
b) Image Persistence
c) Spatial Averaging
d) Frequency Compounding/Averaging
e) Harmonic Imaging

A

Harmonic Imaging

52
Q

Contrast Resolution is:

a) Is the ability to distinguish structures based on variations of brightness
b) Is the ability to distinguish dynamics or changes over time
c) Is divided into Lateral, Axial and Elevational Resolution
d) All of the above

A

Is the ability to distinguish structures based on variations of brightness

53
Q

Which two parameters directly affect the natural focus of a transducer?

Crystal thickness and operating frequency

Crystal diameter and operating frequency

Crystal thickness and focal depth

Crystal diameter and focal depth

A

Crystal diameter and operating frequency

54
Q

What is meant by a True Negative?

A

The test is correct because it matches the gold standard and the test is negative for disease

55
Q

Two major differences between SonoCT and Image Persistence are:

The angle is not changed between frames in Image Persistence

A weighted average is applied in Image Persistence

Newer frames do not count for more than older frames in SonoCT

The both use angles

a and b

c and d

A

A & B

56
Q

Which of the following is not a natural advantage of PZT for ultrasound use?

High coupling coefficient (efficiency)

Low Impedance

High Frequency of natural resonance

Repeatable Characteristics

A

Low Impedance

57
Q

Multi-Hertz operation allows:

a) The user to change the transmit frequency while imaging a patient without switching transducers
b) To image at a higher frequency and perform Doppler at a lower frequency
c) involves transmitting over a broad range of frequencies and then receiving/processing the beam at two or more different narrower frequency bands
d) More than one of the above is correct
e) None of the above are correct

A

More than one of the above is correct

58
Q

Changing the amplification directly changes the signal to noise ratio

A

FALSE

59
Q

Diagnostic Ultrasound falls within which range?

A

2-20MHz

60
Q

What is the DICOM Standard?

a) It is an established standardized file format for patient data and images
b) It defines criteria for the transfer, storage and display of this information
c) How we process our images
d) a and b
e) a and c

A

A&B

61
Q

The cosine of 0 is ____. This means that ____ of the true Doppler shift is detected.

A

1, 100%

62
Q

For a simple disk shaped crystal in a pulsed mode, if the thickness is tripled and the diameter is increased by a factor of 2, what change would occur to the operating frequency?

The operating frequency would not change

The operating frequency would increase by a factor of 2

The operating frequency would decrease by a factor of 6

The operating frequency would increase by a factor of 3/2

The operating frequency would decrease by a factor of 3

A

The operating frequency would decrease by a factor of 3

63
Q

If the wavelength is 2mm and the frequency is doubled, the wavelength becomes:

a) 0.5mm
b) 1mm
c) 4mm
d) None of the above

A

1mm

64
Q

C-Mode is used mainly for:

a) Colour Doppler
b) PW Doppler
c) Power Doppler
d) 2D Imaging

A

PW doppler