Brainscape's Knowledge GenomeTM

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


See full index

Physics > Chapter 15 > Flashcards

Chapter 15 Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards AP® Physics flashcards
1
Q

Images composed of only 2 shdes: black and white

A

Bistable

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

_ presents multiple levels of brightness (white, light gray, medium gray, etc.)

A

Gray scale

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

In gray scale, the numerous levels allows the system to _

A

assign different gray shades to different echo amplitudes and differentiate biologic tissues of different reflectivity.

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

Two user controls on video monitors can

alter characteristics of displayed images

A
  1. Contrast

2. Brightness

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

Determines the range of brilliancies within the displayed image.

A

Contrast

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

Bistable images (only black and white) are _ contrast

A

High

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

Determines the brilliance of the displayed image

A

Brightness

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

Functions of scan convertors

A

Store digital image information to later display it.

Change format of data; translate data

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

Scan converters _ and then later _

A

Store information

Display it

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

Storage of information is called

A

Writing

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

Image data is _ for display on the monitor.

A

“read” from the scan converter

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

scan convertors used to be _, now they use _

A

Analog

Digital technology

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

scan converters:

Ultrasound information is obtained from the body from

A

multiple scan lines (spokes)

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

Monitors display video information as

A

Horizontal lines

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

Scan converter translates the information from _ format into the _ format

A

“Spoke”

Video

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

Data stored in the scan converter can be altered between

A

the writing process and the reading process.

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

_ numbers are real world numbers

found in our everyday lives

A

Analog

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

Numbers with unlimited and continuous range of values

A

Analog

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

_ numbers are associated with computer devices and have discrete values

A

Digital

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

_ scan converter:
Funnel-shaped vacuum tube with an electron gun
located within its smaller end.

A

Analog

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

Analog Scan Converter:

_ containing the image information are shot out of the electron gun

A

Electrons

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

Analog Scan Converter:

The larger end of the tube contains

A

a dielectric matrix or silicon wafer.

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

Analog scan converter:

The electrons strike the _ and are _

A

Matrix

Stored

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

Analog scan converter:

The matrix is divided into _

A

Millions of tiny storage elements

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

Analog scan converter:

The stored electrons are _

A

Read to retrieve the image info

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

Analog Scan Converter has _ spatial resolution

A

Excellent

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

Limitations of analog scan converteers

A

Image fade – stored charges on the silicon wafer dissipate
over time
Image flicker – caused by switching between read and wrote modes
Instability – picture quality depends on many different factors
Deterioration – image degrades as the device ages

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

_ scan converters use computer technology to convert images into numbers (_)

A

Digital

Digitizing

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

Digital scan converter:

Image is stored in _ as _

A

Computer memory

Series of zeroes and ones

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

Digital scan converters:

The numerical representation of the image is _ and then _

A

Processed

then retranslated into an image displayed on a monitor.

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

Advantages of digital scan converters:

A 
Uniformity – consistent gray scale quality throughout the image
Stability – does not fade or drift 
Durability
Speed
Accuracy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Two important elements of digital scan converters

A
  1. Pixel

2. bit

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

Smallest building block of a digital picture

A

Pixel

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

At any instant in time, the entire pixel is _

A

A single shade of gray

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

number of pixel elements per inch

A

Pixel density

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q 
Low pixel density:
_ pixels per inch
_ pixels 
_ detailed image
_ spatial resolution
A

Few
Larger
Less
Lower

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q 
High pixel density:
_ pixels per inch
_ pixels 
_ detailed image
_ spatial resolution
A

Many
Smaller
More
Higher

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

Smallest amount of computer memory

A

Bit

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

A bit is _, has a value of _

A

Bistable

Either 0 or 1

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

a group of bits; simply a series of zeroes and ones.

A

Binary number

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

group of eight bits of computer memory

A

Byte

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

Two bytes (16) bits

A

Word

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

Each pixel’s shade of gray is determined by _

A

the cluster of bits assigned to it.

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

Fewer bits per pixel:
_ shades of gray
_ contrast resolution

A

Fewer

Degraded

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

More bits per pixel:
_ shades of gray
_ contrast resolution

A

More

Improved

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

To determine the number of gray shades that can be represented by a cluster of bits, _

A

multiply the number 2 by itself the same number of times there are bits: 2^n

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

Number of bits:5

Number of shades: _

A

32

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

digital information is _ susceptible to noise contamination

A

Less

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

Information is taken from the transducer in _ form. It is then changed into _ form for _. It then must be _ for display.

A

Analog

Digital

Computer storage

Analog

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

Step 1. electrical signals created by the transducer during reception are converted from _ to _ form by the _

A

Analog

Digital

Analog to digital converter

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

Step 2:

The digital information is stored in the _. Any processing of the reflected signals before storage is called _

A

scan converter’s computer memory

Preprocessing

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

Step 3:
The image information (digital form) is processed by the _. Any processing after storage in the digital scan converter is called

A

US systems computer

Postprocessing

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

Step 4:

Digital signals are translated _ to be displayed on the analog display devices by a

A

back into analog form

digital-to- analog (D-to-A) converter.

46
Q

Step 5:

The signal is now in _ form and can be displayed on the analog display.

A

Analog

46
Q

Modern flat-panels are _ display devices

A

Digital

47
Q

cases of digital display devices, step _ is unnecessary.

A

4

48
Q

the manipulation of image data before

storage in the scan converter.

A

Preprocessing

49
Q

Preprocessing is controlled by _

A

Sonographer

50
Q

_ alters image data forever and cannot be reversed or undone

A

Preprocessing

51
Q

manipulation of image data after storage in the scan converter

A

Postprocessing

51
Q

Postprocessing is controlled by

A

Sonographer

52
Q

Pre or postprocessing:
Changes can be reversed
Alterations to a frozen image

A

Postprocessing

52
Q

Functions of Image Processor:

A 
◼ Preprocessing
◼ Persistance
◼ 3-D acquisition
◼ Storing imaging frames 
◼ Cine loop
◼ Post processing
◼ Grayscale
◼ 3-D presentation 
◼ D-A conversion
52
Q

Enlarging a portion of the image to fill the entire screen

A

Magnification/zoom

53
Q

Selected part of image is called

A

Region of interest (ROI)

54
Q

Two types of magnification

A

Read

Write

55
Q

_ magnification occurs after the image data is stored in the scan converter

A

Read

56
Q

Read magnification: 3 steps:

A
  1. US System scans the anatomy
  2. Image is converted from analog to digital form and stored in the scan converter
  3. Sonographer identifies the ROI and the system reads and displays only the original data that pertains to that area. The ROI is not rescanned.
56
Q

Read magnification:

Number of pixels or scan lines in the magnified image is

A

the same as the original image

57
Q

Does spatial resolution change with read magnification

A

No

57
Q

Read magnification:

Are the pixels larger, smaller, or the same size in the zoomed image

A

Larger

58
Q

_ magnification can be used on a frozen image

A

Read

59
Q

Is read magnification pre or postprocessing

A

Postprocessing

60
Q

_ magnification is applied during data acquisition, before data is stored in the scan converter

A

Write

60
Q

Write magnification: 4 steps:

A
  1. The US system scans the anatomy and creates an image
  2. Image is converted from analog to digital and is stored in the scan converter
  3. Sonographer identifies the ROI. The US system then discards all the existing data in the scan converter
  4. The US System then rescans only the region of interest and writes new data into the scan converter.
61
Q

Write magnification: the image used to identify the _ is discarded and _ is acquired

A

ROI

All new image info

61
Q

_ magnification:

The number of pixels or scan lines in the ROI image is greater than that in the ROI’s portion of the original image

A

Write

62
Q

_ magnification has increased number of pixels which improves _

A

Write

Spatial resolution for the ROI

62
Q

Can write magnification be used on a frozen image?

A

No

63
Q

Is write magnification pre or postprocessing

A

Preprocessing

64
Q

Sophisticated method of improving image quality. Developed within the context of bioeffects due to high intensity levels of short sound pulses

A

Coded excitation

65
Q

Coded excitation creates _ sound pulses containing _.

A

Very long

A wide range of frequencies

66
Q

Long pulses distribute energy _

A

Over a broad frequency range

67
Q

Does coded excitation improve penetration

A

Yes

68
Q

Coded excitation occurs in

A

The pulser

68
Q

Special mathematical techniques alter the long reflected pulses into a form suitable for high image quality

A

Coded excitation

68
Q

The coding of the excitation _ the pulse mathematically and _ resolution

A

Shortens

Improves

69
Q

Produces image with a wider field of view

A

Panoramic imaging

70
Q

Panoramic imaging is achieved by

A

sliding transducer parallel to the scan plane

[extending the scan plane]

71
Q

Panoramic imaging: old information from previous frame are _ and _

A

Retained

New echoes are added to the image in the same direction the scan plane is moving

71
Q

Is panoramic imaging pre or postprocessing

A

Preprocessing

71
Q

A method of using sonographic information from several different imaging angles to produce a single image

A

Spatial compounding

72
Q

_ compounding:

Number of frames and steering angles varies

A

Spatial

73
Q

Spatial compounding has _ frames= _ compound image quality

A

More

Better

74
Q

Does spatial compounding reduce speckle and shadowing artifact?

A

Yes

74
Q

Spatial compounding reduces _

A

Speckle and shadowing artifacts

74
Q

Speckle reduction improves

A

dynamic range and contrast resolution.

75
Q

_ compounding reduces speckle artifact and noise in ultrasound images

A

Frequency

76
Q

All reflected sound pulses contain

A

a large range of frequencies.

76
Q

Frequency compounding:

Reflected signal is divided into _ and an image is created from_. Images from the sub-bands are then _

A

sub-bands of limited frequencies
Each sub-band
combined into a single image.

77
Q

Frequency compounding: Noise components of the reflections are _ and _

A

different for each sub-band

Noise is reduced when they are combined

78
Q

Image processing method that

makes pictures look sharper

A

Edge enhancement

79
Q

Edge enhancement: the computer identifies and _

A

emphasizes sharp edge boundaries in the image

80
Q

Increases the image contrast in the area immediately around the edge

A

Edge enhancement

81
Q

Creates subtle bright and dark highlights on either side of these boundaries to make them appear more defined

A

Edge enhancement

82
Q

An image processing technique that continues to display information from older images. A number of previous frames are superimposed on the most current frame.

A

Temporal compounding

83
Q

Temporal compounding creates _

A

smoother image with reduced noise and improved image quality

84
Q

Temporal compounding aka

A

persistence, temporal averaging

85
Q

Temporal compounding: reduction of _

A

Frame rate/temporal resolution

85
Q

Temporal compounding is most effective with

A

Slowly moving structures

86
Q

With sector shaped images, the scan lines _. This creates _.

A

Separate at increasing depths.

Gaps between the scan lines

87
Q

_ method of constructing new simulated data points to fill in the gaps.

A

Interpolation

88
Q

Fill in interpolation: the know gray scale level of neighboring pixels are used to _

A

Predict the missing info

88
Q

Is fill in interpolation pre or postprocessing

A

Preprocessing

88
Q

Fill in interpolation: _ resolution is improved

A

Spatial

89
Q

Dynamic technique that produces images from sound reflections in an entirely new way.

A

Elastography

90
Q

Elastography is related to _. Tissue will _

A

the mechanical properties of the tissue

Deform differently following the application of a force

91
Q

Elastography: _ are obtained and combined with US reflections into images called _

A

Estimates of tissue stiffness

Elastograms

91
Q

_ is potential as a complementary tool for the diagnosis of cancer

A

Elastography

92
Q

2 [general] methods for performing elastography

A

Strain elastography and shear weave elastography

93
Q

Strain elastography:
_ dependent
Measures _
Qualitative or quantitative?

A

Operator
Tissue strain
Qualitative

94
Q

Aka transient elastography

A

Shear wave elastography

94
Q

Shear wave elastography:
Compressions applied by _
Measures _
Qualitative or quantitative?

A

Sound pulse
Stiffness
Quantitative

94
Q

PACS

A

Picture Archiving and Communications System

94
Q

Digital ultrasound lab where images and additional medical information are digitized and stored on a computer network

A

PACS

95
Q

3 major advantages of PACS

A
  1. Virtually instant access to archived studies
  2. No degradation of data
  3. “store and forward” telemedicine – can electronically transmit images and reports to remote sites
96
Q

_ are the primary digital storage devices used in PACS

A

Computer hard drives

97
Q

DICOM

A

Digital Imaging and Computers in Medicine

97
Q

A set of rules that allows imaging systems to share information on a network

A

DICOM

98
Q

If an US system adheres to _, the system can successfully connect to a PACS network

A

DICOM standards

99
Q

DICOM guarantees _

A

that all devices developed in the future will work with PACS as well.

100
Q

Developed within the context of bioeffects

A

Coded excitation

Physics (25 decks)

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