Chapter 4 Kremkau final review

Question 1

mode of operation in which the display presents echo amplitude versus depth

Answer 1

A mode

Question 2

the process by which small voltages are increased to larger one

Answer 2

amplification

Question 3

a device that accomplishes amplification

Answer 3

amplifier

Question 4

related to a procedure or system in which data are represented by proportional, continuously variable, physical quantities

Answer 4

analog

Question 5

a device that converts voltage amplitude to a number

Answer 5

analog-to-digital converter

Question 6

Mode of operation in which the display presents a spot of appropriate brightness for each echo received by the transducer.

Answer 6

B mode

Question 7

A B-mode image that represents an anatomic cross section through the scanning plane

Answer 7

B scan

Question 8

arrangement of electronic components that allows only those electric waves lying within a certain range, or band, of frequencies to pass and blocks all other

Answer 8

bandpass filter

Question 9

the part of an instrument that accomplishes electronic beam scanning, apodization, steering, focusing, and aperture with arrays

Answer 9

beam former

Question 10

having two possible states

Answer 10

bistable

Question 11

binary digit; one or zero

Answer 11

bit

Question 12

a single one- or two-way path for transmitting electric signals, in distinction from other parallel paths; an independent transmission delay line and transducer element path; an independent reception transducer element, amplifier, analog-to-digital converter, and delay line path

Answer 12

channel

Question 13

sequential display of all the frames stored in memory at a controllable frame rate

Answer 13

cine loop

Question 14

a sophisticated form of transmission in which the driving voltage pulses have intrapulse variations in amplitude, frequency, and/or phase

Answer 14

coded excitation

Question 15

equalization of received echo amplitude differences caused by different attenuations for different reflector depths

Answer 15

compensation

Question 16

reduction in differences between small and large amplitudes. Region of high density and pressure in a compressional wave

Answer 16

compression

Question 17

ability of a gray-scale display to distinguish between echoes of slightly different intensities

Answer 17

contrast resolution

Question 18

detection

Answer 18

demodulation

Question 19

compensation

Answer 19

depth gain compensation

Question 20

detection

Answer 20

conversion of voltage pulses from radio frequency to video form

Question 21

related to a procedure or system in which data are represented by numberic digits

Answer 21

digital

Question 22

a device that converts a number to a proportional voltage amplitude

Answer 22

digital-to-analog converter

Question 23

a device that presents a visual image derived from voltages received from an image processor

Answer 23

display

Question 24

ratio (in decibels) of largest to smallest power that a system can handle; ratio of the largest to smallest intensity of echoes encountered

Answer 24

dynamic range

Question 25

imaging tissue stiffness by tracking movement under mechanical stress

Answer 25

elastography

Question 26

a backlighted rectangular matrix of thousands of liquid-crystal display elements

Answer 26

flat-panel display

Question 27

a single image produced by one complete scan of the sound beam

Answer 27

frame

Question 28

number of frames of echo information stored each second

Answer 28

frame rate

Question 29

constant display of one of the frames in memory

Answer 29

freeze

Question 30

ratio (in decibels) of amplifier output to input electric power

Answer 30

gain

Question 31

range of brightness (gray levels) between white and black

Answer 31

Gray-scale

Question 32

the part of the image processor where echo information is stored in image format

Answer 32

image memory

Question 33

an electronic device that manipulates and prepares images for visual presentation

Answer 33

image processor

Question 34

gain controls that enable different gain values to be applied laterally across an image to compensate for differing attenuation values in different anatomic regions

Answer 34

lateral gain control

Question 35

A B-mode presentation of changing reflector position (motion) versus time

Answer 35

M mode

Question 36

the extension of the field of view beyond the normal limits of a transducer scan plane

Answer 36

panoramic imaging

Question 37

averaging sequential frames together

Answer 37

persistence

Question 38

a beam of light

Answer 38

physical beam

Question 39

the system provides means for electronically communicating images and associated information to workstations and devices external to the sonographic instrument, the examining room, and even the building in which the scanning is done

Answer 39

picture archiving and communications system

Question 40

picture element; the unit into which imaging information is divided for a storage and display in a digital instrument

Answer 40

pixel

Question 41

imaging processing done after storage in the memory

Answer 41

postprocessing

Question 42

signal and image processing accomplished before storage in the memory

Answer 42

preprocessing

Question 43

the high frequency generator generates short waves

Answer 43

pulse-echo principle

Question 44

voltages representing echoes in cyclic form

Answer 44

radio frequency

Question 45

imaging with a rapid frame sequence display

Answer 45

real-time

Question 46

a display that, with a sufficient frame rate, appears to image moving structures or a changing scan plane continuously

Answer 46

real-time display

Question 47

the number of times each second that information is sent from the image memory to the display. The number of times per second that a computer monitor redraws the information found in the memory

Answer 47

refresh rate

Question 48

a line produced on a display that represents ultrasonic echoes returning from the body. A sonographic image is composed of many such lines.

Answer 48

scan line

Question 49

the sweeping of a sound beam through the anatomy to produce an image

Answer 49

scanning

Question 50

transverse wave

Answer 50

shear wave

Question 51

information-bearing voltages in an electric circuit; an acoustic, visual, electric, or other conveyance of information, The physical representation of a message or information

Answer 51

signal

Question 52

an electronic device that manipulates electric signals in preparation for appropriate presentation of information contained in them

Answer 52

signal processor

Question 53

averaging of frames that view the anatomy from different angles

Answer 53

spatial compounding

Question 54

the increase or decrease of the length of a segment of a material, subjected to a stress, divided by its original length

Answer 54

strain

Question 55

a force per unit area applied to a material that compresses or stretches it

Answer 55

stress

Question 56

ability to distinguish closely spaced events in time; improves with increased frame rate

Answer 56

temporal resolution

Question 57

equalization of echo amplitude differences caused by different attenuations for different reflector depths

Answer 57

time gain compensation

Question 58

an imaginary beam that describes the result of retrospective, computed beam forming.

Answer 58

virtual beam

Question 59

three-dimensional imaging

Answer 59

volume imaging

Question 60

a measure of the hardness of a material. It is the ratio of the applied stress to the resulting strain in a material subjected to the stress

Answer 60

Young's modulus

Question 61

The ultrasound PRF is equal to the voltage ______ repetition frequency of the pulser.

Answer 61

pulse

Question 62

Increased voltage amplitude produced by the pulser increases the ______ and _______ of ultrasound pulses produced by the transducer.

Answer 62

amplitude, intensity

Question 63

If a 6 MHz transducer images to a depth of 10 cm, to avoid range ambiguity, the maximum PRF permitted is ______.

Answer 63

7.7 kHz

Question 64

Functions performed by the signal processor include ______, _______, and _______.

Answer 64

filtering, detection, compression

Question 65

If the input voltage to an amplifier is 1 mV and the output voltage is 10 mV, the voltage amplication ratio is ______. The power ratio is ______. The gain is _____ dB.

Answer 65

10, 100 20

Question 66

An amplifier with a gain of 60 dB has 1 uW of power applied to the input. The output power is ______ W.

Answer 66

1

Question 67

An amplifier with a gain of 60 dB has 10 uV of voltage applied to the input. The output voltage is ______.

Answer 67

10

Question 68

Time gain compensation is accomplished in the

Answer 68

beam former

Question 69

Compensation takes into account reflector _____.

Answer 69

depth

Question 70

Compensation amplifies echoes differently, according to their arrival ______.

Answer 70

times

Question 71

Compression decreases the ______ range to a range that the _____ and human _____ can handle.

Answer 71

dynamic, display, vision

Question 72

If a display has a dynamic range of 20 dB and the smallest voltage it can handle is 200 mV, then the largest voltage it can handle is _____ V.

Answer 72

2.0

Question 73

Detection converts voltage pulses from ______ form to ______ form.

Answer 73

radio frequency, amplitude

Question 74

Filtering widens bandwidth

Answer 74

false

Question 75

Filtering is accomplished in the

Answer 75

signal processor

Question 76

The compression or dynamic range control reduces the range of echo amplitudes displayed by reducing the weakest to _____ and/or the strongest ones to the ______ value and assigning the others to increasing values. This produces a(n) _______ contrast image with elimination of weakest and maximizing of strongest echoes.

Answer 76

zero, maximum, higher

Question 77

An amplifier has a power output of 100 mW when the input power is 0.1 mW. The amplifier gain is _____.

Answer 77

30

Question 78

If the beam-former output to the transducer is reduced by 3, 6, or 9 dB, the ultrasound pulse output intensity is reduced by _____%, _____%, or _____%, respectively.

Answer 78

50, 75, 87.5

Question 79

One watt is _____ dB below 100 W.

Answer 79

20

Question 80

One watt is ______ dB above 100 mW.

Answer 80

10

Question 81

If the input power is 1 mW and the output is 10,000 mW, the gain is _____ dB.

Answer 81

40

Question 82

If an amplifier has a gain of 15 dB, the ratio of output power to input power is ______.

Answer 82

32

Question 83

If the output of a 22-dB gain amplifier is connected to the input of a 23-dB gain amplifier, the total gain is _____ dB. The overall power ratio is _____.

Answer 83

45, 32,000

Question 84

If a 17-dB electric attenuator is connected to a 15-dB amplifier, the net gain is _____ dB. The net attentuation is _____ dB. The net attenuation is _____ dB. For a 1-W input, the output is _____ W.

Answer 84

-2,2,0.63

Question 85

The contrast resolution for an instrument that has an echo dynamic range of 43 dB and 32 shades is ____ dB per shade.

Answer 85

1.3

Question 86

The contrast resolution for an instrument that has a 6-bit memory and a 45-dB echo dynamic range is _____ dB per shade.

Answer 86

0.7

Question 87

Typical image pixel dimensions are _____.

Answer 87

512 x 384

Question 88

_____ total memory elements are required for a 100 x 100 pixel, 5-bit digital memory.

Answer 88

50,000

Question 89

Memories of _____ bits per pixel are common in ultrasound today.

Answer 89

6 to 8

Question 90

Digital memories store _____.

Answer 90

numbers

Question 91

______ is commonly controllable by the operator.

Answer 91

postprocessing

Question 92

In binary numbers, how many symbols are used?

Answer 92

2

Question 93

The term binary digit is commonly shortened into the single word _____.

Answer 93

bit

Question 94

Each binary digit in a binary number is represented in the memory by a memory element, which, at any time, is in one of _____ states that are ______ or ______.

Answer 94

2, on, off

Question 95

The binary number 10110 represents zero 1, one 2, one 4, zero 8, and one 16; that is, the decimal number 0+2+4+0+16=22. What decimal number does the binary number 11001 represent?

Answer 95

25

Question 96

The decimal number 13 is made up of one 1, zero 2, one 4, and one 8 (8+4+0+1=13). The number therefore is represented by the binary number

Answer 96

1101

Question 97

The primary formats of image presentation are called _____ mode, ______ mode, and _____ mode. They are used in _____, ______, and ______ types of clinical imaging, respectively

Answer 97

B (brightness), M (motion), A (amplitude), all, cardiac, ophthalmic

Question 98

_____ mode is used for studying the motion of a structure such as a heart valve.

Answer 98

M

Question 99

A B scan presents a cross section through the _____ plane.

Answer 99

scan

Question 100

A display that shows various echo strengths as different brightnesses is called a ______ - ______ or _______ display.

Answer 100

gray-scale, B mode

Question 101

The ______ stores the gray-scale image and allows it to be displayed on a computer monitor.

Answer 101

image memory

Question 102

If the PRF of an instrument is 1 kHz and it displays (single focus) 25 frames per second, there are ____ lines per frame.

Answer 102

40

Question 103

The PRF is _____ Hz if 30 frames (40 lines each) are displayed per second (single focus).

Answer 103

1200

Question 104

Imaging involving 10-cm penetration, a single focus, 100 scan lines per frame, and 30 frames per second can be accomplished without range ambiguity.

Answer 104

true

Question 105

The maximum frame rate permitted for 15-cm penetration, 3 foci, and 200 scan lines per frame is _____.

Answer 105

8.5