Brainscape's Knowledge GenomeTM

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


See full index

Ch1 Foundations of Sonography > Cha 1 Foundations of Sonography > Flashcards

Cha 1 Foundations of Sonography Flashcards

1
Q

Acoustic impedance

A

Measure of a material’s resistance to the propagation of sound;expressed as the product of acoustic velocity of the medium and density of the medium

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

angle of incidence

A

Angle at which a sound beam strikes the interface between two types of tissue

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

attenuation

A

Reduction in amplitude and intensity of a sound wave as it propagates through a medium

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

axial resolution

A

Refers to the minimum distance between two structures positioned along the axis of the beam where both structures can be visualized as separate objects

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

compression

A

region of increased particle density

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

crystal

A

Special material in the transducer that has the ability to convert electric impulses onto sound waves

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

decibel

A

Unit used to quantitatively express the ratio of two amplitudes or intensities

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

focal zone

A

Region over which the effective width of the sound beam is within some measure of its width at the focal distance

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

frequency

A

Number of cycles per second that a periodic events or function undergoes

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

intensity

A

Power per unit area

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

interface

A

Surface forming the boundary between media having diffeent properties

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

megahertz (MHz)

A

1,000,000Hz

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

piezoelectric

A

Generation of electric signals as the result of an incident sound beam on a material that has piezoelectric properties

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

power

A

Rate of energy flow over the entire beam of sound

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

refraction

A

Change in the direction of propagation of a sound wave transmitted across an interference where the speed of sound varies

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

resolution

A

Ability of the transducer to distinguish between two structures adjacent to one another

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

transducer

A

Any device that convert energy from one form to another

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

wave

A

Propagation of energy that moves back and fourth or vibrates at a steady rate

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

wavelength

A

Distance over which a wave repeats itself during one period of oscillation

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

resistance

A

Passive force in opposition to another, active force; when tissue exert pressure against the flow

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

angle of reflection

A

Angle of incidence at which the sound beam strikes the interface

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

velocity

A

Speed of the ultrasound wave;determined by tissue density

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

cycle

A

Sequence of events occurring at regular intervals

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

Fraunhofer zone

A

Field farthest from the transducer during formation of the sound beam

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

hertz Hz

A

Unit for frequency; equal to 1 cycle per second

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

kilohertz kHz

A

1000Hz

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

lateral resolution

A

Minimum distance between two objects at which they still can be displayed as separate objects

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

pulse duration

A

Time interval required for generating the transmitted pulse

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

Fresnel zone

A

Field closet to the transducer during formation of the sound beam

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

slice thickness

A

Thickness of the section in a patient that contributes to echo signals on any one image

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

aliasing

A

Technical artifact that occurs when the frequency change is so great that it exceeds the sampling view and pulses repetition frequency

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

amplitude

A

Strength of the ultrasound wave measured in decibels

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

continuous wave (CW) Doppler

A

One transducer continuously transmits sound and one continuously receives sound; used in high velocity flow patterns

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

Doppler angle

A

Angle that the reflector path makes with the ultrasound beam; the most accurate velocity is recorded when the beam is parallel to flow

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

Doppler shift

A

Change in frequency of a reflected wave; cause by motion between the reflector and the transducer’s beam

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

dynamic range

A

Ratio of the largest to the smallest signals that an instrument or a component of an instrument can respond to without distortion

37
Q

frame rate

A

Rate at which images are updated on the display;dependent on transducer frequency and depth selection

38
Q

gain

A

Measure of strength of the ultrasound signal

39
Q

gray scale

A

B-mode scanning technique that permits the brightness of the B mode dots to be displayed in various shades of gray to represent different amplitudes

40
Q

laminar

A

Normal pattern of vessel flow; flow in the center of the vessel in faster than it is at the edge

41
Q

Nyquistsamping limit

A

In pulsed Doppler the Doppler signal must be sampled at least twice for each cycle in the wave if Doppler frequencies are to be detected accurately

42
Q

pulse repetition frequency (PRF)

A

In pulse echo instruments, it is the number of pulses launched per second by the transducer

43
Q

pulsed wave (PW) Doppler

A

Sound transmitted and received intermittently with one transducer

44
Q

real time

A

Ultrasound instrumentation that allows the image to be displayed many times per second to achieve a “real time” image of anatomic structure and their motion patterns

45
Q

spectral analysis

A

Analysis of the entire frequency spectrum

46
Q

spectral broadening

A

Echo fill in of the spectral windows that is proportional to the severity of stenosis

47
Q

temporal resolution

A

Ability of the system to accurately depict motion

48
Q

time gain compensation (TGC)

A

Ability to compensate for attenuation of the transmittal beam as the sound wave travels through tissue in the body

49
Q

gate

A

Sample site from which the signal is obtained with pulsed Doppler

50
Q

frequency shift

A

Amount of change in the returning frequency compared with transmitting frequency when the sound waves hits a moving target such as blood in an artery

51
Q

Acoustics is the study of ____, _____, and ___ sound waves.

A

generation, propagating, receiving

52
Q

Ultrasound is defined as sound frequencies beyond the upper limits of human hearing, that is , greater than ____.

A

20 kilohertz

53
Q

Name three pioneers who made a significant contribution to ultrasound

A

Donald Baker, Hertz and Inge Edler, William Fry, Joseph Holmes, Douglass Howry, George Ludwig, Robert Rushmer, John Wild

54
Q

The terms ___, ____, and ____ have all been used to describe a imaging technique by which soft tissue structure of the body are visualized by recording the returning reflection of ultrasonic waves directed into the body.

A

Diagnostic medical ultrasound, ultrasound, ultrasonography

55
Q

The term that applies to the ultrasound evaluation of cardiac structures is ____.

A

echocardiograpghy

56
Q

One who preforms ultrasound studies and gather diagnostic data under the direct or indirect supervision of a physician is a ___.

A

sonographer

57
Q

List the qualities of a good sonograher

A

Good physical health, emotional stability, communication skills, dedication, independence, ability to conceptualize two dimensional image into 3, intellectual curiosity

58
Q

As the ceramic element vibrates, it periodically presses against and pulls away from the adjacent medium with resultant particle ___ and ___ in the medium

A

Compression, rarefaction

59
Q

A transducer converts ____ energy into ____ energy.

A

electrical, mechanical

60
Q

A propagation of energy that moves back and fourth or vibrates at a steady rate is a ____.

A

waves

61
Q

The time required to produce each cycle depends on the ___ of the transducer.

A

frequency

62
Q

The distance between two peaks over a period of time is the ___.

A

wavelength

63
Q

Wavelength is inversely related to frequency, which means that the higher the frequency, the ___ wavelength

A

shorter

64
Q

As frequencies become higher, the pulse duration ____, yielding a decrease in the depth of field.

A

decreases

65
Q

The rate at which energy is transmitted is referred to as the ____.

A

power

66
Q

Power per unit are is defined as ____.

A

intensity

67
Q

If you double the power, the intensity ____.

A

Double

68
Q

The piezoelectric effect was first described by the _____ brother in 1880

A

Curie

69
Q

Air-filled structures, such as lungs and stomach, or gas-filled structures, such as bowel,____. sound transmission.

A

impede

70
Q

Bone conducts sound at a ____ speed than soft tissue.

A

faster

71
Q

Normal transmission of sound through soft tissue travels at ____m/sec.

A

1540

72
Q

Acoustic impedance is the product of the ____ in a medium and the density of that medium.

A

velocity of sound

73
Q

The angle of reflection is equal to the ___.

A

angle of incidence

74
Q

If specular are aligned ____ to the direction of the transmitted pulse, they reflect sound directly back to the active crystal elements in the transducer and produce a strong signal.

A

perpendicular

75
Q

The sum of acoustic energy losses resulting from absorption, scattering, and reflection is the ____.

A

attenuation

76
Q

Minimum reflector separation along the sound path required to produce separate echos is _____ resolution

A

axial

77
Q

The ____ resolution refers to the ability to produce separate echoes perpendicular to the sound path; it is affected by transducer diameter and focusing.

A

lateral

78
Q

Lateral resolution is determined by ____.

A

beam width

79
Q

______ resolution refers to the ability to resolve objects that are the same distance from the transducer but are located perpendicular to the plane of imaging.

A

azimuthal

80
Q

Identify 3 criteria that determine the type of transducer selected for a particular examination

A

examination, size of patient, and amount of fatty or muscular tissue present

81
Q

The number of pulses launched per second is the ____.

A

pulse repetition frequency

82
Q

If the gain is set too _____, artifactual echo noise will be displayed throughout the image.

A

high

83
Q

A dynamic presentation of multiple image frames per second over selected area of the body is provided by ___ imaging

A

real time

84
Q

A one dimensional image displaying the amplitude strength of returning echo signals along the vertical axis and the time (distance) along the horizontal axis is produced by______.

A

amplitudes modulation

85
Q

The intensity (amplitude) of an echo attained by varying the brightness of a dot correspond to echo strength is displayed by the ___ method.

A

brightness modulation

86
Q

The condition of assigning each level of amplitude a particular shade of gray is referred to as the _____.

A

gray scale

87
Q

The ____ displays the time along the horizontal axis and depth along the vertical axis to depict movement, especially in cardiac structures

A

motion mode

88
Q

With pulsed Doppler, for accurate detection of Doppler frequencies, the Doppler signal must be sampled at least _____ for each cycle in the wave.

A

twice

89
Q

When the Nyquist limit is exceeded, an artifact called ____ occurs.

A

aliasing

Ch1 Foundations of Sonography (2 decks)

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