Brainscape's Knowledge GenomeTM

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


See full index

ULTRASOUND > Week 3 // UTZ Interaction and Attenuation > Flashcards

Week 3 // UTZ Interaction and Attenuation Flashcards

1
Q

also known as tissue interface

A

acoustic boundaries

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

position within the tissue where the values of acoustic impedance change

A

acoustic boundaries

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

weakening of the sound as it propagates through a medium

A

attenuation

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

reduction in amplitude and intensity as sound travels

A

attenuation

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

unit of attenuation

A

decibel

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

2 factors affecting attenuation

A

medium
frequency

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

attenuation that occurs with each centimeter the sound wave travels

A

attenuation coefficient

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

for soft tissues, the typical value for attenuation coefficient is ____

A

0.5 dB/cm

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

term used to describe the average tissue that makes up the soft tissues of the human body

A

soft tissue

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

5 types of attenuation

A

absorption
reflection
scattering
refraction
divergence

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

converted to heat

A

absorption

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

back to the transducer

A

reflection

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

reflected in multiple directions

A

scattering

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

redirection of part of the sound beam

A

refraction

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

power spread over a large area

A

divergence

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

Process by which energy in the ultrasound beam is transferred to the propagating medium, where it is transformed into a different form of energy, mostly heat. The medium is said to absorb energy from the beam.

A

absorption

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

The dominant factor contributing to attenuation of ultrasound in soft tissues.

A

absorption

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

Occurs when two large structures of significantly different acoustic impedance form an interface, the interface
becomes a reflector and some of the wave energy is reflected back to the transducer. The energy remaining in the wave is decreased.

A

reflection

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

the major interaction of interest for diagnostic ultrasound

A

reflection

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

the sound that hits an acoustic interface

A

incident energy

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

reflected beam

A

echo

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

reflectors can either be

A

specular
diffuse

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

reflector that occurs when the boundary is smooth and larger than the beam

A

specular reflector

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

reflector that occurs when the reflecting interface is irregular in shape and its dimensions are smaller than the diameter of the ultrasound beam

A

diffuse reflector

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

Occurs when an ultrasound waves strikes a boundary or interface between 2 small structures and the wave is scattered in different directions.

A

scattering

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

is responsible for providing the internal texture of organs in the image

A

scattering

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

when the scatter in equal in all direction

A

rayleigh scattering

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

the change in direction of a sound beam as it enters the medium

A

refraction

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

transmission with a bend

A

refraction

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

physics of refraction are described by ______ law

A

physics of refraction are described by SNELL’S LAW

31
Q

two requirements for refraction to occur

A

oblique incidence
different propagation speed

32
Q

As a beam of ultrasound travels through it will diverge. This divergence will result in the same power spread over larger area. The intensity of the beam will therefore be reduced.

A

divergence

33
Q

converts one form of energy to another

from electrical energy to ultrasound energy

A

transducer

34
Q

5 compositions of transducer

A

physical housing
electrodes
piezoelectric elements
backing material
impedance matching layer

35
Q

Contains all the individual components including the crystals, electrodes, matching layer, and backing material.

A

physical housing

36
Q

provides structural support and acts as an electrical and acoustic insulator

A

physical housing

37
Q

are connected to the UTZ machine which generates the short burst of electrical pulses to excite the crystals

A

electrodes

38
Q

outside electrode

A

grounded electrode

39
Q

inside electrode

A

live electrode

40
Q

transducer element, active element, crystals

A

piezoelectric element

41
Q

crystalline materials composed of dipolar molecules

A

piezoelectric element

42
Q

naturally occurring material with piezoelectric properties

A

quartz

43
Q

man made ceramic, more efficient, better sensitivity and can be easily shaped

A

lead zirconate titanate

44
Q

to press

A

Piezo

45
Q

Elektron

A

amber

46
Q

was described 1880 by Pierre and Jacques Curies

A

piezoelectricity

47
Q

Derived from the
Greek term Piezo (to press) and Elektron (amber, which is an organic plant resin that was used in early electrical study).

A

piezoelectricity

48
Q

States that some materials produced a voltage when deformed by an applied pressure.

A

piezoelectricity

49
Q

eliminate the vibrations from the back face and to control the length of vibrations from the face of the crystals

A

backing/damping material

50
Q

consists of tungsten powder and plastic or epoxy resin

A

backing/damping material

51
Q

sandwiched between the piezoelectric crystal and the patient

A

matching layer

52
Q

has acoustic impedance value halfway between that of the crystal and soft tissue

A

matching layer

53
Q

Area through which the sound energy emitted from the transducer travels.

A

ultrasound beam

54
Q

2 regions of UTZ beam

A

near field/Fresnel
far field/Fraunhofer

55
Q

Region nearest the transducer face, characterized by a highly collimated beam with more uniform intensity.

A

near field
Fresnel zone

56
Q

Region farthest from the transducer and characterized by the divergence of the beam with great variation in intensity.

A

far field
Fraunhofer zone

57
Q

The location where the beam reaches its minimum diameter

A

focus or focal point

58
Q

Energy from the transducer that radiates at various angles from the transducer face.

A

side lobes

59
Q

the arrangement of crystals within the transducer

A

array

60
Q

3 types of electronic array transducer

A

linear
curvilinear/sector
phased

61
Q

refers to the physical size of the part of the ultrasound that contacts the patients

A

footprint

62
Q

is the width of the image that is seen on the screen

A

field of view

63
Q

array that produces parallel scan lines and has a rectangular field of view

A

linear array

64
Q

array that extensively used for vascular, small parts and musculoskeletal applications

A

linear array

65
Q

array used to image superficial structures and vessels and therefore operate at frequencies above 4MHz

A

linear array

66
Q

Similar to the linear array but the transducer face is formed into a
curve (convex in shape) which provides a wide field of view which diverges with depth.

A

curvilinear/sector array

67
Q

array that is main application are in abdominal and obstetric scanning

A

curvilinear/sector array

68
Q

Transducer designed to enter the body via the vagina, rectum, esophagus or a blood vessel (catheter-mounted
type)

A

invasive transducer

69
Q

Quartz - _____
Ba. Titanate - ______
PZT-4 - ______
PZT5A - _______

A

Quartz - 573°C
Ba. Titanate - 100°C
PZT-4 - 328°C
PZT5A - 365°C

70
Q

is the temperature at which polarization in a crystal is lost

A

curie point

71
Q

is a more through cleaning method that often recommended for cleaning endocavitary probes after use

A

high level disinfection (HLD)

72
Q

protect probes from contamination and the patient from potential infection

A

probe covers and sheaths

73
Q

usually an aqueous gel

improves sound transmission into and out of the patient by eliminating air reflection

A

coupling medium

74
Q

composition of coupling medium

A

EDTA
Carbomer
Propylene glycol
Trolamine
Distilled Water

ULTRASOUND (6 decks)

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