Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Spring: Physics > final pt 2 > Flashcards

final pt 2 Flashcards

1
Q

Empirical approach

A

searches for a relationship between exposure and response

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

Contrast: shrinking and swelling

A

bubbles shrink when exposed to compression and they expand when exposed to rarefaction

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

What is the primary investigative technique of epidemiology?

A

reviewing data from patients

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

What is the intensity most related to tissue heating?

A

thermal mechanism (TI)

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

Bioeffects study in nonliving things:

A

In vitro

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

What type of transducers cause the least amount of temp elevation in tissues?

A

(gray scale imaging)

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

The possibility of patient or technologist shock:

A

cracked transducer housing and frayed wires

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

When is it safe to perform an US?

A

when the benefits outweigh the risks

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

Electronic component used for gray scale imaging:

A

scan converters

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

Know all the preprocessing functions:

A

TGC

log compression(dB)

write magnification

persistence

spatial compounding

edge enhancement

fill-in interpolation

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

Know all the processing functions:

A

any change after freeze frame

black/white inversion

read magnification

contrast variation

3-D rendering

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

What function steers the scan lines in different directions?

A

sloped pattern in phased array transducer

(spatial compounding?)

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

Advantages of PACS systems:

A

instant access to archived studies

no degradation of data

ability to electronically transmit images and reports to remote sites

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

Signal from the transducer to the receiver:

A

pulser-determines amp

beam former-firing patterns

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

Know the requirements for contrast agents:

A

safe

metabolically inert(metabolized throughout system, then removed)

long lasting

strong reflector of US

small enough to pass through capillaries

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

Harmonics vs fundamental frequencies

A

fundamental-initial freq of probe

harmonics-double the fundamental freq

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

Acceleration and deceleration of velocities from cardiac contraction:

A

pulsatile

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

Acceleration and deceleration of velocities from respiration:

A

phasic

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

Flow pattern with normal physiological states:

A

laminar

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

Reynolds number for turbulent flow:

A

> 2,000

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

What are the effects of a stenosis?

A

change in flow direction

increased velocity as vessel narrows

turbulence downstream from the stenosis

pressure gradient across the stenosis

loss of pulsatility

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

Know hydrostatic pressure at all locations:

A

Supine- all numbers are 0

ankle- 100mmHg

knee- 75mmHg

waist- 50mmHg

mid chest- 0mmHg

top of head- -30mmHg

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

What is it referred to when the vessel collapses (venous)?

A

coaptation

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

Venous flow in the leg decreases, what is the patient doing?

A

inspiration

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

What is the Doppler shift when source and receiver are moving apart?

A

negative Doppler shift

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

What is the typical range of Doppler shift?

A

20Hz to 20,000Hz (range of audible sound)

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

Phenomenon with high velocities appear negative:

A

aliasing

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

Five ways to eliminate aliasing:

A

adjust the scale to its maximum (increase Nyquist limit)

select a new ultrasonic view with a shallower sample volume (increases Nyquist limit)

select a lower freq transducer (decreases Doppler shift)

use baseline shift (aliasing remains but display is more appealing)

use continuous wave Doppler (never aliases, but range ambiguity)

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

Horizontal access of the Doppler spectrum:

A

time

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

What is Doppler shift inversely related to?

A

propagation speed

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

Basic Doppler system just identified a freq shift:

A

(Power Doppler?)

32
Q

Know traveling towards the transducer and away (Doppler shifts)

A

towards- positive (arteries)

away- negative (veins)

33
Q

Primary advantage of pulsed wave

A

range resolution (being able to select the exact location where velocities are measured)

34
Q

Primary advantage of continuous wave

A

ability to accurately measure very high velocities

35
Q

What is the limitation for color Doppler imaging?

A

no measurement of velocity or direction

lower frame rate

more time needed to acquire data

reduced frame rate

decreased temporal resolution

36
Q

What is the area of interrogation for Doppler?

A

sample volume or gate

37
Q

What method will have increased sensitivity to low flow states?

A

Power Doppler

(color Power Doppler?)

38
Q

Portions of the image that are brighter than surrounding tissues:

A

hyperechoic

39
Q

Structures without echoes

40
Q

similar echo characteristics

A

isoechoic (homogeneous?)

41
Q

Know the cause for artifacts

A

violation of assumptions

equipment malfunction or poor design

the physics of ultrasound

operation error

42
Q

Which artifact has multiple equally spaced parallel lines?

A

reverbations

43
Q

Which artifact is unrelated to the US pulse?

A

refraction

(enhancement?)

44
Q

Which artifact produces an image with incorrect number of reflectors?

A

side lobe artifacts, grating lobe, refraction

45
Q

Two distinct reflectors, one is an artifact, one is deeper than the other:

A

mirror image

46
Q

What is the artifact if they are side by side?

A

side lobe, grating lobe, refraction

(lateral resolution?)

47
Q

Which artifact creates only one reflection from two reflectors?

A

Axial resolution

48
Q

What are lobes created by array transducers called?

A

grating lobes

49
Q

Refraction at the edge of circular structure:

A

edge shadow (shadowing by refraction)

50
Q

What is it called when there is too much gain in the focal zone?

A

focal enhancement

51
Q

Which artifact occurs when you see reflectors at incorrect depths?

A

speed error or range ambiguity

52
Q

a grainy appearance

53
Q

What artifact occurs when your PRF is too high?

A

range ambiguity

54
Q

What artifact is found only with Doppler?

55
Q

Know about tissue equivalent phantom:

A

similar to soft tissue

speed of sound

attenuation

scattering characteristics

echogenicity

56
Q

Know about informed consent:

57
Q

Know about gold standard:

A

a perfect technique, for ex MRI or angiography, that we deem 100% accurate to which our US results are compared

(all tests confirm the same result: MRI, CT, Xray, US)

58
Q

Ability to position echoes in their correct position along a distance perpendicular to the sound

A

(lateral resolution?)

59
Q

Stratigically located pin cysts in masses, what kind of phantom?

A

tissue equivalent phantom

60
Q

Know the intensity imits for unfocused and focused transducers:

A

unfocused- 100mw/cm2

focused- 1w/cm2

61
Q

Know the appropriate way to introduce yourself to the patient:

A

first action when sonographer enters the room

state your name and what type of exam you are performing

62
Q

Use of more active elements to receive reflections with a greater time of flight:

A

dynamic apeture

63
Q

Lateral resolution improves with what?

A

multi-focusing

(narrower beam, smaller field of view)

64
Q

Know all about temporal resolution

A

depends on frame rate, “real time movie”, depth and # of pulses

65
Q

Know all about spatial resolution

A

more pixels= more detail ^ line density

66
Q

Know all about contrast resolution

A

more shades of gray= better contrast resolution

67
Q

Know how to calculate the time it takes to make a single image when given the frame rate

A

Tframe= number of pulses * PRP

68
Q

Imaging depth is 15cm, with 100 lines. The number of pulses making up the scan is what?

69
Q

Of the receiver functions, which one treats the signal differently due to depth of the reflector?

A

TGC (compensation)

70
Q

Output power vs receiver gain

A

output power:

changes brightness of entire image, alters signal-to-noise, alters patient exposure, bioeffect concerns, decrease this first if image is too bright

receiver gain:

changes brightness of entire image, does not affect signal-to-noise ratio, does not change patient exposure, no bioeffect concerns, increase this first if image is too dark

71
Q

Mechanical transducer

A

1 crystal

fan shape (secter)

entire image lost

focusing- fixed lens

steering- mechanical

72
Q

Linear sequential (switched)

transducer

A

120-250 crystals

rectangle shaped

drop out (drop down)

focusing-electronic: curved elements and external lens

steering- electronic: phasing

73
Q

Linear phased array transducer

A

200 crystals

sector shape

poor steering and focusing

focusing- electronic: curved elements and external lens

steering- electronic: phasing

74
Q

convex sequential transducer

A

over 200 crystals

blunted sector shape

drop out of image

focusing- electronic: curved elements and external lens

steering- electronic: phasing

75
Q

vector transducer

A

200 crystals

flat top sector (trapezoid)

poor steering and focusing

focusing- electronic: curved elements and external lens

steering- electronic: phasing

76
Q

3D/4D

A

over 200 crystals

rectangle shape/checkerboard shape

drop down

focusing- electronic: both in lateral and thickness

steering- electronic: phasing

77
Q

annular phased transducer

A

5 crystals- in concentric rings

sector shape

horizontal drop out

focusing- electronic: multiple zones

steering-mechanical: motor physically moves the ringed-element array

Spring: Physics (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions