Brainscape's Knowledge GenomeTM

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


See full index

ISP > US > Flashcards

US Flashcards

1
Q

List 5 characteristics of sound waves

A

-Amplitude
-Frequency
-Wavelength
-Compression
-Speed (1540m/s in tissue)
-Rarefaction

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

Define the Piezoelectric Effect

A

When an electrical current is applied across the crystal, it resonates sending out a sound wave

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

What frequency is the human hearing range?

A

20Hz - 20kHz

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

What does a long wavelength mean for the frequency?

A

It shortens

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

True or False?
Ultrasound waves are transverse electromagnetic waves.

A

False.
It is X-rays that have transverse EM waves. US waves are longitudinal and mechanical.

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

What frequency is above 20kHz?

A

Ultrasound

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

What is Attenuation?

A

The reduction in intensity with distance and is due to Reflection, Refraction, Scatter and Absorption

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

True or False?
The Medical US frequency is 2-17MHz

A

True

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

In the Piezoelectric Effect, what is produced when a perpendicular force is applied?

A

An electrical charge/signal

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

How are Ultrasound waves generated?

A

By stressing the elastic medium

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

Name the different types of ultrasound

A

-A Mode (Amplitude)
-B Mode (Brightness)
-M Mode (Movement)
-3D/4D’
-Doppler (Colour and Spectral)

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

What is the Doppler Effect equation?

A

f(d) = f(r) - f(t) = 2f(t) v (cos)u/c

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

If frequency is determined by the source of the sound wave, what does a shorter wavelength mean for the frequency?

A

It becomes higher

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

List 3 causes of artefacts

A

-The operator
-Equipment malfunction
-Tissue type

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

What does the safe practice ALARA acronym stand for?

A

As
Low
As
Reasonably
Achievable

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

Name and explain the two types of Acoustic Shadowing

A
  1. Calculi-beam (reflected shadowing underneath
  2. Polyp-soft (tissue with no shadowing)
17
Q

If “high frequency = good resolution and poor penetration” then “low frequency = …”

A

“…poor resolution and high penetration”

18
Q

Define Absorption

A

The transfer of energy into heat

19
Q

How is Echo produced?

A

When the beam hits the interface between 2 tissue types and strengthens it with difference

20
Q

What do the white and bright image interpretations represent?

A

The signal from dense tissue, like bone or a strong interface, between 2 different tissues (i.e. Diaphragm)

21
Q

True or False?
Black image interpretations represent no signal from fat-filled areas such as blood and ionic fluids

A

False.
They represent fluid-filled areas such as blood and ionic fluids

22
Q

What can machine assumptions cause?

A

-The beam to become effortless
-Propagation becomes straight-lined
-Brightness of the echo to directly relate to the reflectivity of the target

23
Q

What does the Doppler colour setting show?

A

Whether the bloodflow is present and it’s direction (red flows towards and blue flows away)

24
Q

Where is ultrasound energy lost?

A

At every interface the beam encounters

25
Q

Define Acoustic Impedance

A

The measurement of how much resistance there is between two or more interfaces

26
Q

What is Reflection?

A

When the beam echoes back off an interface/surface

27
Q

What does grey matter represent?

A

Different soft tissues such as Muscle, Fat, Liver and Brain

28
Q

Name 4 ultrasound considerations

A

-Probe shape
-Unaffected by artefacts superior to strong interfaces like metal implants
-Coupling gel
-Bone, Calcification and Bowel gas causing shadowing

29
Q

What Probe Shape is the better for skin contact?

A

Linear, depending on the anatomy

30
Q

Why are manmade crystals used more frequently?

A

Because frequency is determined by the thickness of the crystal

31
Q

What does the Doppler Spectral setting show?

A

Indications of issues based on trace and quantifiable measurements of velocity (above baseline is forward and below is reverse)

ISP (13 decks)

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