Ultrasound Flashcards

1
Q

T/F: Ultrasound uses sound waves at high frequencies?

A

True

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

What type of modality is ultrasound?

A

Deep heating

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

Can ultrasound penetrate fat?

A

Yes, it can be used to heat muscles, tendons, ligaments, joint capsules, scar tissue etc

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

What is the most common heating modality used by chiropractors in the US?

A

Moist hot packs ( 71%)

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

What is the most common heating modality used by chiropractors of all nations?

A

Ultrasound

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

Electrical current is passed through _________ causing it to vibrate?

A

a crystal

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

What is the frequency range of musculoskeletal treatments?

A

800,000 Hz to 3.3MHz

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

How do you calculate duty cycle?

A

Dividing time sound is delivered by the total treatment time

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

What does a duty cycle of 100% mean?

A

Continuous Ultrasound

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

What is the result of continuous ultrasound?

A

Tissue heating

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

What is the result of pulsed ultrasound?

A

Mechanical/non-thermal effects

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

What is the Piezoelectric effect?

A

Mechanical deformation of a crystal causes an electrical current to form

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

Explain the Reverse Piezoelectric effect

A

AC current is passed through a crystal, results in very fast contraction and expansion of the crystal, this vibration produces high frequency sound waves.

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

What is ERA?

A

Effective Radiating Area: Area of the sound head that produces sound energy. Always smaller than the size of the ultrasound head!

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

What is BNR?

A

Beam Nonuniformity Ratio: Ultrasound beams are not uniform across the US head.
BNR= the amount of variability of the beam.
Ratio between the peak intensity of the US beam divided by the average intensity of the US beam.
Used to compare quality of machines.

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

What is the Ideal BNR?

A

1:1 but within range of 2:1-8:1.

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

What does a 2:1 BNR mean?

A

At 1W/cm^2, the peak intensity is 2 W/cm^2

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

T/F: Lower the BNR the more uniform the intensity of the sound wave

A

True!

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

What is PAMBNR?

A

Peak area of the Maximum beam nonuniformity

Describes the area of the sound head covered by the peak intensity

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

Does a LARGE or small PAMBNR mean less uniform heating?

A

LARGER

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

What is the best conducting media for ultrasound?

A

Gel and Gel pads specifically designed for US

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

T/F:Underwater is a type of direct ultrasound?

A

False; It is a type of indirect ultrasound

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

Why do you not want to use a metal bucked for underwater US?

A

Because it will cause reflection of the sound waves.

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

What do you need change about your technique when going from standard US to underwater US?

A

Increase intensity or Increase time of treatment.

25
Q

Is it normal for bubbles to form on patients skin during underwater US?

A

Yes, wipe them off from skin and sound head occasionally during the treatment.

26
Q

Which frequency of US is more superficial?

A
High Frequency (3MHz): absorbed more
rapidly therefore affects superficial tissues
27
Q

Which frequency is for deeper tissues?

A

Low Frequency (1MHz): absorbed at a
slower rate therefore affects deeper
tissues

28
Q

What type of tissues absorb most sound energy from US?

A

Bone, tendon, cartilage, ligaments, and joint

capsules absorb most

29
Q

Which type of tissues absorb the least amount of sound energy from US?

A

Skin and fat absorb the least

30
Q

More Watts = ???

A

More heating NOT greater penetration

31
Q

Frequency affects what two things?

A

Depth and Time

32
Q

What is reflection in terms of US scattering?

A

Reflection: the reversal of the direction of

propagation of the ultrasound wave

33
Q

What is refraction in terms of US scattering?

A

Refraction: change of ultrasound wave from a
straight path when passing obliquely from one
medium to another

34
Q

T/F: Tissues close to the bone: periosteum, tendons,
and aponeurotic attachment of muscle,
cartilaginous coverings of joint surfaces, and
peripheral nerves lying close to bones receive
increased dose (increased heating)

A

TRUE

35
Q
T/F: The bending of US
energy within tissue
can lead to
concentrations of US
at the point of
refraction
A

TRUE

36
Q

What is the main effect of US?

A

Tissue heating

37
Q

What are the Therapeutic Effects of US?

A
• Increase extensibility of collagen fibers of
tendons and joint capsules
• Increase blood flow
• Increase cell metabolism
• Increase collagen synthesis
• Decreased joint stiffness
• Decreased muscle spasm
• Enhanced tendon, ligament, and muscle healing
38
Q

Do superficial or deep tissues cool more rapidly?

A

Superficial!

39
Q

Any tissue manipulation or stretching should

be performed when?

A

Immediately after ultrasound treatment

40
Q

What is acoustical streaming?

A

Movement of fluids along cell membranes
due to mechanical pressure exerted by the
sound waves

41
Q

What is cavitation?

A

– Formation of gas filled bubbles from pressure
changes in tissue fluids
– Bubbles expand and contract with ultrasound waves

42
Q

What are the different types of Cavitation?

A

Stable and Unstable

43
Q

Define Stable cavitation

A

Rhythmic expansion and contraction of bubbles
during repeated pressure changes over many
acoustic cycles
– Facilitates fluid movement and membrane transport

44
Q

Define Unstable cavitation

A

– Collapse of gas bubbles which may cause tissue
damage
– Associated with low frequency high intensity
ultrasound (not therapeutic)

45
Q

What are the contraindications for US?

A
  • Malignancy
  • Hemorrhage
  • Ischemia
  • Thrombus
  • Infection
  • Gonads
  • Eye
  • Pelvic, abdominal, and lumbar areas of pregnant women
  • Spinal cord after laminectomy
  • Plastic and cemented implants (metal is OK)
  • Near or over electronic implants
  • Unknown etiology
46
Q

What are the risks associated with US?

A

May alter bone growth.

Avoid bony prominences..

47
Q

Describe the movement of the US head when apply therapy

A

• Slow controlled movement of the US head

– 2–4 cm2/s (2 inches per sec)

48
Q

What is the treatment time for US?

A

Generally 5-8 minutes.

49
Q

What is the maximum time you can treat someone with US?

A

NEVER treat for more than a total of 15

minutes (several treatment areas)

50
Q

What do you do if you have a large treatment area?

A

– break it up into 2 or 3 smaller areas and treat

for 5 minutes per region

51
Q

Phonophoresis is AKA what?

A

Sonophoresis

52
Q

What is Phonophoresis/Sonophoresis?

A

Uses sound energy to drive medication

into the tissue

53
Q

Why would someone use Combo US therapy?

A
Research is lacking but claims for use
include:
– trigger points
– epicondylitis
– superficial pain areas
– decrease adhesions
54
Q

What is combo US therapy?

A

Theoretically to create effects of both US and
electrical stimulation
Ultrasound head becomes the treating
electrode when used with a dispersal pad

55
Q

LIPUS stands for what?

A

Low intensity Pulsed US

56
Q

When would you use LIPUS?

A

To stimulate the healing of a fracture.

• Good evidence for effectiveness

57
Q

What is NCLFUS?

A

Noncontact Low-Frequency US

58
Q

When would you use NCLFUS?

A

Wound cleaning and debridement
• US propels sterile saline across wound
• Stimulates healing