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PHTH 545 > Ultrasound > Flashcards

Ultrasound Flashcards

1
Q

US must be _______ by the tissue to have an effect

A

absorbed

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2
Q

US is preferentially absorbed by tissues with a higher ______ content

A

protein

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3
Q

What 5 tissues are going to have the best US absorption

A
  1. tendon
  2. ligament
  3. fascia
  4. joint capsule
  5. scar tissue
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4
Q

For tissue in combination, absorption of US depends on what 2 things?

A
  1. Half-value depth in each tissue component

2. Amount of reflection at tissue boundaries

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5
Q

___MHz is preferable for heating large soft tissue volumes if bone is deeply located

A

1

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6
Q

__MHz or low intensity _MHz is preferable where superficial bone is present

A

3;1

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7
Q

If using US on your hand, what Hz would you use?

A

3

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8
Q

If using US on your thigh, what Hz would you use

A

1

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9
Q

What are 2 categories of biophysical effects of US ?

A
  1. thermal

2. non-thermal

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10
Q

Proteins ____ as they absorb US energy

A

vibrate

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11
Q

The resulting ______ ______ of proteins vibrating from absorbing US causes heating, aka thermal US

A

molecular friction

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12
Q

The temp increase in thermal US depends on what 4 things?

A
  1. amount of energy applied
  2. frequency of sound wave
  3. type of tissue being insonated
  4. duration of treatment
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13
Q

There is a ___ and ____ dependent increase in tissue temp with thermal US

A

time; dose

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14
Q

3MHz heats significantly ____ than 1 MHz, but at a ______ depth

A

faster; shallower

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15
Q

Vigorous heating (__-__ deg C) for at least 5 mins may temporarily increase the extensibility of ____ ______, _____ , _____ and ______ ______ ; also causes vasodilation

A

40-45; joint capsules; ligaments; tendons; scar tissues

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16
Q

Vigorous heating will provoke a mild ______ reaction, which can be useful for tissue healing

A

inflammatory

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17
Q

Temps > ___ degrees C are destructive

A

45

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18
Q

What are 6 effects of mild heating?`

A
  1. reduce pain
  2. reduce muscle spasms
  3. promote healing
  4. alter nerve conduction
  5. vasodilation
  6. increase enzymatic activity
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19
Q

Soft-tissue bone interface heats substantially due to _____ impedance mismatch

A

acoustic

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20
Q

US is an effective way to heat near ____ or ____

A

joint; bone

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21
Q

______ has limited blood supply and cannot dissipate heat quickly

A

periosteum

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22
Q

To avoid overheating periosteum (which may lead to deep bone pain) always keep transducer head ______

A

moving

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23
Q

What 4 things is thermal US used for?

A
  1. pain relief
  2. decrease joint stiffness
  3. improve blood flow
  4. promote tissue healing
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24
Q

What are 4 mechanisms whereby non-thermal US may work?

A
  1. cavitation
  2. acoustic
  3. standing waves
  4. micromassage
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25
Q

_______ = formation of tiny gas bubbles in tissues as a result of US

A

cavitation

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26
Q

______ may be stable or unstable

A

cavitation

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27
Q

Unstable cavitation is _______, and unlikely to occur in mammalian tissue at therapeutic intensities

A

destructive

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28
Q

In stable cavitation, bubbles form, then ______, increasing and decreasing in volume.

A

oscillate

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29
Q

Stable bubbles may play a therapeutic role in _____ streaming

A

acoustic

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30
Q

_______ _______ = unidirectional, localized liquid flow occurring around stable bubbles and cell membranes during US current

A

acoustic streaming

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31
Q

Acoustic streaming causes _____ on cell membranes

A

stress

32
Q

What are 3 effects of the stress caused on cell membranes with acoustic streaming?

A
  1. altered sodium permeability
  2. influx of calcium into cells
  3. diffusion of other ions and metabolites away from cell membranes
33
Q

Acoustic streaming can accelerate ______ repair

A

tissue

34
Q

______ _____ = US beam reflected from an interface between tissues with significantly different acoustic impedances, and incident and reflected waves superimpose to create peaks of high-intensity energy

A

standing waves

35
Q

_________ _____ may cause cellular damage, impede flow of blood cells locally, or damage blood vessel endothelium causing clot formation or free radical formation

A

standing waves

36
Q

How do you avoid making standing waves ?

A

always keep transducer head moving!!!

37
Q

_________ is caused by waves of compression/rarefaction

A

micromassage

38
Q

______ causes pressure difference between cell layers and at tissue boundaries

A

micromassage

39
Q

_______ is thought to reduce edema

A

micromassage

40
Q

5 non-thermal US effects?

A
  1. increased membrane permeability
  2. stimulation of protein synthesis
  3. degranulation of mast cell and histamine release
  4. increased transport of calcium across membrane
  5. stimulation of collagen synthesis
41
Q

There is (min/mod/good) evidence that non-thermal US is beneficial for wound healing

A

good

42
Q

non-thermal US can alter ____ _____ formation

A

scar tissue

43
Q

US treatment activates _____ ______

A

tissue repair

44
Q

Via what 3 mechanisms does US treatment activate tissue repair ?

A
  1. inflammation optimizer (when used at correct dose!)
  2. appears to accelerate inflammatory stage of tissue repair
  3. may promote resolution of chronic inflammation
45
Q

US causes releaser of wound-healing factors - _____ from mast cells, ______ from platelets, probably by altering membrane permeability to calcium and other ions

A

histamine; serotonin

46
Q

US appears to accelerate the inflammatory stage to make it as _______ as possible

A

efficient

47
Q

LIPUS accelerates _____ healing by up to 40%

A

fracture

48
Q

US encourages ____ to occur more rapidly, and then subside more quickly

A

edema

49
Q

In the inflammation stage, use ___-____! Too much US is counterproductive

A

low-dose (still pro-inflammatory but increases tissue healing)

50
Q

How does US effect proliferation and granulation tissue healing stage?

A

by affecting fibroblasts, endothelial cells and myofibroblasts

51
Q

US increase collagen secretion from _______ (20-30%)

A

fibroblasts

52
Q

US increases fibroblast proliferation, probably secondary to direct stimulation of _______

A

macrophages

53
Q

During stage 2/3 of healing, higher dose is pro-inflammatory, but increases tissue healing! Too ____ US will be ineffective

A

little

54
Q

US dose must be matched to _____ of healing!

A

phase

55
Q

Total ______ of US is important in determining outcomes

A

energy

56
Q

Deos total energy by itself ensure an effective treatment?

A

NO; also dependent on type of tissue/condition being treated and stage of healing

57
Q

How can total energy per treatment be determined?

A

watts per cm^2 X applicator size (in cm^2) x time (in s)

58
Q

6 determinants of energy in US?

A
  1. intensity
  2. continuous vs pulsed
  3. frequency of US
  4. size of area being treated
  5. duration of treatment
  6. total number of treatments
59
Q

Most studies showing benefit in later stages of soft tissue injuries (> 4 weeks old) were using _____ doses of US

A

higher

60
Q

US dose for acute injuries ?

A

LOW

61
Q

US dose for chronic injuries?

A

HIGHER

62
Q

After first stage of tissue healing, move _____ to higher energy per treatment

A

quickly

63
Q

Very low dose intensity ?

A

0.1 W/cm^2

64
Q

Low dose intensity ?

A

0.5 W/cm^2

65
Q

Medium dose intensity?

A

1-1.2 W/cm^2

66
Q

High does intensity?

A

> 1.5-2 W/cm^2

67
Q

Total energy depends on what 2 things?`=

A
  1. intensity

2. duration of application

68
Q

What is the usual time guidelines for treatment?

A

5-10 mins per treatment are a

69
Q

What is the treatment area?

A

2xERA

70
Q

If heating tissue, ~__ mins to raise skeletal muscle temp by 3.5 deg

A

11

71
Q

Treatment frequency for for acute conditions ?

A

low dose, once per day

72
Q

Treatment frequency for chronic conditions ?

A

high dose, alternate days

73
Q

Dosage of US depends on what 4 things?

A
  1. nature of problem
  2. nature of tissue environment
  3. depth of tissue being treated
  4. size of treatment area
74
Q

What are 3 treatment progression options?

A
  1. pulse ratio: 1:8 –> 1:1 –> continuous
  2. intensity - 0.25W/cm^2 –> 2.5 W/cm^2
  3. time (duration) - shorter –> longer
75
Q

Clear evidence of benefit of LIPUS in management of ____-____ and ___-____ fractures

A

delayed - union; non - union

76
Q

Some evidence that LIPUS may stimulate cartilage repair in mild to moderate ______

A

OA

77
Q

How does LIPUS potentially stimulate cartilage repair in development of OA?

A

downregulates IL-1beta

PHTH 545 (23 decks)

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