Procedures: Ultrasound

Question 1

Ultrasound was first used when and by who?

Answer 1

19th Century by the United States using SONAR

Question 2

Why were the damaging underwater life?

Answer 2

Because sound waves were heating it up

Question 3

More recently, it was found that ultrasound could be used clinically why?

Answer 3

Because it can heat tissue w/ a high collagen content, such as tendons, ligaments, or fascia

Question 4

Power

Answer 4

The amount of energy per unit of time(Watts)

Question 5

Intensity

Answer 5

the power per unit area of the sound head(Watts/cm2)

Question 6

Frequency (def.)

Answer 6

the # of compression rarefaction cycles per unit of time(Relates to depth of penetration)

Question 7

What is the therapeutic ultrasound frequency?

Answer 7

Between 0.7 and 3.3 MHz

Question 8

What frequency is considered best for treating tissue up to 5 cm deep?

Answer 8

1 MHz

Question 9

What frequency is considered best for treating tissue up to 1-2 cm deep?

Answer 9

3 MHz

Question 10

Increasing the frequency causes what?

Answer 10

Higher concentration of US in the superficial tissue

Question 11

Duty Cycle

Answer 11

The proportion of the total tx time the US is on

Question 12

How can duty cycle be expressed?

Answer 12

As a percentage or a ratio.
Ex.20% or 1:5
20% means it is on 20% of the time and off 80%

Question 13

Continuous Ultrasound

Answer 13

The delivery of ultrasound throughout the entire tx period

100% duty cycle

Question 14

Continuous Ultrasound produces what effects on tissue?

Answer 14

Thermal effects

Question 15

Pulsed Ultrasound

Answer 15

the intermittent delivery of US throughout the tx period

general see 10%, 20%, or 50% in clinic

Question 16

Pulsed Ultrasound minimizes what and provides what effect?

Answer 16

It minimizes thermal effects and provides nonthermal effects

Question 17

Effective Radiating Area

Answer 17

The area of the transducer where the energy radiates

this area is smaller than the area of the treatment head

Question 18

Spatial Peak Intensity

Answer 18

The peak intensity of the US output over the area of transducer

Question 19

Beam Nonuniformity Ratio (BNR)

Answer 19

The ration of the spatial peak intensity to the spatial average intensity
(For most units, this is usually between 5:1 & 6:1)

Question 20

If BNR is 5:1 , w/ the spatial average intenisty set at 1 W/cm2, the spatial peak intensity is what?

Answer 20

As high as 5 W/cm2

Question 21

Absoption

Answer 21

The conversion of mechanical energy into heat

Question 22

Reflection

Answer 22

Redirection of the US beam away from the surface at an angle equal & opposite to the beam

Question 23

What do we use to prevent reflection?

Answer 23

Gel or lotion

Question 24

Refraction

Answer 24

redirection of an US beam

when the beam enters the tissue at one angle it is redirected within the tissue in a new angle

Question 25

Attenuation

Answer 25

The degree in the US intensity as it travels through the tissue(occurs as a result of absorption, reflection, and refraction)

Question 26

Standing Wave

Answer 26

occurs when the ultrasound transducer & a reflecting surface are the exact wave length apart

Question 27

How can Standing Waves be avoided?

Answer 27

Move the US head around in a steady pace

Question 28

Cavitation

Answer 28

Gas filled bubbles that are formed by the US

Question 29

Stable Cavitation is thought to be on of the mechanisms for what?

Answer 29

Nonthermal effects of US

Question 30

Phonophoresis

Answer 30

the application of topical drug w/ US ( can be absorbed systemically)

Question 31

Ultrasound Can:

Answer 31

- Accelerate metabolic rate - Reduce Pain - Alter nerve conduction rates - Increase circulation - increase tissue extensibility

Question 32

Ultrasound is ideal for heating tissue w/ increased collagen such as?

Answer 32

- Tendons - Ligaments - Joint Capsules - Fascia - Scar tissue

Question 33

Why is it not ideal for heating muscles?

Answer 33

Because muscle has a low absorption coefficent

Question 34

Factors that affect the ultrasound's temperature increase includes:

Answer 34

- Tissue Type - Frequency - Intensity - Duration

Question 35

What will happen if the intensity is too high?

Answer 35

The patient will complain of deep pain

Question 36

What will happen if the intensity is too low?

Answer 36

The patient may not feel an increase in tissue temperature

Question 37

The longer the duration....

Answer 37

The higher the tissue heating(5 to 10 min duration)

Question 38

Nonthermal Effects of US(part 1)

Answer 38

- Increased intracellular calcium lvls, which stimulates the syntheses of proteins - Increasing skin & membrane permeability - Increasing mast cell degranulation

Question 39

Nonthermal Effects of US(part 2)

Answer 39

- Promoting macrophage responsiveness | - Increasing the rate of protein synthesis by fibroblasts and tendon cells

Question 40

What frequency should be used when treating tissue up to 5 cm deep?

Answer 40

1 mhz

Question 41

What frequency should be used when treating tissue up to 1-2 cm deep?

Answer 41

3.3 Mhz

Question 42

What duty cycle is recommended for nonthermal effects?

Answer 42

20%

Question 43

Parameters for: Soft Tissue Stretching

Answer 43

Frequency: 1 MHZ Intensity: 1.5

Question 44

Parameters for: Pain Control

Answer 44

Continuous 100% Frequency: 1 to 3 MHZ (depending on tissue depth) Intensity: .5 to 3.0 W/cm2 Duration: 3 to 10 min

Question 45

Parameters for: Dermal Ulcers

Answer 45

Pulsed 20% Frequency: 3 MHZ Intensity: 0.8 to 1.0 W/cm2 Duration: 5-10 min

Question 46

Parameters for: Surgical Skin Incisions

Answer 46

``` Pulsed 20% Frequency: No conclusion on which is best Intensity: 0.5 to 0.8 W/cm2 Duration: 3-5 min Time: 3-5 times per week ```

Question 47

Parameters for: Tendon Injuries Post-op

Answer 47

Continuous or Pulsed Frequency: 1 or 3 MHZ Intensity: 0.5 to 2.5 W/cm2 Duration: 3 to 5 min

Question 48

Parameters for: Ligament Injuries Post-op

Answer 48

Pulsed US 0.5 to 1.0 W/cm2

Question 49

Parameters for: Bone Fractures

Answer 49

Pulsed 20% Frequency: 1.5 Mhz Intensity: .15w/cm2 Duration: 15-20 minutes, Daily

Question 50

Parameters for: Phonophoresis

Answer 50

Pulsed 20% Frequency: 1 or 3 Mhz Intensity: 0.5 to 0.75 w/cm2 Duration: 5-10 min

Question 51

What intensity should be used for 1 mhz

Answer 51

1.5 w/cm2

Question 52

What intensity should be used for 3 Mhz?

Answer 52

0.8 w/cm2

Question 53

In what ways can US be applied to dermal ulcers?

Answer 53

Applying gel & US to the intact skin around the wound Put a coupling sheet directly over a wound Performing US near the wound under water

Question 54

it is thouht that US is beneficial for surgical skin incisions because it has the ability to do what?

Answer 54

Improve blood circulation Limited ischemic necrosis Facilitation of tissue repair

Question 55

How doe the delivery of US differ for acute and chronic tendonitis?

Answer 55

Acute: Pulsed; low intensity Chronic: Continuous; higher intensity

Question 56

What role does the stratum corneum play in phonophoresis

Answer 56

I dont know hahaha

Question 57

What are the contraindication of US?.

Answer 57

Malignant tumor, pregnancy CNS tissue, Joint cement or plastic components Pacemaker, Throbophlebitis Eyes, Reproductive organs

Question 58

What are the precautions of US?

Answer 58

Acute inflammation Growth plates in children Fractures Breast implants