Ultrasound

Question 1

What is the most common DEEP heating modality

Answer 1

Ultrasound

Question 2

What is the most common heating modality

Answer 2

Moist hot packs

Question 3

How are sound waves generated in ultra sound

Answer 3

Current passes through a crystal causing it to vibrate and produce a sound

Question 4

How is duty cycle calculated

Answer 4

Divide the time sound is delivered by the total treatment time

Question 5

What is the duty cycle for continuous ultrasound

Answer 5

100% duty cycle

Question 6

what are the common duty cycles for ultrasound

Answer 6

50% and 20%

Question 7

What is the result of continuous ultrasound

Answer 7

Tissue healing

Question 8

What type of effects does pulsed ultrasound have

Answer 8

Mechanical/ non-thermal

Question 9

What is the piezoelectric effect

Answer 9

Mechanical deformation of a crystal causes an electrical current to form

Question 10

What effect causes the high frequency sound waves produced in ultrasound

Answer 10

Reverse Piezoelectric effect

Question 11

What two things determine the quality of an ultrasound machine

Answer 11

ERA (effective radiating area)

BNR (beam non uniformity ratio)

Question 12

Since the Effective Radiating area (ERA) is always smaller than the size of the head, what is the ideal size

Answer 12

Only slightly smaller than the head

Question 13

What determines BNR (Beam non uniformity ratio)

Answer 13

Amount of variability of the beam

Question 14

What is the ideal BNR

Answer 14

1:1

Question 15

What is the acceptable range for BNR

Answer 15

8:1

Question 16

What does having a lower BNR do

Answer 16

Eliminate hot spots
Allows for higher dosages without discomfort
Allows for greater comfort and safety

Question 17

What describes the area of the sound head covered by the peak intensity

Answer 17

PAMBNR (Peak area of the Maximum bean non-uniformity ratio)

Question 18

What does a large PAMBNR indicate

Answer 18

less uniform heating

Question 19

Other than using ultrasound gel or a pad what else can you use to conduct ultrasound waves

Answer 19

Place the head and the anatomy under water

Question 20

How far should you keep the ultrasound head from the patient when using underwater ultrasound

Answer 20

0.5cm to 3.0cm

Question 21

What frequency do you use for superficial tissues

Answer 21

3 MHz

Question 22

What frequency do you use for deep tissue

Answer 22

1MHz

Question 23

What tissues absorb ultrasound the most

Answer 23

Higher density (bone, ligament, Cartilage)

Higher protein concentration (muscles)

Question 24

What causes scattering in ultrasound

Answer 24

When they encounter a boundary between tissues

Question 25

Where are ultrasound waves reflected

Answer 25

Bone

Question 26

Where is the highest point of refraction in ultrasound

Answer 26

The point of refraction (ex. where tendon joins bone)

Question 27

An increase of how many degrees is associated with an increase of metabolic activity

Answer 27

1

Question 28

An increase of how many degrees is associated with a reduction of muscle spasm, increase in blood flow, reduction of chronic inflammation

Answer 28

2-3

Question 29

An increase of how many degrees alters viscoelastic properties of collagen

Answer 29

4

Question 30

How long does it take to increase tissue to 4 degrees C at 3MHz

Answer 30

4-5 min

Question 31

How long it take to increase tissue to 4 degrees C at 1MHZ

Answer 31

10 min

Question 32

What should be done to tissues immediately after ultrasound treatment

Answer 32

Manipulation or stretching

Question 33

What has pulsed ultrasound been shown to do to tissues

Answer 33

Increase cellular activity and tissue healing

Question 34

What does pulsed ultrasound do at a cellular level

Answer 34

Stimulate fibroblast activity Increase blood flow Increase protein association

Question 35

Unstable cavitation (cause tissue damage) is associated with what type of ultrasound

Answer 35

Low frequency, high intensity (not therapeutic)

Question 36

What are risks associated with ultrasound

Answer 36

Bony prominence | Epiphyseal plate

Question 37

How large should the treatment area be for ultrasound

Answer 37

2-3 times the size of the ERA

Question 38

Never use ultrasound longer than how many minutes

Answer 38

15 min

Question 39

What is the term used to describe the use of sound energy to drive medication into the tissue

Answer 39

Phonophoresis

Question 40

What special instrument is used to stimulate fracture healing

Answer 40

Low intensity pulsed Ultrasound

Question 41

What is noncontact Low-frequency ultrasound used for

Answer 41

(the ultrasound sprays) | Used for wound cleaning and debridment