Test 2 Part1

Question 1

What deep heating modality uses sound waves at high frequencies, penetrates the skin and subcutaneous fat, and also has mechanical effects?

Answer 1

Ultrasound

Question 2

What is the second most common heating modality used among chiropractors (63%)?

Answer 2

Ultrasound (moist hot packs is #1)

Question 3

What is the frequency range of most Ultrasound machines?

Answer 3

0.8-3.3 MHz

Question 4

How is the duty cycle for US calculated?

Answer 4

time sound is delivered divided by total treatment time

Question 5

Duty cycle of 100% =?

50% or 20%?

Answer 5

continuous US;

pulsed US

Question 6

What is the purpose of continuous Ultrasound? of Pulsed?

Answer 6

tissue healing;

mechanical/nonthermal effects

Question 7

Mechanical deformation of a crystal causes an electrical current to form…

Answer 7

Piezoelectric effect

Question 8

Alternating current is passed through a crystal resulting in very fast contraction and expansion of the crystal producing high frequency sound waves…

Answer 8

Reverse piezoelectric effect

Question 9

What is the ERA?

BNR?

Answer 9

Effective Radiating Area;

Beam Nonuniformity Ratio

Question 10

What is the term for the area of the sound head that produces sound energy which is always smaller than the size of the US head?

Answer 10

Effective Radiating Area

Question 11

What is the term for the ratio between the peak intensity of the US beam divided by the average intensity of the US beam?

Answer 11

Beam Nonuniformity Ratio

Question 12

What is the BNR used to determine?

Answer 12

comparison of the quality of different US machines

Question 13

What is the ideal BNR?

Answer 13

1:1 but within the range of 2:1-8:1 is acceptable

Question 14

T/F: The lower the BNR, the less uniform the intensity of the sound wave.

Answer 14

False; lower ratio equals more uniform

Question 15

What does PAMBNR stand for? and what does it describe?

Answer 15

Peak Area of the Maximum Beam Nonuniformity; describes the area of the sound head covered by the peak intensity

Question 16

T/F: Larger PAMBNR means less uniform heating.

Answer 16

True (peak intensity covers a larger area)

Question 17

T/F: Air is a poor conductor of US.

Answer 17

True, hence the use of gel and gel pads

Question 18

T/F: Underwater ultrasound is considered indirect ultrasound and should only be done in plastic buckets, not metal due to reflection.

Answer 18

True

Question 19

T/F: With US, more watts equals greater penetration.

Answer 19

False; equals more heating

Question 20

Frequency of US dictates depth of heating. What is the typical range?

Answer 20

1-3 MHz

Question 21

T/F: High frequency US (3MHz) is absorbed at a slower rate and therefore affects deeper tissues.

Answer 21

False; This is true of Low freq (1MHz), High freq is absorbed more rapidly affecting superficial tissues.

Question 22

T/F: More tissue healing occurs with continuous US than with pulsed.

Answer 22

True

Question 23

What is the difference b/w reflection and refraction?

Answer 23

reflection: reversal of direction
refraction: change from a straight path when passing obliquely from one medium to another

Question 24

T/F: The bending of US energy within tissue can lead to concentration of US at the point of reflection, such as where tendon joins bone.

Answer 24

False; should say point of REFRACTION

Question 25

T/F: 2-3 degrees C increase of tissues increases blood flow and reduces muscle spasm, whereas 4 degrees C increase alters viscoelastic properties of collagen.

Answer 25

True

Question 26

T/F: With US therapy, longer times are needed when lower intensities are used.

Answer 26

True

Question 27

Since superficial tissues cool faster than deeper ones, when should tissue manipulation or stretching occur with regard to US treatment?

Answer 27

Immediately after (while things are “warm and loose”)

Question 28

T/F: Pulsed US has been shown to stimulate fibroblast activity.

Answer 28

True

Question 29

What is the term for the movement of fluids along cell membranes due to mechanical pressure exerted by the sound waves?

Answer 29

Acoustical streaming

Question 30

What is the term for the rhythmic expansion and contraction of bubbles during repeated pressure changes over many acoustic cycles?

Answer 30

stable cavitation

Question 31

What is the term for the collapse of gas bubbles which may cause tissue damage, which is associated with low frequency high intensity US?

Answer 31

Unstable cavitation

Question 32

T/F: Metal implants are a contraindication for US, but plastic and/or cemented implants are not.

Answer 32

False; vice versa

Question 33

Why should you avoid using US over an Epiphyseal plate?

Answer 33

may alter bone growth