Exam 2: Ultrasound

Question 1

What type of physical agent is ultrasound

Answer 1

mechanical

Question 2

What is the head of the ultrasound instrument called

Answer 2

the transducer

Question 3

Sound is a compression _____ wave. Ultrasound is sound with frequency of greater than ______ Hz.

Answer 3

rarefaction; 20,000

Question 4

Sound waves enter the body and are attenuated by what three things?

Answer 4

absorption, reflection, refraction

Question 5

What does attenuated mean

Answer 5

The sound waves lessen the deeper/further it goes into the tissue

Question 6

The sound waves of an ultrasound are created by crystals with ______ properties

Answer 6

piezoelectric

Question 7

How does the crystal in the transducer produce sound waves

Answer 7

The crystal expands and contracts at a certain frequency to produce compression and rarefaction due to the electric energy

Question 8

What are the parameters of ultrasound

Answer 8

intensity, frequency, duty cycle, effective radiation area, and beam nonuniformity ratio

Question 9

What are the units for intensity of ultrasound

Answer 9

W/cm^2

Question 10

What are the units for frequency of ultrasound

Answer 10

MHz

Question 11

What are the units for duty cycle of ultrasound

Answer 11

%

Question 12

What are the units for effective radiating area of ultrasound

Answer 12

cm^2

Question 13

What are the units for beam nonuniformity ratio of ultrasound

Answer 13

ratio

Question 14

Which parameter of ultrasound can be thought of as the force or how strong the soundwaves go into the tissue

Answer 14

intensity

Question 15

Which frequency will reach deeper tissue? 1 MHz or 3MHz?

Answer 15

1MHz

Question 16

Which parameter of ultrasound can be thought of as the relationship of how long the waves are on compared to how long they are off

Answer 16

duty cycle

Question 17

Is a 20% duty cycle thermal or nonthermal?

Answer 17

nonthermal

Question 18

Which parameter of ultrasound can be thought of as the amount of area that the crystal takes up

Answer 18

effective radiating area (ERA)

Question 19

Which duty cycle will give of a thermal effect?

Answer 19

100% continuous duty cycle

Question 20

What is the typical ratio of beam nonuniformity for ERAs

Answer 20

6:1

Question 21

An intensity of __ or less is considered a low intensity

Answer 21

1

Question 22

An intensity of __ or more is considered a high intensity

Answer 22

2

Question 23

True or False:

The speed of ultrasound transducer movement does not alter temperature affects

Answer 23

true

Question 24

True or False:

Higher temperatures are achieved in tissues by higher frequencies

Answer 24

True: but recognize that it won’t penetrate deeper into the skin, the temp is just hotter

Question 25

What are the benefits of non-thermal pulsed ultrasound

Answer 25

cavitation, micro/acoustic streaming, increased intracellular calcium, and promotes cell function and tissue healing

Question 26

True or False: cavitation can lead to unstable cavitation which can be damaging to tissues

Answer 26

true

Question 27

what are the clinical indications for ultrasound

Answer 27

phonophoresis, pain control, tendon and ligament injuries, carpal tunnel, surgical incisions, dermal ulcers, short tissue shortening

Question 28

What are some adverse effects that can occur with ultrasound

Answer 28

Burns, cross contamination/infection via staff infection

Question 29

What are the contraindications of ultrasound

Answer 29

malignancy, pregnancy, pace maker, thrombus, reproductive organs, inflammation, fractures, implants, plates, plastic, joint cement

Question 30

What is the rule of thumb for knowing how big of an area that can be treated

Answer 30

2-3x the size of the transducer

Question 31

How long is the duration of ultrasound

Answer 31

5-10 minutes