Chapter 1-3

Question 1

Is the conservation of energy theory always true in ultrasound?

Answer 1

No

Question 2

What kind of interference do inphase waves have?

Answer 2

They have constructive interference

Question 3

What kind of interference do outphase waves have?

Answer 3

They have destructive interference

Question 4

What is constructive interference? How does it appear on ultrasound

Answer 4

The compression and infractions line up. The result is a larger amplitude and more hyperechoic appearance.

Question 5

What is destructive interference? How does it appear on ultrasound

Answer 5

The compression and infractions are opposite. They would be subtracted for a smaller amplitude and hypoechoic appearance.

Question 6

What does it mean when two things are related in physics?

Answer 6

They can either be directly or inversely proportional

Question 7

What does it mean when two things are unrelated in physics?

Answer 7

They are not associated with the other option

Question 8

what is a medium

Answer 8

the material you are scanning through.

Question 9

what is the source?

Answer 9

the origin of the ultrasound beam

Question 10

What are the four properties of a soundwave

Answer 10

mechanical, cannot travel through a vaccuum, travels in a straight line, longitudinal wave

Question 11

what are the three acoustic variables?

Answer 11

Pressure, density, distance.

Question 12

Define pressure

Answer 12

concentration of force in an area

Question 13

Define density

Answer 13

the concentration of mass in an area.

Question 14

what direction is a transverse wave?

Answer 14

perpendicular to the wave travel

Question 15

What does it mean that sound cannot travel through a vacuum

Answer 15

it needs a medium (skin, water, air, gel) to travel through.

Question 16

Hz is a term that is interchangable with ..?

Answer 16

cycles

Question 17

what does adjustable or non adjustable mean?

Answer 17

Whether the property can be adjusted within a given wave.

Question 18

define a period in physics. What is it determined by and is it adjustable?

Answer 18

the measurement of time taken to complete one cycle. It is determined by the source and is not adjustable.

Question 19

define wavelength in physics. What is it determined by and is it adjustable?

Answer 19

the measurement of the distance of one cycle. It is determined by both the source and the medium and it is not adjustable.

Question 20

define frequency in physics. What is it determined by and is it adjustable?

Answer 20

the number of events that occur in a given amount of time. It is determined by the source and is not adjustable.

Question 21

The Frequency is inversely related to which property?

Answer 21

The period and wavelength

Question 22

What do the acoustic variables determine?

Answer 22

They distinguish between soundwaves and other waves

Question 23

What are the acoustic parameters?

Answer 23

Period, frequency, wavelengeth, amplitude, power, intensity, velocity

Question 24

What is interference?

Answer 24

When two sound waves occur at the same time in the same medium. They join to create one wave.

Question 25

define amplitude in physics. What is it determined by and is it adjustable?

Answer 25

the difference between the maximum or minimum value and the average. It's determined by source and is adjustable

Question 26

What is Peak-to-Peak amplitude

Answer 26

Difference between the maximum and minimum values

Question 27

define power in physics. What is it determined by and is it adjustable?

Answer 27

the rate at which work is performed. It is determined by source and is adjustable.

Question 28

define insensity in physics. What is it determined by and is it adjustable?

Answer 28

concentration of energy in a sound beam in Watts. It is determined by the source and adjustable.

Question 29

How are intensity, power, and amplitude related?

Answer 29

They are directly related. Intensity and power are related to amplitude squared.

Question 30

define propagation speed in physics. What is it determined by and is it adjustable?

Answer 30

rate at which a sound wave travels through a medium. it's determined by medium and not adjustable

Question 31

What is the average speed of sound in soft tissue

Answer 31

1540 m/s

Question 32

How are frequency and wavelength related

Answer 32

they are inversely related.

Question 33

What is attenuation? What determines it?

Answer 33

Attenuation is the weakening of the beam during a cycle. A high frequency and longer path will increase attenuation.

Question 34

Between solid, liquid, and gas, which does sound travel fastest? slowest?

Answer 34

Fastest in solid, slowest in gas

Question 35

what happens to the speed when you increase frequency?

Answer 35

notthing.

Question 36

Are wavelength and velocity related?

Answer 36

No

Question 37

If the sonographer has increased the amplitude of a wave by a factor of 4, what happens to power

Answer 37

it increases by 16

Question 38

What is the equation for wavelength?

Answer 38

divide 1.54 mm by the frequency

Question 39

Out of a group of period lengths, which would have the lowest frequency?

Answer 39

The longest period of time.