Ultrasound

Question 1

How fast does ultrasound propagate through soft tissue?
a. 343 m/sec
b. 1,540 m/sec
c. 3,051 m/sec
d. 4,892 m/sec

Answer 1

B. 1,540 m/sec

Question 2

_____ forms the peak of the sound wave.

Answer 2

Compression (a region of high pressure)

Question 3

______ forms the trough of the sound wave.

Answer 3

rarefaction (a region of low pressure)

Question 4

A sound is simply a ______ that travels in a longitudinal wave.

Answer 4

pressure wave ( a form of mechanical energy)

Question 5

Frequency is a measure of _______

Answer 5

pitch.

Question 6

Frequency tells us how many

Answer 6

cycles occur in a given period of time

Question 7

________ is the distance between two identical points on adjacent cycles.

Answer 7

Wavelength

Question 8

______ frequencies produce shorter wavelengths, and _____ frequencies produce longer wavelengths

Answer 8

higher; lower

Question 9

______ represents the sound’s loudness

Answer 9

Amplitude

Question 10

Sound propagates through _____ at 343 m/sec and ____ at 3,000-5,000 m/sec

Answer 10

air; bone

Question 11

Frequency is expressed in

Answer 11

hertz or cycles per second

Question 12

When no medium is present (such as in a vacuum or outer space), there can

Answer 12

be no sound

Question 13

Which concept BEST explains why lead zirconate titanate is commonly used in ultrasound transducers?
a. echolocation
b. doppler effect
c. Snell’s law
d. Piezoelectric effect

Answer 13

D. Piezoelectric effect

Question 14

What is echolocation?

Answer 14

the use of sound and echoes to determine where objects are located in space.

Question 15

A piezoelectric material can transduce

Answer 15

electric energy to mechanical energy and vice versa

Question 16

The piezoelectrical material used by modern ultrasound transducers is called

Answer 16

lead zirconate titanate

Question 17

What is the primary determinant of the vertical placement of each illuminated pixel on the ultrasound monitor?
a. time delay
b. resolution
c. acoustic impedance
d. doppler effect

Answer 17

A. time delay
the vertical placement of each dot is determined by how long it takes for the echo to return to the transducer (time delay)

Question 18

The horizontal placement of each dot is determined by

Answer 18

the particular crystal that receives the returning echo

Question 19

The vertical placement of each dot is determined by

Answer 19

how long it takes for the echo to return to the transducer (time delay)

Question 20

The ultrasound transducer emits ultrasound waves into the body at a fixed rate, and then it listens

Answer 20

for echoes between each pulse- a process that repeats many times each second

Question 21

______ produces high amplitude echos

Answer 21

Hyperechoic

Question 22

_______ appear as dark shades of grey

Answer 22

hypoechoic

Question 23

________does not produce echos

Answer 23

Anechoic

Question 24

The brightness of each dot is determined by the

Answer 24

amplitude of the returning signal

Question 25

______ describes a tissue's ability to transmit or reflect sound waves in the context of the surrounding tissues

Answer 25

Echogenicity

Question 26

______ structures appear bright

Answer 26

Hyperechoic examples- bone

Question 27

____ produce weak (low amplitude) echoes

Answer 27

Hypoechoic examples include solid organs, liver, skin, adipose, cartilage

Question 28

_____ appear black

Answer 28

anechoic

Question 29

Vascular structures appear as

Answer 29

black circles in short-axis and black tubes in long-axis

Question 30

______ pulsate, ______ do not

Answer 30

arteries; veins

Question 31

Peripheral nerves near the neuraxis tend to appear _________, but distal peripheral nerves are _______

Answer 31

anechoic; hyperechoic (white) with a characteristic honeycomb appearance

Question 32

Which process describes a sound wave that bounces off a tissue boundary that has a different acoustic impedance? a. absorption b. reflection c. scatter d. refraction

Answer 32

b. reflection

Question 33

______ is the process where a sound wave bounces off a tissue boundary of differing acoustic impedance

Answer 33

reflection

Question 34

_________ occurs as the ultrasound waves are lost to the body as heat

Answer 34

absorption

Question 35

______ occurs when the ultrasound wave encounters an object smaller than the wave

Answer 35

scatter

Question 36

________ is the bending of ultrasound wave that encounters a tissue boundary at an oblique angle

Answer 36

refraction

Question 37

Resolution is the ability to see

Answer 37

two separate things as two separate things

Question 38

The three types of resolution are

Answer 38

axial, lateral, and elevational

Question 39

Ultrasound waves leaving the transducer tend to

Answer 39

converge before diverging beyond a certain point they don't travel in a straight line

Question 40

The _____ is the region where the beam is the narrowest

Answer 40

focal zone

Question 41

The region between the transducer and the focal zone is called the ______

Answer 41

near zone (Fresnel zone)

Question 42

The region beyond the focal zone is called the

Answer 42

far zone (Fraunhofer zone)

Question 43

Examples of attenuation include

Answer 43

absorption, reflection, scatter, and refraction

Question 44

A _____ view looks at a structure in cross-section, while a _____ view looks at a structure along its length.

Answer 44

short-axis; long-axis

Question 45

As a sound wave propagates through the body, its strength naturally_____ and some of the sound waves never return to the transducer. These factors conspire to

Answer 45

decreases; reduce image quality through a process called attenuation

Question 46

Lower frequency transducers allows us to see_____________

Answer 46

Deeper inside the body but we sacrifice image resolution

Question 47

The array configuration describes the

Answer 47

Arrangement of piezoelectric crystals inside the ultrasound transducer

Question 48

The linear array transducer has a flat footprint that contains piezoelectric crystals arranged

Answer 48

In parallel

Question 49

The curvilinear array transducer has a convex footprint with the arrangement of piezoelectric crystals inside

Answer 49

Following suit

Question 50

A ____________ is very narrow in the near field and fans out with increasing depth

Answer 50

Phased array transducer

Question 51

Describe the frequency range, imaging depth, & application examples for a high frequency array US transducer

Answer 51

>10 MHz, <3 cm below skin, Interscalene, supraclavicular, axillary, forearm, ankle, wrist, femoral, ankle, superficial blood vessels

Question 52

Describe the frequency range, imaging depth, & application examples for A medium frequency array transducer

Answer 52

5-10 MHz, 3-6 cm below skin, Infraclavicular, sciatic, popliteal, deeper blood vessels

Question 53

Describe the frequency range, imaging depth, & application examples for a low frequency array transducer

Answer 53

>6 cm below skin,