Review

Question 1

What is the units for pulse repetition frequency
A. Kilohertz (kHz)
B. Hertz (Hz)
C. Megahertz

Answer 1

Kilohertz

Question 2

What is the formula for pulse repetition frequency

Answer 2

PRF = 1/PRP

Question 3

Is PRF independent of operating frequency
True or false

Answer 3

True

Question 4

What is the number of pulses occurring in one second

Answer 4

Pulse repetition frequency

Question 5

What is the formula for pulse duration

Answer 5

PD = T x n

Question 6

What is the formula for pulse repetition period

Answer 6

PRP = 1/PRF

Question 7

Is depth directly proportional to PRP?
True or false

Answer 7

True

Question 8

What is the time it takes for the active phase of the pulse to occur
A. Pulse duration
B. PRP
C. PRF
D. Wavelength

Answer 8

A. Pulse duration

Question 9

What is the formula for pulse duration

Answer 9

PD (us) = T (period) x n (number of cycles)

Question 10

If the frequency is increased, the period increases
True or false

Answer 10

False the period decreases

Question 11

What is determined by the sound source
A. Period
B. Frequency
C. Amplitude, power, and intensity
D. All of the above

Answer 11

D. All of the above

Question 12

What does the AIUM state that no effects have been observed for:

Answer 12

Unfocused transducer less than 100 mW/cm^2
Focused transducer less than 1000 mW/cm^2 or 1 W/cm^2

Question 13

Does one pulse = one scan line?
T or F

Answer 13

True

Question 14

What is frame rate?

Answer 14

How many frames are going into the memory per second

Question 15

What type of transducers fall under phased array technology

Answer 15

sector or vector

Question 16

What twow features does phased operation allow?

Answer 16

Beam steering and electronic focusing

Question 17

What does 3D images allow the user to see?

Answer 17

Height, width, and depth

Question 18

Is 4D imaging displayed in real time?
Yes or no

Answer 18

Yes, it is basically 3D imaging in real time

Question 19

Which of the following is described as the ability of an object to resist compression and relates to the hardness of a medium?
A. Stiffness
B. Density
C. Pressure
D. Intertia

Answer 19

A. stiffness

Question 20

An increase in PRF would lead to:
A. an increase in DF
B. a decrease in PD
C. an increase in the number of cycles
D. A decrease in resolution

Answer 20

A. an increase in DF

Question 21

Which of the following would have the highest propagation speed?
A. air
B. Bone
C. soft tissue
D. water

Answer 21

B. bone

Question 22

Which of the following would have the lowest propagtaion speed?
A. water
B. soft tissue
C. Bone
D. lung tissue

Answer 22

A. water

Question 23

As imaging depth increases, the PRF must:
A. not change
B. Increase
C. Decrease
D. PRF does not relate to imaging depth

Answer 23

C. Decrease

Question 24

Which of the following describes the amount of refraction that occurs at an interface?
A. Bernoulli’s law
B. Piseuilles’s law
C. law of reflection
D. Snell’s Law

Answer 24

D. snells law

Question 25

What is the formula for wavelength?

Answer 25

wavelength (upsidedown y) = C/F C = propagation speed

Question 26

What is he formula for time?

Answer 26

T (us) = 1/Frequency (mHz)

Question 27

What is the range for human hearing?

Answer 27

20-20,000 Hz

Question 28

What is the range for ultrasound?

Answer 28

20,000 Hz and higher

Question 29

What is the range for infrasound?

Answer 29

Less than 20 Hz

Question 30

What is the range for medical ultrasound?

Answer 30

2-15 MHz (or 20 mHz)

Question 31

What are the units for propagation speed?

Answer 31

mm/us or m/s

Question 32

What is the average propagation speed in soft tissue?

Answer 32

1540 m/s or 1.54 mm/us

Question 33

Are stiffness and propagation speed proportional? Y or N

Answer 33

Yes

Question 34

Density and propagation speed are directly proportional? T or F

Answer 34

False, it is inversely proportional

Question 35

Is frequency and wavelength inversely porportional? Y or N

Answer 35

Y

Question 36

What is the equation for power?

Answer 36

P = A^2

Question 37

What are the units for intensity?

Answer 37

milliwatts per centimeter ^2

Question 38

What is the maximum variation that occurs in an acoustic variable? A. Amplitude B. Power C. Intensity

Answer 38

Amplitude

Question 39

What are the units for amplitude?

Answer 39

Pascals (Pa) for pressure amplitude

Question 40

What is defined as the rate of energy transfer from one part of the system to another or the energy that travels along the ultrasound beam? A. Intenstity B. Density C. Power

Answer 40

C. Power

Question 41

What is the rate at wich energy passes through a unit area? A. Intensity B. Power C. Amplitude D. Density

Answer 41

A. Intensity

Question 42

What is the units for intensity?

Answer 42

Milliwatts per centimeter squared (mW/cm^2 or W/cm^2)

Question 43

What is the formula for intensity?

Answer 43

I = P/A P = power A = amplitude

Question 44

Is intensity related to amplitude? Y or N

Answer 44

Yes, I = A^2

Question 45

What detemines how much of an incident sound wave is reflected back and how much is transmitted into the second medium? A. Power B. Amplitude C. Impedance D. Intensity

Answer 45

C. Impedance

Question 46

What are the units for impedance?

Answer 46

rayls

Question 47

What is the formula for impedance?

Answer 47

Impedance (rayls) = Density (kg/m^3) x propagation speed (m/s) Z = p x C

Question 48

Impedance will increase if density and or prop speed increases, because they are both directly proportional/related to impedance T of F

Answer 48

True

Question 49

Perpendicular incidence at a boundary between two media (tissues): A. No reflection will occur if the two different media have the same impedance B. Small reflection will occur if the differences in the two impedances are small C. Large relection will occur if the differences in the two impedances are large D. All of the above

Answer 49

D. all of the above

Question 50

What are the parameters of continuous ultrasound wave? A. Including frequency, period, propagation speed, and wavelength B. Sound that is continuously transmitted is referred to as CW. It is only used in Spectral Doppler. C. None of the above D. Both a and b

Answer 50

D. Both a and b

Question 51

What happens when pusles are sent out; and the ultrasound instrument listens for the echoes to come back? A. Continuous wave B. Pulse-echo technique C. Tri-phasic wave D. Phasic flow

Answer 51

B. pulse-echo technique

Question 52

Does the brightness of the dot correspond to the echo strength? Yes or no

Answer 52

Yes

Question 53

Location doesn't correspond to the echo return time T of F

Answer 53

F, it does correspond

Question 54

Ultrasound transducer: transforms electric energy into ultrasound energy T or F

Answer 54

True

Question 55

Is lead zirconate titante the most common material used? Y or N

Answer 55

Yes

Question 56

When a voltage is applied, the thickness of the element increases or decreases depending on the polarity of the voltage? Y or N

Answer 56

Yes

Question 57

What is a sound wave that is generated by a transducer that is divided into an active phase and a listening phase. The sound wave is broken up a collection of cycles called pulses with gaps in between? A. continuous wave B. Phasic flow C. pulsed wave D. triphasic flow

Answer 57

C. pulsed wave

Question 58

One pulse equals one scan line T or F

Answer 58

True

Question 59

Pulsed wave uses one crystal. Is that crystal active during transmission created by an application of a voltage which generates 2-3 cycles per pulse? Y or N

Answer 59

Yes

Question 60

What 3 modalities does PW ultrasound provides us? A. Gray scale. B. Color doppler C. PWD D. none of the above E. all of the above

Answer 60

E. all of the above

Question 61

What happens with PRF when the depth is adjusted? A. The deeper the depth - PRF decreases B. The shallower the depth - PRF increases C. The shallower the depth - PRF decreases D. A and B E. The deeper the depth - PRF increases

Answer 61

D. A and B

Question 62

Are depth and PRP proportional? Y or N

Answer 62

Yes

Question 63

The greater the depth, the longer the PRF T or F

Answer 63

F - the shorter the PRF

Question 64

The greater the depth the longer the wait time, therefore the ____ the PRP A. shorter B. Greater

Answer 64

B. greater

Question 65

what is the units for PRP?

Answer 65

millisecond (msec)

Question 66

What is the time form the beginning of one pulse to the beginning of the next pulse or from the start of the active part of one pulse to the active pulse of the next pulse? A. Pulse repetition period B. PRF C. DF

Answer 66

A. PRP

Question 67

What is the percentage of time that pulsed ultrasound is on? A. PRP B. PFR C. PD D. DF

Answer 67

D. DF - duty factor

Question 68

What is the formular for duty factor?

Answer 68

DF = pulse duration/pulse repetition period

Question 69

DF for sonography is 0.1%-1% T or F

Answer 69

True

Question 70

CW of ultrasound will have 100% of DF? T or F

Answer 70

True

Question 71

What is the formula for SPL?

Answer 71

SPL (mm) = wavelength (mm) x number of cycles in the pulse SPL = WL (upside down y) x n

Question 72

If the number of cycles in a pulse increases, SPL increases T or F

Answer 72

True

Question 73

If frequency increases, the wavelength decreases therefore the SPL decreases too T or F

Answer 73

True

Question 74

What is the decrease of the amplitude and intensity of a sound wave as it propagates through the different media of the body? A. DF B. attenuation and absorption C. pRF d. PRP

Answer 74

B.

Question 75

What are the units for attenuation and absorption?

Answer 75

decibels (dB)

Question 76

What are the three factors for attenuation? A. Absorption B. Reflection C. Scattering D. all of the above

Answer 76

D. all of the above

Question 77

The body temperature should not be raised more than 1.5-2.0 degrees above the normal body temperature? T or F

Answer 77

True

Question 78

What is the creation of odd and and even multiples of the original operating frequency? A. Harmonics B. DF C. PRP D. PRF

Answer 78

A. Harmonics

Question 79

What uses a series of pulses and gaps, rather than a single driving pulse? A. Coded excitation B. Duty factor C. PRP

Answer 79

Coded excitation

Question 80

What features does coded excitation provide?

Answer 80

Multiple transmission foci, improved penetration, speckle reduction, improved contrast resolution, and gray scale imaging of blood flow

Question 81

What is when the pulse crosses a boundary at an angle not perpendicular (some angle other than 90 degrees) A. Normal incidence B. Oblique incidence

Answer 81

Oblique incidence

Question 82

Thicker elements will produce a lower frequency; and thinner elements will produce a higher frequency T or F

Answer 82

True

Question 83

What is the formula for transducer frequency?

Answer 83

Prop speed of element/ 2 x thickness

Question 84

What is another word for damping material?

Answer 84

Backing material

Question 85

What is a material placed on the transducer face to improve sound transmission across the element tissue boundary? A. Backing material B. Matching layer C. Housing D. Acoustic insulator

Answer 85

B. Matching layer

Question 86

What is the formula of quality factor- q factor

Answer 86

Q factor = operating frequency/bandwidth

Question 87

CW transducers have a narrow bandwidth (no backing) resulting in a high q factor T or F

Answer 87

True

Question 88

What measures the ability of a system to display two structures that are very close together? A. Lateral resolution B. Contrast resolution C. Axial resolution

Answer 88

C. Axial

Question 89

What is the formula for axial resolution?

Answer 89

Axial resolution (mm) = SPL/2

Question 90

What two ways is a shorter pulse created?

Answer 90

Less ringing and higher frequency

Question 91

What measures the ability of a system to display two structures that are very close together. That is when the structures are perpendicular to the beams main axis? A. Axial resolution B. Lateral resolution C. Contrast resolution

Answer 91

B. Lateral resolution

Question 92

How is lateral resolution determined?

Answer 92

By the width of the sound beam

Question 93

What is the formula for lateral resolution

Answer 93

Lateral resolution (mm) = beam diameter (mm)

Question 94

What are the five terms to describe the Anatomy of the sound beam?

Answer 94

Focus, near zone, far zone, focal zone, diameter of the transducer also called aperture