Ultrasound Physics

Front 1

Turbulent blood flow will likely demonstrate:

Back 1

eddies

Front 2

The minimum number of samples required to avoid aliasing is termed:

Back 2

Nyquist limit

Front 3

The change in frequency resulting from motion is termed:

Back 3

Doppler shift

Front 4

The amount of space within a specific boundary defines:

Back 4

area

Front 5

The diameter of the beam determines the:

Back 5

near zone length and lateral resolution

Front 6

The mechanical index is proportional to the:

Back 6

system output

Front 7

A sudden burst of color Doppler most likely represents:

Back 7

flash artifact

Front 8

The area from the transducer to the spatial peak intensity is termed:

Back 8

near field
(spatial peak intensity=focus)

Front 9

Which component adjusts the amplitude of the received echoes:

Back 9

output

Front 10

Which of the following describes the range of frequencies found in a pulse:
A. duty factor
B. bandwith
C. pulse duration
D. pulse repetition period
E. pulse repetition frequency

Back 10

B. bandwith

Front 11

Which of the following demonstrates the fastest propagation speed:
A. air
B. fat
C. blood
D. muscle
E. soft tissue

Back 11

D. muscle

Front 12

Scan lines are aimed in a variety of pathways when utilizing:
A. 4D imaging
B. pulse inversion
C. pixel interpolation
D. spatial compounding
E. three-dimensional imaging

Back 12

D. spatial compounding

Front 13

Which of the following intensity values describes the average intensity within the beam during the highest intensity in time:
A. SATA
B. SPTP
C. SATP
D. SPPA
E. SPTA

Back 13

C. SATP
(the average intensity within the beam=SA. The highest intensity in time=TP.)

Front 14

Which of the following may directly affect the intensity of the Doppler signal:
A. pressure gradient
B. radius of the vessel
C. length of the vessel
D. velocity of the RBC
E. concentration of RBC

Back 14

E. concentration of RBC

Front 15

WIth perpendicular incidence, the larger the impedance difference between the media, the greater the:

Back 15

reflection

Front 16

Pulse wave Doppler requires a minimum of:

Back 16

5 cycles per pulse
(and up to 30 cycles per pulse)

Front 17

The size of the displayed image is directly related to the:

Back 17

pulse repetition frequency

(field of view or imaging depth is directly related to PRF and inversely related to the frame rate and PRP)

Front 18

Intensity in a sound beam is highest:

Back 18

near the center of the beam

Front 19

Which of the following control the amplitude of the transmitted and received signals:
A. pulser
B. receiver
C. transducer
D. beam former
E. output power

Back 19

E. output power

Front 20

The Doppler shift is inversely related to the:

Back 20

propagation speed of the medium

(and directly related to the operating frequency, blood velocity, and Doppler angle.)

Front 21

If the received frequency is greater than the transmitted frequency, what will occur:

Back 21

positive Doppler shift

Front 22

The digital memory of a scan converter:
A. accepts signals from the receiver
B. stores data as binary numbers
C. sends stored data to the display
D. changes received signals into numeric numbers
E. determines the brightness of the displayed echoes

Back 22

B. stores data as binary numbers

Front 23

What must occur for blood to flow:

Back 23

pressure gradiant

Front 24

Which imaging display commonly utilizes pixel interpolation:

Back 24

sector

(in sector imaging, scan lines diverge further apart in the far field. Pixel interpolation fills in the missing pixels.)

Front 25

Which component instructs the US system to send a signal to the transducer:

Back 25

master synchronizer

(master synchronizer is the brain or manager of the US system.)

Front 26

All of the following statements correctly describe M-mode EXCEPT:
A. M-mode is a one dimensional display
B. Time is represented on x-axis
C. Motion of the reflector is represented on the vertical axis
D. Obstetrical imaging utilizes M-mode
E. M-mode is a qualitative series of brightness mode pixels

Back 26

E. M-mode is a qualitative series of brightness mode pixels

Front 27

Oblique incidence refers to:

Back 27

an incident sound beam traveling at an oblique angle to the media

Front 28

All of the following describes sound wave EXCEPT:
A. Sound cannot travel in a vacuum
B. Sound waves are mechanical
C. Matter must be present for sound to travel
D. Sound waves carry matter from one place to another
E. Sound waves contain regions of high and low pressure

Back 28

D. Sound waves carry matter from one place to another.

(sound waves carry energy not matter)

Front 29

The ratio of the largerst to smallest amplitude a system can handle describes:

Back 29

compression or dynamic range

Front 30

Multihertz transducers utilize:
A. the bandwidth
B. wider crystals
C. thicker elements
D. pixel interpolation
E. spatial compounding

Back 30

A. the bandwidth

(multihertz transducers utilize the range of frequencies found in a pulse or bandwidth)

Front 31

Increasing the number of focal zones will:

Back 31

increase transverse resolution and PRF

Front 32

Thermal index has a low risk of adverse effects if the value is:

Back 32

less than 2

Front 33

Flow rate is proportional to the:

Back 33

pressure gradient

Front 34

Pixel interpolation is an imaging technique with the purpose of:

Back 34

allocating amplitude to missed reflections

(pixel interpolation assigns value to missed pixels based on the intensities of the adjacent pixels)

Front 35

The Bernoulli effect describes the:

Back 35

decrease in pressure prior to stenosis

(pressure decreases before stenosis allows fluid to accelerate into the stenosis and decelerate out of it as described by Bernoulli effect)

Front 36

The testing used to collect data on the US system's performance is termed:

Back 36

quality control

Front 37

When the operating frequency increases, the:
A. flow speed decreases
B. Doppler shift increases
C. pressure energy increases
D. detail resolution decreases
E. penetration depth increases

Back 37

B. Doppler shift increases

Front 38

Which of the following imaging techniques utilizes pulse inversion:
A. real time imaging
B. harmonic imaging
C. panoramic imaging
D. multi-focal imaging
E. three-dimensional imaging

Back 38

B. harmonic imaging

Front 39

Electronic beam steering in an array assembly is accomplished by the:

Back 39

beam former

Front 40

Individual signal paths for reception and transmission of the sound beam are termed:

Back 40

channels

Front 41

Individual transducer elements within a single transducer assembly describe:

Back 41

channels

(multiple transducer elements with individual wiring and system electronics are termed channels)

Front 42

What is the period of a 10.0 MHz cycle:

Back 42

0.10 microseconds

(period is equal to one divided by the frequency)

Front 43

What reveals the state of the downstream arterioles:

Back 43

Diastolic flow

Front 44

Which of the following frequencies is above human hearing:
A. 5 Hz
B. 20 Hz
C. 20 kHz
D. 20,000 Hz
E. 25,000 kHz

Back 44

E. 25,000 kHz

Front 45

Periodic evaluation of collected test data is termed:

Back 45

quality assurance

Front 46

The ability of a diagnostic technique to identify true disease is termed:

Back 46

sensitivity

Front 47

Pulse repetition period is defined as the time:

Back 47

from beginning of one pulse to the start of the next pulse

Front 48

Which material is commonly used when manufacturing imaging transducer elements:
A. ceramic
B. tourmaline
C. Rochelle salt
D. lead zirconate titanate
E. polyvinylidene diflouride

Back 48

D. lead zirconate titanate (PZT)

Front 49

Normally, the number of channels utilized does not exceed the number of:

Back 49

transducer elements

Front 50

Which of the following best describes spatial compounding:
A. smoothes non-specular surfaces
B. interrogates the structures once
C. continuous wave transducers utilize spatial compounding
D. Speckle is increased when utilizing
E. improves visualization beneath highly attenuating structures

Back 50

E. Spatial compounding improves visualization beneath highly attenuating structures.

Front 51

Which system control adjusts the intensity of the sound beam:

Back 51

power output

Front 52

3D imaging acquires volume data at rates up to:

Back 52

30 volumes/second

Front 53

Which of the following is a function of the pulser:
A. establishes time delays during reception
B. delivers electric voltage to the memory
C. controls the amplitude of the transmitting signal
D. coordinates components of the US system
E. communicates with the receiver once the crystal is excited

Back 53

E. communicates with receiver once the crystal is excited

Front 54

Which of the following statements accurately describes harmonic frequencies:
A. demonstrates wide beam widths
B. Grating lobes are increased
C. Harmonic frequencies are generated in superficial structures
D. Lateral resolution is reduced
E. generate in the highest intensity of the sound beam

Back 54

E. Harmonic frequencies generate in the highest intensity of the sound beam

Front 55

Which of the following resolutions inversely relates to the number of focal zone frame:
A. axial
B. spatial
C. lateral
D. contrast
E. temporal

Back 55

E. temporal

(temporal resolution inversely relates to the number of focal zones, number of lines per frame and penetration depth utilized)

Front 56

Which resolution diminishes with pulse inversion:
A. axial
B. detail
C. lateral
D. contrast
E. temporal

Back 56

E. temporal

Front 57

Altered forward flow in the internal carotid artery is a characteristic finding in:

Back 57

disturbed flow

Front 58

Which portion of the transducer increases the transmission of sound across the element-tissue boundary:
A. focus
B. aperture
C. damping
D. acoustic gel
E. matching layer

Back 58

E. matching layer

Front 59

The five major components of a pulse-echo US system are:

Back 59

pulser, transducer, receiver, image memory, display

Front 60

Which testing device can produce retrograde flow:

Back 60

moving string

Front 61

In order to image deeper structures the US system must:

Back 61

decrease the number of pulses per second

Front 62

Which testing device reflects amplitude received by the transducer:

Back 62

beam profiler

Front 63

Utilizing a high pulse repetition frequency results in a(n):

Back 63

decrease in maximum penetration depth

Front 64

Which material demonstrates natural piezoelectric properties:
A. lead
B. silver
C. quartz
D. copper
E. barium

Back 64

C. quartz

Front 65

Gain compensation is necessary due to:

Back 65

attenuation of the sound beam

Front 66

The output of an US system determines the:

Back 66

amplitude of the transmitted sound beam

Front 67

The ability of a test to determine abnormal findings defines:

Back 67

positive predictive value

Front 68

If the frame rate increases and the PRF is unchanged, the:
A. line density will decrease
B. pulse duration will increase
C. temporal resolution is reduced
D. operating frequency will increase
E. number of scan lines will increase

Back 68

A. line density will decrease

Front 69

Even and odd multiples of the fundamental frequency describes:

Back 69

harmonic frequencies

Front 70

Even and odd multiples of the fundamental frequency describes:

Back 70

harmonic frequencies

Front 71

Redirection of a portion of the sound beam towards the transducer is termed:

Back 71

reflection

Front 72

The greatest intensity during the pulse is the:

Back 72

temporal peak

Front 73

The mechanical index:

Back 73

predicts the likelihood of cavitation occurring

Front 74

Averaging frames that view anatomy from different angles describes:

Back 74

spatial compounding

Front 75

Damping the transducer improves:

Back 75

axial resolution

Front 76

Utilizing previous echo reflections while adding new echoes to the image along a parallel scanning plane describes:

Back 76

panoramic imaging

Front 77

A transducer is a component of which testing device:

Back 77

hydrophone

Front 78

Metallic electrodes are components of a:

Back 78

hydrophone

Front 79

In vivo, focal lesions will occur with intensities greater than:

Back 79

10mW/cm2 SPTP

Front 80

Which of the following is a function of the power control:
A. filters out weak reflections
B. levels out the returning signals
C. improves the signal-to-noise ratio
D. amplifies returning reflections
E. changes the gray scale of the returning echoes

Back 80

C. improves the signal-to-noise ratio

Front 81

Increasing voltage received from the transducer to a level suitable for processing denotes:

Back 81

amplification

Front 82

The ability of a test to establish normal findings defines:

Back 82

negative predictive value

Front 83

Attenuation is most dependent on what intensity value:

Back 83

SATA

Front 84

The width of the element in a linear phased array transducer is approximately:

Back 84

one-quarter of the wavelength

Front 85

Spatial pulse length is inversely proportional to the:

Back 85

operating frequency

Front 86

The amount of time pulse US is transmitting is termed:

Back 86

duty factor

Front 87

An one dimensional display presenting the depth of a reflection in the vertical axis and the strength of the returning signal in the horizontal axis is termed:

Back 87

A-mode

Front 88

During reception, diagnostic US transducers convert:

Back 88

acoustic energy into electrical energy

Front 89

Which method of testing considers only the pulser and transducer of the US system:

Back 89

acoustic output

Front 90

Formation of gas bubbles in soft tissue is a result of:

Back 90

pressure changes

Front 91

The electronic transfer of images from the US system to another location is called:

Back 91

PACS

Front 92

Which testing devices measures the duration of a pulse:

Back 92

hydrophone

Front 93

Increasing the frame rate will:

Back 93

decrease the maximum imaging depth

Front 94

Which of the following is an advantage of sub-dicing:
A. reduction of side lobes
B. increases the frame rate
C. reduction of grating lobes
D. increase in penetration depth
E. increase in temporal resolution

Back 94

C. reduction of grating lobes

Front 95

Which of the following transducer frequencies demonstrates the longest focal length:
A. 2.5 MHz
B. 5.0 MHz
C. 7.5 MHz
D. 10.0 MHz
E. 15.0 MHz

Back 95

E. 15.0 MHz

(higher frequencies demonstrates longer focal lengths)

Front 96

Apodization is a function of which of the following instruments:
A. pulser
B. receiver
C. transducer
D. beam former
E. master synchronizer

Back 96

D. beam former

Front 97

Which type of transducer operates by applying voltage pulses to groups of elements in succession:
A. mechanical
B. vector array
C. phased array
D. annular array
E. sequenced array

Back 97

E. sequenced array

Front 98

The time for a wave to complete one cycle is termed the:

Back 98

period

Front 99

Convert the binary number 0101001 to decimal equivalent:
A. 17
B. 21
C. 41
D. 60
E. 82

Back 99

C. 41

(Binary number 0101001=
0 + 32 + 0 + 8 + 0 + 0 + 1 = 41)

Front 100

The onset of turbulence is determined by the:

Back 100

Reynolds number

Front 101

The imaging transducer exceeding the Curie point will result in:

Back 101

a loss of the piezoelectric properties

Front 102

Focal lesions may occur at intensities greater than:

Back 102

10W/cm2 SPTA

Front 103

The sonographer is unable to control, which of the following functions:
A. rejection
B. rectification
C. compression
D. amplification
E. power output

Back 103

B. rectification

Front 104

In unfocused transducer the focal length is determined by the:
A. beam diameter
B. penetration depth
C. element thickness
D. operating frequency
E. propagation speed of the medium

Back 104

A. beam diameter

Front 105

Which of the following remains constant throughout the vessel:
A. velocity
B. pressure
C. direction
D. resistance
E. volumetric flow rate

Back 105

E. volumetric flow rate

Front 106

What is the minimum of memory bits necessary to display 64 shades of gray:

Back 106

6

(2 x 2 x 2 x 2 x 2 x 2 =2 to the 6th power)

Front 107

Reducing a 20dB amplifier by one-half will give a new gain setting of:

Back 107

17dB

(3 dB reduction in a 20dB amplifier will give a new gain setting of 17 dB)

Front 108

The dimension of the sound beam at the focal point is equal to:

Back 108

one-half of the transducer width

Front 109

Intensity of a focused sound beam is more uniform in the:

Back 109

Fraunhofer zone (far field)