Ultrasound Review - Ch 4 Physics/pulse-Echo Instrumentation

Front 1

The motion of moving structures in a 2D image display describes:

a) motion mode

b) amplitude mode

c) real time imaging

d) temporal resolution

Back 1

c) real time imaging

Front 2

In a brightness mode display, the y axis represents the:

a) penetration depth

b) compensation slope

c) amplitude of the reflector

d) right or left aspect of the body

Back 2

a) penetration depth

Front 3

The number of images per second defines the:

a) frame rate

b) line density

c) pulse repetition period

d) pule repetition frequency

Back 3

a) frame rate

Front 4

The frame rate in real time imaging can be modified by adjusting the:

a) output power

b) dynamic range

c) amplification

d) imaging depth

Back 4

d) imaging depth

Front 5

Which of the following display modes demonstrates the strength of the reflections along the vertical axis?

a) M mode

b) B mode

c) A mode

d) E mode

Back 5

c) A mode

Front 6

Frame rate is determined by penetration depth and:

a) temporal resolution

b) operating frequency

c) pulse repetition frequency

d) propagation speed of the medium

Back 6

d) propagation speed of the medium

Front 7

A pulse repetition frequency of 10,000 Hz will demonstrate a maximum penetration depth of:

a) 7 -8 cm

b) 8 - 10 cm

c) 10 - 11 cm

d) 12 - 14 cm

Back 7

a) 7 - 8 cm

77/PRF

77/10 = 7.7

Front 8

If the line density is increased which of the following is most likely to occur?

a) frame rate will decrease

b) spatial resolution will decrease

c) temporal resolution will increase

d) pulse repetition frequency will decrease

Back 8

a) frame rate will decrease

Front 9

Propagation speed of a medium limits which of the following?

a) penetration depth

b) pixel interpolation

c) harmonic frequencies

d) spatial compounding

Back 9

a) penetration depth

Front 10

The maximum amount of lines per frame a transducer can employ at a depth of 10 cm when using 30 frames/s and two focal zones is:

a) 116

b) 128

c) 135

d) 178

Back 10

b) 128

depth X # of focal zones X lines per frame X frame rate < or = to 77000

10X2X?X30 < or = to 77000

600 <= 77000

77000/600 = 128

Front 11

Which of the following is directly related to pulse repetition frequency?

a) line density

b) imaging depth

c) spatial resolution

d) operating frequency

Back 11

a) line density

Front 12

Increasing the amplitude of the sound beam by 3 dB will:

a) quadruple the acoustic intensity

b) increase the signal to noise ration

c) increase the pulse repetition frequency

d) increase the frequency of the transducer

Back 12

b) increase the signal to noise ration

Front 13

Which of the following describes a function of the T/R switch?

a) delivers electric voltage to the memory

b) generates electric pulses to the crystal

c) protects the receiver components from the pulse voltage

d) adjusts the pulse repetition frequency with imaging depth

Back 13

c) protects the receiver components from the pulse voltage

Front 14

output of a diagnostic ultrasound system ranges between just above zero to:

a) 100 v

b) 200 V

c) 500 V

d) 600 V

Back 14

c) 500 V

Front 15

Which of the following offsets for attenuation of the sound beam?
a) amplifier

b) compression

c) demodulation

d) compensation

Back 15

d) compensation

Front 16

Which of the following describes a function of the transducer?

a) delivers acoustic voltages to the display

b) delivers electrical voltages to the memory

c) controls the amplitude of the received signals

d) adjusts the pulse repetition frequency for imaging depth

Back 16

b) delivers electrical voltages to the memory

Front 17

The knee of a time gain compensation curve represents the:

a) area of minimum amplification

b) area of maximum amplification

c) depth at which variable compensation begins

d) deepest region attenuation compensation can occur

Back 17

d) deepest region attenuation compensation can occur

Front 18

Which component of the ultrasound system adjusts the pulse repetition frequency with changes in imaging depth?

a) pulser

b) T/R switch

c) beam former

d) master synchronizer

Back 18

a) pulser

Front 19

the transmit and receiver switch is part of which of the following instruments?

a) pulser

b) receiver

c) beam former

d) digital scan converter

Back 19

c) beam former

Front 20

Which of the following constitutes a transmission channel?

a) an electrical voltage & an element

b) an electrical voltage & firing delay

c) a delay path & an individual element

d) an independent pulse delay & an element

Back 20

d) an independent pulse delay & an element

Front 21

Which of the following statements accurately describes demodulation?

a) demodulation suppresses low level echoes

b) demodulation changes the gray scale characteristics of an image

c) structure boundaries are accentuated when using demodulation

d) processing the received signal is made possible by demodulation

Back 21

d) processing the received signal is made possible by demoduation

Front 22

Which of the following receiver functions decreases acoustic noise?

a) smoothing

b) threshold

c) rectification

d) compression

Back 22

b) threshold

Front 23

Which of the following allows for multiple focal zones and harmonic frequencies?

a) channeling

b) code excitation

c) dynamic focusing

d) constructive interference

Back 23

b) code excitation

Front 24

Which of the following is a postprocessing feature?

a) cine loop

b) persistence

c) write zoom

d) 3D acquisition

Back 24

a) cine loop

Front 25

The binary number 0110010 corresponds to a decimal number of:

a) 25

b) 50

c) 74

d) 100

Back 25

b) 50

0110010 = 0+32+16+0+0+2+0=50

Front 26

How many shades of gray are in a 6 bit memory?

a) 32

b) 48

c) 64

d) 96

Back 26

c) 64

2x2x2x2x2x2

Front 27

What is the term used to describe a volume picture element?

a) bit

b) byte

c) pixel

d) voxel

Back 27

d) voxel

Front 28

Which of the following is a characteristic of read zoom?

a) acquires new data

b) displays only original data

c) improves spatial compounding

d) rescans only in the area of interest

Back 28

b) displays only original data

Front 29

The number of frames per sec necessary for a real time image to be free of flicker is:

a) 20

b) 30

c) 40

d) 60

Back 29

b) 30

Front 30

Which of the following is most likely related to pixel density?

a) log compression

b) spatial resolution

c) contrast resolution

d) temporal resolution

Back 30

b) spatial resolution

Front 31

Storage of several preceding real time frames describes:

a) cine loop

b) freeze frame

c) video imaging

d) frame averaging

Back 31

a) cine loop

Front 32

Which of the following best describes a digital matrix?

a) storage of picture elements

b) smallest amount of computer memory

c) number of picture elements in a digital image

d) rows and columns of picture elements in a digital image

Back 32

d) rows and columns of picture elements in a digital image

Front 33

Which of the following improves contrast resolution?

a) rejection

b) b color

c) persistence

d) compression

Back 33

b) b color

Front 34

Which of the following components increases the number of scan lines?

a) read zoom

b) b color

c) persistence

d) write zoom

Back 34

d) write zoom

Front 35

Which of the following artifacts improperly displays a true reflector's location?

a) mirror image

b) reverberation

c) focal banding

d) range ambiguity

Back 35

d) range ambiguity

Front 36

When the Doppler gain setting is too high, which of the following artifacts is most likely to occur?

a) aliasing

b) mirror image

c) range ambiguity

d) acoustic speckle

Back 36

b) mirror image

Front 37

Which of the following decreases the likelihood of range ambiguity artifact?

a) perpendicular incidence

b) decreasing the receiver gain

c) decreasing the operating frequency

d) decreasing the pulse repetition frequency

Back 37

d) decreasing the PRF

Front 38

the design of ultrasound systems assumes:

a) the thickness of the imaging plane is uniform

b) sound travels at variable speeds in soft tissue

c) sound travels directly to & from a reflector

d) secondary beams travel lateral to the primary beam

Back 38

c) sound travels directly to & from a reflector

Front 39

Weakening of echoes distal to a strongly attenuating structure describes:

a) refraction

b) ring down

c) shadowing

d) enhancement

Back 39

c) shadowing

Front 40

Enhancement of echo reflections occur distal to a:

a) nonspecular reflector

b) strongly reflecting structure

c) weakly attenuating structure

d) structure of high impedance

Back 40

c) weakly attenuating structure

Front 41

A change in direction of the ultrasound beam is more commonly a result of:

a) the resonance phenomenon

b) interference from multiple scatterers

c) striking a boundary at an oblique angle

d) secondary sound beams emitted from a phased array

Back 41

c) striking a boundary at an oblique angle

Front 42

Spaces between the active elements of a phased array transducer result in:

a) multipath reflections

b) the production of side lobes

c) enhancement in the focal zone

d) the production of grating lobes

Back 42

d) the production of grating lobes

Front 43

the distance to a reflector is determined by the:

a) intensity of the returning echo

b) thickness of the imaging plane

c) time it takes for an echo to return

d) propagation speed of the medium

Back 43

c) time it takes for an echo to return

Front 44

A surgical clip will most likely demonstrate which of the following artifacts?

a) refraction

b) multipath

c) comet tail

d) acoustic speckle

Back 44

c) comet tail

Front 45

Shadowing and enhancement are a result of which type of imaging artifact?

a) reflection

b) refraction

c) attenuation

d) propagation speed error

Back 45

c) attenuation