Chapter 14 quiz Flashcards

(20 cards)

1
Q

Is patient exposure levels to ultrasound energy altered when the sonographer changes amplification?

A

No

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2
Q

TRUE OR FALSE

Smoothing converts all negative voltages into positive voltages

A

False

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3
Q

Which does not belong as a major component in the ultrasound system?

a. master synchronizer
b. transducer
c. switch
d. pulser and beam former

A

Switch

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4
Q

TRUE OR FALSE

When signal-to-noise ratio is high, the signal is much stronger than the noise and the image is of high quality

A

True

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5
Q

In the amplification process, the typical values are measured in dB, the range is

A

60-100dB

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6
Q

TRUE OR FALSE

Compensation is performed twice

A

False

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7
Q

This allows the sonographer to control whether the low-level gray scale information within the data will appear on the displayed image

A

Reject

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8
Q

What does ALARA mean

A

As low as reasonably achievable

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9
Q

Place these functions in order in which the ultrasound system performs them

a. reject
b. amplification
c. demodulation
d. compensation
e. compression

A
  1. b. amplification
  2. d. compensation
  3. e. compression
  4. c. demodulation
  5. a. reject
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10
Q

Receiver gain is also called

A

amplification

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11
Q

Can the sonographer change demodulation

A

no

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12
Q

All electrical signals in the receiver are affected ______________ by amplification

A

Identically

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13
Q

Preamplification occurs as close to the active elements as is practical, often in the

A

Transducer

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14
Q

TRUE OR FALSE
The pulser creates electrical signals that excite the PZT crystals and create sound beams. When pulser voltage is high, the transducer’s active element vibrates more forcefully and transmits stronger sound beams into the body

A

True

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15
Q

Another name for pulser voltage is

A

Transmitter output

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16
Q

Can output power alone make an image of uniform brightness from top to bottom?

17
Q

Which of the following choices is best when the image on your ultrasound system is too bright everywhere?

a. decrease the amplification or gain
b. use a higher frequency transducer
c. decrease the output power
d. adjust the reject

A

decrease the output power

18
Q

Which of the following choices is best when the image on your ultrasound system displays reflections only in a region far from the transducer but no reflectors in a region closer to the transducer?

a. adjust the system’s compensation
b. use a higher frequency transducer
c. decrease the output power
d. adjust the reject level

A

adjust the system’s compensation

19
Q

TRUE OR FALSE

Both levels of reject can be adjusted by the sonographer

20
Q

BONUS

Draw the anatomy of the TGC curve

A
Near gain
Delay
Slope
Knee
Far gain