Instrumentation Flashcards
Which of the following is not considered a component of an ultrasound system?
a. master synchronizer
b. pulser
c. receiver
d. image intensifier
d. image intensifier
True or False?
The pulser of a mechanical transducer is typically more complex than the pulser of a phased array transducer.
False
What is a typical pulser output voltage that excites a piezoelectric crystal?
a. 0.1 volts
b. 500 millivolts
c. 40 volts
d. 10 microvolts
c. 40 volts
What is the typical voltage of the signal that is the input to the receiver of an ultrasound system?
a. 0.1 volts
b. 500 millivolts
c. 250 volts
d. 10 microvolts
d. 10 microvolts
The output of an ultrasound pulser determines the ____ of the acoustic pulse.
a. imaging depth
b. intensity
c. duration
d. pulse repetition period
b. intensity
Which one of the following does not belong in the group below?
a. receiver gain
b. energy output
c. pulser power
d. acoustic power
e. transmitter output
f. output gain
a. receiver gain
True or False?
The sonographer can alter the pulser power.
True
Which of the following actions will improve the signal-to-noise ratio?
a. increase dynamic range
b. increase receiver gain
c. increase output power
d. increase time-gain compensation
c. increase output power
Which of these functions are performed by the receiver of an ultrasound system? (more than one answer may be correct).
a. amplification
b. threshold
c. compensation
d. demodulation
a. amplification
b. threshold
c. compensation
d. demodulation
Which of the following tasks is not performed by the receiver an on ultrasound system? (more than one answer my be correct).
a. rectification
b. smoothing
c. compression
d. degaussing
d. degaussing
True or False?
The sonographer can adjust the receiver gain.
True
True or False?
The signal-to-noise ratio remains unchanged when a sonographer adjusts receiver gain.
True
True or False?
The sonographer can make an image of uniform brightness by adjusting both output power and receiver gain.
False
Which of the following is a typical value for the amplification of a signal by the receiver?
a. 50 to 100 watts
b. -50 to -100 dB
c. 50 to 100 dB
d. 5 to 25 W/cm^2
c. 50 to 100 dB
What is the process of adjusting for path length related attenuation called?
a. compression
b. compensation
c. time-gain compensation
d. reconfirmation
b. compensation
Which receiver function creates an image of comparable brightness from top to bottom?
a. receiver gain
b. output power
c. swept-gain compensation
c. swept-gain compensation
Which transducer system is most likely to have the longest delay in its TGC curve?
a. a 5 MHz linear array
b. a 2.5 MHz annular array
c. a 7.5 MHz mechanical transducer
d. a 5 MHz annular array
b. a 2.5 MHz annular array
All of the following are used to described compensation except:
a. swept gain
b. depth gain
c. time gain
d. amplitude gain
d. amplitude gain
Which term best describes the region of minimum amplification on a standard TGC curve?
a. far field
b. focus only
c. area close to the transducer
d. focal zone
c. area close to the transducer
What does the far gain of a depth gain compensation curve represent?
a. the median amplification related to compensation
b. the maximum amplification related to compensation
c. the minimum amplification related to compensation
d. the maximum attenuation related to compensation
b. the maximum amplification related to compensation
At which imaging depth is the slope of the TGC curve most effective?
a. the region very close to the transducer
b. the far zone
c. the focal zone
c. the focal zone
True or False?
The lower the frequency of the ultrasound beam, the shallower is the delay of the TGC curve.
False
True or False?
Typically, the sonographer can adjust the compression function of a receiver.
True
The process of demodulation incorporates which of the following tasks? (more than one answer may be correct).
a. smoothing
b. amplification
c. rectification
d. decompression
a. smoothing
c. rectification
Which of the following best describes the demodulation process:
a. changing the gray scale of an image
b. changing the frequency of a signal
c. changing the form of a sound pulse
d. changing an electrical signal’s form
d. changing an electrical signal’s form
True or False?
The primary purpose of demodulation is the preparation of the electrical signal for display on a television monitor.
True
True or False?
Typically, the sonographer can control the demodulation process performed by a receiver.
False
The process of eliminating low amplitude signals from further processing is called all of the following except ______.
a. reject
b. subordination
c. threshold
d. suppression
b. subordination
True or False?
Typically, the sonographer can adjust the threshold level.
True
