Ch. 4 Flashcards
The pulse delays have a ______ input from the pulser but _____ output(s) to the transducer element.
a. slow; faster
b. controlled; uncontrolled
c. single; multiple
d. single; double the
c. single; multiple
A two-dimensional image plane is usually divided like a checkerboard in a ______ or similar matrix.
a. 1540 x 7700
b. 256 x 525
c. 1024 x 786
d. 265 x 521
c. 1024 x 786
The primary beam is much narrower, improving lateral resolution with ____.
a. harmonic imaging
b. pixel interpolation
c. real-time imaging
d. spatial compounding
a. harmonic imaging
The display form that presents the depth in the vertical axis and amplitude of the echo in the horizontal axis is _____.
a. A (amplitude) mode
b. B (brightness) mode
c. C (color) mode
d. M (motion) mode
a. A (amplitude) mode
The pulse repetition frequency (PRF) in real time imaging typically ranges from _____.
a. 2 - 20 MHz
b. 4 - 15 MHz
c. 5 - 50 MHz
d. 2 - 15 MHz
b. 4 - 15 MHz
When the fundamental frequency is filtered out, which of the following occurs?
a. volume imaging
b. pixel interpolation
c. harmonic frequencies
d. spatial compounding
c. harmonic frequencies
Panoramic imaging expands the image ____.
a. quality, allowing for a much smoother image
b. by using a special panoramic transducer
c. resolution
d. beyond the normal limits of a transducers field of view
d. beyond the normal limit of a transducers field of view
A flat panel display presents image information in the form of ______.
a. vertical lines read out from left to right
b. horizontal lines read out from left to right
c. vertical lines read out from right to left
d. horizontal lines read out from right to left
b. horizontal lines read out from left to right
Analog-to-digital converters convert the _____ voltage representing echoes to ____ for digital signal processing and storage.
a. analog; numbers
b. analog; bits
c. digital; analog
d. ultrasound; numbers
a. analog; numbers
Gain is the ratio of _____.
a. amplifier input to output voltage power
b. ampltifier output to input electric power
c. voltage ratio squared or voltage ratio to the second power
d. transmission output to amplifier input
b. amplifier output to input electric power
Utilizing additional focal points causes the temporal resolution to _____.
a. double
b. improve
c. degrade
d. remain unchanged
c. degrade
The _____ is where the action originates.
a. signal processor
b. code excitation
c. beam former
d. transmit/receive (T/R) switch
c. beam former
Golay codes _____.
a. are coding schemes using “gaps” or missing pulses
b. use pairs of transmitted pulses with the second being a bipolar sequence
c. are coding schemes that stack up the individual pulses
d. reduce speckle, which improves contrast resolution
b. use pairs of transmitted pulses with the second being a bipolar sequence
When gain is too high, which of the following occurs? A. Contrast resolution is improved B. Weak echoes are not imaged C. Temporal resolution is reduced D. Differences in echo strength are lost
D. Differences in echo strength are lost
The \_\_\_\_\_\_\_ determines the brightness of the echoes on the display A. Analog-to-digital converter B. Digitizer C. Digital-to-analog converter D. Cathode ray tube
C. Digital-to-analog converter
The \_\_\_\_\_\_\_\_ determines how much amplification is accomplished in the amplifier A. TGC control B. Postprocessing control C. Gain control D. Persistence control
C. Gain control
In which of the following code excitation techniques do ensembles of pulses drive the transducer to generate a single scanline? Time game compensation make up for: A. Absorption B. Attenuation C. Reverberation D. Refraction
B. Attenuation
The number of voltage pulses sent to the transducer each second is called the \_\_\_\_\_\_\_\_\_\_. a. Duty factor B. Pulse duration C. Pulse repetition. D. Pulse repetition frequency
D. Pulse repetition frequency
Pixel interpolation, persistence, and panoramic imaging are examples of \_\_\_\_\_\_\_\_\_. A. Preprocessing B. Spatial compounding C. Postprocessing D. Signal processors
A. Preprocessing