Final Review Flashcards
All of the following are examples of postprocessing except ____.
a. volume presentation
b. B color
c. read zoom
d. write zoom
d
An analog-to-digital converter is also called a ______.
digitizer
An increase in the number of channels _____.
allows more precise control of the beam characteristics
Averaging sequential frames improves ______/
dynamic range
Brightness mode is also called _____.
gray-scale
Contrast resolution depends on _____ of bits per pixel.
number
Displays have dynamic ranges up to ___ dB.
30
Filtering of the sound beam is used to eliminate _____.
frequencies outside of the bandwidth
Gain the ratio of ______.
amplifier output to input electric power
Holding and displaying one frame out of the sequence is known as ____.
freeze
If the operating frequency is reduced,
maximum penetration depth increases
In order to image deeper structures, the
PRF needs to be decreased
Increasing the frame rate improves
temporal resolution
Maximum amplifier gain is determined by
noise
Normally the number of channels does not exceed the number of _____
elements in the transducer
Pixel interpolation, persistence, and panoramic imaging are examples of
preprocessing
Retention of previous frames while new echo information is added in the same scanning plane is called
panoramic imaging
Storage of the last several frams acquired before freezing is called
cine loop
The ____ and ____ determine the maximum imaging depth.
attenuation; maximum amplifier gain
The ____ determines how much amplification is accomplished in the amplifier.
gain control
The _____ determines the brightness of the echoes on the display.
digital-to-analog converter
The direct(s) the driving voltages from the pulser to the transducer during transmission and directs returning echo voltages to amplifiers during reception.
transmit/receive switch
The _____ drive(s) the transducer forming the beam that sweeps through the tissue to be imaged
pulser
The _____ is where the action originates.
beam former
The ability of a gray-scale display to distinguish between echoes of slightly different intensities is called _____.
contrast
The averaging of sequential frames together to provide a smoother image appearance is called _____
persistence
The display form that presents the depth in the vertical axis and the amplitude of the echo in the horizontal axis is _____.
A mode
The frequency of the _____ determines the frequency of the resulting ultrasound pulse
voltage pulse
The harmonic beam is much narrower than the fundamental, improving _____
lateral resolution
The maximum frame rate permitted for a 15 cm penetration depth, three focuses, and 200 scan lines per frame is _____.
8.5
The pulse repetition frequency (PRF) in real time imaging typically ranges from
4-15 kHz
The purpose of a bandpass filter is to
eliminate frequencies outside the echo bandwidth
The ratio of the largest to the smallest amplitude that a system can handle is called the
dynamic range
Time gain compensation amplifiers compensate for _____ decibels of attenuation
60
To avoid echo misplacement _____
all echoes must be received before another pulse is emitted
To receive information for display at a rapid rate, it is desirable to use a ______
high pulse repetition frequence
Volume imaging is accomplished by
acquiring many parallel two dimensional scans
What is the macimum penetration depth with a frame rate of 32 frames per second and a line density of 100 lines per frame and using only one focus?
24 cm
When gain is too high, which of the following occurs?
a. difference in echo strength are lost
b. contrast resolution is improved
c. weak echoes are not imaged
d. Temporal resolution is reduced
a
When the fundamental frequency is filtered out, which of the following occurs?
a. pixel interpolation
b. harmonic frequencies
c. spatial compounding
d. volume imaging
b
Which imaging technique is most likely to visualize a structure beneath a calcification?
a. pixel interpolation
b. panoramic imaging
c. harmonic imaging
d. spatial compounding
d
Which of the following constitutes a reception channel?
a. beam former, signal processor, image processor, and display
b. Beam former, pulser, amplifier, and scan converter
c. Elements, pulser, signal processor, and delay path
d. elements, amplifier, digitizer, and delay path
d
Which of the following digitally filters, detects, and compresses echo data?
a. digitizer
b. summer
c. signal processor
d. beam former
c
Which of the following is not an advantage of harmonic imaging>
a. increased lateral resolution
b. reduction in superficial reverberation artifacts
c. elimination of grating lobe artifacts
d. wide primary beam
d
Which of the following operator controls adjusts compression?
a. depth
b. time gain compensation
c. dynamic range
d. overall gain
c
Which of the following reformats data into image form for processing, storage, and display?
a. summer
b. digitizer
c. signal processor
d. beam former
b
Which of the following techniques is considered the imaging version of palpation?
a. elastography
b. panoramic imaging
c. pixel interpolation
d. volume imaging
a
Which system component produces the electrical voltages that drive the transducer?
pulser
Which system control equalizes amplitudes by different reflector depths?
time gain compensation
_____ determines how echo data stored in memory appear on the display.
postprocessing
A duplication artifact associated with echoes interacting with a strong reflector is called ____
mirror-image
A reduction in echo amplitude from reflectors behing a strongly reflecting structure is called ____.
shadowing
Aliasing does not occur in _____.
continuous wave Doppler
Axial resolution is determined by _____ and lateral resolution is determined by _____.
pulse length; pulse width
Clutter is also known as ____.
flash
Echo reflections that produce bright and dark spots in the gray-scale image are called ______.
speckle
Edge shadowing is a result of
refraction of the sound beam
Edge shadowing is caused by
refraction
Enhancement of an echo results from a structure having _____ than surrounding structures
lower attenuation
Equally spaced reflections that decrease in amplitude with increases in depth describe ____.
reverberation