Davies Ultrasound Part2 Exam 2026
Questions and Answers
***What system control converts the numbers stored in memory to proportional
voltage that control the brightness on a CRT (cathode ray tube) monitor? - Correct
answer-Digital to analog converter
For display, the numbers stored in memory must be converted to proportional
voltages to drive the brightness of the monitor. Monitors are digital in modern
ultrasound equipment
A digital scan converter is another name for what system component? - Correct
answer-Image memory
What control allows the user to freeze and then scroll back thru the most recently
acquired image frames? - Correct answer-Cineloop
A group of 8 bits is called: - Correct answer-Byte
Where are the images stored in the ultrasound system? - Correct answer-Scan
converter
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,What is the maximum number of shades of gray in an 8 bit digital scan converter?
- Correct answer-256
An 8 bit system produces a maximum of 2 to the 8th power or 258 shades of gray.
A 4 bit system is capable of a maximum of 16 shades of gray, 5 bits-32 shades, etc.
The more bits, the greater the number of shades of gray.
The spatial resolution of the scan converter is determined by: - Correct answer-
Number of pixels in the scan converter matrix
A matrix of 512 x 512 pixels is capable of must better spatial resolution than a
similarly size matrix containing only 64 x 64 pixels. In the latter example, the
image would appear blocky w discrete square-shaped segments. Image resolution
would be degraded. The more pixels in the scan converter matrix, the greater the
spatial resolution
What system component is most responsible for transmit focusing? - Correct
answer-Beam former
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,Specifically, the transmit beam former, which introduces time delays into the
excitation pulse sequence applied to the elements
How many levels of information can a single bit represent? - Correct answer-Two
A single bit can represent only 2 values, on and off. The earliest ultrasound systems
showed only 1 bit of info.
The picture elements in a scan converter matrix are termed? - Correct answer-
Pixels
Digital to analog conversion of the ultrasound signal must occur at what part of the
imaging process? - Correct answer-Between the scan converter and the display
In the scan converter, interpolation is performed to: - Correct answer-Fill in the
empty pixels that occur between acoustic scan lines
Interpolation is necessary bc there is not data available for all pixels in the scan
converter matrix. As the line density i the ultrasound image is decreased, more
interpolation becomes necessary to fill in the image is decreased, more
interpolation becomes necessary to fill in the empty spaces. Although there are alot
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, of different interpolation schemes used by different manufacturers, in general the
empty pixels are filled in w a value that is averaged between adjacent pixels.
Without interpolation, which of the following would best describe the resultant B
mode image? - Correct answer-A series of scan lines w blank data between the
lines
Very early real time systems created images that looked like jail bars, in which the
scan lines were displayed but the space between each pair of scan lines were
displayed but the space between each pair of scan lines was left blank, Today,
interpolation of the data is used to fill in the blank spaces to make the image
appears smooth and continuous, even though it is still created by combining the
values from surrounding scan lines
What 3 colors are used on a color monitor to produce the range of available colors?
- Correct answer-Red, green and blue
These three colors are commonly referred to as the RBG signal
When you "freeze" the ultrasound image, where is the echo information stored? -
Correct answer-Scan converter
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Questions and Answers
***What system control converts the numbers stored in memory to proportional
voltage that control the brightness on a CRT (cathode ray tube) monitor? - Correct
answer-Digital to analog converter
For display, the numbers stored in memory must be converted to proportional
voltages to drive the brightness of the monitor. Monitors are digital in modern
ultrasound equipment
A digital scan converter is another name for what system component? - Correct
answer-Image memory
What control allows the user to freeze and then scroll back thru the most recently
acquired image frames? - Correct answer-Cineloop
A group of 8 bits is called: - Correct answer-Byte
Where are the images stored in the ultrasound system? - Correct answer-Scan
converter
©COPYRIGHT 2025, ALL RIGHTS RESERVED 1
,What is the maximum number of shades of gray in an 8 bit digital scan converter?
- Correct answer-256
An 8 bit system produces a maximum of 2 to the 8th power or 258 shades of gray.
A 4 bit system is capable of a maximum of 16 shades of gray, 5 bits-32 shades, etc.
The more bits, the greater the number of shades of gray.
The spatial resolution of the scan converter is determined by: - Correct answer-
Number of pixels in the scan converter matrix
A matrix of 512 x 512 pixels is capable of must better spatial resolution than a
similarly size matrix containing only 64 x 64 pixels. In the latter example, the
image would appear blocky w discrete square-shaped segments. Image resolution
would be degraded. The more pixels in the scan converter matrix, the greater the
spatial resolution
What system component is most responsible for transmit focusing? - Correct
answer-Beam former
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,Specifically, the transmit beam former, which introduces time delays into the
excitation pulse sequence applied to the elements
How many levels of information can a single bit represent? - Correct answer-Two
A single bit can represent only 2 values, on and off. The earliest ultrasound systems
showed only 1 bit of info.
The picture elements in a scan converter matrix are termed? - Correct answer-
Pixels
Digital to analog conversion of the ultrasound signal must occur at what part of the
imaging process? - Correct answer-Between the scan converter and the display
In the scan converter, interpolation is performed to: - Correct answer-Fill in the
empty pixels that occur between acoustic scan lines
Interpolation is necessary bc there is not data available for all pixels in the scan
converter matrix. As the line density i the ultrasound image is decreased, more
interpolation becomes necessary to fill in the image is decreased, more
interpolation becomes necessary to fill in the empty spaces. Although there are alot
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, of different interpolation schemes used by different manufacturers, in general the
empty pixels are filled in w a value that is averaged between adjacent pixels.
Without interpolation, which of the following would best describe the resultant B
mode image? - Correct answer-A series of scan lines w blank data between the
lines
Very early real time systems created images that looked like jail bars, in which the
scan lines were displayed but the space between each pair of scan lines were
displayed but the space between each pair of scan lines was left blank, Today,
interpolation of the data is used to fill in the blank spaces to make the image
appears smooth and continuous, even though it is still created by combining the
values from surrounding scan lines
What 3 colors are used on a color monitor to produce the range of available colors?
- Correct answer-Red, green and blue
These three colors are commonly referred to as the RBG signal
When you "freeze" the ultrasound image, where is the echo information stored? -
Correct answer-Scan converter
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