When referring to digital imaging, what does the term digital mean?
Using numbers to compute images
. Computers operate using a binary machine language.
Why do backs of cassettes contain lead?
The back of the cassette may also be made of metal or plastic. Inside the back is a layer of lead foil. The purpose of this
layer is to prevent backscatter
. … When the film is placed in the cassette, it is sandwiched between the intensifying screens.
Which of the following is a universal standard that allows various digital imaging devices to work together within a network no matter who the manufacturer?
| Question Answer | What is the unit of radiation exposure in air Roentgen | 266. What is the universal standard that allows various digital imaging devices to work together no matter the manufacturer DICOM | 267 . What is the voltage supplied to the auto transformer Line voltage |
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Which of the following is an advantage of digital imaging over film screen imaging?
1-
Lower dose of radiation required as both
types of digital image receptors are much more efficient at recording photon energy than conventional films. 2- No need for conventional processing, thus avoiding all processing film faults and the hazards associated with handling the chemical solutions.
What determines grayscale in digital imaging?
BIT DEPTH is determined by the number of bits used to define each pixel.
The greater the bit depth, the greater
the number of tones (grayscale or color) that can be represented. Digital images may be produced in black and white (bitonal), grayscale, or color.
Which of the following is a disadvantage of computed radiography CR )?
| CR DR | More portable Less portable unless newer wireless systems used | More flexible positioning and sizes Difficult to acquire awkward views | Higher risk of overexposure Lower risk of overexposure | Suitable for low or moderate workflow Ideal for high workflow |
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Why is contrast needed in a radiographic image quizlet?
As contrast lowers, how is the number of densities in an image affected? Lower contrast means a
longer scale of contrast
. Scale of contrast refers to the number of different densities seen in the radiograph. A long scale means there are several densities visible.
What is the purpose of intensifying screens?
Intensifying screens are used
to shorten exposure times and, some- times, to increase the photographic contrast
. Considering that roentgen radiation was discovered through its fluorescent action (on barium plati- nocyanide), it is not strange that roentgen diagnostics very soon found a use for intensifying screens.
What is the function of the cassette?
Cassettes are used in association with intensifying screens and have related FUNCTIONS: 1.
To contain a film 2
. to exclude light, 3. to maintain the film in close, uniform contact with both screens during the exposure, 4. to protect the intensifying screens from physical damage.
What size cassettes are the most commonly used to take radiographic images?
The formats of the cassettes used in conventional radiology are:
13 x 18 cm
; 18 x 24 cm; 24 x 30 cm; 20 x 40 cm; 30 x 40 cm; 35 x 35 cm; 35 x 43 cm; 30 x 90 cm. No cassette is used in digital radiography.
What is the purpose of using digital imaging?
THE PURPOSE OF digital image processing is threefold;
to improve the appearance of a image to a human observer, to extract from an image quantitative information that is not readily apparent to the eye, and to calibrate an image in photometric or geometric terms
. Image processing is an art as well as a science.
What is the importance of digital imaging?
Better Images – Digital Imaging also
provides a higher resolution image than film radiography
, allowing the image to be magnified or manipulated after processing. This can allow Doctors to get a better look at anatomical features they might not see on traditional film.
Which of the following is an advantage of digital imaging group of answer choices?
| Question Answer | Advantages of digital radiography… superior gray-scale resolution, reduced exposure to x-radiation , increased speed of image viewing, lower equipment and film cost, increased efficiency, enhancement of diagnostic image, effective patient education tool |
|---|
How many shades of grey can the human eye recognize in a digital image?
The human eye can discern
more than 720 shades
of gray, approximately 9-10 bits. Contrast resolution is the ability to distinguish the differences between shades, and is difficult to define because each person is unique in their ability to see separate colors.
What is the grayscale mode?
Grayscale Mode is the latest feature in Android smartphones. The purpose of this mode is
to save the life of the battery
. It turns your device screen into white and black. Because of this mode, the elements of GPU renders only in these two colors instead of 32-bit color, which automatically consumes less power.
What is a grey level image?
A gray-level image f is
defined on a domain D included in the plan (or in the space for 3D images)
and takes its values (gray levels) in the gray scale . For 8-bits images, and the 256 gray levels are in the scale of integers [0, …, 255].
