1.
Cassette selection for CR images is more critical than: screen-film images
2.
CR images are displayed in a matrix of: pixels, and the pixel size is an important factor in determining the resolution of the displayed image
3.
CR reader scans the IP at a relatively constant frequency,: about 2000 x 2000 pixels
4.
Exposures should not be repeated in: DR because of brightness or contrast concerns
Overexposed images do not have to be repeated and should not become a habit
5.
Grid frequency: Number of grid lines per centimeter or per inch
6.
Grid ratio: The relationship between the height of the lead strips and the space between the lead strips
7.
Grid selection will depend on: Part size
kVp desired
Scatter cleanup desired
Grid frequency (lines per inch or cm)
8.
Grid use in CR occurs more often due to the: sensitivity of the IP to scatter
9.
high resolution cassets are most comonly used for: Most often used for extremities mammography and other exams requiring increased detail
10.
How many shades of grey can screen-film image display on a view box?: 30
11.
Image density/brightness on the display monitor is controlled by: winder leveling
12.
Image size on hardcopy and softcopy is affected by: cassette selection
13.
Manufacturers produce two types of imaging plates: Standard
High Resolution
14.
mAs no longer controls density: in digital
15.
Moiré effect/pattern: Occurs if the scan laser and grid lines are parallel.
A wavy artifact pattern occurs when the grid lines and the scanning laser are parallel
16.
Most grids chosen by departments are: are parallel and focused
17.
Parallel grids are less critical in beam centering but should not be used at distances less than !slide 96!: 48 inches
18.
Practitioners have the opportunity to reduce patient dose by: 20% to 50%, depending on the exam
19.
Proper image plate selection helps eliminate: scatter outside the initial collimation and increases image resolution.
20.
Quantum mottle or quantum noise occurs when: an insufficient light is produced and the image is grainy
21.
The closer the grid frequency is to the laser scanning frequency,: the greater the likelihood of frequency harmonics or matching and the more likely the risk of moiré effect
22.
The higher the frequency,: the finer the grid lines in the image and the less they interfere with the image
23.
the higher the grid ratio: the more scatter radiation absorbed and the more critical the positioning. not a good idea for modile radiography.
24.
The smaller the cassette being used, the higher the: sampling rate ...
25.
Two important factors should be considered when selecting the CR Imaging cassette: Type
Size
26.
Typically grid frequency is between: 80-152 lines/in
27.
Using the smallest imaging plate possible for each examination results in the: highest sampling rate
28.
What is a key factor for penetration and the type and amount of contrast desired?: kVp
29.
What is critical in determining proper digital image receptor exposure?: mAs
30.
What is the optimum kVp range for CR?: 60kVp to 110kVp
31.
What two important factors should be considered when selecting a CR Imaging cassette?: type and size
32.
with cassettes 10x12 or smaller it's important to select a: high frequency grid to eliminate scatter
