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78 Cards in this Set
- Front
- Back
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If mas increases, density/ir exposure _____ |
increases |
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If kVp decreases, density/ir exposure____
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decreases
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What happens to contrast if mAs is increased? |
It has no effect |
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If we increase Grid Ratio, what happens to density/ir exposure? |
It decreases |
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T or F: Film screen speed affects contrast and density |
false |
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Exposure/density maintenance formula
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mAs 1 Distance 1^2 _______ = _______________ mAs2 Distance 2^2 |
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Inverse square law |
Intensity 1 distance 2^2 ___________ = ______________ Intensity 2 distance 1^2 |
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Grid formula
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mAs 1 Grid factor 1
_______ = ____________________ mAs 2 Grid Factor 2 |
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Relative Film Screen Speed Conversion Formula
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mAs 1 RS 2
______ = _______ mAs 2 RS 1 |
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For every change in part thickness of 4-5cm, by what factor should the mAs be adjusted? |
By a factor of 2 |
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What is the Grid Conversion factor for no Grid? |
1 |
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What is the grid conversion factor for a 5:1 Grid? |
3 |
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What is the grid conversion factor for an 8:1 grid? |
4 |
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What is the grid conversion factor for an 12:1 grid? |
5 |
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What is the grid conversion factor for an 16:1 grid? |
6 |
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When increasing kVp by 15%, what do you divide the original mAs by? |
2 |
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States that the intensity of the xray beam is inversely proportional to the square distance from the source |
Inverse Square Law |
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T or F: OID has a greater effect on contrast and sharpness |
True |
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T or F: The more sensitive the film-screen system is to radiation, the faster the speed |
True |
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Increasing the film-screen speed requires a ____ in mAs to maintain density |
Decrease |
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T or F: The more efficient the output of the generator, more exposure technique needed |
False |
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The degree of difference between adjacent densities/ir exposures |
Radiographic Contrast |
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Describes the concept of contrast for the soft copy on the monitor |
Dynamic Range |
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T or F: A foot xray should have high contrast |
True |
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High Contrast: _____ Scale |
Short |
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What are some characteristics of low contrast?
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More discernable shades of grey
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T or F: Higher kVp, less absorption, low contrast, long scale |
True |
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If using a high-frequency x-ray generator, which of the following will have the greatest effect on increasing exposure? a. 15% increase in kVp b. 25% increase in SID c. 50% increase in mAs d. 75% increase in grid ratio |
A. 15% increase in kVp |
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If the SID is halved, which of the following changes must be made in order to maintain the same exposure? a. mAs halved b. mAs reduced by 4x c. mAs doubled d. mAs increase by 4x |
b. mAs reducedby 4x |
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If the mAs is 30 and the time is .1s, the mA setting must be what? |
300mA |
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How much mAs will be generated if the control panel is set at 200 mA and 1/5 second? |
40mA |
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A radiographic technique of 300mA, 1/10 second and 60 kVp is to be changed to 69kVp, what would the new time be? |
1/20 second |
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How much must the mAs be increased when changing from no grid to an 8:1 grid?
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4x |
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If the mA is set at 400 and the mAs obtained is 80, what must the time be set at? |
.2 second |
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in order to maintain the same exposure to the image receptor, if a technique of 200mA, .2s and 70kVp is changed to .1s, what is the new kVp? |
80kVp |
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If 60 mAs is obtained and the time setting was .2s, the mA must have been set at what? |
300mA |
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A technique of 150mA, 3/20 s and 100 kVp could be change d to 300 mA, ___ s and 85 kVp. |
3/20s |
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When going from a 16:1 grid to a 6:1 grid, how must the mAs be adjusted? |
Reduced by 1/2 |
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Time can be decreased by 1/2 if the kVp is increased by what percentage? |
15% |
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How many milliseconds are in 0.05 seconds? |
50 |
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An exposure with a 12:1 grid requires 40mAs, how much should be used if no grid was used? |
8mAs |
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A technique of 400 mA, .25s, non-grid could be converted to a techique of 200mA with an 8:1 grid at ___ seconds. |
2 |
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If motion is a problem, and 50 mAs is needed, which of the following mA stations should be selected? A. 100 B. 200 C. 400 D. 800 |
D. 800 |
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How can the fraction 1/5 be written in decimal form? |
.20 |
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If 60 mAs provides optimum density with 100 speed screen, how much mAs is needed with 200 speed screens? |
30mAs |
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Which of these sets of technical factors will produce an image with the longest scale of contrast? a. 50mA, 1 second, 70 kVp b. 100mA, .5s, 80kVp c. 200mA, .25s, 90kVp d. All are equal |
C.200mA, .25s, 90kVp |
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Which of the following techniques will produce the greatest image receptor exposure? a. 100mA, .5s, 80kVp b. 200mA, .5s, 70kVp c. 300mA, .33, 80kVp d. 400mA, .25s, 70kVp |
c. 300mA, .33, 80kVp |
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Which of the following techniques will produce the greatest image receptor exposure?
a. 50mAs, 70 kVp, 40" b. 100mAs, 70kvp, 40" c. 100mAs, 70 kVp, 80" d. 100mAs, 80kVp, 80" |
b. 100mAs, 70kvp, 40" |
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Which of the following techniques will produce the highest contrast? a. 50 mAs, 80 kVp, 5:1grid b. 100mAs, 70 kVp, 8:1 grid c. 100mAs, 80kVp, 8:1 grid d. 200mAs, 70kVp, 5:1 grid |
b. 100mAs, 70 kVp, 8:1 grid |
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Which of the following screen speeds will produce the greatest density on a radiograph? a.50 b.100 c.200 d.400 |
d. 400 |
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A light radiograph may be caused by which of the following 1. grid cut-off 2. sid too low 3. grid ratio too low
a. 1 only b. 2 only c. 3 only d. 1 & 3 only |
a.1 only |
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Luminance refers to the brightness of the light emitted from an image display monitor. What are the SI units for luminance? a. Joules per volt b. Candela per meter squared c. Coulombs per meter squared d. Newtons per watt |
B. Candela per meter squared |
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The brightness of a digital image affects which of the following? a. Sharpness of detail b. visibility of detail c. distortion d. exposure |
b. visibility of detail |
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How will the use of radiographic grids affect the contrast of an image? |
Produce higher contrast |
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Which of the following factors would be used to control contrast in a film-screen system? A. mAs B. kVp C. SID D. OID |
b. kVp |
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Which of the following controls contrast in a digital system? a. look-up table b. histogram c. high frequency laser d. analog-to-digital converter |
a. look-up table |
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When using iodinated contrast agents and high-frequency x-ray equipment, the kVp should not exceed what? |
80 kVp |
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Which of the following affect subject contrast? 1. part thickness 2. kVp 3. Part density
a. 1 and 2 only b. 1 and 3 only c. 2 and 3 only d. 1, 2, & 3 |
D. 1, 2, &3 |
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Which of the following directly influences radiographic contrast? a. mA b. SID c. Grid Ratio d. Exposure time |
c. Grid Ratio |
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Low energy radation will result in which of the following? a. short scale of contrast b. medium scale of contrast c. long scale of contrast d. low scale of contrast |
a. short scale of contrast |
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How will high kVp techniques affect radiographic contrast? |
produce lower contrast |
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The quality of an x-ray beam is determined by which of the following? a. mAs b. kVp c. SID d. Focal spot size |
b. kVp |
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What is the greatest advantage of digital imaging? |
Contrast resolution |
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Which of the following grid ratios should be used to maintain contrast when using over 100 kVp? a. 5:1 b. 6:1 c. 8:1 d. 12:1 |
D. 12:1 |
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How would an image with just a few, wide density differences be described?
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High Contrast |
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Which of the following techniques will produce a radiograph with the highest contrast? a. 50mAs, 50 kVp b. 30mAs, 60kVp c. 15mAs, 70kVp d. 10mAs, 80kVp |
a. 50mAs, 50 kVp |
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Which of the following describes a short scale of contrast? a. High Contrast b. Low Contrast c. low number of density differences d. Greater film latitude |
a. High Contrast |
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Which of the following will have the greatest effect on radiographic contrast?
a. tube filtration b. close collimation c. focal spot size d. reducing scatter radiation |
d. reducing scatter radiation
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Why is contrast needed in a radiographic image? 1. makes detail visible 2. decreases sharpness of detail 3. decreases need for distortion
a. 1 only b. 2 only c. 3 only d. 1 and 2 only |
a. 1 only |
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Which of the following will produce a longer scale of contrast? a. increasing mAs b. increasing kVp c. increasing grid ratio d. increasing SID |
b. increasing kVp |
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Scatter radiation will have the greatest effect on which of these radiographic qualities? a. recorded detail b. density c. contrast d. distortion |
c. contrast |
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Which of the following statements is true? a. high kVp, high contrast b. high kVp, low contrast c. high kVp, short scale d. high kVp, low density/brightness |
b. high kVp, low contrast |
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Which of the following radiographic procedures requires a long scale of contrast? a. lumbar spine b. chest c. myelography d. angiography |
b. chest |
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Which of the following would not be used as contrast media in radiography? a. air b. saline c. barium sulfate d. sodium iodide |
b. saline |
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Which of the following determines the visibility of detail in a film-screen radiograph? a. density and distortion b. contrast and recorded detail c. density and contrast d. density, contrast, and recorded detail |
c. density and contrast |
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How will an air gap technique affect radiographic contrast? a. produce higher contrast b. produce lower contrast c. eliminate contrast d. have no effect on contrast |
a. produce higher contrast |
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Which of the following describes a long scale of contrast? a. high contrast b. low contrast c. less film latitude d. low number of density differences |
b. low contrast |
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How will an increase in radiographic fog affect contrast? a. contrast will be higher b. contrast will be lower c. contrast will be eliminated d. contrast will remain the same |
b. contrast will be lower |
