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contrast factors
Radiographic contrast and Density
Question | Answer |
---|---|
What is the controlling factor for subject contrast? | kilovoltage |
The Function of contrast on the radiographic image is to | Make detail visible |
Even though mentioned as a factor, why would kVp be a poor choice to control radiographic density? | Changes the scale of contrast |
How much must mAs be increased before a noticeable change can be seen with the human eye? | 30% |
Of the following factors: SID, OID and Focal spot size, which has the greatest affect on density? | SID |
Adjustment of the mA controls the: | Quantity of xrays produced |
Of the following factors, which will have the GREATEST affect on contrast. kVp, mAs, time or SID? | kVp |
Of the factors listed below, the easiest to penetrate is Fat,Muscle,Gas/Air,Cartilage,Bone | Gas/Air |
In what way would the air gap technique affect radiographic contrast | Increase contrast |
Of the following statements, which is true? High kVp = High contrast High kVp = Low contrast High kVp = Short scale contrast High kVp = Low density High kVp = Increased patient dose | High kVp = Low contrast |
Which of the following sets of factors will produce the highest contrast? 50mA @ 3/4 sec@ 50kVP 100mA@ 1/4 sec@ 70kVp 150mA @ .50 sec @ 80 kVp 200mA @ .70 sec@ 120kVP 200mA @ 3/4 sec @ 120kVP | 50mA @ 3/4 sec@ 50kVP |
Long wavelength radiation will produce a image with | High contrast |
When detail in radiograph cannot be displayed due to insufficient radiographic density the radiograph is said to be: | Underexposed |
mAs is obtained by: | Multiplying the mA by the time |
Short scale contrast can be described as: | An image with high contrast |
Scatter radiation can destroy the quality of the image. The chief way to control this problem is by decreasing | kVp |
High kVp yields an x-ray beam of: | Short wavelength |
The degree of blackening of an image is dependent on all factors in this list EXCEPT one. Which is not a density factor? | mAs, kVp, Focal spot size, Speed of the image receptor ,Photon energy reaching the image receptor |
Long scale contrast can be changed to short scale contrast by: | Decreasing the kilovoltage |
When needed, you can decrease you mAs by half, if you increase kVp by: | 15% |
Density on a radiographic image is: | Overall blackness of the image |
The primary function of mAs is: | Regulate density |
When the mA is changed from 300 to 600, what affect will this have on density? | Increase density |
An addition of a beam restrictor to reduce the field size to 3” would increase: | Contrast |
Adding 10 kVp to an exposure, would decrease | Contrast |
Scatter radiation affecting the radiographic image would be increasing: kVp, Grid ratio,Filtration or mA? | kVp |
A large number of grey densities of varying tonal values is said to possess: | Long scale contrast |