-
4 EXPOSURE FACTORS
- kVp,
- mA,
- exposure time,
- and (SID).
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List the four patient factors and explain their effects on radiographic technique.
- Composition
- Thickness
- Pathology
-
Identify four image-quality factors
- OD,
- contrast,
- image detail,
- and distortion
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Optical density is
he degree of blackening of the finished radiograph
-
Optical density can be controlled in radiography by two major factors:
mAs and SID
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Detail describes the
sharpness of appearance of small structures on the radiograph
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radiographic density is
The amount of overall blackening of a radiographic image
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When a film is exposed, _____ halide crystals are converted to ____ metallic silver.
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The latent image is the _____ Image on ______ film, consisting of ______ ions from the interaction with x-rays
- (invisible)
- exposed
- silver
-
A radiograph that appears too dark is said to be overexposed
overexposed
-
Densitometer
: An instrument that measures film blackness
-
Which imaging system has a linear exposure relationship
Film/Screen
Digital
or Both
Digital
-
Focal track :
The area of the anode where x-ray photons are produced by bombardment of electrons from the cathode
-
fat
muscle
water
bone
bone
-
which one has the lowest Atomic #
fats
water
muscle
bone
fats
-
Photoelectric effect absorbed or scattered
absorbed
-
compton effect absorbed or scattered
scattered
-
Fat has the ______ water content
Lowest
-
The primary problem with fat in terms of radiographic contrast is the _____ effect, not the tissue density, atomic number, or its ability to produce scatter.
layering
-
Muscle also has the____water content of the tissue groups.
highest
-
Grids act to _____contrast (higher contrast) by removing _____ before it exposes the image receptor.
- increase
- scatter radiation
-
(OID) or (SID) does have an effect on contrast
OID
-
There are two categories of contrast media to consider:
- negative contrast media
- positive contrast media,
-
negative contrast media is usually
(usually air)
-
Scatter radiation has what effect on contrast
increases
decreases
no effect
Decreases
-
a increase i developer time will have what effect on contrast
increase
decrease
none
decrease
-
Collimation will have what effect on contrast
increase
decrease
none
increase
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