Chapter 8
the stepwedge is used for
-demonstrate short-scale and long-scale contrast -to monitor quality control of film processing
the type of contrast preferred in dental imaging is:
a compromise between short-scale contrast and long-scale contrast
which appears most radiolucent on a dental image
air space
increasing the exposure time will cause
an increase in density; the image appears darker
increasing the milliamperage (mA) will cause
an increase in density; the image appears darker
increasing the operating kilovoltage (kV) will cause
an increase in density; the image appears darker
which appears most radiopaque on a dental image
bone, enamel, dentin
the difference in the degrees of densities between adjacent areas on a dental image is termed:
contrast
beam perpendicular to object and receptor=
decrease distortion
object and receptor are parallel =
decrease distortion
decrease object-receptor distance =
decrease magnification
increase target-receptor distance =
decrease magnification
increase crystal size =
decrease sharpness
increase movement =
decrease sharpness
the overall blackness or darkness of a dental image is the termed
density
a variation in the true size and shape of the object being imaged is termed:
distortion
a dental image that demonstrates very dark areas and very light areas is said to have:
high contrast
beam not perpendicular to object and receptor =
increase distortion
increase object-receptor distance =
increase magnification
decrease crystal size =
increase sharpness
decrease focal spot size =
increase sharpness
decrease movement =
increase sharpness
a dental patient has thick soft tissues and dense bones. To compensate for this increase in subject thickness and to provide an image of diagnostic density, the dental radiographer may:
increase the exposure time, increase the milliamperage, increase the kilovoltage
the one exposure factor that has a direct influence on the contrast of a dental image is
kilovoltage
a dental image that demonstrates many shades of gray is said to have:
low contrast
the geometric characteristic that refers to an image that appears larger than its actual size is termed
magnification
the unsharp or blurred edges seen on an image is termed
penumbra
the portion of a dental image that appears dark or black is termed
radiolucent
the portion of a dental image that appears light or white is termed
radiopaque
the capability of the receptor to reproduce distinct outlines of an object is termed
sharpness
