Ch. 6 Dental X-ray Image Characteristics

portion of an image that is dark or black

radiolucent

What is an example of a structure that usually appears most radiolucent in an x-ray?

air space

portion of an image that appears light or white

radiopaque

What is an example of a structure that usually appears the most radiopaque in an x-ray? 

amalgam

overall blackness or darkness or a dental image

density

What factors affect density?

kilovoltage, milliamperage, and exposure time

difference in the degrees of blackness between adjacent areas on an x-ray

contrast

What factors affect contrast?

ONLY kilovoltage

high contrast

many areas of black and white

short-scale contrast

What is short-scale contrast the best for detecting? 

caries

low contrast

many shades of gray

long-scale contrast

What is long-scale contrast the best for detecting?

periodontal disease and calculus detection

a device constructed of aluminum steps used to demonstrate short scale and long scale contrast

stepwedge

capability of a receptor to reproduce distinct outlines of an object

sharpness

unsharpness or blurring of edges of a structure on an image

penumbra

What are the three factors that affect image sharpness?

focal spot size, film composition, and movement

a radiographic image that appears larger than the actual size of object it represents

magnification

What factors affect magnification?

target-receptor distance and object receptor distance

variation in the true size and shape of the object being radiographed

distoration 

What occurs if your vertical angulation is too excessive?

foreshortening

What occurs if your vertical angulation is insufficient?

elongation