Diagnostic Film Rating
Lecture Chapter 4
Clinical Tip #4
A patient arrives in your chair, and tells you that his lower left molar has been keeping him up at night, hurting. However, he does not want a “x-ray” because his finances are scarce. It is important to let your patient know that the dentist, under the guidance from the Oregon Board of Dentistry, cannot diagnose the problem, or perform any treatment without a radiograph.
Definitions
ANSI film rating: desigrates film speed (sensitivity) by using letters A-F (A-slowest, F-fastest)
Characteristic curve: Film contrast is usually expressed in the slope of the line in the diagnostically useful part of the characteristic curve.
Cassette: A container for x-ray film that is light-tight yet permits penetration of x-rays.
Double …show more content…
The size of the silver bromide crystals is the main factor in film speed: The larger the crystals, the faster the film. Fast film equals less exposure to produce a desired density than a slow film. Film speed is designated by group from the American National Standards Institute (ANSI) using the letters A-F. F is the fastest film. D,E and F are the only film speeds that should be used. More sensitive films require fewer mAs are said to have greater film speed, these are fast films. Therefore, fewer mAs are needed for E-speed film than D-speed film. A double-film packet contains the same articles as a regular film packet, but has two films in it. After radiation and processing, two films are available for viewing. “X-ray film is composed of a clear cellulose acetate film base that is coated with an emulsion of silver halide (usually silver bromide) grains suspended in a layer of gelatin. The emulsion with its protective coating is attached to the acetate base by an adhesive” (Frommer, p.
Clinical Tip #4
A patient arrives in your chair, and tells you that his lower left molar has been keeping him up at night, hurting. However, he does not want a “x-ray” because his finances are scarce. It is important to let your patient know that the dentist, under the guidance from the Oregon Board of Dentistry, cannot diagnose the problem, or perform any treatment without a radiograph.
Definitions
ANSI film rating: desigrates film speed (sensitivity) by using letters A-F (A-slowest, F-fastest)
Characteristic curve: Film contrast is usually expressed in the slope of the line in the diagnostically useful part of the characteristic curve.
Cassette: A container for x-ray film that is light-tight yet permits penetration of x-rays.
Double …show more content…
The size of the silver bromide crystals is the main factor in film speed: The larger the crystals, the faster the film. Fast film equals less exposure to produce a desired density than a slow film. Film speed is designated by group from the American National Standards Institute (ANSI) using the letters A-F. F is the fastest film. D,E and F are the only film speeds that should be used. More sensitive films require fewer mAs are said to have greater film speed, these are fast films. Therefore, fewer mAs are needed for E-speed film than D-speed film. A double-film packet contains the same articles as a regular film packet, but has two films in it. After radiation and processing, two films are available for viewing. “X-ray film is composed of a clear cellulose acetate film base that is coated with an emulsion of silver halide (usually silver bromide) grains suspended in a layer of gelatin. The emulsion with its protective coating is attached to the acetate base by an adhesive” (Frommer, p.