What is an intensifying screen in radiography?
Intensifying screens are used in the x-ray cassette to intensify the effect of the x-ray photon by producing a larger number of light photons. It decreases the mAs required to produce a particular density and hence decreases the patient dose significantly.
What is the purpose of intensifying screens?
Intensifying screens are used to shorten exposure times and, some- times, to increase the photographic contrast. Considering that roentgen radiation was discovered through its fluorescent action (on barium plati- nocyanide), it is not strange that roentgen diagnostics very soon found a use for intensifying screens.
What are the four basic components of an intensifying screen?
An intensifying screen consists of a protective coating, a phosphor layer, an undercoating layer, and a base layer (Fig. 1-32).
Why are two intensifying screens placed in the radiographic screen?
The receptor used for most radiographic procedures contains two intensifying screens mounted on each side of double-emulsion film. Using two screens in this manner increases x-ray absorption and receptor sensitivity with the least amount of image blurring.
What is cassette in radiography?
Cassettes are rigid holders used in conventional and computed radiography (CR) for the screen film system and imaging plate respectively. The back side of the cassette has rubber or felt for adequate contact between the screen film system or with the imaging plate.
Where are the intensifying screens attached to?
Intensifying screens are attached to one or both inside panels of the cassette. Screens “amplify” the effect that x-ray photons have on the x-ray film. When an incoming x-ray photon interacts with phosphor crystals contained in an intensifying screen, light is emitted.
Which of the following types of intensifying screens are used in industrial radiography?
Types of Radiographic Intensifying Screens As previously discussed, the common types of industrial intensifying screens are lead screens, fluorescent screens, and fluorometallic screens.
What is the active layer in an intensifying screen?
INTENSIFYING SCREENS PHOSPHOR LAYER • The active layer of the screen is the phosphors. • The phosphors emit light when stimulated by x-rays.
Who was the first to demonstrate the use of radiographic intensifying screens?
Max Levy (Germany) was apparently the first to recommend and use, in 1897, a double-coated film between two intensifying screens.
What is the purpose of cassette?
Also called cassette tape . a compact case containing a length of magnetic tape that runs between two small reels: used for recording or playback of audio or video in a tape recorder, cassette deck, video camera, or VCR, and for storage of data by some small computer systems.
How many types of cassettes are there?
Since then, the four cassette tape types were known as IEC I, IEC II, IEC III and IEC IV. The numerals follow historic sequence in which these types were commercialized, and do not imply their relative quality or intended purpose.
What is an intensifying screen made of?
An intensifying screen is a plastic sheet coated with fluorescent material called phosphors. Phosphors are materials which convert photon energy to light. LUMINESCENCE is the emission of light from a substance bombarded by radiation.