What is a radiographic film cassette?
2. Introduction A radiographic film cassette is a rectangle or square plastic or metallic container used to hold x-ray films (exposed or unexposed) and intensifying screens in close and uniform contact with one another.4-4-2011 RADIOGRAPHIC CASSETTES BY SUDIL 2 3. Functions1. Hold intensifying screens and protect them from damage.2.
What is the difference between CR and conventional radiography cassettes?
In case of conventional radiography, two screens are mounted on each side of the cassette, except in mammography, where a single screen is mounted on the back side. These cassettes have to loaded with film in the darkroom unlike the cassettes used in CR which can be loaded with imaging plate in the light.
What is the back side of the cassette made of?
The back side of the cassette has a rubber or felt for adequate contact between screen film system or with the imaging plate. The front is made of low atomic number material (e.g. plastic or carbon) and the back is made of high atomic number material (e.g. lead) to reduce backscatter.
What is photo fluorography cassette?
Photo fluorography cassette Photo fluorography or the recording of images from output phosphor of an image intensifier tube is usually carried out on 70 mm or 105 mm roll film or on 100 mm sheet film. All the above various film formats have their individual cassette system.4-4-2011 RADIOGRAPHIC CASSETTES BY SUDIL 28 29.
What is radiography cassette?
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.
What is a radiographic cassette and what are its functions?
An X-ray cassette is a light-resistant container that protects the film from exposure to daylight, holds the film between two intensifying screens and allows the passage of X-rays through the front cover on to the film.
What is a cassette film?
The film cassette contains film that is adjacent to fluorescent screens. When the x-rays reach the film cassette, a photochemical interaction occurs between the x-rays and the screen coated with fluorescent particles. The x-rays activate the fluorescent particles to emit light rays.
What is a cassette in darkroom term?
When an x-ray is taken, the films are exposed in a cassette, which is a type of metal or plastic envelope. Inside the closed cassette, the films are safe from visible light but can be exposed to x-rays. The cassette should only be opened in the darkroom under the safelights.
What is the function of a cassette?
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. See also audiocassette, videocassette.
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.
What are film cassettes made of?
Cassette tapes are made of a polyester-type plastic film with a magnetic coating. The original magnetic material was based on gamma ferric oxide (Fe2O3).
Is a cassette and image receptor the same?
An image receptor may be a radiographic film and cassette, a phosphorescent screen (used in fluoroscopy or computed radiography), or a special detector placed in a table or a bucky (used in direct digital radiography).
What is film in radiography?
X-ray films for general radiography consist of an emulsion-gelatin containing radiation sensitive silver halide crystals, such as silver bromide or silver chloride, and a flexible, transparent, blue-tinted base.
What are the components of darkroom?
The essential components of a darkroom are a stable, flat, level place for your enlarger to sit and a platform, preferably a sink, for holding your trays for processing your prints. While a large, deep sink is ideal, a table or countertop is adequate as long as there is nearby access to running water.
What is safelight in radiology?
Darkroom safelights provide working light in a darkroom so clinicians or technicians can see while developing x-ray films. These lights are designed to provide light in wavelengths that will not expose the x-ray film or impact the development process.
How do I know what kind of cassette I have?
Stick with a Type I or Type II tape. The 4 notches found at the top of a metal cassette are the easiest way to identify the tape type. The notches on the outside of the tape tell the cassette deck to use the bias of a Type II tape. The notches on the inside of the cassette tell the player to push the bias even further!
What is intensifying screens 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 meant by intensifying screen?
Intensifying screens intensify the effect of the X-ray beam energy on the film by energy conversion. Some X-ray energy is absorbed by the screen and re-emitted as u. v. and visible light energy (Figure 5.1), to which the film has a greater sensitivity, thus producing a greater film response.
What is a film in radiography?
Terms & Definitions. Film Radiography (RT) A form of radiographic imaging, where photographic film is. exposed to radiation transmitted through an item being inspected, and light or radioactive rays, an invisible image (called a latent image) and a latent image is formed in the emulsion layer of the film.
What are the criteria for the selection of cassette before performing a radiographic exposure?
The criteria for an effective cassette include: Light in weight, yet robust and durable. Rounded corners. Provides intimate contact between film and intensifying screen.
What is a cassette in radiography?
Cassette. 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.
How many screens are there in a radiography cassette?
In the case of conventional radiography, two screens are mounted, one on each side of the cassette, except in mammography, where a single screen is mounted on the back side. These cassettes have to be loaded with film in the darkroom unlike the cassettes used in CR which can be loaded with a imaging plate in the light.
What material is the front of a cassette made of?
The front of the cassette is made of a low atomic number material (e.g. plastic or carbon) to enable ease in passage of x-rays and the back is made of a high atomic number material (e.g. lead) to reduce backscatter.
What is the back of a screen film cassette?
The back side of the cassette has rubber or felt for adequate contact between the screen film system or with the imaging plate. The front of the cassette is made of a low atomic number material (e.g. plastic or carbon) to enable ease in passage of x-rays and the back is made of a high atomic number material (e.g. lead) to reduce backscatter.
Can you use a cassette in digital radiography?
No cassette is used in digital radiography.
What is radiographic film?
Radiographic film is composed of a film base with an active emulsion layer adhered using a subbing layer, with a protective super-coat.
What is the process of producing an X-ray image?
The production of an X-ray image depends upon the existence of materials that are unstable and, when exposed to light or electromagnetic radiation, change their nature. Halogens such as bromine or iodine are combined with silver to produce silver bromide or silver idobromide.
How to extend sensitivity of film emulsion?
During the manufacturing process the inherent sensitivity of the emulsion can be extended to other wavelengths by adding a suitable dye, usually to the surface of the crystal. The spectral sensitivity of the film emulsion can be arranged to fall into one of three categories: monochromatic, orthochromatic and panchromatic.
Why are radiographic images blurry?
No radiographic image is truly sharp and all images are to some extent blurred as a result of imperfections within the imaging system itself.
How is latent image converted into permanent visible image?
The latent image is converted into a permanent visible image through the use of developer and fixer. The chemicals used in processing should be replenished and replaced on a regular basis. Maintenance and quality assurance are essential to maintain high quality diagnostic images.
Can wet film be used to produce a visible image?
Within the imaging department the use of automatic wet film processors to produce a visible image on a conventional film, which is exposed to light originating from intensifying screens held within a cassette, is declining. However, films exposed to a combination of light and X-radiation, using screen film, or directly to X-radiation alone using direct-exposure film, may still be encountered.
