What is cassette in radiography PPT?
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.
What is gridded cassette?
a light-proof housing for x-ray film and electrostatic imaging plates, containing front and back intensifying screens, between which the film is placed; a magazine for film or magnetic tape. grid cassette a cassette that has its front replaced by a built-in grid.
What is speed of film in radiography?
Most manufacturers provide three speeds of photographic film—200, 400, and 800. Changing from one speed film to a higher speed film will result in a 50 percent reduction of patient dose, e.g., going from 200 to 400 speed results in a 50 percent reduction of dose, as does going from 400 to 800 speed.
What are the 5 sizes of radiographic cassettes?
The formats of the cassettes used in conventional radiology are: 13 x 18 cm; 18 x 24 cm; 24 x 30 cm; 20 x 40 cm; 30 x 40 cm; 35 x 35 cm; 35 x 43 cm; 30 x 90 cm. No cassette is used in digital radiography.
What is the function of cassette in radiology?
Cassettes are used in association with intensifying screens and have related FUNCTIONS: 1. To contain a film 2. to exclude light, 3. to maintain the film in close, uniform contact with both screens during the exposure, 4. to protect the intensifying screens from physical damage.
What is grid xray?
An X-ray grid is the part of an X-ray machine that filters out randomly deflected radiation that can obscure or blur an image produced by the machine. It was invented in 1913.
What is cassette hatch?
The Cassette Hatch enables you to transfer cassettes from the X-ray room into the darkroom saving the darkroom from the incidence of daylight and X-ray radiation. Technical Data: Housing: powder-coated steel. Bottom: specially coated for. safety of cassettes.
What does kVp stand for in radiology?
Kilovoltage peak (kVp) is the peak potential applied to the x-ray tube, which accelerates electrons from the cathode to the anode in radiography or computed tomography. Tube voltage, in turn, determines the quantity and quality of the photons generated.
What is low kV technique in radiography?
The low kV image has superior contrast because of reduced levels of scatter. As the kV is reduced, the average photon energy is reduced; accordingly, the proportion of photoelectric interactions increases and the proportion of scatter events is reduced.
What is labial mounting?
Current convention is that all dental radiographs are mounted/interpreted with “labial mounting”. This means that the film is viewed from the outside in. Imagine that your eyes are in the same position that the X-ray tube was in when the film was taken.
Which is the fastest film speed?
The film typically used for the intraoral bitewing exam falls into three film speed classes – D (slowest), E and F-speed (fastest). Like photographic film, the faster the film, the less exposure it needs.
What is the size of a radiology cassette?
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. The formats of the cassettes used in conventional radiology are: 13 x 18 cm; 18 x 24 cm; 24 x 30 cm; 20 x 40 cm; 30 x 40 cm; 35 x 35 cm; 35 x 43 cm; 30 x 90 cm.
What are the specs of a 9-speed cassette?
H92 9-speed cassettes are nickel plated for durability, and constructed using the same processes as microSHIFT’s higher end cassettes, resulting in rapid … read more Must use 9-speed chain. Reduced cog spacing: 9-speed is same overall width as 8-speed. Speeds: 9. Cassette Cogs: 12,3,4,5,6,7,9,21,23.
How do I know what size cassette to get?
Depending on what exactly you are looking for, you might want to look up a document for a specific cassette as the numbers might be slightly different. *These chain widths are the standard widths, which I assume are recommended. I wouldn’t go wider, but a narrower chain will probably work as some chains are cross-compatible.
What is the difference between a 9-speed and a 10-speed?
8 speed – 7.1mm (all brands) 9 speed – 6.6 to 6.8mm (all brands) 10 speed – 6.2mm (Shimano, Campagnolo) 10 speed (Narrow, Direction) – 5.88mm (Shimano CN-5700,CN-6700,CN-7900)