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NOTES
RADIOLOGY NOTES
Question | Answer |
---|---|
Adhesive | A thin coating applied to the base material before it is coated with the emulsion to prevent bubbles or other distortion during processing or handeling |
Antihalation Coating | A substance applied to the back of a single emulsion film designed to absorb light coming from the emulsion and preventing backscatter |
Base | The base material that the film is made from; it is usually polyester, tough, stable, rigid, and uniformly lucent; it usually contains a blue tint. |
Cathode Ray Tube Imaging (CRT) | A type of imaging that requires a film that is sensitive to the light emitted by the CRT; also called video imaging |
Coating | The phase of the film production process in which the adhesive layer is applied to the base, the emulsion and , finally the supercoat |
Contact Surgical Radiograpgy | A type of imaging which uses nonscreen film in sterilized packages. |
Crossover effect | Blurring of the image caused by light from one sreen crossing into the light from another screen. |
Crystal Production | The part of the film namufacturing process that must be done in total darkness silver nitrate and potassium bromide are combined in the prescence of gelatin' the silver bromide precipitates out and the potassium nitrate can be washed away as a waste |
Detail Extremity Radiograpgy | A type of imaging that uses fine grain films with slow speed screens |
Duplication Film | A type of film designed to provide an exact image of the original film |
Duplitized | Describes a film that is coated with emulsion of both sides |
Emulsion with Crystals | A gelatin in which photosensitive silver halide crystals are suspended. A very thin coating that acts as a neutral lucent suspension medium for the silver halide crystals to separate and allow chemical to interact with them |
Fluroscopic Spot Filming | A type of imaging that is done with 70 mm roll film or 105 mm roll film chips that are sensitive to green light |
Halation | An effect on radiographic image caused when light that is reflected from the air interfaces on the back of the base material |
Laser Film | A type of film that is directly exposed by the laser used in the imaging camera |
Mammography | X-ray examination of the breast |
Mixing | The period of film production in which the shredded emulsion is melted at a precise temprature to properly sensitize the crystals |
Orthochromatic | A film that is not sensitive to the red spectrum |
Panchromatic | A film that is sensitive to all colors |
Ripening | The period of film production during which silver halides are allowed to grow |
Sensitivity Speck | An impurity added to silver halide crystals to act as an electrode that attracts free silver ions during latent image formation |
Silver Bromide | Type of dilver halide crystal used to create X-ray films |
Silver Chloride | Type of silver halide crystal used to create X-ray films |
Silver Iodide | Type of silver halide crystal used to create X-ray films |
Silver Iodobromide | Type of silver halide crystal used to create X-ray films |
Supercoat | A layer of hard, proctective gelatin designed to prevent the soft emulsion underneath from being physically or chemically abused due to handeling |
Photosensitive film | used in radiography, the film responds to an exposure from photons of visible light and X-rays. |
T\F; It is possible to make film insensitive to portions of the spectrum | True |
What is the total thickness of radiographic film? | the total varies form 175-300 micrometers |
What are the layers in radiographic film? | Base, Adhesive layer, Emulsion, supercoat |
What is the modern base of radiographic film? | Polyester |
What is the usual thickness of the film base? | 150-200 mm |
What material was used as the first radiographic film base? | Glass plates with emulsion coating were used, but were difficult to maintain, exposure factors had to be very high, during WW1 a glass plating shortage |
What is Cellulose Nitrate? | a highly flammable material used as a base that started several devistating hospital fires in th 1920's and 1930's |
What is Cullulose Triacetate? | material used as a base in the 1920's, known as a safety base because it was not famable. Films would warp with age and not very resiliant |
When was the current base for radiogaphic film introduced? | 1960's by dupont |
What reduces eyestrain and increases diagnostic accuracy? | A blue tint |
What is a single emulsion film? | when emulsion is one one side of the film. the emulsion side is to be placed toward the intensifying screen. Emuslion side is dull |
What does the adhesive layer do? | allows for proper emuldion sidtribution over the base througout use and processing |
What is the "heart" of the film? | the emulsion layer that is composed of silver halide crystals that are suspended in gelatin |
What does the gelatin do? | allows an even distribution, it is radiolucent and non reactive. Has a low Z number |
What are the types of silver halide crystals | silver bromide, silver iodide, silver chloride |
T\F: a duplitized film is double emulsion or double coated | True |
the protective layer of gelatin is what? | the supercoat |
What is the purpose of the supercoat? | to provide protection form scratches, pressure, or contamination during storage, handeling, and processing |
What are the steps in film manufacturing? | crystal production, ripening, mixing, and coating |
T\F; The film manufacturing process does not matter if it is light or dark. | False; all must take place in total darkness |
What is the first step in silver halide crystal formation? | the pure metalic silver is dissolved into nitric acid |
What is the second step in silver halide crystal formation? | the silver nitrate is combined with potassuim bromide. this combination yields silver bromide and potassium nitrate which is a waste product |
What are the shapes of crystals? | Conventional and tabular |
What are the advantages of tabular crystals over conventional crystals? | tabular absorb more photons, they use a thinner emulsion, and it speeds up processing |
What substance is in the sensitivity speck that creates the imperfections in the crystals? | silver-gold-sulfide |
When is it appropriate to add "extra" ingrediants during film production? | during the mixing stage. adding dyes fungicide or bactericide, or antifogging agents that reduce the sensitivity to heat. |
What are the most common film sizes? | 8X10, 10X12, 11X14, and 14X17 |
What is the latent image? | the unseen image |
How many atoms does it take to make an image? | At least three |
What temprature should the film be stored at? | below 68 degrees F |
What does heat do to film? | reduces contrast and increases fog |
what is a safelight | an incandescent lamp with a color filter that provide sufficient illumination in the darkroom while ensuring the film remains unexposed |
When would you use a amber cover on the safelight? | for blue sensitive film |
When would you use a red filter on the safelight? | for green and blue sensitive film |
What are some special applications film? | Mammography, digital extremity radiography, contact surgical radiography, CRT imaging, Laser, duplication, and fluroscopic spot. |
What are the types of film? | Direct exposure film or nonscreen film, intensigying screen film, and special applications |
Direct-Exposure Film | used without intensifying screens, the emulsion is thicker, less sensitive to light, requires 10-100X's more radiation, used in 1970's for mammography |
What should be on the film? | date of exposure, full name of patient, name of instutition, and side markers |
What must be the humidity level of the storage room for film? | 30 - 60 % |