Digital & Film Radiography Flashcards
What x-ray receptors are used in digital film?
- phosphor plate
- solid-state sensor
What x-ray receptors are used in film radiography?
- direct action film
- indirect action film
What size of phosphor plate receptors should be used for anterior periapicals?
Size 0
What size of phosphor plate receptors should be used for bitewings and posterior periapicals?
size 2
What size of phosphor plate receptors should be used for occlusal radiographs?
size 4
What do more pixels in digital radiography lead to?
better detail & higher resolution
What is the format of digital images used in medical fields?
DICOM
- digital imaging & communications in medicine
What software is used to manage digital radiographs?
PACS
What environmental factors will improve your experience of viewing digital radiographs?
- subdued lighting
- avoid glare
- have a monitor which is clean, adequately displays resolution, adjustable brightness level, suitable contrast level
What can be used to assess the resolution, contrast and brightness of monitors used to view digital radiographs?
SMPTE test
What are the type of digital intra-oral receptors used in radiography?
- solid state sensors
- phosphor plates
How is an image created using phosphor plates in dental radiography?
- receptor exposed to x-ray beam
- phosphor crystals in receptor excited by the x-ray energy resulting in creation of a latent image
- receptor scanned by a laser
- laser energy causes the excited phosphor crystals to emit visible light
- light is detected and image created
What are the types of solid-state digital receptors?
- CCD (charge-coupled device)
- CMOS (complimentary metal oxide semiconductor)
How can the orientation of radiographs be aided?
identification dot located in corner of receptor
How do phosphor plates & solid-state senors differ?
Phosphor plates
- thinner, lighter & flexible
- wireless so more stable & comfortable
- variable room light sensitivity (BAD)
- latent image needs to be processed in scanner separately
- handling similar to film
Solid-state sensor
- bulkier & rigid
- usually wired
- smaller active area
- no issues with room light control (GOOD)
- arguably more durable
- more expensive
What is the purpose of the black paper located in an intra-oral film packet?
protects film from light exposure, damage by fingers & saliva
What is the active component in intra-oral dental film?
Silver halide crystals embedded in a gelatin binder
How does the speed of the film alter the radiation dose required?
increased speed —> lower radiation required to achieve an image
What are the common steps of film processing?
- developing
- washing
- fixing
- washing
- drying
What is the advantage of using self-developing film?
- no darkroom or processing facilities required
- faster
What are the disadvantages of using self-developing film?
- poorer image quality
- image deteriorates more rapidly over time
- no lead foil
- difficult to use
- expensive
What are potential causes for a pale image production in radiography?
- radiation exposure factors too low
- film removed from solution too early
- film solution too cold
- film solution too dilute/old
What is fixing in film radiography?
involves a chemical reaction which removes non-sensitised crystals and hardens the remaining emulsion
What can inadequate fixing of film radiography lead to?
- image greenish-yellow or milky
- image becomes brown over time
