Xray - Outcome 5 Flashcards
(48 cards)
Automatic Processor - for Film
Automatic processor units can improve the efficiency and consistency of resulting radiographic images on traditional x-ray film. The radiographic images are transported through solutions, to a wash, and then finished at a dryer. A series of rollers are used to carry the films along and squeegee the solutions from the films between solutions. This reduces the contamination of one solution with anothe
How long does an automatic processor take?
Using an automatic unit, the total processing time, from developing to receiving the dried films, usually takes from 4 to 6 minutes depending on the manufacturer. This is achieved by using special processing chemistry at a higher temperature (80° to 95° F) and an internal dryer
Daylight loader - Automatic Processing
The automatic processing unit may be used in a traditional darkroom setting or in daylight if a daylight loader is attached to the unit. The daylight loader allows the films to be unwrapped and fed into the processor outside of a darkroom
Maintanence of Automatic Processors
If maintained according to the manufacturer’s instructions, automatic processors will produce consistent, quality radiographs. Maintenance includes checking solution levels, replenishment of solutions, thorough cleaning of tanks and rollers on a regular maintenance schedule as well as the replacement of solutions on a regular basis. Cleaning films should be run through the processor at the beginning of each day to remove any contaminants on the rollers. The chemistry used in automatic processors is different from manual processing solutions. Only chemistry specifically designed for automatic processors can be used because it is manufactured to perform at high temperatures. A care and maintenance schedule for developing equipment is one of the contributors to quality assurance
There are two processing solutions involved in processing conventional dental x-ray films. They are:
- Developer
- Fixer
When a conventional X-ray film enters an automatic processor it will go through the following stages:
- Developing the developer solution
- Fixing the fixer solution
- Washing in the water bath
- Drying
2 Types of Silver Haide used in the emulsion of dental film
- Silver Bromide
- Silver Iodide
When silver halide grains are exposed to light or xrays they…
..they store energy from the radiation. Various areas on the film receive more or less radiation depending on the density of the tissue being exposed (differential absorption) and therefore, exposed films have areas in which silver halide crystals contain various levels of stored energy. The pattern formed by the energized and non-energized crystals creates the latent image within the emulsion
The developer permeates the..
…the gelatin and reacts with all the silver halide crystals . The energized crystals are easily excited and react quickly with the developing chemicals.
The silver halide separates into..
….into bromide (or iodide) and metallic silver
Metallic Silver produces what on a developed radiograph?
Black areas on a developed radiograph. This black metallic silver is deposited on the film.
Silver halide crystals that did not receive x-radiation gives us…
Silver halide crystals that did not receive x- x-radiation and are not energized, do not react with the developer and are washed away. The corresponding area on the film will be white
Density of a radiograph
The number of X-rays used to expose the film determines the overall darkness of the processed radiograph. This degree of blackness is referred to as the density of the radiograph. An over-exposed film will appear to be too dark while an under-exposed film will appear too light.
Contrast of a radiograph
Contrast is the difference in densities of adjacent shadows recorded on the film. The greater the difference in densities between two adjacent structures, the greater the image contrast.
Long-Scale Contrast
An increased range of grays between the blacks and whites on a radiograph. Higher kilovoltage increases this range.
Short-Scale Contrast
A reduced range of grays between the blacks and whites on a radiograph.
Fixing in the Fixer Solution
The fixer dissolves and removes the unexposed silver halide crystals from the film emulsion which clears the film so that the black or darker images become more perceptible. The fixer also hardens the emulsion, allowing you to handle the film.
Washing in the Water Bath
After the fixer, the film is fed into the water bath to remove all the agents used to process the film.
Drying
An internal dryer found in the automatic processor dries the films after the washing stage before the films are expelled out of the automatic processor and ready for viewing
In the past, radiographs could be processed in two ways:
- Time-temperature method in a darkroom (manual)
- Automatic processing unit (automatic/mechanical)
However, as times change, techniques change. The manual method of processing conventional X-ray film has become obsolete. However, the use of automatic processing units, whether in a dark room or as day-light loaders, is still common.
The Dark Room
Dark rooms are designed to filter out visible light, except for safelights. The room must be completely dark because conventional x-ray films are sensitive to light
Errors in the Darkroom
Errors in the darkroom can easily ruin a good film, making it necessary to retake the films resulting in loss of time and increased radiation exposure to the patient and loss of tim
Darkroom Responsibility
The darkroom is one of the areas in a dental office for which the dental auxiliary has complete responsibility. In addition to processing films, the auxiliary must keep the darkroom clean, change solutions regularly, and keep accurate records of the radiographs processed. Only through meticulous attention to detail can proper dark room technique be maintained. It is important to realize that the processing of film is a vital link in the production of the diagnostic radiograph.
Latent Image
Radiographs, having been exposed in the patient’s mouth, contain a “latent image”. Processing the film makes this latent (or invisible) image visible and permanent