Processing Of X Ray Film

Processing Of X Ray Film

Discuss in detail about various techniques of processing of X-ray films.
or
Discuss processing of radiograph in detail.
Answer. Following techniques of processing X-ray films are as follows:

• Manual method
  • Time-temperature method
  • Visual method
  • Rapid processing method
• Automatic method
• Monobath method
• Day light method
• Digitalized processing method
• Self-developing films

X-ray film processing

Time-Temperature Method

Manual method consists of following steps:

• Replenish solutions:
  • The first step is to replenish the developer and fixer.
  • Eight ounces per gallon of fresh developer and fixer are made to maintain the proper strength of each solution.
  • Solutions are checked to ensure that the developer and fixer cover the films on the top clips of the film hangers.
• Stir solutions:
  • Both the developer and fixer are stirred by a separate paddle to mix the chemicals and equalize the temperature throughout the tanks.
  • By using separate paddle chances of cross-contamination are reduced.
  • Proper developing time varies with the temperature of the solution; the temperature of the developer should be checked after stirring.
• Mount films on hangers:
  • The exposed film is removed from its light proof packet or cassette, under safety light illumination in the darkroom.
  • Films are held only by their edges. This avoids damage to the film surface.
  • Care should be taken that film is not bent and the emulsion is not touched with wet fingers.
  • Bare film is clipped onto a film hanger, one film to one clip.
• Set Timer:
  • Temperature of the developer is checked.
  • The interval timer is set to the time indicated by the manufacturer for the solution temperature.
  • For intraoral film processing, the following developing times are used.

• Developing of film:
  • The timer is started and the hanger and films are immersed immediately in the developer.
  • The hanger should be agitated mildly for 5 seconds to sweep air bubbles off the film.
  • The films are left in the developer for the pre determined time with out further agitation.
  • The films are removed and the excess developer is drained into the water bath.
• Rinsing of film:
  • As the films are developed the film hanger is removed from the developer solution tank and is placed in the running wash bath for 30 seconds.
  • Films are agitated continuously in the rinse water to remove excess developer and thus slow the development and minimize contamination of the fixer solution.
• Fixing of film:
  • Hanger and film are then immersed in the fixer solution for 4 minutes and agitated for 5 seconds every 30 seconds.
  • This eliminates bubbles and brings fresh fixer into contact with the emulsion.
  • Excess fixation is avoided, this reduces the density of the film.
  • When the films are removed, then excess fixer is drained into the wash bath.
• Wash and dry:
  • After fixation of the films is complete, they are placed in running water for at least 10 minutes to remove remaining processing solutions.
  • After the films have been washed, surface moisture is removed by gently shaking excess water from the films and hanger.
  • Films are dried in circulating, moderately warm air.
  • If the films dry rapidly with small drops of water clinging to their surface, then this uneven drying causes distortion of the gelatin resulting in spots that frequently are visible and detract from the usefulness of the finished radiograph.
  • After drying, the films are ready to mount.

X-ray films Visual Methods

• It is a type of manual processing method.
• This method is done in the darkroom under safety light conditions.
• In this method an exposed X-ray film is immersed in developing solution and is viewed under the safelight for emerging the clear image.
• As image appears, the film is washed and is immersed in fixing solution.

X-ray films Rapid Processing Methods

Manufacturers have created rapid processing solutions which develop a film in 15 seconds at room temperature. These solutions consist of higher concentration of hydroquinone and a more alkaline pH.

X-ray films Automatic Method

It uses the equipment, which automate all of the processing steps. They are of two types, i.e.

• Automatic dunking models which produces a washed film which has to be dried.
• Miniature roller type which produces a dry film.

X-ray films Mechanism

The processor consists of transport mechanism which picks the unwrapped film and passes it via developing, fixing, washing and drying sections. This all is done through rollers which are driven by constant speed motor.

X-ray films Monobath Method

• In this method, developer and fixer are combined in one solution.
• Fixer is alkaline and does not neutralize the developer.
• The monobath is sprayed into a special waterproof film packet and the film is developed by rubbing the film packet.

X-ray films Daylight Method

It is done in a special device which consists of safe light filters and two glove-like compartments by which operator can put his hands and develop the films. Films are opened and processed in a subdued day light.

X-ray films Digitalized Processing Method

The digital images are processed by two systems, i.e.

• CR system or computed radiography system
• DR system or digitalized radiography system.

CR system: In this system, an IP cassette is used.After exposing, the cassette is loaded in a reader unit. The image is read-off and cassette is cleared. Captured image is transferred to workstation where operator views same on monitor. Image can be enhanced, restored, analyzed, compressed or synthesized and output can be taken on printer.

DR system: In place of a cassette, a sensor is used which is directly connected to the workstation through cables or wireless devices. Image is analyzed, interpreted and is stored to other departments.

Self-developing Films

• In this, X-ray film lies in a special sachet which consists of a developer and fixer.
• Following with exposure the developer tab is pulled and developer solution is released which run towards the film and massaged around it.
• After the gap of 30 seconds, fixer tab is pulled and fixer solution is released which run down over the film.
• As fixing is over the chemicals are discarded and film is rinsed thoroughly under running water for 10 min.