Radiographic Film Processing Long and Short Essays

Radiographic Film Processing Long Essays

Question 1. Write about the composition of X-ray film. Describe the mechanism of image formation. Write a note on the composition of developing and fixing solution and their functions.
Answer.

Composition Of Film:

Emulsion:

• It is sensitive to X-rays and visible light
• It records the image
• It consists of:
• Silver halide crystals
• They are composed of mainly silver bromide and lesser content of silver iodide which are photosensitive
  • Each silver grain diameter is 1.8μm
  • Gold may be added to improve its sensitivity
  • Gelatin matrix
  • It suspends silver halide crystals evenly in the gel made from cattle bone
  • It absorbs the processing solution
  • This allows the chemicals to react with silver halide crystals

Base:

• It is made up of Polyethylene terephthalate (polyester)
• Its diameter is 0.18mm
• The function of the base is to support the light-sensitive silver halide crystals
• The base is a slightly blue-tinted to enhance the image quality
• Its translucency cast no patterns on the resultant radiograph
• It withstands exposure during processing without distortion
• It is flexible for proper handling
• Adhesive layer
  • It is applied to the base before the emulsion is applied for proper adaptation

Formation Of Image:

• The film emulsion is made up of silver bromide crystals and silver iodide crystals that are precipitated in gelatin
• When the silver halide crystals are irradiated by X-ray photons it will result in the release of electrons usually by the bromide ions
• This leads to the conversion of bromide ions to bromine atoms by removing electrons
• This recoil electron thus produced has sufficient kinetic energy with which it moves in the crystal and strikes the image site
• This imparts a negative charge to that region
• The free positively charged interstitial silver ions are attracted to the negative latent image site
• This neutralizes the image site with the result that an atom of metallic silver is deposited at the site
• After exposure of a film to radiation, the aggregate of silver atoms at the latent image sites comprises the latent image

Composition Of Developer:

 

Read And Learn More: Oral Radiology Question and Answers

Fixing Solution

Question 2. Write in detail about the processing of X-ray film.
Or
Enumerate various film processing techniques. Describe in detail the manual procession.
Answer.

x-ray film Types:

• Manual method:
  • Time-temperature
  • Visual method
  • Rapid processing method
• Automatic method:
• Monobath method
• Daylight method
• Digitalized processing method
• Self-developing films

Time Temperature Method:

• Initially replenish the developer & fixer solutions
• Set the temperature of the developer
• Unwrap the film
• Hold the film along the sides, & clip it to the hanger
• Agitate the film
• Keep it for the predetermined time
• After that place it in the circulating water
• Agitate for 20 – 30 seconds to remove excess solution
• According to the time & temperature of the developer, set that of the fixer
• Immerse the film in The Fixer
• Agitate for 5 of every 30 seconds
• After it, allow to drain the excess fixer solution
• Place it in circulating water for at least 20 minutes
• Dry the film

Visual Method:

• Place the film in the developer
• View them from time to time
• Look for the degree of darkness in the safelight

x-ray film Advantages:

• Developing to desired darkness is possible
• Fewer chances of errors

x-ray film Disadvantages:

• Individually processing required
• Thus, time-consuming

Automatic Film Processing

• This method uses equipment that automates all the processing steps

Automatic Film Processing Advantages:

• Rapid process
• Uniformity of the results is obtained
• Less space required
• The density and contrast of the film are consistent

Automatic Film Processing Disadvantages:

• Low quality as compared to that processed manually
• High cost of equipment

Automatic Film Processing Mechanism:

• The apparatus consists of a transport mechanism
• This picks up the unwrapped films which are passed through the developer, fixer, and drying sections
• The system uses a series of rollers driven by a constant-speed motor that operates through gears, belts, or chains
• The rollers consist of assemblies of multiple rollers
• It is so designed that the film crosses over from one roller to the next
• The operator may also be able to remove them independently for soaking, cleaning, and repairing

Question 3. Formation of latent image. Add a note about a fixer and developer solution
Answer.

Formation Of Image:

• The film emulsion is made up of silver bromide crystals and silver iodide crystals that are precipitated in gelatin
• When the silver halide crystals are irradiated by X-ray photons it will result in the release of electrons usually by the bromide ions
• This leads to the conversion of bromide ions to bromine atoms by removing an electron
• This recoil electron thus produced has sufficient kinetic energy with which it moves in the crystal and strikes the image site
• This imparts a negative charge to that region
• The free positively charged interstitial silver ions are attracted to the negative latent image site
• This neutralizes the image site with the result that an atom of metallic silver is deposited at the site
• After exposure of a film to radiation, the aggregate of silver atoms at the latent image site comprises the latent image

Fixing Solution:

Composition Of Developer

Radiographic Film Processing Short Essays

Question 1. Developer and fixing solution.
Answer.

Composition Of Developer:

Fixing Solution:

Question 2. Formation of latent image.
Answer.

Formation of the latent image

• The film emulsion is made up of silver bromide crystals and silver iodide crystals that are precipitated in gelatin
• When the silver halide crystals are irradiated by X-ray photons it will result in the release of electrons usually by the bromide ions
• This leads to the conversion of bromide ions to bromine atoms by removing an electron
• This recoil electron thus produced has sufficient kinetic energy with which it moves in the crystal and strikes the image site
• This imparts a negative charge to that region
• The free positively charged interstitial silver ions are attracted to the negative latent image site
• This neutralizes the image site with the result that an atom of metallic silver is deposited at the site
• After exposure of a film to radiation, the aggregate of silver atoms at the latent image site comprises the latent image

Question 3. Film processing.
Answer.

Film Processing Types:

• Manual method:
  • Time-temperature
  • Visual method
  • Rapid processing method
• Automatic method:
• Monobath method
• Daylight method
• Digitalized processing method
• Self-developing films

Time Temperature Method:

• Initially replenish the developer & fixer solutions
• Set the temperature of the developer
• Unwrap the film
• Hold the film along the sides, & clip it to the hanger
• Agitate the film
• Keep it for the predetermined time
• After that place it in the circulating water
• Agitate for 20 – 30 seconds to remove excess solution
• According to the time & temperature of the developer, set that of the fixer
• Immerse the film in The Fixer
• Agitate for 5 of every 30 seconds
• After it, allow to drain the excess fixer solution
• Place it in circulating water for at least 20 minutes
• Dry the film

Film Processing Visual Method:

• Place the film in the developer
• View them from time to time
• Look for the degree of darkness in the safelight

Film processing Advantages:

• Developing to desired darkness is possible
• Fewer chances of errors

Film processing Disadvantages:

• Individually processing required
• Thus, time-consuming

Question 4. Manual film processing.
Answer.

Time Temperature Method:

• Initially replenish the developer & fixer solutions
• Set the temperature of the developer
• Unwrap the film
• Hold the film along the sides, & clip it to the hanger
• Agitate the film
• Keep it for the predetermined time
• After that place it in the circulating water
• Agitate for 20 – 30 seconds to remove excess solution
• According to the time & temperature of the developer, set that of the fixer
• Immerse the film in The Fixer
• Agitate for 5 of every 30 seconds
• After it, allow to drain the excess fixer solution
• Place it in circulating water for at least 20 minutes
• Dry the film

Manual Film Processing Visual Method:

• Place the film in a developer
• View them from time to time
• Look for the degree of darkness in the safelight

Manual Film Processing Advantages:

• Developing to desired darkness is possible
• Fewer chances of errors

Manual Film Processing Disadvantages:

• Individually processing required
• Thus, time-consuming

Question 5. Automatic Film Processing.
Answer.

Automatic Film Processing

• This method uses equipment that automates all the processing steps

Automatic Film Processing Advantages:

• Rapid process
• Uniformity of the results is obtained
• Less space required
• The density and contrast of the film are consistent

Automatic Film Processing Disadvantages:

• Low quality as compared to that processed manually
• High cost of equipment

Automatic Film Processing Mechanism:

• The apparatus consists of a transport mechanism
• This picks up the unwrapped films which are passed through the developer, fixer, and drying sections
• The system uses a series of rollers driven by a constant-speed motor that operates through gears, belts, or chains
• The rollers consist of assemblies of multiple rollers
• It is so designed that the film crosses over from one roller to the next
• The operator may also be able to remove them independently for soaking, cleaning, and repairing

Question 6. Coin test.
Answer.

Coin test AIM:

• To evaluate safelight requirements

Coin test Method:

• Shut all the lights
• Put on the safe light
• Open the film packet
• Place the film over the unwrapped surface
• Place a coin over it
• Leave it for approximately the time required for unwrapping the full-mouth radiograph which is about 5 minutes
• Develop the film

Coin test Result:

• If the image of the coin can be seen on the resultant film, the room is not light-safe

Radiographic Film Processing Short Answers

Question 1. Latent image.
Answer.

Latent image

• When the radiographic film is exposed to the information-carrying beam of photons exiting an object, the photosensitive silver halide crystals in the film emulsion interact with these photons and are chemically changed
• These chemically altered crystals constitute the latent image of the film
• This increases the liability of crystals to the chemical action of the developing process that converts the latent image into a visible image

Question 2. Composition of developer
Answer.

Composition Of Developer:

Question 3. Fixing solution
Answer.

Fixing Solution:

Question 4. Darkroom requirements.
Answer.

Size:

• 3 feet x 3 feet for an individual dentist
• 16 – 20 square feet for group practice
  • Should have sufficient space to accommodate the processing tanks
  • It must include an adequate working area where the films are unwrapped
  • It must contain a storage space
  • It should be well-ventilated
  • Room temperature must be 70 degrees
  • Humidity levels must be between 50-70%
  • The room must include both hot & cold running water
  • Wastebasket for disposal of all film wrappings
  • Safe light mounted on the wall or ceiling
  • It should be at least 4 feet from the work surface

Radiographic Film Processing Viva Voce

• The height of safe light from the working area should be 1.22m [4 feet]
• The temperature of X-ray processing tanks should be between 60-75°F
• In developer, sodium sulfite acts as a preservative
• Hydroquinone in developer is added to increase the contrast of the image