Radiographic Film Processing: Types, Handling, and Development

Posted on Mar 2, 2025 in Medicine & Health

Radiographic Film Types

Panchromatic Types:

  • Direct exposure
  • Mammography (fine-grained, single-emulsion, intensifying screen)
  • Video movie format (2×3 and 3×2 choice)
  • P. Laser (digital signal device, it prints a red laser beam)
  • P. Thermosensitive (are impressed with heat)
  • P. Duplication (view box)

Handling and Storage of Radiographic Film

Avoid temperatures exceeding 20°C or humidity levels above 60%. These conditions can lead to decreased contrast and increased fogging. If humidity falls below 40%, artifacts may appear.

Light Sensitivity

Scattered light increases fogging, so films must be protected from light.

Radiation Sensitivity

Film is more sensitive to radiation than humans. Radiation exposure decreases contrast and increases fogging.

Expiration Dates

Always consider expiration dates.

Storage Issues

Aging leads to decreased speed, increased contrast, and fogging. Store films vertically to reduce the chance of sticking. Always check expiration dates.

Film Development Process

The film is exposed, creating a latent image. The image becomes visible only after development. Digital screens enhance the image, emitting light in both digital and analog formats. The chemical reaction during development is a reduction reaction: Ag+ + e– -> Ag, implying an oxidation process as well.

Development Phases

  1. Revealing: Hydroquinone and phenidone are key reducing agents. Insufficient development time prevents complete conversion of exposed silver. Temperature, time, and developer concentration are critical.
  2. Fixing: Acetic acid is used to halt development. Fixers (e.g., hypo/sodium thiosulfate) remove unexposed silver crystals, stabilizing the image: Increase the fixative + Ag – > Ag2S (silver sulfide). Excessive fixer can cause a sepia tone. Retained fixer is a common cause of deterioration.
  3. Hardening: Glutaraldehyde acts as a hardener, especially during development.
  4. Washing: Water removes residual chemicals to prevent hypo-retention.
  5. Drying: Insufficient drying can leave the film wet.

Automatic Film Processing Systems

Temperature Control

Maintain a temperature of 37 degrees Celsius.

Circulation System

Liquids circulate continuously with input and output circuits. Filters are used in the development stage. The washing stage uses an open circuit for drainage.

Filling System

Each system contributes to the tanks. Liquid detectors trigger alarms for low levels, differentiating between replenishing and developing solutions. Fresh solutions increase contrast, while older solutions may struggle to reveal the latent image.

Drying Systems

Hot air is used for drying. A fan draws air from the room, but dust can adhere to the film if not properly filtered. Insufficient hardening can also cause issues.

Components of Automatic Developers

  • Transport system
  • Temperature control
  • Movement system
  • Filling system
  • Drying system
  • Electrical system

Transport System Components

  1. Knee transport subset
  2. Racks
  3. Motor subassembly