Types of Film Flashcards
TYPES OF FILM USED IN MEDICAL IMAGING
- Direct-Exposure Film (Non-Screen Film)
- Screen-Film
- Mammographic Film
- Dental Film
- Cine Film
- Spot Film
- Laser Printing Film
- Copy/Duplicating Film
- Radiation Monitoring Film
- Dry Transfer Film
- Specialty/Special Application Film
Designed for use without intensifying screens, this film type has a thicker emulsion and a higher concentration of silver halide crystals to enhance direct X-ray interaction.
Direct-Exposure Film (Non-Screen Film)
• Applications:
Primarily used for imaging thin body parts, such as extremities.
Direct-Exposure Film (Non-Screen Film)
• Limitations:
Requires a higher radiation dose compared to screen-film systems, limiting its use in medical applications.
Direct-Exposure Film (Non-Screen Film)
The most commonly used film in medical radiography, designed to be used in conjunction with radiographic intensifying screens.
Screen-Film
• Advantages:
Allows for reduced exposure techniques and decreased patient radiation dose.
Screen-Film
• Disadvantages:
May produce images with slightly less sharpness due to screen light diffusion.
Screen-Film
• Characteristics:
Available in blue-sensitive or green-sensitive variants, depending on the spectral emission of the intensifying screens used.
Screen-Film
• Applications:
General radiography.
Screen-Film
screen-film for radiographic imaging, several key characteristics
A. Contrast
B. Film Speed
C. Spectral Matching
D. Anticrossover and Antihalation Dyes E. Safelight Requirements
• Definition:refers to the degree of difference between the light and dark areas on a radiograph, influencing the visibility of anatomical structures.
Contrast
• Considerations: Manufacturers offer films with varying contrast levels, typically categorized as medium, high, or higher contrast. The choice depends on the diagnostic requirements and the specific examination being performed.
Contrast
• Definition: indicates the sensitivity of the film to radiation or light, affecting the exposure required to produce an image.
Film Speed
• Considerations: A higher-speed film requires less exposure but may yield images with more graininess, while a lower-speed film provides finer detail at the cost of increased exposure. The selection balances patient dose and image quality.
Film Speed
• Definition: ensures that the light emitted by the intensifying screen corresponds with the film’s sensitivity spectrum.
Spectral Matching
Matches with calcium tungstate screens emitting blue and blue-violet light.
o Blue-Sensitive Film
Pairs with rare earth screens emitting green light.
o Green-Sensitive Film
• Definition: These dyes are incorporated into the film to prevent light from scattering within the film layers, which can degrade image sharpness.
Anticrossover and Antihalation Dyes
• Considerations: Anticrossover dyes are used in double-emulsion films to prevent light from crossing between emulsions, while antihalation dyes in single-emulsion films absorb light passing through the emulsion, preventing reflection back into the emulsion layer.
Anticrossover and Antihalation Dyes
• Definition: Safelights provide illumination in darkrooms without exposing or fogging the film.
• Considerations:
o Amber Filter (e.g., Kodak Wratten Series 6B Filter): Emits orange-brown light suitable for blue-sensitive films.
o Red Filter (e.g., Kodak GBX Filter): Emits dark-red light appropriate for both green-sensitive and blue-sensitive films.
o Guidelines: Use a 15-watt bulb positioned at least 5 feet (1.5 meters) from the work surface to prevent unintended exposure.
Safelight Requirements
