types of film Flashcards
Description: 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.
Applications: Primarily used for imaging thin body parts, such as extremities.
Limitations: Requires a higher radiation dose compared to screen-film systems, limiting its use in medical applications.
Direct-Exposure Film (Non-Screen Film)
Description: The most commonly used film in medical radiography, designed to be used in conjunction with radiographic intensifying screens.
Advantages: Allows for reduced exposure techniques and decreased patient radiation dose.
Disadvantages: May produce images with slightly less sharpness due to screen light diffusion.
Characteristics: Available in blue-sensitive or green-sensitive variants, depending on the spectral
emission of the intensifying screens used.
Applications: General radiography
Screen-Film
key characteristics when selecting screen film
contrast
film speed
spectral matching
anticrossover and antihilation dyes
safelighr requirements
Definition: refers to the degree of difference between the light and dark areas on a radiograph, influencing the visibility of anatomical structures.
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.
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.
Considerations:
Blue-Sensitive Film: Matches with calcium tungstate screens emitting blue and blue-violet light.
Green-Sensitive Film: Pairs with rare earth screens emitting green light.
Spectral Matching
Matches with calcium tungstate screens emitting blue and blue-violet light.
Blue-Sensitive Film
Pairs with rare earth screens emitting green light.
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.
Considerations:
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: provide illumination in darkrooms without exposing or fogging the film.
Considerations: :
Amber Filter (e.g., Kodak Wratten Series 6B Filter): Emits orange-brown light suitable for blue-sensitive films.
Red Filter (e.g., Kodak GBX Filter): Emits dark-red light appropriate for both green-sensitive and blue-sensitive films.
Guidelines: Use a 15-watt bulb positioned at least 5 feet (1.5 meters) from the work surface to prevent unintended exposure.
Safelight Requirements
Emits orange-brown light suitable for blue-sensitive films.
Amber Filter (e.g., Kodak Wratten Series 6B Filter)
Emits dark-red light appropriate for both green-sensitive and blue-sensitive films.
Red Filter (e.g., Kodak GBX Filter)
Description: Specialized single-emulsion film designed for mammography.
Characteristics: Provides high contrast and fine detail to detect subtle differences in breast tissue.
Applications: Breast imaging.
Mammographic Film
Description: Small-sized films tailored for dental radiography.
Characteristics: Available in various speeds and sizes to accommodate different dental imaging needs.
Applications: Intraoral and extraoral dental imaging.
Dental Film
Description: Motion picture film used to record dynamic imaging studies.
Characteristics: Capable of capturing moving images at high frame rates.
Applications: Angiography and fluoroscopic procedures.
Cine Film
Description: Film used to capture static images during dynamic fluoroscopic examinations.
Characteristics: Provides high-resolution images of specific areas of interest.
Applications: Gastrointestinal studies and interventional procedures.
Spot Film
Description: Film used in laser printers to produce hard copies of digital images.
Characteristics: Designed to work with laser imaging systems, offering high image quality and stability.
Applications: Printing images from modalities like CT, MRI, and digital radiography.
Laser Printing Film
Description: Film used to create duplicates of existing radiographs.
Characteristics: Features a solarized emulsion that reverses image densities during exposure.
Applications: Archiving and sharing patient images.
Copy/Duplicating Film
Description: Film used in dosimetry to monitor radiation exposure.
Characteristics: Sensitive to a wide range of radiation energies, providing a record of cumulative exposure.
Applications: Personnel monitoring and environmental radiation assessment.
Radiation Monitoring Film
Description: Film that does not require wet processing, used in some modern imaging systems.
• Characteristics: Utilizes heat or pressure to develop the image, eliminating the need for chemical
processing.
Applications: Portable imaging systems and situations where traditional processing is impractical.
Dry Transfer Film
• Description: Films designed for specific imaging tasks not covered by standard film types.
Characteristics: Tailored properties to meet unique imaging requirements.
Applications: Angiography, subtraction radiography, and other specialized procedures.
Specialty/Special Application Film
Store unexposed radiographic film in a cool environment, ideally
Elevated temperatures can increase fog and reduce contrast.
Temperature below 20°C (68°F).
Maintain relative humidity between High humidity levels (>60%) can lead to increased fog and condensation, reducing contrast, while low humidity (<30%) may cause static artifacts.
Humidity 30% and 60%.
