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%.
Exposure to light can pre-expose the film, leading to increased fog or obvious artifacts. Ensure films are stored in light-tight containers or areas to prevent accidental exposure.
Light Exposure
Unintended exposure to radiation sources can create image artifacts by increasing fog and reducing contrast. Store unexposed films away from radiation sources to prevent pre-exposure.
Radiation Exposure
Radiographic films have a finite shelf life, typically indicated by an expiration date. Using expired film can result in reduced speed, decreased contrast, and increased fog. It’s advisable to use films before their expiration date and avoid storing them for extended periods.
Shelf Life (Age)
Handle films with clean, dry hands or gloves to prevent contamination. Avoid bending or applying pressure that could cause physical damage. Store films upright on edge to prevent warping and ensure they are kept in appropriate storage conditions to maintain their integrity.
By adhering to these guidelines, the quality of radiographic films can be preserved, ensuring reliable and accurate imaging results.
Handling Practices
