1. RAD 254 Chapter 11 Radiographic Film/Receptor
Image forming rays: remnant beam/exit radiation – scattered radiation (partially absorbed) and non-interacting

3. Rad Film – 2 main parts: emulsion and base
Base: rigid, non-shrinking base to support the emulsion now made of polyester
Emulsion: Silver halide and gelatin. 98% is silver bromide, the rest is usually silver iodide

4. Latent Image
Produced when exit beam (remnant beam) exists the patient and interacts with the emulsion/image receptor
Takes place at the sensitivity spec (center) due to liberated charges traveling in the development center (spec or receptor)

5. Film/Receptor Types
Digital – Computed Radiography (CR)= Photostimulable Phosphor (PSP)
Direct Radiography (DR/DDR)= Solid State X-ray Detector (SSXD)
Film: Screen, Direct Exposure, Mammo, Laser, Duplicating, Spot Film, Subtraction, and Cine

6. Direct exposure Non-screen film sensitive to x-rays
Like “bite wings” at the dentist

7. Screen Film – sensitive to both light and radiation
Comes in a variety of contrast, latitude, speed and light color sensitivity
Larger silver halide crystals = faster speed, less detail
Thicker emulsion layer = faster speed, less detail
Double emulsion layer = faster speed, prone to “crossover”

8. COLOR SENSITIVITY
Spectral matching = matching the color spectrum of light given off by screens to that of the emulsion
Calcium Tungstate Crystals atomic #’s 60/70’s
Rare Earth mainly in the 50’s (57-71)
Orthochromatic = green sensitive film
Panchromatic = sensitive to all color (photographic film)
Laser = sensitive to red light

9. Other type films
Mammo/routine films = some mammo is single emulsion and single screen film and some double/double
Duplicating film = single emulsion, /solarized film
Cine = Dynamic motion (heart caths, etc) 35mm
Spot film camera film = 70mm, 105 mm

10. Safelights
Filter is spectral matched to filter out the light spectrum the film is SENSITIVE TO (wratton 6-B – red safelite filter
Usually 15 watt bulb
Should be no closer than 5 feet from work surface (some “feed trays” have a safelight that turns on after the film has progressed into the processor and out when a film begins to enter the processor)

11. Film Storage Boxes to be stored on end – NEVER flat
68F (20C) best at 50F(10C) AND low humidity (40 percent or LESS)
Unexposed film is much less sensitive to light, radiation, chemicals, heat, etc., than exposed film
Shelf life – limited (film begins to develop as soon as it is made)