Xray Film Flashcards
What is replacing film in X-ray?
Digital systems
Film
Creates a hard copy radiographic image that must be stored in envelopes and warehoused on shelves
Digital images
soft copy images that can be stored electronically in a PACS
Base
Used to support the other portions of the film in order to form the image
Modern film
consists of polyester plastic that is 150 – 200 μm (0.006 to 0.008”) in thickness.
Glass
The original film base material were glass plates, first marketed by John Carbutt in 1896.
These films had a single emulsion placed upon them
What are some problems with glass plate films?
- Low maximum density
- Fragile
- Weight
- Cost
Cellulose Nitrate
Soft, lightweight and flexible, much like modern polyester plastic.
Extremely flammable
Cellulose triacetate
Marketed as safety film since it did not have the flammability of cellulose nitrate
Easily torn
Polyester
Virtually indestructible and does not decompose over time
Adhesive sub layer
Usually gelatin to hold the emulsion to the base
Emulsion
Image forming part of the film. It is made up of:
1. Silver halide crystals - microscopic crystals that are 1 micro mill across usually flat
2. Suspending agent - used to suspend the silver halide crystals across emulsion
3. Sensitivity specks or development centers - impurities of silver unfixed added to the silver halide crystals, act as electron traps
What are the 2 thickness options available for emulsion?
- Single emulsion film - used for fine detail studies such as mammography
- Duplitized emulsion film
Disadvantage of single emulsion films
Higher dose of radiation is required
Duplitized emulsion layer
film with an emulsion layer on both sides of the base.