Prelim | IP Flashcards
CR cxt composition
durable light weight plastic material backed by thin Al that absorbs xr
Instead of IS inside, there is antistatic material that protects against (1), (2), and (3)
- electricity build up
- dust collection
- mechanical damage to plate
IP layers
- Protective layer
- Phosphor/ active layer
- Reflective layer
- Conductive layer
- Color layer
- Support layer
- Backing layer
PPR CC SB
Very thin, tough, clear plastic that protects phosphor layer
Protective layer
Must be constructed so that it provides durability during multiple use
Protective layer
Clear plastic to allow xrs to pass through and allow light from the laser and stimulated light to pass through
Protective layer
Phosphor layer is usually made of phosphor from BaFr family. Examples are
barium fluorohalide
chlorohalide
bromohalide crystals
The phosphor is mixed with a/n (1) abf coated unto the (2)
- organic binder
- suport layer
Example of an organic binder
Polymer, such as polyester
This layer may be black to reduce the spread of stimulating light
Reflective layer
IP layer that sends light in a forward direction and some detail is lost in this process
Reflective layer
Layer of material that absorbs and reduces static electricity that may degrade image quality
Conductive/ Anti-static Layer
Color layer absorbs (1) and reflects (2)
- stimulating light
- emitted light
Newer plates may contain a color layer located bn the (1) and the (2)
- active/ phosphor layer
- support
Semi-sigid material that gives the imaging some strength
Support layer
Example of support layer
Polyester base
Backing layer is a — that protects the back of the CXT
soft polymer
Backing layer is usually made of (1) to stop (2)
- lead
- backscatter
Where some barcode is placed for pt identification
Backing layer
GOOD CHARACTERISTICS OF PHOSPHOR
- Should have good x-ray absorption efficiency
- Capable of being stimulated by Helium-neon laser
- Luminescence of light must be compatible with PMT
- Luminescence must be shorter than 1usec (microsec) to prevent screen lag
- Phosphor should be able to store the latent image for couple of hours without compromising the signal from the IP
A He LL Store
2 TYPES OF IP
- STANDARD RESOLUTION IP
- HIGH RESOLUTION IP
STANDARD RESOLUTION vs HIGH RESOLUTION IP
STANDARD RESOLUTION
- thicker phosphor layer = higher absorption
- lower image quality
- fast screen speed
HIGH RESOLUTION
- thinner phosphor
- high image quality (sharper image)
- slow screed speed
Scatter radiation and image quality relationship
Directly proportional (more scatter = higher quality)
Difference of how low and high img quality is produced
If absorbed = low image quality
If penetrated = high image quality
Relationship of ideal exposure factor
high kVp, low mAs
Latent Image Formation
(1) created a latent image, and (2) produces PSL. The (3) is used to create the CR image
- X-ray exposure of the PSP- IP
- laser scanning of the exposed IP
- information from the PSL
Explain KEY POINT: DOPING OF PSP
PSP plate is coated with Europium-activated BaFl crystals
↓
Doping of Europium creates defects in the BaFBr/I crystals, that allow electrons to be trapped more efficiently
DOPING BARIUM FLUOROHALIDE WITH EUROPIUM
When pure crystals of Barium Fluorohalide are doped with small amount of Europium, crystals develop a tiny defect called (1)
F-centers act like (2) in the crystals that can trap electrons
- metastable sites of F-center
- electronic holes
F center in German
(German: Farbzentren/ color center)
