CR2 Flashcards
What might the phosphor layer contain to improve image quality? How does it work?
A dye that differentially absorbs the stimulating light to prevent spread and absorbs scattered light to reduce image blur, increasing spatial resolution (similar to intensifying screens).
Why might the reflective layer be black?
To reduce the spread of stimulating light and the escape of emitted light.
What is the function of the reflective layer in the imaging plate?
It sends light in a forward direction when released in the cassette reader, improving efficiency.
What is an important design characteristic of the reflective layer regarding the laser beam?
It is designed so as not to reflect the particular color of light used by the laser beam in scanning the plate.
What is the function of the light shielding layer in the imaging plate?
It prevents extraneous light from erasing the plate before it is scanned and prevents light from erasing data or leaking through the backing, decreasing spatial resolution.
What is the purpose of the conductive layer in the imaging plate?
It absorbs and reduces static electricity, preventing static buildup that could cause artifacts and absorbing light to increase sharpness.
How is the support layer protected?
By a very thin coating of plastic that prevents scratches.
What is the support layer of the imaging plate? What is it made of?
A semi-rigid base made of aluminum on which other layers are coated, providing strength and supporting the active phosphor layer.
What is the backing protective layer made of and what is its function?
A soft polymer that protects the back of the cassette.
What is the function of the anti-halo/color layer?
It prevents laser light from penetrating through to the reflective layer while allowing light emitted by the phosphor to pass through it (absorbs stimulating light but reflects emitted light).
Where is the anti-halo layer/color layer located in newer imaging plates?
Between the active layer and the support.
What does a cassette-based PSP system contain to link image information with patient data?
A window with a barcode label or barcode sticker on the cassette.
Why is correct orientation of the CR cassette important?
To minimize image manipulation after processing and ensure correct anatomical orientation of the displayed image.
What are some physical characteristics of CR cassettes that make them convenient?
They are very light for ease of use with mobile procedures.
What is the consequence of incorrect cassette orientation?
It will affect anatomic orientation, requiring the image to be rotated or flipped on the screen.
What materials are CR cassettes typically made of? What is a characteristic of the front panel?
Aluminum or plastic with a low absorbing carbon fiber front.
What does IRD stand for in the context of CR? What is it?
CR-reader device (IRD), a device or machine used for scanning the exposed IP to render the latent image visible by loading the CR cassette into it.
What might the back panel of a CR cassette include? Why?
A thin sheet of lead foil to reduce backscattered x-radiation from reaching the plate.
What material lines both the front and back of the CR cassette? What are its functions?
Felt material that minimizes the buildup of static electricity and cushions the plate from minor shocks.
How are the emitted light photons detected and processed in the CR reader?
They are detected by photosensitive receptors, which are then converted to an electrical signal.
What happens to the electrical signal after it’s generated in the CR reader?
It is then converted to a unique digital value corresponding to the level of luminescence.
