Epson Digital Imaging System EPIX - Manual (Page 27)

Logos Imaging EPIX Scanner
User Manual 26
Appendix A: Storage Phosphor Technology
The EPIX SCANNER Digital Imaging System
produces high quality x-ray images at very low
doses. The imaging plates in the EPIX
SCANNER system are much more efficient at
capturing x-ray energy than x-ray film.
How Storage Phosphor Imaging Plates
Work
Each EPIX SCANNER Imaging Plate is made
up of a very thin layer of tiny storage phosphor
crystals that are bonded together and coated on
a flexible sheet of plastic. These storage
phosphor crystals have the ability to capture
the energy of x-rays and store the pattern as a
latent image (see diagram).
In essence, they act as an “energy trap,”
storing x-ray energy. The amount of energy
stored is directly proportional to the amount of
x-ray energy the crystal was exposed to.
The EPIX SCANNER further excites the
phosphor crystals to an unstable state by
exposing them to a red laser. The phosphor
crystals then release a blue light and return to
their stable ground state. The EPIX
SCANNER reads this blue light and, with the
imaging software, produces an image.
This process does not completely erase the
imaging plate. Some crystals remain as
“energy traps.” This information can be erased
by exposing the imaging plate to light. A few
seconds of low levels of light will usually not
effect the image quality. Once erased, the
imaging plate can be re-exposed and the
process can begin again. With proper handling,
EPIX SCANNER Imaging Plates can be
continually reused.
Stable Excited
State
Unstable Excited
Imaging Plates Ground
State (Erased Imaging
Plates)
Blue light emitted
as molecul es return
to ground state
Expose to Red Laser
Expose IP to X-Rays