Computed Radiography Image Acquisition

image acquisition

x-ray exits tube

beam attenuates through pt

remnant beam strikes IR

IR stores signal until plate is read

Image capture

beam attenuates through pt

attenuated remnant beam strikes PSP plate

latent image is stored until processed

imaging plate construction

protective layer

phosphor layer

conductor layer

support layer

light shield layer

backing

protective layer

protects active phophor layer

phospor layer

AKA: active layer

traps electrons during exposure and holds latent image

contains barium fluorohalide

conductor layer

absorbs light and reduces static on the image

support layer

base to coat other layers

light-shield layer

prevents light from erasing image data

backing

protects the cassette

latent image formation

x-rays strike photosimulable phosphor

phosphor emits light

F centers (AKA electron holes) hold the latent image until the plate is processed

what is the most common type of photostimulable phosphor used in CR

barium fluorohalide

what percent of electrons give off light vs the percent that deposit energy 

50% give off light 

50% deposit energy (creates latent image)

percent of image lost after 8 hours 

25%

F centers

composed of barium fluorohalide laced with europium

the europium creates an additional band between valence and condition