RAD 350 Chapter 16 Digital Radiography Many types/names for the digital imaging processes and devices

Types CR: Barium Fluorohalide PSP SPR (scan projection RAD): Nal scintillator/photodiode Indirect DR: Csl, GdOS scintillator Indirect DR: Csl/Charge couploed device (CCD) Direct DR: a-Se, Thin-film transistor (TFT)

ES’s “Clever approach (capture element, coupling element, collection element “Capture element” – how the x-rays are captured (PSP’s, Csl, gado, etc) “Coupling element” transferring the x-ray “signal” to the collection element “Collection element: - devices to either collect light photons or electrons

Scan Projection Radiography As in CT, uses a “fan beam” (collimated by pre- pt. collimators); Post pt. remnant beam is collimated by a “fan” for the detector array – neither the tube or detector MOVE! SPR is NOT too successful, but is re-emerging for another breath

Charge Coupled Devices CCD’s are SMALL, thus GREAT for digital imaging – Have HIGH sensitivity to radiation and WIDE dynamic range (dim to bright light) – STRAIGHT H & D Curve

Types of CCD’s Cesium Iodide/CCD Cesium Iodide/Amorphous Silicon Amorphous Selenium – Not going into digital mammo at this time