Elements of DR Imaging Systems Capture element The element/material used to capture the x-ray photon Coupling element Transfers the x-ray generated signal to the collection element Fiber optics, lens, contact layer, or a-Se Collection element Photodiode, CCD, TFT, CMOS Photodiodes, CCDs, and CMOS are light sensitive devices that collect light photons TFT collect electrons

Digital Radiography Type CR Indirect DR Direct DR Capture Element Barium fluorohalide CsI CsI – cesium iodide/GdOD gadolinium oxysulfide CsI – cesium iodide a-Se amorphous selenium Coupling element Lens or fiber optics a-Si Amorphous silicon Fiber optics or lens a-Se Collection element CMOS TFT CCD

Indirect w/ CCD and fiber optics Multiple detectors Single detector CCD Fiber optic coupling CsI capture element

Indirect w/CMOS and lens

Indirect TFT a-Si Coupling element

Direct TFT

Review of Indirect DR Basically there are three types of indirect systems CCD A multitude of small CCD (charged coupled devices) receive light from the cesium iodide scintillator. TFT The light from scintillator is recorded by a TFT (thin film transistor) that is also called a flat panel detector. CMOS (complementary metal oxide semiconductor) A lens focuses light on the CMOS chip

Flat panel technology (TFT) indirect and direct DR applications