DR/Flat panel cassette VOCAB

Active-Matrix Array

a panel of electronic detector elements laid out in rows and columns. used to convert incoming light or x-ray signal electrical signal.

Amorphous selenium

Photodetector uses this substance with direct capture systems to convert x-rays to an electrical signal

Amorphous Silicon

Photodetector uses this substance with indirect capture systems to convert to light to electrical signal

Capacitor

Device capable of accumulating and storing an electrical charge (capacitator of a del or dexel stores charge temporarily till it is read out)

del

data element/ hardware pixel- the digital image receptor is constructed using an array of dels

digital radiography (DR)

traditionally the description for cassette-less systems that use an x-ray absorber material couples to a flat panel detector or a charge -coupled device to form the image.

Direct Capture (Conversion)

Active-matrix array (IR) using a single step process in which the photodetector/photoconductor/photodiode, (glass substrate coated with amorphous selenium) converts the x-rays to an electrical signal.

fill factor

that percentage of the detector elements (del) area dedicated to a photon absorption (Because components take up some of the space within the del)

Image Lag

Detector does not clear signal from previous image (faint signal from previous exposure is present)

Indirect Capture (Conversion)

Active-matrix array (IR) that uses a two step process. x-rays strike a scintillator (cesium iodide) which emits light. The photodetector/photodiode/photoconductor then converts the light to an electrical signal. Can be used with either a CCD or a TFT

Photoconductor

a material that absorbs x-rays or a light converts the signal to an electrical charge (conducts electricity when struck by light or x-ray photons)

Scintillator

a material that absorbs x-ray and emits light (isotopically)

Structured scintillator Crystals

Tubular shaped crystals (cesium iodide) used with indirect capture systems that from channels that help control light dispersion (light spread)

Thin film Transistor (TFT)

The electronic switching gate used in detector elements (component found within the del (hardware pixel) that releases the signal to be read out)

the entire array can sometimes be referred to as a TFT: photosensitive array made of small pixels (DELS) that convert light or x-rays into an electrical signal