Digital Radiography (or DR) is a form of x-ray imaging that utilizes digital x-ray sensing technology instead of conventional x-ray which uses film. DR eliminates the need for chemical processing and consumables (film), as well as the need for additional storage as the new x-ray exposures will be stored digitally (not physically like films).
DR technology consists of digital image capture devices, which provide a number of advantages including: rapid image preview and availability, wider dynamic ranges, and the ability to enhance image quality with software.
There are two main DR technologies: Charged Coupled Device (CCD) and Flat Panel Detectors (FPD), which are either direct or indirect capture.
CCD allows digital copies of images to be captured and stored quickly. In the direct method, x-ray photons are absorbed by the CCD, whereas in the indirect method x-ray photons are converted to visible photons, which are then absorbed by the CCD.
FPD are the most common digitizing devices used in DR. FPD come in two forms of semiconductor detectors, which detect x-rays. With an indirect FPD, the outermost layer is a scintillator material, which is often composed of Cesium Iodide (CsI) or gadolinium oxysulfide, also known as Gadox. The detector itself is based on amorphous silicon photodiode technology. These panels convert x-rays to light and then to an electrical charge. The image is then read, digitized, and transmitted by the detector, before being processed to produce the desired digital x-ray image. The outermost layer of a direct FPD is comprised of high voltage bias electrodes and the detector, which converts x-rays to charge directly, is based on amorphous selenium technology.
What’s so great about digital radiography (DR)?