When a flat panel detector is coupled with an appropriate manipulator and image processing software, they can be used for x-ray Computed Tomography (CT) inspection, producing a 3D image of the external and internal structure of the test object.Īnother type of digital x-ray detection media are linear detector arrays (LDAs). This differentiates it from indirect construction. As there is no scintillator, lateral spread of light photons is absent here, ensuring a sharper image.
In the direct conversion process, when x-ray photons impact over the photo conductor, like amorphous Selenium, they are directly converted to electronic signals which are amplified and digitised. The information on both types of detectors is read by thin film transistors. This charge is proportional to the number and energy of x-ray photons interacting with the detector pixel and therefore the amount and density of material that has absorbed the x-rays.ĭirect conversion flat panel detectors use a photo conductor like amorphous selenium (a-Se) or Cadmium telluride (Cd-Te) on a multi-micro electrode plate, providing the greatest sharpness and resolution. Indirect conversion flat panel detectors have a scintillator layer which converts x-ray photons to photons of visible light and utilise a photo diode matrix of amorphous silicon to subsequently convert the light photons into an electrical charge. They can have better signal-to-noise ratio and improved dynamic range, which, in turn, provides high sensitivity for radiographic applications.įlat panel detectors work on two different approaches, namely, indirect conversion and direct conversion. The incident x-ray radiation is converted into an equivalent electric charge and then to a digital image through a detector sensor.Ĭompared to other imaging devices, flat panel detectors, also known as digital detector arrays (DDAs) provide high quality digital images.
This technique uses x-ray sensitive plates to capture data during object examination, which is immediately transferred to a computer without the use of an intermediate cassette. National Structural Integrity Research Centreĭigital radiography (DR) is an advanced form of x-ray inspection which produces a digital radiographic image instantly on a computer.Structural Integrity Research Foundation.