Digital Radiography

Radiography is the art and science of using ionizing radiation to provide images of tissues, organs, bones and vessels that comprise the body. These images may be recorded on film or displayed on a video monitor. Motion studies may also be produced. Digital Radiography (CR) uses very similar equipment to conventional radiography except that in place of a film to create the image, a Flat Panel Detector is used. Hence, instead of taking a film into a darkroom for developing in chemical trays, directly a digital image is generated. The image can then be viewed and enhanced using software that has functions very similar to conventional image-processing software, such as contrast, brightness, and zoom.

The panels are produced with a gadolinium oxysulfide scintillator which is quite rugged to the elements and environmental conditions thus lending it much more readily for portable applications mounted on an Amorphous Silicon plate. The scintillator emits light photons in direct proportion to the energy of the X-ray striking it. Those light photons are made to fall on the Amorphous Silicon Photodiode array. This array will convert light photons into electrical signals which will be converted into a digital signal and will be displayed on a Thin Film Transistor.

We have done some experiments on detection of adhesive bonding in a thin steel sample as shown in fig 1. It is clearly visible that on the left side how the adhesive is present. The fig 2 shows the steel weld sample in which a porosity and the gap between the two plates is shown clearly. The arrangement of fibers inside a tire is shown in the fig 3.