Doctor era of digital photography

Radiography

Doctor):

Dr in a broad sense includes all digital X-ray photography, and dr in a narrow sense refers to the direct use of electronic imaging board technology. The electronic imaging board consists of a large number of tiny detectors with thin film transistors (tft). Due to the different electronic conversion methods, it can be divided into indirect dr board and direct dr board. The former uses cesium iodide scintillation screen to convert X-ray into visible light, and then it is received by detector through photoelectric conversion. The latter uses amorphous selenium to directly release electrons, which are received by the detector. Physically speaking, the quantum conversion efficiency of direct dr plate should be higher than that of indirect dr plate. But at present, the stability of the indirect dr board is still good. Compared with cr, dr has higher image resolution, higher work efficiency and lower X-ray dose. With the increase of imaging speed, dr is developing from static to dynamic, which will make digital perspective possible. However, dr equipment is still very expensive at present, and the original X-ray machine must be greatly upgraded. This technology can realize automatic detection and field detection results, but just like phased array ultrasound, it needs construction vehicles and equipment to arrive at the scene, which is often the most difficult problem to solve in harsh field environment, which limits the field application of dr technology.