1. CR
CR is a mature technology for digitizing flat X-rays, which has been widely used both at home and abroad. CR systems use an imaging plate (IP), which records and reads out X-ray imaging information from a laser, as a carrier, and process the X-rays with X-ray exposure and information reading. CR systems use an imaging plate (IP) that records and reads out X-ray information from a laser as a carrier, which is processed by X-ray exposure and information readout to form a digital or flat image. The current CR system can provide the same resolution as the screen - film photography. CR system realizes the digitalization of conventional radiography information, so that the analog information of conventional radiography is directly converted to digital information; it can improve the resolution of the image, the display ability, and break through the intrinsic limitations of the conventional radiography technology; it can use computer technology to implement a variety of image processing (post-processing) functions to increase the level of the display information, and increase the level of the information.
2. DR
DR is based on the X-ray television system, the use of computer digital processing, so that the analog video signal after sampling, analog / digital conversion (analog to digit, A/D) directly into the computer for storage, analysis and preservation. x-ray digital image of the high spatial resolution, dynamic range, and its image can be observed contrast With high spatial resolution and large dynamic range, X-ray digital images can observe objects with a contrast ratio of less than 1% and a diameter of more than 2MM, and the surface X-ray dose measured on the patient is only 1/10 of that measured by conventional photography. the quantum efficacy (DQE) can reach more than 60%. the X-ray information can be processed by computers after digitization. By improving the details of the image, reducing image noise, gray scale, contrast adjustment, image magnification, digital subtraction, etc., to show the characteristics of the unprocessed image can not be seen in the information. With the help of artificial intelligence and other technologies for quantitative analysis of images and feature extraction, computer-aided diagnosis can be carried out.
Digital radiography includes a variety of modalities such as selenium cartridge mode, direct digital radiography (direct digital radiography; DDR), charge coupled device (charge coupled device; CCD) camera array mode. The digital image has a high resolution, good image sharpness, details show clearly; radiation dose is small, exposure tolerance, and according to the clinical needs of a variety of image post-processing and other advantages, but also to achieve the radiology department without film, between departments, hospitals, networked, to facilitate the teaching and consultation.