X-ray photography position photography distance

Computer radiography (CR) is a mature digital technology of X-ray film, which has been widely used at home and abroad. The CR system uses an imaging plate (imaging plate; IP) as a carrier, X-ray exposure and information reading are used to form digital or plane images. Current CR systems can provide the same resolution as screen film photography. The advantages of editing this paragraph. Computerized X-ray photography (CR) system realizes the digitization of conventional X-ray photography information, so that the analog information of conventional X-ray photography can be directly converted into digital information. It can improve the resolution and display ability of images and break through the inherent limitations of conventional X-ray photography technology. Computer technology can be used to realize various image post-processing functions and increase the level of displayed information; The radiation dose and radiation damage of X-ray photography can be reduced, and multi-level image information can be captured only by one exposure, which meets the requirements of diagnosis. When the exposure is insufficient or excessive, the image can be displayed better to some extent, and the re-shooting caused by improper selection of X-ray photography parameters can be avoided, thus reducing the X-ray dose of the subject. In addition, the image can be stored on the disk, which avoids the degradation of image quality caused by the long storage time of traditional photos, and is convenient for photo printing, online transmission, consulting and resource sharing. Moreover, the improvement of its image quality lies in the post-processing of the computer, which can be improved by techniques such as window width, window level adjustment and edge enhancement, and has played a huge role in the war against SARS without smoke. "Energy subtraction" is one of the computer X-ray photography image processing technologies, which is mainly used for chest examination at present. It can obtain the original image of chest, simple lung tissue image, simple rib image and other image information at the same time, and eliminate the image of bone or soft tissue, thus providing strong evidence for rib fracture or lung mass and its damage to ribs. The main advantage is 1. The dose of X-ray photography is smaller than that of traditional X-ray photography. 2. The digitized information obtained by the computer X-ray photography (CR) system can be transmitted to the lower archiving and communication system (picture archiving and communication system; PACS) to realize telemedicine.