What's the difference between CR and DR? (turning)

DR is a direct digital X-ray photography system, which consists of electronic cassette, scanning controller, system controller and image monitor. It directly converts X-ray photons into digital images through electronic cassette, which is a generalized direct digital X-ray photography. In a narrow sense, direct digital photography, that is, DDR(DirectDigit Radiography), usually refers to digital photography by using the image direct conversion technology of flat panel detector, which is a real direct digital X-ray photography system. The common point of DR and CR is to convert X-ray image information into digital image information, and its exposure latitude has some advantages compared with ordinary intensifying screen-film system: the dynamic range of CR and DR is wide, and the exposure latitude is large, which allows technical errors in photography, even in some parts where exposure conditions are difficult to grasp; CR and DR can perform various image post-processing according to clinical needs, such as various image filtering, window width and window level adjustment, zoom roaming, image mosaic and distance, area and density measurement, etc., which provide technical support for detailed observation, before and after comparison and quantitative analysis in image diagnosis. 1. The performance comparison between them is as follows: 1. Imaging principle: DR is a direct X-ray conversion technology, and selenium is used as an X-ray detector, so there are few imaging links; CR is an indirect X-ray conversion technology. Using an image board as an X-ray detector, there are more imaging links than Dr.2.. Image resolution: DR system has no image blur caused by optical scattering, and the clarity is mainly determined by the pixel size; Because of its own structure, when the CR system is irradiated by X-rays, the phosphorus particles in the image plate scatter X-rays and cause the latent image to be blurred. In the process of reading the latent image, the excitation light of the laser scanner scatters when it passes through the deep part of the image plate, forming stimulated fluorescence along the optical path, blurring the image and reducing the resolution of the image. Therefore, the current CR system mainly has poor time resolution, which can't satisfy the display of dynamic organs and structures. 3.DR is the future development direction, but at present, the structure of DR electronic cassette is14 in×17 in (1in = 2.54 cm). Due to technical limitations, the joints of each piece cannot be seamless. Once one piece is damaged, four pieces must be replaced. 4.CR system is more suitable for X-ray plain film photography, and its non-dedicated model can be matched with many conventional X-ray cameras, which is more suitable for X-ray photography of complex parts and postures; DR system is more suitable for fluoroscopy, spot lighting and various contrast checks. Due to the flux limitation of single machine, it is not easy to use multiple machines to work at the same time to replace conventional X-ray equipment in large hospitals, but it is more suitable for small medical units and clinics to use one machine for multiple purposes. In fact, CR and DR systems will be a pair of parallel development systems for a long time. Second, the characteristics of digital X-ray imaging technology. Digital X-ray machine is an advanced X-ray machine which combines computer digital image processing technology with X-ray radiation technology. On the basis of the original diagnostic X-ray direct film imaging, the real-time image is digitally processed by A/D conversion and D/A conversion, and then the image is digitized. Its appearance broke the traditional concept of X-ray machine and realized the transformation from analog X-ray image to digital X-ray image that people dreamed of. 1, features: 1. Its most prominent advantages are high resolution, clear and delicate images, and doctors can perform various image post-processing such as digital subtraction as needed to obtain ideal diagnosis results. Secondly, the device can display digital images in real time under fluoroscopy, and doctors can take digital photos according to the patient's condition, and then extract rich and reliable clinical diagnosis information from them through a series of image post-processing functions such as edge enhancement, magnification, black-and-white flipping, image smoothing, etc., especially to provide good diagnostic conditions for the discovery of early lesions. Thirdly, the digital image formed by digital X-ray machine needs less X-ray measurement than traditional film imaging, so it can obtain high-definition image with lower X-ray dose and reduce the harm of X-ray radiation to patients. Fourthly, because of changing the traditional film photography mode in the past, the original image management mode can be cancelled in the hospital radiology department, and the film warehouse can be omitted, and the computer filmless file management mode can be used instead, which can save a lot of money and space and greatly improve work efficiency. In addition, due to the appearance of digital X-ray images, the history that X-ray images could not enter the hospital PACS system ended, which provided great convenience for the hospital to conduct remote expert consultation and online communication. In addition, the device can also display multiple images and compare them, which is helpful for doctors to distinguish and diagnose accurately. Through the image rolling playback function, you can also recall the whole fluoroscopy process for doctors. The quality of digital image and the amount of image information contained can be comparable to that of traditional X-ray imaging. The image processing system can adjust the contrast. Therefore, the best visual effect can be achieved; The tolerance range of photographing conditions is large; The patient received less X-rays. Image information can be stored and transmitted by magnetic disk or optical disk, which is the advantage of digital image. Digital images and traditional X-ray images are overlapping images of the whole area, so the areas that can be photographed by traditional X-ray can also be imaged by DR, and the observation and analysis of DR images are the same as those of traditional X-ray. The difference is that the DR image is composed of a certain number of pixels. Digital image is superior to traditional X-ray imaging in displaying bone structure, articular cartilage and soft tissue, and quantitative analysis of mineral salt content is also feasible. Digital images can easily show mediastinal structures such as blood vessels and trachea. The detection rate of nodular lesions is higher than that of traditional X-ray images, but pulmonary interstitial and alveolar lesions are not as good as traditional X-ray images. DR is superior to traditional X-ray images in observing calcium-containing diseases such as intestinal pneumatosis, pneumoperitoneum and calculus. Tomography using digital images is superior to X-ray tomography. Gastrointestinal double contrast radiography is superior to traditional X-ray radiography in displaying gastric cells, tiny lesions and intestinal mucosal folds. DR is a new imaging technology, which is superior to the traditional X-ray image in many aspects, but it is still difficult to replace the traditional X-ray image in terms of cost performance.