The working principle of CR: the first step, X-ray exposure so that the IP image plate image latent shadow; the second step, the IP plate into the laser scanner for scanning, in the scanner IP plate latent shadow is excited and then converted into visible light, read and then converted into electronic signals, transmitted to the computer will be displayed on the digital image, but also to print out the diagnostic requirements of the laser photo, or stored in the tape. disk and CD-ROM storage, The structure of CR system is relatively simple and easy to install; IP image board can be applied to existing X-ray machines, directly realizing the digitization of general radiological equipment, improving work efficiency and bringing great social and economic benefits to hospitals. It is safer to reduce the patient's dose of irradiation; CR's display of bone structure, articular cartilage and soft tissue is significantly better than that of traditional X-ray imaging; it is easy to display mediastinal structures such as blood vessels and trachea; the detection rate of nodular lesions in lungs is higher than that of traditional X-ray imaging; CR (Digital Radiographic Imaging Board) is superior to that of traditional X-ray imaging in the observation of calcium-containing lesions such as intestinal pneumatosis, pneumomediastinum and calculus; it can be used for double-contrast gastrointestinal contrast imaging in the display of gastric microcellulites, microscopic lesions and intestinal mucosal folds. DR (Digital Radiography), digital radiography, the system consists of a digital image acquisition board (detector board, Flat Pannel Dector, on its internal structure can be divided into CCD, amorphous silicon, amorphous selenium several), special filters BUCKY digital image acquisition control radiography system digital image workstation composition. System digital image workstation composition. Its working principle is in the amorphous silicon image board, X-rays through the fluorescent screen into visible light, and then by the TFT thin-film crystal circuitry according to the matrix pixels into electronic signals, transmitted to the computer, the image will be displayed through the monitor, but also can be transmitted into the PACS network. DR technology can be divided into two categories of non-direct conversion and direct conversion of the X-ray detector from the imaging principle. The first generation of non-direct conversion using a sensing screen plus optical lens coupled to the CCD (charge coupled device) to obtain digital X-ray images. The second generation is the use of direct conversion technology, i.e., flat panel detector. x-ray digital image of high spatial resolution, dynamic range, its image can observe the contrast is less than 1%, the diameter of the object is greater than 2MM, in the patient's body measured to the surface of the x-ray dose is only 1/10 of the conventional photographic. x-ray information digitization can be processed by the computer. By improving the details of the image, reducing the image noise, gray scale, contrast adjustment, image magnification, digital subtraction, etc., it shows the characteristic information that cannot be seen in the unprocessed image. Computer-aided diagnosis can be performed with the help of artificial intelligence and other technologies for quantitative image analysis and feature extraction.
DSA is digital subtraction angiography, which is used to image blood vessels by injecting a contrast medium, such as in interventional examinations, and is used more often in cerebral vessels, coronary vessels (vessels that nourish the heart muscle), and so on, to avoid the influence of bones and organs, and to visually determine the shape of the blood vessels and the changes in their condition. At the same time, it is also possible to inject drugs into the lesion at the same time as developing the image, which can also have a therapeutic effect, but this would have to be counted in the field of interventional therapy.
Other imaging tests include ultrasound, molybdenum X-ray, radionuclide imaging, and endoscopy, all of which are useful for a variety of diseases.
Also, the previously introduced X-ray, CT, DSA, such tests are radiation, prolonged exposure to the human body has a bad effect, MRI is not harmful to the human body, but the price is more expensive, and