What's the difference between DR and CR?

1. Imaging principle DR is a direct X-ray conversion technology, which uses a flat panel detector to receive X-rays. Flat panel detectors include CCD, amorphous silicon, amorphous selenium, etc. The crystal circuit covered on the detector directly converts X-ray photons into digital current. Cr is an indirect X-ray conversion technology. It uses an image plate as an X-ray detector, and the image plate emits fluorescence immediately after being irradiated by X-rays. In this process, the energy of X-rays is lost by nearly half, and the remaining X-ray intensity changes in the spatial image are stored as latent images. The latent image signal decays with time. When the scanner scans the image, the latent image signal is converted into visible light by the laser and sent to the computer for imaging through the photoelectric system. 2. Image quality 1. Due to the structure of the image resolution Cr system, when irradiated by X-rays, phosphorus particles in the image panel will scatter X-rays, resulting in blurred latent images. More seriously, in the process of reading the image, the excitation light of the scanner scatters when penetrating the deep part of the image panel, forming stimulated fluorescence along the path, blurring the image and reducing the image resolution. There is no optical blur in DR system, and its clarity is mainly determined by the pixel size. It has high spatial resolution, wide dynamic adjustable range and rich image post-processing functions, thus obtaining satisfactory diagnosis results. 2. Compared with ordinary screen glue system, CR and DR in exposure latitude have wide dynamic range and wide tolerance due to the adoption of digital technology. However, the DR system allows technical errors in photography, and even if some conditions are difficult to grasp, good images can be obtained. 3. There are many noise sources in noise CR system, including structural noise triggered by image, fluctuation introduced in X-ray photon conversion and detection, drift of laser power, drift of laser beam position, fluctuation of laser image trigger probability and noise in electronic chain. The noise in DR system is mainly structural noise, but the structural noise is greatly reduced because DR can automatically restore the detector array before receiving the image directly. In contrast, the signal-to-noise ratio of DR is much higher than that of CR. Thirdly, the exposure dose DR system can directly obtain digital image data, while the CR system generates images by using residual latent images. As time goes on, the signals will be attenuated. Therefore, compared with DR and screen glue system, the X-ray quantum conversion rate (DQE) of CR is relatively low, and the exposure dose requirement is higher. Four. Workflow comparison Cr system needs to expose the IP board first, and then take it to the scanner for reading. The whole process needs multiple steps and takes a long time. In the DR system, the image can be obtained within 40 seconds after exposure, and the detector can be fixed in the equipment, so technicians do not need to move the detector, which reduces the labor intensity, saves time and improves the work efficiency. 5. The network integrates CR and DR systems, both of which are digital images and can be networked. But DR is a direct conversion technology, and the integrated DICOM3.0 standard protocol makes the network integration characteristics of DR stronger. DR technology has revolutionized the traditional projection X-ray image and is superior to CR and screen glue system in many aspects.