What is the difference between DR and CR

I. Imaging Principle - DR is an X-ray direct conversion technology, which uses a flat panel detector to receive X-rays, the flat panel detector has CCD, amorphous silicon, amorphous selenium and other types of amorphous selenium, and there are crystal circuits covered on the detector to convert the X-ray photons directly into a digitized current. - CR is an indirect conversion technique for X-rays, which utilizes an image plate as an X-ray detector. The image plate emits fluorescence immediately after it is irradiated with X-rays, and in the process loses nearly half of the energy of the X-rays and stores the residual X-ray intensity changes in the spatial image in the form of a latent image. The latent image signal decays with time. Scanner scanning image wrench, latent image signal converted to visible light by the laser, through the photoelectric system to the computer imaging. Image quality 1. Image resolution - CR system due to its own structure, when subjected to X-ray irradiation, the phosphorus particles in the image trigger X-ray scattering, causing latent image blurring, more serious in the process of reading out the image, the scanner's excitation of light, in the penetration of the image trigger when the depth of the scattered along the path of the formation of stimulated fluorescence, so that the image blurred, reducing the resolution of the image. - DR systems do not have optical blurring, and their sharpness is mainly determined by pixel size. High spatial resolution, wide dynamic adjustable range, and abundant image post-processing functions make it possible to obtain satisfactory diagnostic results.2 ． Exposure Tolerance Relative to the ordinary screen-gel system, CR and DR both have wide tolerance due to the adoption of digital technology and wide dynamic range, but the DR system allows for technical errors in photography, and even in some occasions where the conditions are difficult to master, very good images can be obtained.3 ． Noise - There are many sources of noise in CR systems, including structural noise in the image wrench, fluctuations introduced in the conversion and detection of X-ray photons, laser power drift, drift in the position of the laser beam, fluctuations in the laser beam laser image wrench issued by the odds, and noise in the electronic chain. - Noise in the DR system is mainly structural noise, but because the DR can automatically recover the detector array before directly receiving the image, so the structural noise is greatly reduced, compared with the DR signal-to-noise ratio is much higher than CR. Third, the exposure dose DR system can directly acquire digital image data, while the CR system is to use the residual latent image to generate images, and with the passage of time, the signal attenuation exists, therefore, compared with the DR and screen glue system, the CR X-ray quantum conversion rate (DQE) is relatively low, the exposure dose is required to be high. Comparison of workflow - CR system to produce an image of the IP plate needs to be exposed, and then get the scanner read out, the whole process requires multiple steps, the time is longer. - In the DR system, the image can be obtained within 40 seconds after the end of the exposure, and the detector can be fixed in the equipment, the technician does not need to move the detector, reducing labor intensity, saving time and improving work efficiency. Fifth, network integration CR and DR systems, the acquisition of digital images, can be networked. However, DR is a direct conversion technology, integrated DICOM3.0 standard protocols to make DR network integration characteristics stronger. DR technology has revolutionized conventional projection X-ray imaging, many aspects are better than CR and screen glue system.