What are the advantages and disadvantages of digital imaging technology?

Advantages and disadvantages of X-ray digital imaging technology

Advantages of digital X-ray imaging technology: Traditional X-ray photography takes film as the medium, and integrates the functions of image acquisition, display, storage and transmission, which limits the promotion of single function. Digital X-ray imaging technology decomposes these functions into different independent parts, so that each function can be optimized independently.

Quantum detection efficiency and x-ray dose of (1) x-rays

The detection efficiency of traditional X-ray photography is only 20%-30%, while the quantum detection rate of digital X-ray imaging system can reach more than 60%. Therefore, compared with the dose of traditional X-ray photography, the dose of digital X-ray imaging can be greatly reduced. At the same time, using its image processing function, the image data obtained by one exposure can obtain the same effect as the traditional method that needs to change the conditions and expose multiple times. Reducing the exposure times in the application can also reduce the radiation dose of the examinee and improve the use efficiency of X-rays.

(2) Contrast resolution and spatial resolution of the image

X-ray examination is to judge whether the internal tissue structure of human body is normal through the difference of material density in human body, which leads to the difference of X-ray attenuation, thus causing the difference of image density and some details on X-ray film. The larger the dynamic range of X-ray detector, the stronger the detection ability of low contrast (small density difference) objects, the more information it can provide, and the greater the reference value of the obtained images for doctors to diagnose diseases. The dynamic range of ordinary X-rays is about 1 ~ 100, so only objects with tissue density difference greater than 1% can be distinguished. In digital X-ray imaging technology, the dynamic range of detector system can reach 1 to 5000 and 1 to 10000, so X-ray digital photography can distinguish objects with tissue density difference less than 1%, with high contrast resolution and large exposure latitude. The spatial resolution of X-ray digital images is generally not as good as that of ordinary X-rays. Because spatial resolution is not the only factor that determines image details. In the case of poor contrast, although the spatial resolution of the image is high, the human eye still can't distinguish the changes of its details. Digital X-ray imaging technology has a large dynamic range of detectors, so it has good detectability for low-contrast objects. Image processing technology can be used to transform the gray level of low-contrast objects, so that this tiny gray level difference can be highlighted. Therefore, although the spatial resolution of X-ray digital image is lower than that of traditional X-ray film, it can still provide doctors with much richer diagnostic basis than traditional X-ray film image after image processing technology.

(3) photographic conditions

Traditional X-ray images need continuous radiation when observing perspective images; Digital X-ray imaging technology has pulse perspective, no need for continuous radiation, and image freezing function. It can choose the best time to freeze the image and observe and analyze the image without X-ray radiation. The tolerance of digital X-ray imaging system is large, and automatic irradiation control is not needed, which can avoid re-shooting due to improper parameter selection. Compared with traditional X-ray imaging system, the tolerance is greatly improved, which is conducive to improving diagnostic efficiency.

(4) Image processing, storage and transmission

Images obtained by traditional X-ray photography cannot be processed. If the image quality can't meet the diagnostic requirements for various reasons, the inspection can only be repeated because the image processing can't be improved. When it is necessary to set the pictures of various image examinations together for reference, their image states cannot be changed as needed. X-ray digital image can not only use various image processing technologies to process the image and improve the image quality, but also display the images obtained by various diagnostic technologies at the same time, complement each other or even merge them, which greatly increases the diagnostic information. Traditional X-ray photographic images use film as image carrier and medium, and store a large amount of image data. With more and more photos, it takes a lot of manpower and material resources to save, manage and find them. Moreover, photos stored for a long time will gradually deteriorate, reducing the image quality. Images obtained by various imaging devices are stored separately, so it is difficult to find and transmit images and photos quickly. Digital X-ray imaging technology is to store, manage, transmit and display images and related information in a digital electronic way by using large-capacity disk and optical disk storage technology, so that clinical medicine can get rid of the dependence on traditional hard copy technology, observe, store and trace more efficiently, and save time, land and labor with low consumption. Digital images make images easy to transmit and can achieve data consistency. Digital images can be networked with hospital information system, radiation information system and personal health records through image archiving and transmission system, and can also be transmitted remotely through telephone network and Internet for remote diagnosis or consultation. The disadvantage of digital perspective is that the image intensifier will lose 5% contrast. Due to the diffusion of light on the input and output screen, the spatial resolution is not as good as that of ordinary X-ray films, and the image quality is slightly worse than that of X-ray films. Because of the small dynamic range of camera tube and DF system, it is impossible to find tiny tissue differences. The field of view of the intensifier tube is small and the observation range is limited. Deficiency of CR system: poor time resolution, unable to meet the display of dynamic organs and structures. In addition, in the display of fine structure, compared with the intensifying screen/film system for X-ray inspection, the spatial resolution of CR system is sometimes a little insufficient, but in many cases it can be made up by direct amplification photography. CR equipment is expensive.