controller, system controller, image monitor, etc. It is a direct digital radiography in the broad sense that X-ray photons are directly converted into
digitized images through the electronic cassette. The narrow sense of direct digital photography that
DDR (DirectDigit Radiography), usually refers to the use of flat panel detector image direct conversion technology
Digital Radiography, is the true sense of direct digital radiography system.
DR and CR **** the same point is the conversion of X-ray image information into digital image information, its exposure tolerance relative to
in the ordinary screen - film system reflects some advantages: CR and DR due to the use of digital technology, the dynamic range of
widespread, both have a wide exposure tolerance, thus allowing for technical errors in the photo, even in some exposure conditions
These two systems have a wide dynamic range, so that they can be used in a variety of ways, including the use of digital technology. CR and DR can perform a variety of image
post-processing according to clinical needs, such as various image filters, window width and position adjustment, magnification and roaming, image splicing, and distance, area
, density measurement and other functions, which can provide detailed observation, before-and-after comparison, quantitative analysis and other technical support for diagnostic imaging.
Supporting technology for diagnostic imaging, before-and-after comparison, and quantitative analysis. Comparison of their performance is as follows:
1. Imaging principle: DR is an X-ray direct conversion technology, which uses selenium as an X-ray detector, imaging ring
section less; CR is an X-ray indirect conversion technology, which uses the image plate as an X-ray detector, imaging links relative
to the DR more.
2. Image resolution: DR system is free from optical scattering and image blurring, and its clarity is mainly determined by the pixel
size; CR system, due to its own structure, when irradiated by X-rays, the phosphorus particles in the image plate make the
X-rays scatter, causing the blurring of the latent image; in the process of reading the latent image, the excitation light of the laser scanner passes through the
image plate, and the image board is used as the X-ray detector, and the image board is used as the X-ray detector.
Scattering occurs when the laser scanner's excitation light passes through the deep part of the image plate, forming excited fluorescence along the path, blurring the image and lowering the image
resolution. Therefore, the shortcomings of the current CR system are mainly the poor temporal resolution, which is not able to satisfy the display of the dynamic organs
and structures.
3. DR is the future direction of development, but at present, the structure of the DR electronic dark box 14 in × 17 in (1
in=2.54 cm) consists of four pieces of 5 in × 8 in, each piece of the seam due to the limitations of the process can not be done
no-seam, and once a piece of damage will lead to the four pieces of the replacement, not only expensive, but also need to modify the already
display of organs and structures, the CR system is mainly short of poor temporal resolution, can not meet the dynamic organs
and structure display. It is not only expensive, but also requires modification of the existing
existing X-ray equipment, while CR is relatively inexpensive, and multiple X-ray machines can be used at the same time, without changing the existing equipment
.
4. CR system is more suitable for X-ray plain film photography, its non-specific models can be matched with multiple conventional X-ray camera
use, and more suitable for complex parts and position of the X-ray photography; DR system is more suitable for fluoroscopy and spot film photography
and a variety of imaging examinations, due to the single-machine flux limitations of the work of a single machine, it is not easy to replace the large hospitals in the simultaneous work of multiple machines
This is the first time in the world that a single machine is used for X-ray film photography, but it is not easy to replace the work of multiple machines.
Conventional radiography equipment, but more suitable for small medical units and clinics for the purpose of multi-purpose machine. In fact,
CR and DR systems will be a pair of parallel development for quite some time.
Features of digital X-ray imaging technology
Digital X-ray machine is an advanced
X-ray machine formed by combining computer digital image processing technology and X-ray radiography. On the basis of the original diagnostic X-ray machine direct film imaging, through the A/D conversion and D/A conversion,
real-time image digital processing, and then make the image to realize the digitalization. Its appearance breaks the traditional X-ray machine
concept, realizing the people's dream of analog X-ray image to digital X-ray image transformation.
Features:
First, its most prominent advantage is the high resolution, clear, detailed images, doctors can be
such as digital subtraction and other image post-processing, in order to obtain the ideal diagnostic results.
Secondly, the device can display digital images in real time under fluoroscopy, and then the doctor can take digital photographs according to the patient's condition, and then through a series of image post-processing, such as edge enhancement, magnification, black and white flipping
, image smoothing and other functions, rich and reliable clinical diagnostic information can be extracted from it, especially for the discovery of early foci, which can provide good diagnostic conditions.
These are the most important features of the new technology, and they are the most important for the future.
Third, the digital X-ray machine formed by the digital image than the traditional film imaging needs to be
less X-ray metering, so it can be a lower dose of X-rays to get high-definition images, but also make the patient to reduce by the X-ray
radiation hazards.
Fourth, because it has changed the traditional film photography method, can make the hospital radiology department cancel the original
image management and eliminating the film storage room, and can be replaced by computerized archive management without film,
can save a lot of money and space, greatly improving work efficiency. In addition, due to the appearance of digital X-ray images
, the end of the X-ray images can not enter the history of the hospital PACS system, for the hospital to carry out remote expert consultation and network
on the exchange provides a great convenience. In addition, the device can also display multiple images for image comparison
, which is conducive to doctors' accurate judgment and diagnosis. Through the image scrolling playback function, it can also recall the whole fluoroscopic
visual examination process for doctors.
Clinical application of digital X-ray
Digital image quality and the amount of information contained in the image can be comparable to traditional X-ray imaging. The image processing
System can adjust the contrast. This allows for optimal visualization, a wider range of imaging conditions, and a reduction in the amount of X-rays the patient receives. The fact that image information can be stored on disk or CD-ROM and transmitted are all advantages of digitized
images.
Both digital and conventional X-ray images are overlapping images of the total area being imaged, so any area that can be imaged with conventional X-rays
can also be imaged with DR, and DR images can be viewed and analyzed in the same way as conventional X-rays.
The difference is that DR images are composed of a certain number of pixels.
Digital images are superior to conventional X-rays for the visualization of bone structure, junctional cartilage, and soft tissues, and they also allow
quantitative analysis of mineral salt content. Digital images can easily visualize mediastinal structures such as blood vessels and the trachea. The detection rate of nodal
lesions is higher than that of conventional radiography, but the visualization of interstitial and alveolar lesions is not as good as that of conventional radiography.
DR is superior to conventional radiography for the visualization of calcium-containing lesions, such as intestinal pneumoperitoneum, pneumomediastinum, and calculi.
Stratigraphy with digitized images is superior to X-ray stratigraphy. Gastrointestinal dual-contrast imaging is superior to conventional X-ray imaging for the visualization of gastric crypts, micro
small lesions, and intestinal mucosal folds.
DR is a new imaging technology, which is superior to traditional X-ray imaging in a number of aspects, but from the benefit-price
ratio, it is still difficult to replace traditional X-ray imaging. In clinical applications, DR is not as irreplaceable as CT and MRI.
Are you satisfied with the above answer?