Medical network - July 11, the image intensifier was born in the 1950 s, is a great product, his appearance, put an end to the history of the screen image. It makes the s X-ray dose reductions and technicians operating convenience, are improved greatly, the patient and the technician got a greater degree of protection.
Also, with the development of technology, image intensifier go today, has gradually entered the old age, be replaced fate has been arranged for a long time. With the breakthrough of various dynamic image technology, image intensifier imaging technology have been phased out.
Isn't here today, the memory of the image intensifier, and everyone together to analyze why the image intensifier is eliminated. I think there are several main reasons:
The first: imaging width is small, easy to misdiagnosis and misdiagnosis.
Can be seen from the chart, the left is a shadow on all images of the digestive tract imaging into, can only part of the checked parts contained within a wide; On the right is the mainstream of large size image, a wide can contain all the digestive tract in the checked parts, which can be more convenient to observe and diagnose.
Under normal circumstances, the shadow imaging, constantly moving the location of the shadow, follow the contrast medium flow direction, the real-time observation, to better capture the focal point, but to contrast velocity faster check easily because of its mobile equipment can't keep up with, to be observed. In esophageal imaging, for example, is prone to shadow increase with contrast agents dislocation phenomenon.
Imaging width is small, be a shadow to add a very important reason for the limited development. That, whether can you put the shadow do big? In fact, the film of working principle, with the increase of imaging is wide, the volume of the whole film increases, the great changes and eventually lead to cannot be used in coordination with the whole machine, so the biggest shadow to reach 12 inch, commonly used is given priority to with 7/9 inch.
Second, easy distortion distortion, easy misdiagnosis and misdiagnosis.
Image intensifier, due to its working principle, the distortion determines its easy to distortion. Distortion distortion mainly has two types: one is round equilibrium geometry distortion; Another kind is asymmetric, often referred to as S distortion.
Geometric distortion is the cause of the X-ray image projected onto a surface, the entrance to the objects on a plane in the input image produced by a the edge of the screen than the middle of the image, this kind of distortion and the input screen geometry and the position of the X-ray source, therefore is called the geometric distortion. A negative lens distortion will be part of the compensation caused by the curvature of the input screen is the distortion, thus can reduce the total distortion of the output image, but cannot avoid distortion phenomenon.
Another type of distortion is called S distortion, this is because the rectilinear characteristic s-shaped image object, this phenomenon is caused by the earth's magnetic field or the surrounding equipment caused by the interference of stray magnetic field.
Because of shadow distortion distortion (pictured), so the diagnosis of X-ray imaging findings have serious interference, easily lead to misdiagnosis and misdiagnosis.
Third, image contrast is low and easy to misdiagnosis and misdiagnosis.
At present the mainstream of the dynamic range of X-ray imaging in 14 or 16, dynamic range and image intensifier is only 10. In other words, the current mainstream dynamic imaging products dynamic range is the shadow of 16 or 32 times.
Dynamic range is different, the result of the diagram below. The comparison of the dynamic range of the left and right, many obvious difference, so the image is exquisite, colour and so on all vary widely.
Shadow image below, the dynamic range of 10, in the image on the observation of density difference between the small lesions, especially such as SARS, early pathological changes change exudative, diffuse lung imaging, will be helpless, can't correct diagnosis, which can easily lead to misdiagnosis and misdiagnosis.
Technology changes with each passing day, the product more earth-shaking changes. Image intensifier through its better days, go to the end of time. Medical imaging diagnosis, inevitably there will be more breakthroughs, remember the past, looking to the future, everything will become history. |
