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VOA常速英语新闻:全息图或可与CT及超声波扫描仪兼容

比目鱼 于2016-06-11发布 l 已有人浏览
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虽然全息显示尚处于初期阶段,但专家称,一旦投入生产,不仅与磁共振扫描仪兼容,也能与电脑断层扫描机(CT)和超声扫描仪兼容。
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Since the 1980s, doctors have used Magnetic Resonance Imaging machines, or MRI scanners, to look into patients’ bodies without exposing them to the harmful effects of X-rays.An alternating magnetic field created inside the MRI's tube excites hydrogen atoms in the body’s tissues, making them emit radio waves. Those waves can be turned into pictures, similar to X-ray images. The magnet of a new MRI, built by Siemens, has 7 tesla units, making it more than 100,000 (7/0.000065 = 107,692) times more powerful than the earth’s magnetic field. 

“Using something like 7-tesla imaging, you can do very high resolution imaging, you can get the contrast that you need in order to identify the particular sub-parts of the nuclei that you need, but even high-resolution two-dimensional black-and-white pictures are quite different from three-dimensional color renditions that can be viewed from all angles.Using MRI-generated images of water molecules moving within the brain’s white matter, scientists at the British company Holoxica created a hologram showing the connections between neurons. 

“The brain is such a complex three-dimensional structure, and sometimes it is quite difficult to describe, or understand, the actual connections.So to see it in 3-D, that may be a short cut to education, and it can reinforce the learning process.”The holographic display is still in prototype phase, but researchers say, once ready for production, it will be compatible not only with MRI machines but also with CT and ultrasound scanners.

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