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X射线管是用来产生X线的,因此,X线影象质量的好坏,首先取决于X线管的结构。如众所知:一个大容量、小焦点的管球就较容量小、焦点大的管球所产生的X线影象质量为好。所以从一八九五年发现X线到现在,X射线管经历了几次大的革新;从离子管进展到热电子管,从固定阳极发展到旋转阳极,以及近年来提高旋转阳极的速度,改进阳极盘的质量、扩大阳极盘的直径,使X线管容量从数千瓦提高到200千瓦以上。电流高达3000毫安,阳极焦点面积则缩小至1毫米平方以内。目的都是为了不断改进放射诊断学所需要的影象质量。尽管X线管发展到现在这样高的水平,但目前的玻璃壁X线管仍然存在着难以克服的影响X线影象质量的严重缺陷。这就是:
X-ray tube is used to generate X-ray, therefore, X-ray image quality is good or bad, first of all depends on the structure of the X-ray tube. As we all know: a large capacity, small focus of the tube on the smaller capacity, the focus of the tube produced by the X-ray image quality is better. So from the X-ray discovery in 1895 to the present, the X-ray tube has undergone several major innovations; it has progressed from ion tubes to hot electron tubes, from fixed anodes to rotating anodes, and in recent years, to improve the speed of rotating anodes, to improve The quality of the anode disk expands the diameter of the anode disk to increase the capacity of the X-ray tube from several thousand watts to over 200 kilowatts. Current up to 3000 mA, the anode focal area is reduced to 1 mm square. The aim is to continuously improve the quality of the images needed for diagnostic radiology. Although the X-ray tube has developed to such a high level now, the current glass-wall X-ray tube still has serious defects that can not be overcome and affect the X-ray image quality. This is: