一、原理医用x光机所采用的荧光屏,对接收的x射线的激发效率低,为得到较好的观察效果,需将输出剂量俗称毫安量增大。但即使剂量大,也无法进行明室透视。X线电视虽可以作明室透视,但因费用昂贵难以普及。在七十年代,随着科学技术的进 First, the principle of the medical x-ray machine used in the screen, the received x-ray excitation efficiency is low, in order to get a better observation, the output dose required to increase the amount of colloidal. However, even if the dose is large, it is impossible to carry out a clear room fluoroscopy. Although X-ray television can make room perspective, but difficult to popularize expensive. In the seventies, with the advancement of science and technology