John V, Ewen K, Bringewald B
Strahlentherapie. 1978 Oct;154(10):734-7.
The soft radiation within the inhomogeneous spectrum of bremsstrahlung, being unable to penetrate the object and not contributing to the build-up of the xeroradiographic picture, only being the cause of additional radiation exposure, is considerably reduced by means of added filters, copper filters in particular. This effect can be demonstrated qualitatively by means of the recorded X-ray spectra. In comparison with the standard record it is possible by hardening of the radiation to reduce the surface dose by a factor 8 at a tube voltage of 120 kV, and by a factor 10 at a tube voltage of 130 to 150 kV if a 0.5 mm thick copper filter is added. The surface dose measured with high-filtration in xeroradiography is within the same order of magnitude as the dose obtained with a conventional film-foil-combination (Cronex 4/Cawo high-definition foil, 75 kV, automatic exposure control, time of development 90 s) and amounts to circa 0.1 R. A loss of information in so-called high-filtration xerograms as compared to conventional xerograms could be excluded, at least with regard to the test object. The practicability of this method e.g. for angiography, particularly angiographic exploration of the limbs, needs further clinical examination.
韧致辐射非均匀光谱中的软辐射无法穿透物体，对干板X线照相图像的形成没有贡献，只是额外辐射暴露的原因，通过添加滤过器，特别是铜滤过器，可使其大幅减少。这种效果可以通过记录的X射线光谱定性地证明。与标准记录相比，如果添加0.5毫米厚的铜滤过器，在管电压为120 kV时，通过使辐射硬化可将表面剂量降低8倍，在管电压为130至150 kV时可降低10倍。在干板X线照相术中用高滤过测量的表面剂量与用传统胶片 - 箔组合（Cronex 4/Cawo高清箔，75 kV，自动曝光控制，显影时间90秒）获得的剂量处于同一数量级，约为0.1伦琴。至少对于测试对象而言，可以排除所谓的高滤过干板X线照片与传统干板X线照片相比的信息损失。这种方法例如用于血管造影，特别是肢体血管造影探查的实用性，需要进一步的临床检查。
