RADIATION REDUCTION FILTER FOR USE IN MEDICAL DIAGNOSIS

摘要

In accordance with the present invention, there is provided an X-ray filter which significantly reduces low energy radiation normally absorbed by the examination object without significantly affecting the desired high energy radiation. The filter is comprised of one or more materials (12) containing as the major component elements selected from the group consisting of aluminum and elements having atomic number between 26 and 50 with the filter being selected to have X-ray filtering characteristics such that the intensity of X-rays having energies of 50 keV are reduced by about 8 % to about 35 % of the normal radiation levels. As a result of the construction immediately above, the filter of the present invention filters energy from the X-ray beam which is usually absorbed by the examination object and does not contribute to the radiographic image of the examination object. This is achieved with little, if any, increased loading of the X-ray tube which would otherwise reduce its effective life.