Abstract
The authors examined the effect of x-ray protection of the mufti-shutter, which can artitrarily and continuously change the size of radiation field as occasion requests. The following results have been obtained:
1) The employment of the multi-shutter in x-ray radiography was able to markedly reduce the dose of scattered rays around the photographed body as compared with the ordinary radiation cones. It was effective not only for the x-ray protection, but also for obtaining the x-ray pictures enriched with contrasts.
2) The employment of this shutter enabled the use of high tube voltage and decreased the development of scattered rays from the photographed body. The combination of this shutter with tube-voltage may be able to minimize the danger of radiation injuries.
