レスポンス関数(MTF)評価によるリニアックグラフィー第一報 増感紙とフィルムの選定

抄録

In high energy X and γ-ray (linacgraphy, cobaltgraphy etc.) absorption is depend upon the electron density of the absorbing material rather than its atomic number. Because of this, bone detail is not prominent but soft tissue shadows are better visualized. We selected the combinations of intensifying screen and X-ray film by using MTF, in order to improve the image quality of linacgraphy. In this paper, the radiographic localization of lesions for the proper place of the treatment are investigated, used mainly medical X-ray film. The results obtained are as follows ; 1. We had like to mention about intensifying screen, front screen was best compere with the double screen faced screens and back screen are worse when we consider MTF. 2. Lead screen was better than fluorometallic screen for the improvement of image quality and, it had few intensifying effect. 3. Industrical X-ray film of fine grain was given good image quality rather than medical one. 4. It is proper that film object distance should keep 15〜20cm since the Graedel-effect enlargement effect were contributed the improvement of image quality. 5. Exposure factors of linacgraphy are 0.5rad (that means 0.5sec) using front lead screen and medical X-ray film, and target-film distance is 1m. We can take linacgraphy of every part using this conditions.