III.消化器用における自動露出装置について(X線装置の自動露出機構について)

概要

論文の詳細を見る
Recently, almost all X-ray diagnostic devices for GI series are provided with automatic control unit of exposure time in radiography. However, it is not so simple to obtain always X-ray pictures of best quality which contain constant film density suited with the diagnostic examination of GI series, because the performance of the automatic control unit of exposure time in radiography is under the influence of tube voltage, thickness of the object, responsibility for very short time exposure, the covered area with contrast material on the input screen and the exposed area in the spot filming. The authors investigated the effect on the film density in respect to the above mentioned factors which have influence on the performance of the automatic control unit of exposure time in radiography, especially on the unit combined with an image intensifier. The results are as follows : 1) Film density as a function of tube voltage or the thickness of the object is more stable for the generators of 12 pulse three phase rectification than for the generators of single phase rectification. 2) The diagnostic table of over-tube system is superior to those of under-tube system on the film density as a function of tube voltage, and when using image intensifier fluorography the effect of the thickness of the object on the film density is reduced to a minimum. 3) Although the effect of covering on the input screen of an image intensifier on the film density is maximum at the central area of the screen, the effect of scattered radiation on the film density can not be negligible. The smaller the thickness of the object is, the more conspicuous is the increase of the film density and when the location of covering in the exposed object grows distant from the table-top the increase of the film density becomes more conspicuous. Generally speaking, the automatic control unit of exposure time in radiography, because of various supplemental circuits, dischages its essential function which produces a constant film density as far as the object of homogeneous construction concerned. However, inability of this sort of unit due to covering of photo pick-up area with contrast material is an urgent problem to be solved.
社団法人日本放射線技術学会の論文
1980-09-01

III.消化器用における自動露出装置について(X線装置の自動露出機構について)

スポンサーリンク

概要

著者

関連論文

スポンサーリンク