1994 年 29 巻 4 号 p. 411-416
It is necessary to know the dose distribution in an irradiated body to evaluate patient doses during radiographic procedures. In this paper, we calculated dose distributions in an irradiated body on the conditions of actual radiographic exposures, by means of a Monte Carlo code with a human voxel phantom. The human voxel phantom, which was used in this calculation code, was constructed with voxels specified as each of soft tissue, lung, bone or air. The shape of this voxel phantom can be changed unrestrictedly by alteration of the voxel size and/or its material which is specified to each voxel. This calculation code, which gives a dose distribution data, is useful in medical exposure analysis, for example, variation of patient doses with exposure conditions or evaluation of organ doses. The dose distributions in a chest radiographic examination and a abdominal examination were calculated by this code. The isodose curves in these exposures were distorted in the lung area, and it was found that the lung having low density influenced the dose distribution from both primary and scattered photons.