Honda Chika, Ohara Hiromu, Ishisaka Akira, Shimada Fumio, Endo Tokiko
MG Research and Development center, Konica Corporation, Japan.
Igaku Butsuri. 2002;22(1):21-9.
Phase contrast X-ray imaging has been studied intensively using X-rays from synchrotron radiation and micro-focus X-ray tubes. However, these studies have revealed the difficulty of this technique's application to practical medical imaging. We have created a phase contrast imaging technique using a molybdenum X-ray tube with a small focal spot size for mammography. We identified the radiographic conditions in phase contrast magnification mammography with a screen-film system, where edge effect due to phase contrast overcomes geometrical unsharpness caused by the 0.1mm-focal spot of a molybdenum X-ray tube. The edge enhancement due to phase imaging was observed in an image of a plastic tube, and then geometrical configuration of the X-ray tube, the object and the screen-film system was determined for phase imaging of mammography. In order to investigate a potential for medical application of this method, we conducted evaluation of the images of ACR 156 mammography phantom. We obtained higher scores for phase imaging using high speed screen-film systems without any increase of X-ray dose than the score for contact imaging using a standard speed screen-film system.
已经使用来自同步辐射和微焦点X射线管的X射线对相衬X射线成像进行了深入研究。然而，这些研究揭示了该技术应用于实际医学成像的困难。我们利用具有小焦点尺寸的钼X射线管创建了一种用于乳腺摄影的相衬成像技术。我们确定了使用屏片系统进行相衬放大乳腺摄影的射线照相条件，其中相衬引起的边缘效应克服了由钼X射线管的0.1mm焦点引起的几何不清晰度。在塑料管的图像中观察到了相成像引起的边缘增强，然后确定了用于乳腺摄影相成像的X射线管、物体和屏片系统的几何配置。为了研究该方法在医学上的应用潜力，我们对ACR 156乳腺摄影体模的图像进行了评估。与使用标准速度屏片系统进行接触成像的分数相比，我们使用高速屏片系统进行相成像时在不增加X射线剂量的情况下获得了更高的分数。
