Spyrou G, Tzanakos G, Nikiforides G, Panayiotakis G
Medical Physics Department, School of Medicine, University of Patras, Greece.
Phys Med Biol. 2002 Mar 21;47(6):917-33.
A simulation model of mammographic x-ray sources with finite size has been developed. The model is based on Monte Carlo methods and it takes into account the electron penetration inside the anode, the anode geometry and material, as well as the resulting heel effect and the spectral and spatial distribution of x-rays. This x-ray source simulation model has been embedded into an earlier developed simulation package of a mammography unit. The main outputs of this model are Monte Carlo generated images that correspond to the irradiation of properly designed phantoms. In this way it is possible to make studies of the influence of x-ray source characteristics on MTF. This paper presents the development of the mammographic x-ray source model, accompanied by a set of simulation studies concerning the influence of magnification effects as well as that of the x-ray spatial and spectral distribution on the mammographic spatial resolution for a certain magnification factor (m = 1.4). The validity level of the model, as well as its limitations and perspectives, rise through comparisons with experimental and theoretical data.
已经开发出一种具有有限尺寸的乳腺X射线源模拟模型。该模型基于蒙特卡罗方法，考虑了电子在阳极内部的穿透、阳极的几何形状和材料，以及由此产生的足跟效应和X射线的光谱与空间分布。这个X射线源模拟模型已被嵌入到一个早期开发的乳腺摄影装置模拟软件包中。该模型的主要输出是蒙特卡罗生成的图像，这些图像对应于对经过适当设计的体模的照射。通过这种方式，可以研究X射线源特性对调制传递函数（MTF）的影响。本文介绍了乳腺X射线源模型的开发，并伴有一组模拟研究，内容涉及放大效应以及X射线空间和光谱分布对特定放大倍数（m = 1.4）下乳腺摄影空间分辨率的影响。通过与实验和理论数据的比较，提高了模型的有效性水平以及其局限性和前景。
