Baneva Yanka, Bliznakova Kristina, Cockmartin Lesley, Marinov Stoyko, Buliev Ivan, Mettivier Giovanni, Bosmans Hilde, Russo Paolo, Marshall Nicholas, Bliznakov Zhivko
Department of Physics and Biophysics, Medical University of Varna, Varna, Bulgaria.
Laboratory of Computer Simulations in Medicine, Technical University of Varna, Varna 9010, Bulgaria.
Phys Med. 2017 Sep;41:78-86. doi: 10.1016/j.ejmp.2017.04.024. Epub 2017 May 5.
In X-ray imaging, test objects reproducing breast anatomy characteristics are realized to optimize issues such as image processing or reconstruction, lesion detection performance, image quality and radiation induced detriment. Recently, a physical phantom with a structured background has been introduced for both 2D mammography and breast tomosynthesis. A software version of this phantom and a few related versions are now available and a comparison between these 3D software phantoms and the physical phantom will be presented.
The software breast phantom simulates a semi-cylindrical container filled with spherical beads of different diameters. Four computational breast phantoms were generated with a dedicated software application and for two of these, physical phantoms are also available and they are used for the side by side comparison. Planar projections in mammography and tomosynthesis were simulated under identical incident air kerma conditions. Tomosynthesis slices were reconstructed with an in-house developed reconstruction software. In addition to a visual comparison, parameters like fractal dimension, power law exponent β and second order statistics (skewness, kurtosis) of planar projections and tomosynthesis reconstructed images were compared.
Visually, an excellent agreement between simulated and real planar and tomosynthesis images is observed. The comparison shows also an overall very good agreement between parameters evaluated from simulated and experimental images.
The computational breast phantoms showed a close match with their physical versions. The detailed mathematical analysis of the images confirms the agreement between real and simulated 2D mammography and tomosynthesis images. The software phantom is ready for optimization purpose and extrapolation of the phantom to other breast imaging techniques.
在X射线成像中，人们制作了能够再现乳房解剖特征的测试物体，以优化诸如图像处理或重建、病变检测性能、图像质量以及辐射损伤等问题。最近，一种具有结构化背景的物理模型已被引入用于二维乳腺摄影和乳腺断层合成。现在有该模型的软件版本以及一些相关版本，本文将对这些三维软件模型与物理模型进行比较。
软件乳房模型模拟一个半圆柱形容器，里面装满了不同直径的球形珠子。使用专用软件应用程序生成了四个计算乳房模型，其中两个模型也有对应的物理模型，用于并排比较。在相同的入射空气比释动能条件下模拟乳腺摄影和断层合成中的平面投影。使用内部开发的重建软件重建断层合成切片。除了视觉比较外，还比较了平面投影和断层合成重建图像的分形维数、幂律指数β以及二阶统计量（偏度、峰度）等参数。
在视觉上，模拟的平面图像和断层合成图像与真实图像之间具有极佳的一致性。比较结果还表明，从模拟图像和实验图像评估的参数总体上非常吻合。
计算乳房模型与其物理版本显示出紧密匹配。对图像的详细数学分析证实了真实的和模拟的二维乳腺摄影及断层合成图像之间的一致性。该软件模型可用于优化目的，并可外推至其他乳房成像技术。
