IEEE Trans Med Imaging. 2018 Mar;37(3):712-723. doi: 10.1109/TMI.2017.2749685. Epub 2017 Sep 7.
In this paper, we aim to produce a realistic 2-D projection of the breast parenchymal distribution from a 3-D breast magnetic resonance image (MRI). To evaluate the accuracy of our simulation, we compare our results with the local breast density (i.e., density map) obtained from the complementary full-field digital mammogram. To achieve this goal, we have developed a fully automatic framework, which registers MRI volumes to X-ray mammograms using a subject-specific biomechanical model of the breast. The optimization step modifies the position, orientation, and elastic parameters of the breast model to perform the alignment between the images. When the model reaches an optimal solution, the MRI glandular tissue is projected and compared with the one obtained from the corresponding mammograms. To reduce the loss of information during the ray-casting, we introduce a new approach that avoids resampling the MRI volume. In the results, we focus our efforts on evaluating the agreement of the distributions of glandular tissue, the degree of structural similarity, and the correlation between the real and synthetic density maps. Our approach obtained a high-structural agreement regardless the glandularity of the breast, whilst the similarity of the glandular tissue distributions and correlation between both images increase in denser breasts. Furthermore, the synthetic images show continuity with respect to large structures in the density maps.
在本文中，我们旨在从三维乳房磁共振图像 (MRI) 生成乳房实质分布的真实二维投影。为了评估我们模拟的准确性，我们将我们的结果与从补充全视野数字乳房 X 光摄影获得的局部乳房密度（即密度图）进行比较。为了实现这一目标，我们开发了一个完全自动化的框架，该框架使用乳房的特定于主体的生物力学模型将 MRI 体注册到 X 射线乳房 X 光片上。优化步骤修改乳房模型的位置、方向和弹性参数，以执行图像对齐。当模型达到最佳解决方案时，将投射 MRI 腺组织并将其与来自相应乳房 X 光片的组织进行比较。为了减少光线投射过程中的信息丢失，我们引入了一种新方法，避免对 MRI 体进行重新采样。在结果中，我们专注于评估腺组织分布的一致性、结构相似性的程度以及真实和合成密度图之间的相关性。我们的方法无论乳房的腺密度如何，都获得了高度的结构一致性，而腺组织分布的相似性和两幅图像之间的相关性在更密集的乳房中增加。此外，合成图像在密度图中的大结构方面显示出连续性。
