Acciavatti Raymond J, Vent Trevor L, Choi Chloe J, Wileyto E Paul, Noël Peter B, Maidment Andrew D A
University of Pennsylvania, Department of Radiology, 3400 Spruce Street, Philadelphia PA 19104.
Proc SPIE Int Soc Opt Eng. 2021 Feb;11595. doi: 10.1117/12.2580280. Epub 2021 Feb 15.
Our previous work showed that digital breast tomosynthesis (DBT) supports super-resolution (SR). Clinical systems are not yet designed to optimize SR; this can be demonstrated with a high-frequency line-resolution pattern. SR is achieved if frequencies are oriented laterally, but not if frequencies are oriented in the perpendicular direction; .., the posteroanterior (PA) direction. We are developing a next-generation tomosynthesis (NGT) prototype with new trajectories for the x-ray source. This system is being designed to optimize SR not just for screening, but also for diagnostic mammography; specifically, for magnification DBT (M-DBT). SR is not achieved clinically in magnification mammography, since the acquisition is 2D. The aim of this study is to investigate SR in M-DBT, and analyze how anisotropies differ from screening DBT (S-DBT). We have a theoretical model of a high-frequency sinusoidal test object. First, a conventional scanning motion (directed laterally) was simulated. In the PA direction, SR was not achieved in either S-DBT or M-DBT. Next, the scanning motion was angled relative to the lateral direction. This motion introduces submillimeter offsets in source positions in the PA direction. Theoretical modeling demonstrated that SR was achieved in M-DBT, but not in S-DBT, in the PA direction. This work shows that, with the use of magnification, anisotropies in SR are more sensitive to small offsets in the source motion, leading to insights into how to design M-DBT systems.
我们之前的研究表明，数字乳腺断层合成（DBT）支持超分辨率（SR）。临床系统尚未设计用于优化超分辨率；这可以通过高频线分辨率图案来证明。如果频率沿横向排列，则可实现超分辨率，但如果频率沿垂直方向排列则不行；……，即前后（PA）方向。我们正在开发一种具有新的X射线源轨迹的下一代断层合成（NGT）原型。该系统不仅旨在为筛查优化超分辨率，还旨在为诊断性乳腺摄影优化超分辨率；具体而言，是为放大DBT（M-DBT）优化超分辨率。在放大乳腺摄影中临床上无法实现超分辨率，因为采集是二维的。本研究的目的是研究M-DBT中的超分辨率，并分析各向异性与筛查DBT（S-DBT）有何不同。我们有一个高频正弦测试物体的理论模型。首先，模拟了传统的扫描运动（横向定向）。在PA方向上，S-DBT和M-DBT均未实现超分辨率。接下来，扫描运动相对于横向倾斜。这种运动会在PA方向上的源位置引入亚毫米级的偏移。理论建模表明，在PA方向上，M-DBT实现了超分辨率，而S-DBT未实现。这项工作表明，通过使用放大，超分辨率中的各向异性对源运动中的小偏移更敏感，从而为如何设计M-DBT系统提供了见解。
