A scatter correction method for contrast-enhanced dual-energy digital breast tomosynthesis.
A scatter correction method for contrast-enhanced dual-energy digital breast tomosynthesis.
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DOI：
10.1088/0031-9155/60/16/6323
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发表时间：
2015-08-21
影响因子：
3.5
通讯作者：
Gindi G
中科院分区：
文献类型：
--
作者：
Lu Y;Peng B;Lau BA;Hu YH;Scaduto DA;Zhao W;Gindi G
对比度增强双能量数字乳腺断层合成摄影（CE-DE-DBT）旨在对碘化肿块成像，同时抑制乳腺解剖背景。散射是一个问题，特别是对于高能量采集，因为它会导致严重的杯状伪影和碘定量误差。我们提出了一种患者特异性散射校正（SC）算法CE-DE-DBT。经验算法的工作原理是将乳房阴影外的散射数据插值到乳房阴影内的估计值中。通过使用容易获得的（从体模）散射-主比（SPR）表的操作进一步改进内插估计-每个乳房厚度和采集角度的单个SPR值。通过将我们的SC算法的SPR与使用光束通过针孔阵列板测量的SPR进行比较，我们验证了我们用于两个乳房模拟体模的SC算法。在我们的SC计算SPR的误差，平均超过采集角度和图像位置，约为5%，与较厚的幻影略差的错误。SC投影数据，使用OS-SART重建，表现出很大程度的decupping。我们还观察到，SC消除了碘定量对体模厚度的依赖性。我们将SC算法应用于CE-DE乳腺X线摄影患者图像，其中活检证实了乳腺周围的肿瘤。在没有SC的图像中，对比增强的肿瘤被杯状伪影掩盖。在我们的SC中，肿瘤很容易看到。锥束CT（CBCT）提出了一种基于插值的SC，但我们的算法和应用在几个方面有所不同。其他相关的SC技术包括CBCT的蒙特-卡罗和基于卷积的方法、DBT的散射图的预先计算库的存储以及乳腺CT的具有射束通过针孔阵列的患者采集。我们的SC算法可以在临床可接受的时间内完成，不需要额外的成像硬件或额外的患者剂量，并且易于在研究中心之间运输。
Contrast-enhanced dual energy digital breast tomosynthesis (CE-DE-DBT) is designed to image iodinated masses while suppressing breast anatomical background. Scatter is a problem, especially for high energy acquisition, in that it causes severe cupping artifact and iodine quantitation errors. We propose a patient specific scatter correction (SC) algorithm for CE-DE-DBT. The empirical algorithm works by interpolating scatter data outside the breast shadow into an estimate within the breast shadow. The interpolated estimate is further improved by operations that use an easily obtainable (from phantoms) table of scatter-to-primary-ratios (SPR) - a single SPR value for each breast thickness and acquisition angle. We validated our SC algorithm for two breast emulating phantoms by comparing SPR from our SC algorithm to that measured using a beam-passing pinhole array plate. The error in our SC computed SPR, averaged over acquisition angle and image location, was about 5%, with slightly worse errors for thicker phantoms. The SC projection data, reconstructed using OS-SART, showed a large degree of decupping. We also observed that SC removed the dependence of iodine quantitation on phantom thickness. We applied the SC algorithm to a CE-DE-mammographic patient image with a biopsy confirmed tumor at the breast periphery. In the image without SC, the contrast enhanced tumor was masked by the cupping artifact. With our SC, the tumor was easily visible. An interpolation-based SC was proposed by for cone-beam CT (CBCT), but our algorithm and application differ in several respects. Other relevant SC techniques include Monte-Carlo and convolution-based methods for CBCT, storage of a precomputed library of scatter maps for DBT, and patient acquisition with a beam-passing pinhole array for breast CT. Our SC algorithm can be accomplished in clinically acceptable times, requires no additional imaging hardware or extra patient dose and is easily transportable between sites.