X-ray scatter correction for dedicated cone beam breast CT using a forward-projection model.
X-ray scatter correction for dedicated cone beam breast CT using a forward-projection model.
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DOI：
10.1002/mp.12213
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发表时间：
2017-06
期刊：
影响因子：
3.8
通讯作者：
Zhu L
中科院分区：
文献类型：
--
作者：
Shi L;Vedantham S;Karellas A;Zhu L
专用锥形束乳腺CT（CBBCT）成像的质量从根本上受到X射线散射污染的限制，这是由于大的照射体积。在本文中，我们提出了一种CBBCT散射校正方法，使用一种新的前向投影模型具有较高的校正效率和可靠性。我们首先粗分割的未校正的，第一遍，重建CBBCT图像到二进制对象的地图和分配的分割的纤维腺和脂肪组织与正确的衰减系数的基础上的平均X射线能量。将修正后的CBBCT图像作为散射校正的先验图像。首先通过在改进的CBBCT上的前向投影来估计主信号。为了避免不准确分割所引起的误差，仅选择估计的原色的稀疏样本用于散布估计。基于傅立叶变换的算法（在下文中称为局部滤波）被开发以有效地估计检测器上的全局散射分布。通过从测量的投影数据中去除估计的散射分布来获得散射校正图像。我们对代表普通人群的六名具有不同乳房大小和形状的患者评估了该方法的性能。结果表明，该方法有效地降低了图像的空间非均匀性从8.27%到1.91%的冠状视图和从6.50%到3.00%的矢状视图。对比度偏差比平均提高了1.41倍。对图像细节的比较表明，所提出的散射校正成功地保留了在分割过程中丢失的纤维腺组织的精细结构。我们提出了一个非常实用和有效的散射校正算法CBBCT通过前向投影模型。该方法在临床CBBCT成像中是有吸引力的，因为它容易在临床系统上实现，而无需修改当前的成像协议或系统硬件。
The quality of dedicated cone-beam breast CT (CBBCT) imaging is fundamentally limited by x-ray scatter contamination due to the large irradiation volume. In this paper, we propose a scatter correction method for CBBCT using a novel forward projection model with high correction efficacy and reliability. We first coarsely segment the uncorrected, first-pass, reconstructed CBBCT images into binary-object maps and assign the segmented fibroglandular and adipose tissue with the correct attenuation coefficients based on the mean x-ray energy. The modified CBBCT are treated as the prior images toward scatter correction. Primary signals are first estimated via forward projection on the modified CBBCT. To avoid errors caused by inaccurate segmentation, only sparse samples of estimated primary are selected for scatter estimation. A Fourier-Transform based algorithm, herein referred to as local filtration hereafter, is developed to efficiently estimate the global scatter distribution on the detector. The scatter corrected images are obtained by removing the estimated scatter distribution from measured projection data. We evaluate the method performance on six patients with different breast sizes and shapes representing the general population. The results show that the proposed method effectively reduces the image spatial non-uniformity from 8.27% to 1.91% for coronal views and from 6.50% to 3.00% for sagittal views. The contrast-to-deviation ratio is improved by an average factor of 1.41. Comparisons on the image details reveal that the proposed scatter correction successfully preserves fine structures of fibroglandular tissues that are lost in the segmentation process. We propose a highly practical and efficient scatter correction algorithm for CBBCT via a forward projection model. The method is attractive in clinical CBBCT imaging as it is readily implementable on a clinical system without modifications in current imaging protocols or system hardware.
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影响因子：
0.9
作者：
Vedantham S;O'Connell AM;Shi L;Karellas A;Huston AJ;Skinner KA
通讯作者：
Skinner KA
影响因子：
3.8
作者：
Altunbas, M. C.;Shaw, C. C.;Wang, T.
通讯作者：
Wang, T.
影响因子：
3.8
作者：
Chen, B;Ning, R
通讯作者：
Ning, R
影响因子：
3
作者：
Cai, Weixing;Ning, Ruola;Conover, David
通讯作者：
Conover, David
影响因子：
3.8
作者：
SIDDON, RL
通讯作者：
SIDDON, RL