Beam hardening correction for computed tomography images using a postreconstruction method and equivalent tissue concept
Beam hardening correction for computed tomography images using a postreconstruction method and equivalent tissue concept
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DOI：
10.1007/s10278-001-0003-2
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发表时间：
2001-06-01
影响因子：
4.4
通讯作者：
Li, MJ
中科院分区：
文献类型：
--
作者：
Chen, CY;Chuang, KS;Li, MJ
提出了一种校正计算机断层扫描 (CT) 图像中束硬化伪影的重建后方法。该方法不需要X射线光谱测量。作者假设 CT 图像中的像素可以分解为等效的组织百分比，具体取决于其 CT 编号。对由这些等效组织制成的阶梯楔进行侦察视图，以获得每个组织的束硬化校正曲线。从不同角度投影 CT 图像，生成模拟投影数据以及沿射线的每个组织的总厚度。使用射线传播的组织厚度来估计校正项，然后将该项添加到其相应的投影数据中。使用校正投影数据进行的第二次重建产生了光束硬化校正图像。初步结果表明，该方法将铝的光束硬化伪影减少了 14%，并将铝-水边界附近的物体对比度提高了 18%。不同位置的CT值变化减小，铝CT值也得到恢复。版权所有 (C) 2001 W.B.桑德斯公司。
A postreconstruction method for correcting the beam-hardening artifacts in computed tomography (CT) images is proposed. This method does not require x-ray spectrum measurement. The authors assumed that a pixel in a CT image can be decomposed into equivalent tissue percentages, depending on its CT number. A scout view of the step wedges made of these equivalent tissues was performed to obtain a beam-hardening correction curve for each tissue. Projecting through the CT image from various angles generated simulated projection data and the total thickness of each tissue along the ray. The correction term was estimated using the tissue thickness traveled by the ray, and this term was then added to its corresponding projection data. A second reconstruction using the corrected projection data yielded a beam-hardening corrected image. The preliminary results show that this method reduces beam hardening artifacts by 14% for aluminum and increased the object contrast by 18% near the aluminum-water boundary. The variation in CT numbers at different locations were reduced, and the aluminum CT number also was restored. Copyright (C) 2001 by W.B. Saunders Company.