Investigation of an image artefact induced by projection noise inhomogeneity in multi-slice helical computed tomography
Investigation of an image artefact induced by projection noise inhomogeneity in multi-slice helical computed tomography
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DOI：
10.1088/0031-9155/48/3/305
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发表时间：
2003-02-07
影响因子：
3.5
通讯作者：
Hsieh, J
中科院分区：
文献类型：
--
作者：
Hsieh, J
多层螺旋计算机断层扫描的引入从根本上改变了放射科医生查看CT图像的方式。越来越多的临床病例采用先进的可视化工具进行检查，如最大强度投影、多平面重组和容积再现。已经发现，在传统的二维重建图像中没有出现的新的图像伪影在由这些新工具生成的图像中变得可见。在本文中，我们调查的原因，这样的文物，威尼斯盲文物，这似乎是明亮和黑暗的带叠加在三维图像。我们证明，这样的伪影是由重建图像中的周期性噪声变化引起的。图像噪声变化又由投影中的噪声不均匀性与螺旋权重的相互作用引起。一个分析公式的开发，准确地预测这种文物的存在。基于我们的分析，提出了几种方法来减少或消除伪影。
The introduction of multi-slice helical computed tomography has fundamentally changed the way radiologists view CT images. Increasing numbers of clinical cases are examined with advanced visualization tools, such as maximum intensity projection, multi-planar reformation and volume rendering. It has been discovered that new image artefacts, which do not appear in the traditional two-dimensional reconstructed images, become visible in images generated by these new tools. In this paper, we investigate the causes of one such artefact, the Venetian blind artefact, which appears as bright-and-dark bands superimposed on three-dimensional images. We demonstrate that such an artefact is caused by the periodical noise variation in the reconstructed images. The image noise variation is, in turn, caused by the interaction of the noise inhomogeneity in the projections with the helical weights. An analytical formula is developed that accurately predicts the presence of such artefacts. Based on our analysis, several approaches are proposed for the artefact reduction or elimination.