Quantitative analysis of shape change in Electrical Impedance Tomography (EIT)
Quantitative analysis of shape change in Electrical Impedance Tomography (EIT)
复制标题
电阻抗断层扫描 (EIT) 形状变化的定量分析
DOI：
10.1007/978-3-540-73841-1_110
复制
发表时间：
2007
影响因子：
3.2
通讯作者：
R. Sadleir
中科院分区：
文献类型：
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作者：
Sungho Oh;T. Tang;R. Sadleir
电阻抗断层成像(EIT)重建是一个不适定的逆问题，这意味着少量的噪声或模型误差可能会在重建的图像中造成较大的伪影。最大的误差源之一是成像对象相对于参考条件的形状变化。在静态成像中，由于物体假设的不准确，会出现系统性的形状变化伪影。在时间序列测量期间，例如在呼吸周期期间，可能会发生规则的形状变化。我们使用Joukowski变换模拟了二维圆形和椭圆形轮廓之间的简化边界形状变化。我们比较了截断奇异值分解(TSVD)和Tikhonov正则化重建方法关于这种形状变化对图像质量和数量指数(QI)的影响，使用图像平面内不同位置的单个异常。在我们的研究中，我们定义了一个新的准则来选择一个合适的正则化参数用于定量图像分析。结果表明，QI在很大的椭圆失真范围内是稳定的，尽管质量没有得到很好的保持。
Electrical Impedance Tomography (EIT) reconstruction is an ill-posed inverse problem, meaning that small amounts of noise or model errors can cause larger artifacts in reconstructed images. One of the largest sources of error is shape change of the imaged object with respect to a reference condition. Systematic shape change artefacts occur in static imaging due to inaccurate assumption of object. Regular shape changes can occur during a time series measurement, such as during the respiratory cycle. We modeled simplified boundary shape changes between circular and elliptic profiles in 2D using the Joukowski transformation. We compared truncated Singular Value Decomposition (tSVD) and Tikhonov regularized reconstruction methods with respect to this shape change in terms of its effect on image quality and Quantity Index (QI) using a single anomaly at various locations within the image plane. During our investigation, we defined a new criterion to choose a suitable regularization parameter for use in quantitative image analysis. The results show that QI is stable over a large range of elliptic distortions, even though quality is not similarly well preserved.