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21 May 1999 Reconstruction bias resulting from weighted projection and iso-center misalignment
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The use of computer graphic techniques to produce 3D and reformatted images from a set of axial computed tomography (CT) images has generated significant interest in recent years. The axial CT images are generated with the projection data set weighted, prior to the reconstruction, to combat motion artifacts, data inconsistency, or redundant data samples. In this paper, we investigate the potential bias introduced to the reconstruction as a result of the interaction of the projection weights and the iso-center misalignment (ISM). Although the error is not easily detected in axial CT images, it can be quite visible in 3D or multi-planar reformed images. We first present a theoretical framework to analyze and predict the bias. The theoretical model quantitatively links the amount of object shift in the reconstructed images with the ISM and projection weighting function. The theoretical prediction is validated by both computer simulations and phantom experiments. Based on the analytical model, several schemes to combat this artifact are subsequently presented.
© (1999) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Jiang Hsieh "Reconstruction bias resulting from weighted projection and iso-center misalignment", Proc. SPIE 3661, Medical Imaging 1999: Image Processing, (21 May 1999);

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