Anoop K P, Rajgopal Kasi
Indian Institute of Science, Department of Electrical Engineering, Sir C. V. Raman Avenue, Bangalore 560012, India.
Comput Med Imaging Graph. 2009 Jun;33(4):283-94. doi: 10.1016/j.compmedimag.2009.01.007. Epub 2009 Feb 28.
Lateral or transaxial truncation of cone-beam data can occur either due to the field of view limitation of the scanning apparatus or in region-of-interest tomography. In this paper, we suggest two new methods to handle lateral truncation in helical scan CT. It is seen that reconstruction with laterally truncated projection data, assuming it to be complete, gives severe artifacts which even penetrates into the field of view. A row-by-row data completion approach using linear prediction is introduced for helical scan truncated data. An extension of this technique known as windowed linear prediction approach is introduced. Efficacy of the two techniques are shown using simulation with standard phantoms. A quantitative image quality measure of the resulting reconstructed images are used to evaluate the performance of the proposed methods against an extension of a standard existing technique.
锥形束数据的横向或轴向截断可能由于扫描设备的视野限制或在感兴趣区域断层扫描中出现。在本文中，我们提出了两种新方法来处理螺旋扫描CT中的横向截断。可以看出，使用横向截断的投影数据进行重建（假设其完整）会产生严重的伪影，甚至会渗透到视野中。针对螺旋扫描截断数据，引入了一种使用线性预测的逐行数据补全方法。还介绍了该技术的一种扩展，即窗口线性预测方法。使用标准体模进行模拟展示了这两种技术的有效性。使用所得重建图像的定量图像质量度量来评估所提出方法相对于现有标准技术扩展的性能。
