Avis N J, Barber D C
Department of Computer Science, University of Hull, UK.
Physiol Meas. 1995 Aug;16(3 Suppl A):A111-22. doi: 10.1088/0967-3334/16/3a/011.
The Sheffield image reconstruction algorithm is based on the assumption that the initial conductivity distribution of the body being imaged is uniform. In many situations this assumption is violated. Previous attempts at incorporating a priori information by modifications to the backprojection matrices were ineffective. An alternative method of including a priori information became apparent following the recent reformulation of the Sheffield image reconstruction algorithm. Applying matrix algebra to the image reconstruction equations reveals that the incorporation of a priori information can be considered as either a modification to the original backprojection matrix or a component of a composite data filter. A simple two-dimensional model of the adult head was chosen to test this approach. The results of imaging studies using synthetic data derived from this model show that a priori information has been successfully incorporated into the image reconstruction process. The ability to include a priori information into the image reconstruction process may have significant implications for the more challenging applications of EIT such as imaging the adult head.
被成像人体的初始电导率分布是均匀的。在许多情况下，这一假设并不成立。以前通过修改反投影矩阵来纳入先验信息的尝试并不成功。随着谢菲尔德图像重建算法最近的重新表述，一种纳入先验信息的替代方法变得明显起来。将矩阵代数应用于图像重建方程表明，纳入先验信息可以被视为对原始反投影矩阵的修改或复合数据滤波器的一个组成部分。选择了一个简单的成人头部二维模型来测试这种方法。使用从该模型导出的合成数据进行成像研究的结果表明，先验信息已成功纳入图像重建过程。将先验信息纳入图像重建过程的能力可能对电阻抗断层成像更具挑战性的应用（如成人头部成像）产生重大影响。
