Meeson S, Killingback A L, Blott B H
Department of Physics, University of Southampton, UK.
Phys Med Biol. 1995 Apr;40(4):643-57. doi: 10.1088/0031-9155/40/4/010.
EIT measurements on humans are often made in regions of the body where the conductivity distribution is far from uniform. This paper addresses the problem of deriving accurate quantitative data in one such region: the conductivity changes associated with the accumulation of blood in the pelvic bowl. A computer map of the bone in the pelvic region was constructed, from which an appropriate reconstruction matrix was generated. Both computer simulations and tank tests were performed to assess whether this bone reconstruction matrix produced impedance images with closer fidelity to the measured object than images produced using a reconstruction based on a uniform conductivity distribution. As expected, images produced by the computer simulation indicated that the bone reconstruction matrix produced images of better fidelity than did the uniform reconstruction matrix. However, in the case of the tank data only a moderate improvement was achieved. The reconstruction matrix based on a uniform conductivity distribution was found to produce satisfactory images for both bone and near-uniform objects, but for regions further into the pelvic bowl, where the signal was lower, the uniform reconstruction matrix was less satisfactory.
对人体进行电阻抗断层成像（EIT）测量时，通常是在人体导电率分布远非均匀的部位进行。本文探讨了在这样一个部位获取准确量化数据的问题：与盆腔内血液积聚相关的导电率变化。构建了盆腔区域骨骼的计算机地图，并据此生成了合适的重建矩阵。进行了计算机模拟和水槽测试，以评估这种骨骼重建矩阵生成的阻抗图像与基于均匀导电率分布的重建方法生成的图像相比，是否能更忠实地反映被测对象。不出所料，计算机模拟生成的图像表明，骨骼重建矩阵生成的图像保真度优于均匀重建矩阵。然而，对于水槽数据，仅实现了适度的改进。基于均匀导电率分布的重建矩阵被发现对于骨骼和接近均匀的对象都能生成令人满意的图像，但对于盆腔更深部位信号较低的区域，均匀重建矩阵就不那么令人满意了。
