German Cancer Research Centre (DKFZ), Department of Medical Physics in Radiology, 69120 Heidelberg, Germany.
IEEE Trans Med Imaging. 2012 Sep;31(9):1754-60. doi: 10.1109/TMI.2012.2200904. Epub 2012 May 22.
Electrical impedance tomography (EIT) is a low-cost, noninvasive and radiation free medical imaging modality for monitoring ventilation distribution in the lung. Although such information could be invaluable in preventing ventilator-induced lung injury in mechanically ventilated patients, clinical application of EIT is hindered by difficulties in interpreting the resulting images. One source of this difficulty is the frequent use of simple shapes which do not correspond to the anatomy to reconstruct EIT images. The mismatch between the true body shape and the one used for reconstruction is known to introduce errors, which to date have not been properly characterized. In the present study we, therefore, seek to 1) characterize and quantify the errors resulting from a reconstruction shape mismatch for a number of popular EIT reconstruction algorithms and 2) develop recommendations on the tolerated amount of mismatch for each algorithm. Using real and simulated data, we analyze the performance of four EIT reconstruction algorithms under different degrees of shape mismatch. Results suggest that while slight shape mismatch is well tolerated by all algorithms, using a circular shape severely degrades their performance.
电阻抗断层成像（EIT）是一种低成本、非侵入性且无辐射的医学成像方式，可用于监测肺部的通气分布。尽管这种信息对于预防机械通气患者的呼吸机相关性肺损伤可能非常有价值，但 EIT 的临床应用受到解释结果图像困难的阻碍。这种困难的一个来源是频繁使用与解剖结构不对应的简单形状来重建 EIT 图像。众所周知，真实身体形状与用于重建的形状之间的不匹配会引入误差，但迄今为止这些误差尚未得到适当的描述。因此，在本研究中，我们 1）描述并量化了几种流行的 EIT 重建算法的重建形状不匹配引起的误差，2）为每种算法确定了可接受的不匹配量的建议。使用真实和模拟数据，我们分析了四种 EIT 重建算法在不同程度的形状不匹配下的性能。结果表明，虽然所有算法都能很好地容忍轻微的形状不匹配，但使用圆形形状会严重降低它们的性能。
