Paulsen K D, Moskowitz M J, Ryan T P
Thayer School of Engineering Dartmouth College, Hanover, NH 03755.
Int J Hyperthermia. 1994 Mar-Apr;10(2):209-28. doi: 10.3109/02656739409009344.
Algorithmic methods for estimating complete temperature fields during hyperthermia treatments based on surface and internal electrical measurements are presented. The techniques utilized draw upon impedance imaging concepts, but rather than limit the measurements to positions on the body surface, internal impedance recording sites are allowed. Theoretical simulations show that this strategy improves the reconstructed image in the target region when either internal measurement locations are added to a given number of external recording sites or some external measurement locations are replaced by internal recording positions. The algorithms developed are tested on a set of problems with increasing levels of complexity. The culmination of these investigations is a complete simulation of a hyperthermia treatment and reconstruction of a thermal image for a body cross-section of an actual cancer patient. The results of this work suggest that the surface plus internal measurement approach holds some promise as a method for estimating temperature distributions during hyperthermia treatments. However, the simulations while promising are idealizations in that they are two-dimensional with modest levels of additive noise. In a companion paper, we explore the viability of this approach in several laboratory phantom experiments which include both static and heat-induced transient electrical property profiles.
本文介绍了基于体表和体内电学测量来估计热疗过程中完整温度场的算法方法。所采用的技术借鉴了阻抗成像的概念，但并不局限于体表位置的测量，还允许进行体内阻抗记录。理论模拟表明，当将内部测量位置添加到给定数量的外部记录点，或者用内部记录位置替换一些外部测量位置时，该策略可改善目标区域的重建图像。所开发的算法在一系列复杂程度不断增加的问题上进行了测试。这些研究的最终成果是对热疗治疗进行了完整模拟，并为一名实际癌症患者的身体横截面重建了热图像。这项工作的结果表明，体表加体内测量方法作为一种估计热疗过程中温度分布的方法具有一定前景。然而，这些有前景的模拟是理想化的，因为它们是二维的，且附加噪声水平适中。在一篇配套论文中，我们在几个实验室模型实验中探索了这种方法的可行性，这些实验包括静态和热诱导瞬态电学特性分布。
