【摘要】 目的:获得肝组织的EIT图像与温度的关系,为采用电阻抗成像法监测在肝肿瘤热疗时的体内温度奠定基础。方法:将新鲜离体猪肝放入装有盐溶液的物理模型中,测温探头插入肝组织的不同位置用于监测过程中的温度分布,用EIT实时图像监测肝组织的阻抗变化。结果:EIT图像显示组织温度上升时,组织阻抗逐渐下降。随着温度的上升,EIT图像目标区域颜色明显有变红,并呈扩散趋势。用边界电压、感兴趣区域重构值等表征温度时,可以获得较好的拟合效果,边界电压的最大拟合绝对误差在3.6℃左右,感兴趣区域重构值的最大拟合绝对误差在1℃左右。结论:温度变化与图像变化之间存在一定的关系,高温时组织电阻抗特性发生显著改变,在临床热疗中有可能通过EIT来实时监测热疗时的温度。更多还原

【Abstract】 Objective To obtain the relationship between Electrical Impedance Tomography(EIT) image and temperature of liver tissue in order to apply EIT to non-invasively monitor the temperature in during hyperthermia treatment of liver.Methods A piece of pig liver was put into a phantom filled with salt solution,during heating the pig liver sample,the temperatures in different positions were measured and the impedance changes caused by heating were monitored in real-time by EIT.Results The images showed the resistivity of the heated liver tissue decreased gradually while its temperature raised higher.The color of region of interest(ROI),corresponding to the heating tissue,became redder and the size of the ROI grew larger as temperatures elevation.The maximum absolute fitting error of boundary voltage and reconstruction of ROI were around 3.6 and 1 degree Celsius respectively.Conclusion The changes in images are correlated with the temperature of the tissue.High temperature causes nonlinear significant changes of resistivity of liver tissue,and in clinical hyperthermia therapy it is possible to monitor temperature in real time by EIT.更多还原