【摘要】 目的:构建前列腺电阻抗断层成像(electrical impedance tomography,EIT)模型,并开展仿真实验研究。方法:依据前列腺位置、尺寸和EIT要求,仿真建立基于经直肠电阻抗断层成像(transrectal electrical impedance tomography,TREIT)方法的场域模型,寻求合适的开放场域边界进行成像。模拟理想条件和有限测量分辨力(measurement resolution,MR)条件下的TREIT检测,对比2种条件下不同激励模式的成像效果。结果:确定了距离探头外径4 cm(量化为8层剖分)处作为场域边界。理想条件下不同激励模式的重建图像,其质量与激励电极对间距(量化为电极对间隔的电极数目)成反比;在MR为0.1 mV的EIT检测条件下,当激励电极对间距为5或6时,重建图像质量高于理想条件下相邻激励模式所得图像。结论:TREIT场域模型可实现对前列腺较好成像。理想条件下相邻激励模式较其他激励模式更优,采用高性能EIT系统成像应选择相邻激励模式;在MR略低的情况下,选择激励电极对间距为5或6的激励模式将获得更优的图像重建效果。更多还原

【Abstract】 Objective To construct an electrical impedance tomography(EIT) model of the prostate and execute prostate EIT simulated experimental study.Methods A field model based on the transrectal(TREIT) was simulated according to the prostate location,size and EIT requirements,so as to find the appropriate open field boundary for imaging.The TREIT test was simulated under ideal conditions and with limited measurement resolution(MR) to compare the imaging results of the two conditions with different excitation modes.Results A distance of 4 cm from the outer diameter of the probe(quantified as an 8-layer profile) was determined as the field boundary.The quality of the reconstructed images for different excitation modes under ideal conditions was inversely proportional to the distance between the exitation electrode pairs(quaniofied as the number of electrodes spaced between the excitation electrode pairs);under EIT detection conditions with MR of 0.1 mV,the quality of the reconstructed images was higher than that obtained from adjacent excitation modes under ideal conditions when the distance between the excitation electrode pairs was 5 or 6 ones.Conclusion The transrectal EIT field model facilitates prostate imaging.In ideal conditions,the adjacent excitation mode is preferable to other excitation modes and should be selected for imaging with high performance EIT systems;with a slightly lower MR an excitation mode with the distance between the excitation electrode pairs being 5 or 6 ones should be selected for better image reconstruction.[Chinese Medical Equipment Journal,2021,42(6):26-31]更多还原