Smit H J, Handoko M L, Vonk Noordegraaf A, Faes Th J C, Postmus P E, de Vries P M J M, Boonstra A
Department of Pulmonary Medicine, VU University Medical Center, Amsterdam, The Netherlands.
Physiol Meas. 2003 May;24(2):491-9. doi: 10.1088/0967-3334/24/2/359.
A possible clinical application of electrical impedance tomography (EIT) might be to monitor changes in the pulmonary circulation, provided the reproducibility of the EIT measurement is adequate. The purpose of this study was threefold: the intra- and inter-investigator variability of repeated measurements was investigated. Three different regions of interest (ROI) were analysed to assess the optimal ROI. Twenty-four healthy subjects and six patients were included. The Sheffield applied potential tomograph (DAS-01P, IBEES, Sheffield, UK) was used. Electrodes were attached by investigator A, and duplicate EIT measurements were performed. After detachment and 45 min of rest, the protocol was repeated by another investigator B, and afterwards by the initial investigator A. Three ROIs were analysed: whole circle, 'inner half circle' and contour. The mean difference in impedance changes between observers is presented in arbitrary units (AU) +/- SD. Finally, the influence of age, body composition and sex on the EIT result was examined. For the contour ROI, the mean difference for the intra-investigator situation was -1.44 x 10(-2) +/- 18.45 x 10(-2) AU (-0.7 +/- 9.0%), and was 5.46 x 10(-2) +/- 21.66 x 10(-2) AU (2.7 +/- 10.8%) for the inter-investigator situation. The coefficient of reproducibility of the intra- and inter-investigator reproducibility varied between 0.89 and 0.97 for all ROIs (P < 0.0001). There is a relation between impedance change and age (correlation coefficient r = -0.63, P < 0.01 for contour ROI), and between impedance change and body mass index (BMI) (r = -0.53, P < 0.05). We found a significant difference in mean impedance change between groups of males and females. In conclusion, EIT results are highly reproducible when performed by the same investigator as well as by two different investigators.
如果电阻抗断层成像（EIT）测量具有足够的可重复性，那么它在临床上的一个可能应用是监测肺循环的变化。本研究的目的有三个：调查重复测量时研究者内部和研究者之间的变异性。分析了三个不同的感兴趣区域（ROI）以评估最佳ROI。纳入了24名健康受试者和6名患者。使用了谢菲尔德应用电位断层扫描仪（DAS - 01P，IBEES，英国谢菲尔德）。研究者A连接电极，并进行重复的EIT测量。在电极拆除和休息45分钟后，另一位研究者B重复该方案，然后最初的研究者A再次重复。分析了三个ROI：全圆、“内半圆”和轮廓。观察者之间阻抗变化的平均差异以任意单位（AU）±标准差表示。最后，研究了年龄、身体成分和性别对EIT结果的影响。对于轮廓ROI，研究者内部情况的平均差异为 - 1.44×10⁻²±18.45×10⁻² AU（-0.7±9.0%），研究者之间情况的平均差异为5.46×10⁻²±21.66×10⁻² AU（2.7±10.8%）。所有ROI的研究者内部和研究者之间可重复性的可重复性系数在0.89至0.97之间（P < 0.0001）。阻抗变化与年龄之间存在关系（轮廓ROI的相关系数r = -0.63，P < 0.01），以及阻抗变化与体重指数（BMI）之间存在关系（r = -0.53，P < 0.05）。我们发现男性和女性组之间的平均阻抗变化存在显著差异。总之，当由同一位研究者以及两位不同的研究者进行EIT测量时，结果具有高度可重复性。
