Electrical Impedance Tomography: Tissue Properties to Image Measures

Electrical impedance tomography (EIT) uses electrical stimulation and measurement at the body surface to image the electrical properties of internal tissues. It has the advantage of noninvasiveness and high temporal resolution but suffers from poor spatial resolution and sensitivity to electrode movement and contact quality. EIT can be useful to applications, where there are conductive contrasts between tissues, fluids, or gasses, such as imaging of cancerous or ischemic tissue or functional monitoring of breathing, blood flow, gastric motility, and neural activity. The past decade has seen clinical application and commercial activity using EIT for ventilation monitoring. Interpretation of EIT-based measures is complex, and this review paper focuses on describing the image interpretation “pathway.” We review this pathway, from Tissue Electrical Properties, EIT Electrodes & Hardware, Sensitivity, Image Reconstruction, Image Processing to EIT Measures. The relationship is discussed between the clinically relevant parameters and the reconstructed properties. An overview is given of areas of EIT application and of our perspectives for research and development.

[1]  Andy Adler,et al.  Conductivity perturbations in EIT , 2015 .

[2]  J. Kaipio,et al.  Compensation of errors due to discretization, domain truncation and unknown contact impedances in electrical impedance tomography , 2009 .

[3]  Brian H. Brown,et al.  Imaging spatial distributions of resistivity using applied potential tomography , 1983 .

[4]  Andy Adler,et al.  Regional lung opening and closing pressures in patients with acute lung injury. , 2012, Journal of critical care.

[5]  D. Geselowitz.  An application of electrocardiographic lead theory to impedance plethysmography. , 1971, IEEE transactions on bio-medical engineering.

[6]  W. J. Tompkins,et al.  Iterative reconstruction methods using regularization and optimal current patterns in electrical impedance tomography. , 1991, IEEE transactions on medical imaging.

[7]  Marcelo B. P. Amato,et al.  Bedside estimation of recruitable alveolar collapse and hyperdistension by electrical impedance tomography , 2009, Intensive Care Medicine.

[8]  Andy Adler,et al.  3D EIT image reconstruction with GREIT , 2016, Physiological measurement.

[9]  Andy Adler,et al.  Electrical Impedance Tomography , 2019, Wiley Encyclopedia of Electrical and Electronics Engineering.

[10]  Manuchehr Soleimani,et al.  Electrical impedance tomography imaging using a priori ultrasound data , 2006, Biomedical engineering online.

[11]  M. Soleimani,et al.  Imaging of conductivity changes and electrode movement in EIT , 2006, Physiological measurement.

[12]  Peter Herrmann,et al.  Regional Lung Perfusion as Determined by Electrical Impedance Tomography in Comparison With Electron Beam CT Imaging , 2002, IEEE Transactions on Medical Imaging.

[13]  Jean-Philippe Thiran,et al.  Non-invasive monitoring of pulmonary artery pressure from timing information by EIT: experimental evaluation during induced hypoxia , 2016, Physiological measurement.

[14]  Te Tang,et al.  Detection of intraventricular blood using EIT in a neonatal piglet model , 2009, 2009 Annual International Conference of the IEEE Engineering in Medicine and Biology Society.

[15]  J Kaipio,et al.  Generalized optimal current patterns and electrical safety in EIT. , 2001, Physiological measurement.

[16]  David Isaacson,et al.  Electrical Impedance Tomography , 1999, SIAM Rev..

[17]  Liliana Borcea,et al.  Electrical impedance tomography , 2002 .

[18]  James Avery,et al.  Cerebral perfusion imaging using EIT , 2017 .

[19]  D S Holder.  Electrical impedance tomography with cortical or scalp electrodes during global cerebral ischaemia in the anaesthetised rat. , 1992, Clinical physics and physiological measurement : an official journal of the Hospital Physicists' Association, Deutsche Gesellschaft fur Medizinische Physik and the European Federation of Organisations for Medical Physics.

[20]  William R B Lionheart,et al.  Finite elements and anisotropic EIT reconstruction , 2010 .

[21]  D. Malonek,et al.  The T-SCANTM technology: electrical impedance as a diagnostic tool for breast cancer detection , 2001 .

[22]  Eung Je Woo,et al.  Frequency-difference electrical impedance tomography (fdEIT): algorithm development and feasibility study , 2008, Physiological measurement.

[23]  John G. Webster,et al.  An Impedance Camera for Spatially Specific Measurements of the Thorax , 1978, IEEE Transactions on Biomedical Engineering.

[24]  Camille Gomez-Laberge,et al.  A Unified Approach for EIT Imaging of Regional Overdistension and Atelectasis in Acute Lung Injury , 2012, IEEE Transactions on Medical Imaging.

[25]  B H Brown,et al.  Applied potential tomography: a new non-invasive technique for assessing gastric function. , 1987, Clinical physics and physiological measurement : an official journal of the Hospital Physicists' Association, Deutsche Gesellschaft fur Medizinische Physik and the European Federation of Organisations for Medical Physics.

[26]  Steffen Leonhardt,et al.  Electrical impedance tomography: the holy grail of ventilation and perfusion monitoring? , 2012, Intensive Care Medicine.

[27]  Sanjay P. Prabhu,et al.  Mechanical Ventilation Guided by Electrical Impedance Tomography in Experimental Acute Lung Injury* , 2013, Critical care medicine.

[28]  Kirill Y Aristovich,et al.  A method for reconstructing tomographic images of evoked neural activity with electrical impedance tomography using intracranial planar arrays , 2014, Physiological measurement.

[29]  John Sylvester,et al.  A uniqueness theorem for an inverse boundary value problem in electrical prospection , 1986 .

[30]  Marc Bodenstein,et al.  Principles of electrical impedance tomography and its clinical application , 2009, Critical care medicine.

[31]  W. Windisch,et al.  Assessment of silent spaces at different PEEP levels by electrical impedance tomography in severe COPD , 2015, Intensive Care Medicine Experimental.

[32]  R H Bayford,et al.  Multi-frequency electrical impedance tomography (EIT) of the adult human head: initial findings in brain tumours, arteriovenous malformations and chronic stroke, development of an analysis method and calibration , 2006, Physiological measurement.

[33]  Louis Allaud,et al.  Schlumberger: The history of a technique , 1977 .

[34]  Keith D. Paulsen,et al.  Electrical Impedance Spectroscopy of the Human Prostate , 2007, IEEE Transactions on Biomedical Engineering.

[35]  A. Adler,et al.  A Primal Dual-Interior Point Framework for Using the L 1-Norm or the L 2-Norm on the Data and Regularization Terms of Inverse Problems , 2009 .

[36]  Ryan Halter,et al.  Transrectal electrical impedance tomography of the prostate: spatially coregistered pathological findings for prostate cancer detection. , 2013, Medical physics.

[37]  William R B Lionheart,et al.  GREIT: a unified approach to 2D linear EIT reconstruction of lung images , 2009, Physiological measurement.

[38]  Gunther Uhlmann,et al.  Electrical impedance tomography and Calderón's problem , 2009 .

[39]  Andy Adler,et al.  Whither lung EIT: Where are we, where do we want to go and what do we need to get there? , 2012, Physiological measurement.

[40]  David S. Holder,et al.  Electrical Impedance Tomography : Methods, History and Applications , 2004 .

[41]  Rob M. Heethaar,et al.  On the flow dependency of the electrical conductivity of blood , 2004, IEEE Transactions on Biomedical Engineering.

[42]  Andy Adler,et al.  A primal–dual interior-point framework for using the L1 or L2 norm on the data and regularization terms of inverse problems , 2012 .

[43]  C. Gabriel,et al.  Electrical conductivity of tissue at frequencies below 1 MHz , 2009, Physics in medicine and biology.

[44]  D. Malonek,et al.  The T-SCAN technology: electrical impedance as a diagnostic tool for breast cancer detection. , 2001, Physiological measurement.

[45]  Manuchehr Soleimani,et al.  Electrical Impedance Tomography for Artificial Sensitive Robotic Skin: A Review , 2015, IEEE Sensors Journal.

[46]  A Korjenevsky,et al.  A 3D electrical impedance tomography (EIT) system for breast cancer detection. , 2001, Physiological measurement.

[47]  Richard A Williams,et al.  Process tomography: a European innovation and its applications , 1996 .

[48]  Jean-Philippe Thiran,et al.  Influence of heart motion on cardiac output estimation by means of electrical impedance tomography: a case study , 2015, Physiological measurement.

[49]  J Rosell,et al.  Errors in prolonged electrical impedance measurements due to electrode repositioning and postural changes. , 1995, Physiological measurement.

[50]  U Faust,et al.  Fast EIT data acquisition system with active electrodes and its application to cardiac imaging. , 1996, Physiological measurement.

[51]  R. Guardo,et al.  Monitoring of peripheral edema using electrical bioimpedance measurements , 1995, Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society.

[52]  K D Paulsen,et al.  Sensitivity study and optimization of a 3D electric impedance tomography prostate probe , 2009, Physiological measurement.

[53]  Inéz Frerichs,et al.  Correlation between alveolar ventilation and electrical properties of lung parenchyma , 2015, Physiological measurement.

[54]  Andy Adler,et al.  Functional Validation and Comparison Framework for EIT Lung Imaging , 2014, PloS one.

[55]  Andy Adler,et al.  Why is EIT so hard, and what are we doing about it? , 2015, Physiological measurement.

[56]  David Isaacson,et al.  Optimal current patterns for three-dimensional electric current computed tomography , 1989, Images of the Twenty-First Century. Proceedings of the Annual International Engineering in Medicine and Biology Society,.

[57]  Andy Adler,et al.  Electrical impedance tomography (EIT) for quantification of pulmonary edema in acute lung injury , 2015, Critical Care.

[58]  Jonas Larsson,et al.  Electromagnetics from a quasistatic perspective , 2007 .

[59]  B H Brown,et al.  Clinical applications of electrical impedance tomography. , 1993, Journal of medical engineering & technology.

[60]  D S Holder,et al.  Comparison of frequency difference reconstruction algorithms for the detection of acute stroke using EIT in a realistic head-shaped tank , 2012, Physiological measurement.

[61]  Andy Adler,et al.  Toward Morphological Thoracic EIT: Major Signal Sources Correspond to Respective Organ Locations in CT , 2012, IEEE Transactions on Biomedical Engineering.

[62]  I. Frerichs,et al.  Electrical impedance tomography: a method for monitoring regional lung aeration and tidal volume distribution? , 2003, Intensive Care Medicine.

[63]  Willis J. Tompkins,et al.  Comparing Reconstruction Algorithms for Electrical Impedance Tomography , 1987, IEEE Transactions on Biomedical Engineering.

[64]  R H Bayford,et al.  Bioimpedance tomography (electrical impedance tomography). , 2006, Annual review of biomedical engineering.

[65]  T. Faes,et al.  Electrical impedance tomography to measure pulmonary perfusion: is the reproducibility high enough for clinical practice? , 2003, Physiological measurement.

[66]  J. Bronzwaer,et al.  Determination of stroke volume by means of electrical impedance tomography. , 2000, Physiological measurement.

[67]  William R B Lionheart,et al.  Uses and abuses of EIDORS: an extensible software base for EIT , 2006, Physiological measurement.

[68]  D. C. Barber,et al.  Three-dimensional electrical impedance tomography , 1996, Nature.

[69]  Antonello Tamburrino,et al.  A new non-iterative inversion method for electrical resistance tomography , 2002 .

[70]  Andy Adler,et al.  Adjacent stimulation and measurement patterns considered harmful , 2011, Physiological measurement.

[71]  A Thiagalingam,et al.  A review on electrical impedance tomography for pulmonary perfusion imaging , 2012, Physiological measurement.

[72]  G. Hahn,et al.  Changes in the thoracic impedance distribution under different ventilatory conditions. , 1995, Physiological measurement.

[73]  Ryan J. Halter,et al.  FPGA-Based Voltage and Current Dual Drive System for High Frame Rate Electrical Impedance Tomography , 2015, IEEE Transactions on Medical Imaging.

[74]  Hervé Gagnon,et al.  Accounting for hardware imperfections in EIT image reconstruction algorithms , 2007, Physiological measurement.

[75]  Raul Gonzalez Lima,et al.  Electrical impedance tomography , 2009, Current opinion in critical care.

[76]  Matthias Kott,et al.  Dynamics of regional lung aeration determined by electrical impedance tomography in patients with acute respiratory distress syndrome , 2012, Multidisciplinary Respiratory Medicine.

[77]  Andy Adler,et al.  Impact of Model Shape Mismatch on Reconstruction Quality in Electrical Impedance Tomography , 2012, IEEE Transactions on Medical Imaging.

[78]  Jean-Philippe Thiran,et al.  A Versatile Noise Performance Metric for Electrical Impedance Tomography Algorithms , 2017, IEEE Transactions on Biomedical Engineering.

[79]  D. Isaacson.  Distinguishability of Conductivities by Electric Current Computed Tomography , 1986, IEEE Transactions on Medical Imaging.

[80]  Jason H. T. Bates,et al.  Utility of an esophageal reference electrode for thoracic electrical impedance tomography , 1995, Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society.

[81]  Andy Adler,et al.  Addressing the computational cost of large EIT solutions , 2012, Physiological measurement.

[82]  B H Brown,et al.  Electrical impedance tomography (EIT): a review , 2003, Journal of medical engineering & technology.

[83]  J Solà,et al.  Electrical impedance tomography for non-invasive assessment of stroke volume variation in health and experimental lung injury , 2017, British journal of anaesthesia.

[84]  I Frerichs,et al.  Electrical impedance tomography (EIT) in applications related to lung and ventilation: a review of experimental and clinical activities. , 2000, Physiological measurement.

[85]  Jennifer L. Mueller,et al.  Direct 2-D Reconstructions of Conductivity and Permittivity From EIT Data on a Human Chest , 2015, IEEE Transactions on Medical Imaging.

[86]  B H Brown,et al.  The Sheffield data collection system. , 1987, Clinical physics and physiological measurement : an official journal of the Hospital Physicists' Association, Deutsche Gesellschaft fur Medizinische Physik and the European Federation of Organisations for Medical Physics.

[87]  J. Newell,et al.  Assessment of acute pulmonary edema in dogs by electrical impedance imaging , 1996, IEEE Transactions on Biomedical Engineering.

[88]  Steffen Leonhardt,et al.  Electric impedance tomography for monitoring volume and size of the urinary bladder , 2011, Biomedizinische Technik. Biomedical engineering.

[89]  A. Adler,et al.  Impedance imaging of lung ventilation: do we need to account for chest expansion? , 1996, IEEE Transactions on Biomedical Engineering.

[90]  A. Calderón,et al.  On an inverse boundary value problem , 2006 .

[91]  Andy Adler,et al.  FEM electrode refinement for electrical impedance tomography , 2013, 2013 35th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC).

[92]  David Isaacson,et al.  A Reconstruction Algorithm for Breast Cancer Imaging With Electrical Impedance Tomography in Mammography Geometry , 2007, IEEE Transactions on Biomedical Engineering.

[93]  Alexander März,et al.  Performance of Novel Patient Interface for Electrical Impedance Tomography Applications , 2017 .

[94]  Andrea Borsic,et al.  Generation of anisotropic-smoothness regularization filters for EIT , 2002, IEEE Transactions on Medical Imaging.

[95]  Inéz Frerichs,et al.  Electrical impedance tomography imaging of the cardiopulmonary system , 2014, Current opinion in critical care.

[96]  J Jossinet,et al.  The impedivity of freshly excised human breast tissue , 1998, Physiological measurement.

[97]  David Isaacson,et al.  Layer stripping: a direct numerical method for impedance imaging , 1991 .

[98]  David Isaacson,et al.  NOSER: An algorithm for solving the inverse conductivity problem , 1990, Int. J. Imaging Syst. Technol..

[99]  Steffen Leonhardt,et al.  Chest electrical impedance tomography examination, data analysis, terminology, clinical use and recommendations: consensus statement of the TRanslational EIT developmeNt stuDy group , 2016, Thorax.

[100]  Hervé Gagnon,et al.  A parametric model of the relationship between EIT and total lung volume , 2005, Physiological measurement.

[101]  Andy Adler,et al.  Non-invasive monitoring of central blood pressure by electrical impedance tomography: first experimental evidence , 2011, Medical & Biological Engineering & Computing.

[102]  Ola Stenqvist,et al.  Electrical impedance tomography: potentials and pitfalls , 2012, Current opinion in critical care.

[103]  John M. Lee,et al.  Determining anisotropic real-analytic conductivities by boundary measurements , 1989 .

[104]  William R B Lionheart,et al.  A Matlab toolkit for three-dimensional electrical impedance tomography: a contribution to the Electrical Impedance and Diffuse Optical Reconstruction Software project , 2002 .

[105]  Jorn Justiz,et al.  Evaluation and Real-Time Monitoring of Data Quality in Electrical Impedance Tomography , 2013, IEEE Transactions on Medical Imaging.

[106]  D. Isaacson,et al.  Electrode models for electric current computed tomography , 1989, IEEE Transactions on Biomedical Engineering.

[107]  R. W. Lau,et al.  The dielectric properties of biological tissues: III. Parametric models for the dielectric spectrum of tissues. , 1996, Physics in medicine and biology.