A compensated radiolucent electrode array for combined EIT and mammography

Kao, Tzu-Jen; Saulnier, G.J.; Xia, Hongjun; Tamma, Chandana; Newell, J.C.; Isaacson, David

doi:10.1088/0967-3334/28/7/s22

Cited by 29 publications

(25 citation statements)

References 11 publications

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“…Patterns of voltages are applied to the breast using two parallel planar arrays of radiolucent electrodes [23] that are attached to the compression plates of an X-ray mammography unit [24], (Fig. 1).…”

Section: Registration With Tomosynthesis Imagesmentioning

confidence: 99%

“…This system reconstructs approximations to the conductivity and permittivity inside the breast over a broad frequency band, at high speed, and displays these properties in 3-D. The system has been designed with radiolucent electrodes [23], permitting simultaneous X-ray and electrical study of breast cancer patients. Regional impedance spectroscopy is acquired simultaneously and in register with digital breast tomosynthesis (DBT) mammography at Massachusetts General Hospital.…”

Section: Introductionmentioning

confidence: 99%

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Regional Admittivity Spectra With Tomosynthesis Images for Breast Cancer Detection: Preliminary Patient Study

Kao

Boverman

Kim

et al. 2008

IEEE Trans. Med. Imaging

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It has been known for some time that many tumors have a significantly different conductivity and permittivity from surrounding normal tissue. This high “contrast” in tissue electrical properties, occurring between a few kilohertz and several megahertz, may permit differentiating malignant from benign tissues. Here we show the ability of electrical impedance spectroscopy (EIS) to roughly localize and clearly distinguish cancers from normal tissues and benign lesions. Localization of these lesions is confirmed by simultaneous, in register digital breast tomosynthesis (DBT) mammography or 3-D mammograms.

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Section: Registration With Tomosynthesis Imagesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Regional Admittivity Spectra With Tomosynthesis Images for Breast Cancer Detection: Preliminary Patient Study

Kao

Boverman

Kim

et al. 2008

IEEE Trans. Med. Imaging

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“…Infrared transceivers are a possible means of acquiring this data by optically measuring the surface at a few points. None of the existing techniques for estimating the shape in EIT are sufficiently accurate or practical, so image quality has suffered (Frerichs 2000, Holder 1992, Kao et al 2007, Poplack et al 2007). …”

Section: Introductionmentioning

confidence: 99%

Optical breast shape capture and finite-element mesh generation for electrical impedance tomography

Forsyth

Borsic²,

Halter³

et al. 2011

Physiol. Meas.

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X-Ray mammography is the standard for breast cancer screening. The development of alternative imaging modalities is desirable because Mammograms expose patients to ionizing radiation. Electrical Impedance Tomography (EIT) may be used to determine tissue conductivity, a property which is an indicator of cancer presence. EIT is also a low-cost imaging solution and does not involve ionizing radiation. In breast EIT, impedance measurements are made using electrodes placed on the surface of the patient’s breast. The complex conductivity of the volume of the breast is estimated by a reconstruction algorithm. EIT reconstruction is a severely ill-posed inverse problem. As a result, noisy instrumentation and incorrect modelling of the electrodes and domain shape produce significant image artefacts. In this paper, we propose a method that has the potential to reduce these errors by accurately modelling the patient breast shape. A 3D hand-held optical scanner is used to acquire the breast geometry and electrode positions. We develop methods for processing the data from the scanner and producing volume meshes accurately matching the breast surface and electrode locations, which can be used for image reconstruction. We demonstrate this method for a plaster breast phantom and a human subject. Using this approach will allow patient-specific finite element meshes to be generated which has the potential to improve the clinical value of EIT for breast cancer diagnosis.

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“…At Rensselaer, we have developed an EIT breast scanning system, the Adaptive Current Tomograph (ACT) 4 [11], [12], used in conjuction with a three-dimensional digital tomosynthesis system [13], which produces 3-D X-ray reconstructions of the breast’s structure. A radiolucent electrode array [14] makes possible the simultaneous employment of these imaging modalities and the presence of the fiducial markers at the edge of the array enables the near-perfect co-registration of the X-ray and electrical impedance reconstructions. The ACT 4 system, as used with a digital tomosynthesis instrument, can be seen in Fig.…”

Section: Introductionmentioning

confidence: 99%

Methods for Compensating for Variable Electrode Contact in EIT

Boverman

Isaacson

Saulnier

et al. 2009

IEEE Trans. Biomed. Eng.

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Electrical Impedance Tomography (EIT) is an imaging modality which currently shows promise for the detection and characterization of breast cancer. A very significant problem in EIT imaging is the proper modeling of the interface between the body and the electrodes. We have found empirically that it is very difficult, in a clinical setting, to assure that all electrodes make satisfactory contact with the body. In addition, we have observed a capacitive effect at the skin/electrode boundary that is spatially heterogeneous. To compensate for these problems, we have developed a hybrid nonlinearlinear reconstruction algorithm using the complete electrode model in which we first estimate electrode surface impedances, by means of a Levenberg-Marquardt iterative optimization procedure with an analytically computed Jacobian matrix. We subsequently use a linearized algorithm to perform a three-dimensional reconstruction of perturbations in both contact impedances and in the spatial distributions of conductivity and permittivity. Results show that, with this procedure, artifacts due to electrodes making poor contact can be greatly reduced. If the experimental apparatus physically applies voltages and measures currents, we show that it is preferable to compute the reconstruction with respect to the Dirichlet-to-Neumann map rather than the Neumann-to-Dirichlet map if there is a significant possibility that electrodes will be fully disconnected. Finally, we test our electrode compensation algorithms for a set of clinical data, showing that we can significantly improve the fit of our model to the measurements by allowing the electrode surface impedances to vary.

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A compensated radiolucent electrode array for combined EIT and mammography

Cited by 29 publications

References 11 publications

Regional Admittivity Spectra With Tomosynthesis Images for Breast Cancer Detection: Preliminary Patient Study

Regional Admittivity Spectra With Tomosynthesis Images for Breast Cancer Detection: Preliminary Patient Study

Optical breast shape capture and finite-element mesh generation for electrical impedance tomography

Methods for Compensating for Variable Electrode Contact in EIT

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