Correlation of permittivity and water content during cerebral edema

Kao, Hua-Lin; Cardoso, Roberta; Shwedyk, E.

doi:10.1109/10.784144

Cited by 32 publications

(18 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[12][13][14][15] In human tissues the dielectric properties are strongly related to tissue water content. 16,17 Since the water content in skin is high and the dielectric constant of water is much greater than those of macromolecules (mainly proteins and proteoglycans) and adipose tissue, the measured TDC value is directly proportional to water content in skin. 14,16,18 Therefore, measurements of tissue water are best focused into skin where the first signs of lymphedema are often thought to manifest [19][20][21][22][23][24] and where edema is often located.…”

Section: Introductionmentioning

confidence: 99%

Experimental and Analytical Comparisons of Tissue Dielectric Constant (TDC) and Bioimpedance Spectroscopy (BIS) in Assessment of Early Arm Lymphedema in Breast Cancer Patients after Axillary Surgery and Radiotherapy

Lahtinen

Seppälä

Virén

et al. 2015

Lymphatic Research and Biology

View full text Add to dashboard Cite

Discrepancies between TDC and BIS techniques in assessing lymphedema are related to different measurement techniques and assessed tissue water components. Independently of selected technique-specific threshold limit, the TDC technique was more sensitive than the BIS technique in the early assessment of BCRL and demonstrated that nearly 20% of early lymphedema are only superficially localized. The results further supported the complementary role of TDC and arm volume measurements as a highly diagnostic method for early lymphedema.

show abstract

Section: Introductionmentioning

confidence: 99%

Experimental and Analytical Comparisons of Tissue Dielectric Constant (TDC) and Bioimpedance Spectroscopy (BIS) in Assessment of Early Arm Lymphedema in Breast Cancer Patients after Axillary Surgery and Radiotherapy

Lahtinen

Seppälä

Virén

et al. 2015

Lymphatic Research and Biology

View full text Add to dashboard Cite

show abstract

“…Magnetic brain monitoring could, in fact, provide a useful method, as there exists still no noninvasive and continuous instrumentation for the detection of brain edema. This application relies on the fact that water accumulations in tissue cause local changes of the PEP and , as has been demonstrated with invasive measurements, e.g., in [11] and [12].…”

Section: B Example 1: Brain Edema Monitoringmentioning

confidence: 99%

“…A spurious change can be calculated according to (11) In terms of the model parameters, can be expressed as (12) Decomposition into real and imaginary part gives (13) The calculation of the partial derivatives and of (13) was carried out automatically with the symbolic toolbox of MATLAB.…”

Section: B Thermal Mismatch Of the Gradiometer Coilsmentioning

confidence: 99%

Biological tissue characterization by magnetic induction spectroscopy (MIS): requirements and limitations

Scharfetter

Casañas

Rosell

2003

IEEE Trans. Biomed. Eng.

120

View full text Add to dashboard Cite

Abstract-Magnetic induction spectroscopy (MIS) aims at the contactless measurement of the passive electrical properties (PEP), , and of biological tissues via magnetic fields at multiple frequencies. Whereas previous publications focus on either the conductive or the magnetic aspect of inductive measurements, this article provides a synthesis of both concepts by discussing two different applications with the same measurement system: 1) monitoring of brain edema and 2) the estimation of hepatic iron stores in certain pathologies. We derived the equations to estimate the sensitivity of MIS as a function of the PEP of biological objects. The system requirements and possible systematic errors are analyzed for a MIS-channel using a planar gradiometer (PGRAD) as detector. We studied 4 important error sources: 1) moving conductors near the PGRAD; 2) thermal drifts of the PGRAD-parameters; 3) lateral displacements of the PGRAD; and 4) phase drifts in the receiver. All errors were compared with the desirable resolution. All errors affect the detected imaginary part (mainly related to ) of the measured complex field much less than the real part (mainly related to and ). Hence, the presented technique renders possible the resolution of (patho-) physiological changes of the electrical conductivity when applying highly resolving hardware and elaborate signal processing. Changes of the magnetic permeability and permittivity in biological tissues are more complicated to deal with and may require chopping techniques, e.g., periodic movement of the object.Index Terms-Brain edema, impedance spectroscopy, iron overload, magnetic induction tomograpy, passive electrical properties of tissue.

show abstract

“…It has been shown that tissue dielectric properties depend on its physiological and pathological conditions, including tissue blood [14] and water contents [8,[13][14][15], hypoxia [16], ischemia [14,16] infarction [14,16], and malignancies [2,7,23,25]. These findings have presented a very promising opportunity for the use of microwave tomography for physiological imaging, i.e., non-invasive assessment of functional and pathological conditions of biological tissues.…”

Section: Introductionmentioning

confidence: 98%

Microwave Tomographic Imaging of the Heart in Intact Swine

Semenov¹,

Posukh²,

Bulyshev³

et al. 2006

Journal of Electromagnetic Waves and Applications

View full text Add to dashboard Cite

Microwave tomography is a new imaging modality based on differentiation of tissue dielectric properties. The main objective of our research project is to develop a microwave tomographic approach for non-invasive assessment of functional viability of myocardial tissue, including detection of infarcted tissue. Imaging of the heart in intact, euthanized animals is the first step towards this objective. When microwave tomography is used to image the thorax of intact animals, it faces two major problems: -the structural complexity of the rib area with high reflection of electromagnetic (EM) radiation from its boundaries, and the potential for high reflection of EM radiation from the lung, filled with air. In addition, when a targeted object (a heart in our case) is located inside of a larger high scattered object (a torso), the level of EM field scattered by the internal object has to be technically detectable from the stronger EM field Downloaded by [McGill University Library] at 07:25 17 November 2014 874 Semenov et al.scattered by torso. The goal of this research study is to evaluate the degree of complexity of these problems, to understand some technical requirements for clinically applicable MWT system and to demonstrate the feasibility of microwave tomography for imaging of the heart in intact mammals using a swine model. Experiments were conducted on pigs (Yorkshire Domestic Cross/Farm Pigs) using a modified threedimensional (3D) microwave tomographic (MWT) system operating at frequency 0.9 GHz. The presence of the heart in torso changes the amplitude of EM field by about 10-20% and changes the phase of EM field by about 7-10 degrees (mean absolute differences). Microwave tomographic images of swine torso and intact euthanized animals were obtained and discussed. Images reveal intra-torso and organ anatomy, including the heart and left ventricular chamber.

show abstract

Correlation of permittivity and water content during cerebral edema

Cited by 32 publications

References 21 publications

Experimental and Analytical Comparisons of Tissue Dielectric Constant (TDC) and Bioimpedance Spectroscopy (BIS) in Assessment of Early Arm Lymphedema in Breast Cancer Patients after Axillary Surgery and Radiotherapy

Experimental and Analytical Comparisons of Tissue Dielectric Constant (TDC) and Bioimpedance Spectroscopy (BIS) in Assessment of Early Arm Lymphedema in Breast Cancer Patients after Axillary Surgery and Radiotherapy

Biological tissue characterization by magnetic induction spectroscopy (MIS): requirements and limitations

Microwave Tomographic Imaging of the Heart in Intact Swine

Contact Info

Product

Resources

About