Dielectric properties of CO-γ-irradiated and microwave-heated rat tumour and skin measured in vivo between 0.2 and 2.4 GHz

Zywietz, F.; Knöchel, R.

doi:10.1088/0031-9155/31/9/007

Cited by 19 publications

(4 citation statements)

References 27 publications

(18 reference statements)

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“…It is possible to determine the free water content in tissue by extracting the values of dielectric permittivity (ε ) at around 1 GHz. For example, Zywietz and Knöchel (1986) observed changes of ε at 2.4 GHz for rat skin after a hyperthermia treatment, due to changes in the tissue water content. Peyman et al (2001) reported significant decreases in ε at 900 MHz, 1.8 GHz and 2 GHz for rat tissue (including skin) as a function of age, as a result of decreases of the tissue water content.…”

Section: Drying Process Of Human Finger After Soakingmentioning

confidence: 99%

Free water content and monitoring of healing processes of skin burns studied by microwave dielectric spectroscopyin vivo

Hayashi¹,

Miura²,

Shinyashiki³

et al. 2005

Phys. Med. Biol.

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We have investigated the dielectric properties of human skin in vivo at frequencies up to 10 GHz using a time-domain reflectometry method with open-ended coaxial probes. Since gamma-dispersion results from the reorientation of free water molecules, the free water content of skin is quantitatively determined by dielectric measurements. The free water content of finger skin increased by about 10% after soaking in 37 degrees C water for 30 min, and it systematically decreased again through the drying process, as expected. Thus this analytical method has been applied to the study of skin burns. The free water content of burned human cheek skin due to hydrofluoric acid was significantly lower than that of normal skin, and the burned skin recovered through the healing process. In the case of a human hand skin burn due to heat, although the free water content was almost the same as that of normal skin at the beginning, it decreased during the healing process for the first 10 days, then began to increase. Although the number of test subjects was one for each experiment, it was shown that free water content is a good indicator for evaluating skin health and can be well monitored by dielectric spectroscopy.

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Section: Drying Process Of Human Finger After Soakingmentioning

confidence: 99%

Free water content and monitoring of healing processes of skin burns studied by microwave dielectric spectroscopyin vivo

Hayashi¹,

Miura²,

Shinyashiki³

et al. 2005

Phys. Med. Biol.

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“…Peloso et al (1984) measured rat tumour in vitro at 1 MHz to 1 GHz and found no significant difference to normal tissue. Others report results in the microwave frequency range where the differences between normal and tumour tissue stem primarily from differences in water content (Schepps and Foster 1980, Zywietz and Knoechel 1986, Burdette et al 1977. There are no known reports on in vivo measurements of electrical conductivity of hepatic tumours at audio and radio frequencies.…”

Section: Introductionmentioning

confidence: 99%

In vivoelectrical conductivity of hepatic tumours

et al. 2003

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Knowledge of electrical tissue conductivity is necessary to determine deposition of electromagnetic energy and can further be used to diagnostically differentiate between normal and neoplastic tissue. We measured 17 rats with a total of 24 tumours of the K12/TRb rat colon cancer cell line. In each animal we measured in vivo hepatic tumour and normal tissue conductivity at seven frequencies from 10 Hz to 1 MHz, at different tumour stages between 6 and 12 weeks after induction. Conductivity of normal liver tissue was 1.26 +/- 0.15 mS cm(-1) at 10 Hz, and 4.61 +/- 0.42 mS cm(-1) at 1 MHz. Conductivity of tumour was 2.69 +/- 0.91 mS cm(-1) at 10 Hz, and 5.23 +/- 0.82 mS cm(-1) at 1 MHz. Conductivity was significantly different between normal and tumour tissue (p < 0.05). We determined the percentage of necrosis and fibrosis at the measurement site. We fitted the conductivity data to the Cole-Cole model. For the tumour data we determined Spearman's correlation coefficients between the Cole-Cole parameters and age, necrosis, fibrosis and tumour volume and found significant correlation between necrosis and the Cole-Cole parameters (p < 0.05). We conclude that necrosis within the tumour and the associated membrane breakdown is likely responsible for the observed change in conductivity.

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“…The frequency dependence of the permittivity of various mammalian tumor tissues has been reported by several investigators. [Fricke and Morse, 1926;Bottomley and Andrew, 1978;Singh et al, 1979;Rogers et al, 1983;Schepps and Foster, 1980;Chaudhary et al, 1984;Zywietz et al, 1986;Smith et al, 1986;Surowiec et al, 19871. However, data at frequencies below 50 MHz are limited. To the best of our knowledge, only three studies have been reported on the dielectric properties of excised tumor tissues at low radiofrequencies [Bottomley and Andrew, 1978;Smith et al, 1986;Surowiec et al, 19873.…”

Section: Introductionmentioning

confidence: 99%

Dielectric properties of mouse MCA1 fibrosarcoma at different stages of development

Swarup

Stuchly

Surowiec

1991

Bioelectromagnetics

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The in vitro bulk electrical properties of MCA1 fibrosarcoma induced in C57B1/6 male mice were measured at frequencies of 10 kHz to 100 MHz, with some tissues measured to 2 GHz. The properties of normal surrounding tissue also were measured. A comparison of the dielectric properties between three different stages of tumor development as well as that between various locations within the tumor is reported. Statistical analysis of the experimental results revealed statistically significant differences in the dielectric constant and conductivity of the tumor tissues at various stages of development as measured at frequencies below 10 MHz. Conductivity values at different stages also differ at a frequency of 100 MHz. At other frequencies these differences were found to be statistically insignificant.

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Dielectric properties of CO-γ-irradiated and microwave-heated rat tumour and skin measured in vivo between 0.2 and 2.4 GHz

Cited by 19 publications

References 27 publications

Free water content and monitoring of healing processes of skin burns studied by microwave dielectric spectroscopyin vivo

Free water content and monitoring of healing processes of skin burns studied by microwave dielectric spectroscopyin vivo

In vivoelectrical conductivity of hepatic tumours

Dielectric properties of mouse MCA1 fibrosarcoma at different stages of development

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