Microwave Imaging for Detecting Breast Cancer Amir Golnabi ENGS 166 Spring 2008.

14
Microwave Imaging Microwave Imaging for Detecting Breast for Detecting Breast Cancer Cancer Amir Golnabi ENGS 166 Spring 2008

Transcript of Microwave Imaging for Detecting Breast Cancer Amir Golnabi ENGS 166 Spring 2008.

Microwave Imaging for Microwave Imaging for Detecting Breast CancerDetecting Breast Cancer

Amir GolnabiENGS 166

Spring 2008

Outline:

•Electrical Properties

•Tissue Dielectric Properties

•Dielectric Property Measurement

•Measured Tissue Dielectric Properties

•Normal Tissue vs. Malignant Tissue

•Microwave Tomography

•Breast Microwave Imaging at Dartmouth College

•Acknowledgements and References

Basic Concepts of Electrical Properties:

•The interaction of an electromagnetic (EM) field with a

biological system

•Electrical properties:

–Conductivity: σ the conductance of a unit volume of

matter

–Permittivity: ε the capacitance of a unit volume of matter

•Complex Permittivity:

– Loss Factor

– permittivity of free space (=8.85 x 10^(-12) F/m)

– angular frequency and f represents the

frequency of the EM field in hertz

0 jj

0f 2

Tissue Dielectric Properties: Range 1Hz – 30GHz

•3 Dispersion regions: α, β, and γ

•Alpha Dispersion (0.1-100kHz):–Frequency dependence of the outer

cell membrane

•Beta Dispersion (1-20MHz):

–Insulating structure

–Cellular membrane enclose bound water

–EM frequency ↑ → Cellular membranes are short-circuited →

Bound water insulating effects ↓ → Conduction through cell

membrane ↑ → σ ↑

•Gamma Dispersion (about 20GHz)

–Dipolar relaxation of water in the tissue

Dielectric Properties of Different tissues:Blood, Muscle, and Fatty tissue in Microwave

Frequencies Range: Water and electrolyte content

•Tissues:

–High water content: Muscle, Blood, Brain, and Internal organs

–Low water content: Fat, Bone, Lung, and Outer layer of skin

•Low water content

Low Permittivity

Dielectric Property Measurement:

•Measuring the effects of the intervention of tissue with an

electromagnetic field at specific frequency:

–Open-ended coaxial cable

•Network Analyzer: Measures the relative amplitude and

phase difference between the reference and reflected signal

channels.

•Computer Algorithm: Computes the dielectric properties.

•Joines et.al. 1994, In-vitro: Normal vs. Malignant

Tissues

–Colon, kidney, liver, lung, and breast

–Frequency range: 50-900 MHz

–ratio of the power absorbed in the malignant tissue (Pm)

to that absorbed in the normal tissue (Pn)

• n: Normal

• m: Malignant

Measured Dielectric Properties (results):

222

2

22

19

nnnmnm

nnnm

n

m

P

P

Measured Dielectric Properties (results):

Higher water

content in

malignant tissue

Higher dielectric

properties

•Meaney et.al. 2000, In-vivo: clinical prototype of a

microwave tomographic system for breast imaging

–contrast between normal and malignant breast tissue close

to 2:1

•Sha et.al. 2002: Diagnostic value of dielectric properties of

normal and malignant breast tissue at a wide range of

frequencies

–The low conductivity values of the normal breast tissue

enable penetration of microwave frequencies up to the low

GHz range.

–At 100 MHz – 1 GHz, dielectric properties can significantly

help classify normal and malignant breast tissues.

Measured Dielectric Properties (results):

•Basic idea

•Microwave Imaging at Dartmouth College:

Microwave Tomography:

A

BC

D

E

(A) Microwave illumination tank

(B) Antenna motion actuator;

(C) the coupling medium reservoir;

(D) Patient examination table

(E) Electronics cart.

•16 monopole antennas

•Frequency range: 500-2500 MHz

•7 vertical positions

•1 antenna transmits and

other 15 antennas receive

the signal

•2D Image reconstruction

Microwave Imaging at Dartmouth College:

1, 1 2, 2

•Reconstructed Images: patient 1914 left Breast

Microwave Imaging at Dartmouth College: (cont.)

r

r

•Reconstructed Images: patient 1914 left Breast

Microwave Imaging at Dartmouth College: (cont.)

r

r

References:•Larsen, Lawrence, and John Jacobi. Medical Applications of Microwave Imaging. New York: IEEE Press, 1985.

•J. R. Reitz and F. J. Milford. Functions of electromagnetic theory. Addison Wesley Publishing Company, 1967

•Von Hippel, A. R. Dielectric Materials and Applications. M.I.T. Press, 1954

•Schwan, H. P. Electrical properties of tissue and cell suspensions. Adv, Biol. Med. Phys. Vol. 5

•E.H. Grand, S.E. Keefe, and S. Takashima, “The dielectric behavior of aqueous solutions of bovine serum albumin from radiowave to microwave frequencies,”

J.Phys. Chem., Vol. 72, pp. 4373-4380, 1968

•H.F. Cook, “The dielectric behavior of some types of human tissue at microwave frequencies,” Br. J. Appl. Phys., Vol 2, pp. 295-296, Oct. 1951.

•J. E. Roberts and H. F. Cook, “Microwave in medical and biological research,” Br. J. Appl. Phys., Vol. 3, pp. 33-40, Feb 1952.

•C. C. Johnson and A.W. Guy, “Nonionizing electromagnetic wave effects in biological materials and systems,” Proc. IEEE, Vol. 60, pp. 694-695, June 1972.

•Fear, Elise, Paul Meaney, and Maria A. Stuchly. "Microwaves for breast cancer detection?". IEEE POTENTIALS 2003: 12-18.

•E. C. Burdette, F. L. Cain, and J. Seals, “In-vivo probe measurement technique for determining dielectric properties at VHF through microwave frequencies,”

IEEE Trans. Microwave Theory Tech., Vol. MTT 28, No. 4, pp. 414-423, 1980.

•W. T. Joines, Y. Z. Dhenxing, and R.L. Jirtle. “The measured electrical properties of normal and malignant human tissues from 50 to 900 MHz,” Medical

Physics, vol. 21, 1994, pp. 547-550.

•P.M. Meaney, M.W. Fanning, D. Li, S.P. Poplack, and K.D Paulsen,“A clinical prototype for active microwave imaging of the breast,” IEEE Trans. Microwave

Theory Tech., vol. 48, pp. 1841-1853, Nov.2000.

•L. Sha, E. R. Ward, and B. Story, “A Review of Dielectric Properties of Normal and Malignant Breast Tissue”, IEEE SoutheastCon 2002 pp. 457-462

•R.Smith,K.R Foster and J L.Wolf. "Dielectric properties of VX-2 carcinoma vs. normal liver Tissues”, IEEE trans Biomed. Eng.. BME-33,522,1986

•H. Fricke and S. Morse, “The Electric Capacity of Tumor of the Breast", J. CancerRes., vol. 16, pp. 310-376, 1926.

•R.Pethig, “Dielectric Properties of Biological Materials: Biophysical and Medical applications", EEE trans. un Electrical insulation Oct.1984;vol El-I9 No

5:453472S

•W. T. Joines, R. L. Jirtle, M. D. Rafal, D. J. Schaefer, "Microwave Power Absorption Differences Between Normal and Malignant Tissue", Int. J. Radiation

Oncology Biol. Phys., voI.6, pp. 681-687, 1980

•A J. Suruwiec. S S. Stuchly. J R. Barr. A. Swarup. "Dielectric Properties of Breast Carcinoma and the Surrounding tissues". IEEE Trans. Biomd. Eng. 1988; VoI

35. No.4.257-263

Acknowledgements:

Prof. Paul Meaney, Prof. Keith Paulsen, MIS group at Thayer School of Engineering