publications by Nimmi Ramanujam.


Papers Published

  1. M. Lazebnik and C. F. Zhu and G. M. Palmer and J. Harter and S. Sewall and N. Ramanujam and S. C. Hagness, Electromagnetic Spectroscopy of Normal Breast Tissue Specimens Obtained From Reduction Surgeries: Comparison of Optical and Microwave Properties, Ieee Transactions On Biomedical Engineering, vol. 55 no. 10 (October, 2008), pp. 2444 -- 2451 .
    (last updated on 2009/09/02)

    Abstract:
    Techniques utilizing electromagnetic energy at microwave and optical frequencies have been shown to be promising for breast cancer detection and diagnosis. Since different biophysical mechanisms are exploited at these frequencies to discriminate between healthy and diseased tissue, combining these two modalities may result in a more powerful approach for breast cancer detection and diagnosis. Toward this end, we performed microwave dielectric spectroscopy and optical diffuse reflectance spectroscopy measurements at the same sites on freshly excised normal breast tissues obtained from reduction surgeries at the University of Wisconsin Hospital, using microwave and optical probes with very similar sensing volumes. We found that the microwave dielectric constant and effective conductivity are correlated with tissue composition across the entire measurement frequency range (vertical bar r vertical bar similar to 0.5-0.6, p $<$ 0.01) and that the optical absorption coefficient at 460 nm and optical scattering coefficient are correlated with tissue composition (vertical bar r vertical bar similar to 0.4-0.6, p $<$ 0.02). Finally, we found that the optical absorption coefficient at 460 nm is correlated with the microwave dielectric constant and effective conductivity (r = -0.55, p $<$ 0.01). Our results suggest that combining optical and microwave modalities for analyzing breast tissue samples may serve as a crosscheck and provide complementary information about tissue composition.

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