Biomedical Ultrasonic Signal Processing and Tissue Characterization

Graduate Students:
C. Simon
J. Shen
O. S. Haddadin


Ultrasonic tissue characterization techniques offer the promise of non-invasive discrimination between normal and diseased tissue in real-time using existing imaging technology and appropriate digital signal processing. Different parameters extracted from the processed ultrasound echo data, like integrated back scatter attenuation, reflection coefficient, scatterer distribution, and mean scatterer spacing have been considered in the literature, with variable degrees of success.

Mean scatterer spacing (MSS) has been recognized as a tool for tissue characterization for certain kinds of tissues and diseases. Furthermore, it has recently been shown to be a valuable tool for non-invasive estimation of temperature change caused by an externally applied heating field.

Certain tissues (like human liver and spleen) present a histologic structure, where each histologic unit consists of several cels and a tiny blood vessel in the ceter. These units are about 1mm in diameter and are organized in a semi-regular way. The ultrasound echo of these tissues present semi-regular reflections due to this structure. Mean scatterer spacing is defined to be the average distance between these semi-regular scatterers.

In our group we have been working on the development of robust and fast algortihms for estimating the MSS in tissue. Our envisioned applications include the aplication of MSS estimation in the differentiation between normal liver tissue and tumors in the case of ultrasonic images of patients with liver cancer. We are also exploring the application of MSS estimation techniques for the non-invasive estimation of temperature change in hyperthermia treatments.


Publications

  • Claudio Simon, Ralf Seip, and Emad S. Ebbini, "Estimation of Mean Scatterer Spacing Based on Autoregressive Spectral Analysis of Pre-Filtered Echo Data," to appear in Proceedings of the 1995 IEEE Ultrasonics Symposium, Seattle, November, 1995.
  • Claudio Simon , "A Study on Mean Scatterer Spacing Estimation Techniques," Research Oriented Directed Study Report, Department of Electrical Engineering and Computer Science, The University of Michigan, Ann Arbor, January 1996.


    Correspondence:

    Link to: http://bul.eecs.umich.edu/bio_us_signal/