Ultrasonic Imaging: A New Tool for Early Detection of Breast Cancer

Rensselaer Polytechnic Institute, Troy NY

Investigators

Abstract

Nolan 0104573 The investigator seeks to improve ultrasound imaging in order for it to be a more effective tool in breast cancer diagnosis and treatment. He uses modern methods of partial differential equations and microlocal analysis to provide images of the breast that are artifact-free and of a higher resolution than currently available. He models propagation and scattering of ultrasonic waves using microlocal analysis and geometrical optics. In particular, the approach uses the complete waveform of the ultrasound instead of just its phase. Microlocal analysis provides a clear explanation of artifacts that appear in acoustic images. More importantly, it provides a means of avoiding and removing such artifacts. To help in obtaining clear images, the investigator looks for an arrangement of transducers providing the strongest measurable scattered signal at the surface of the breast. The optimal configuration is based on a power method that starts with a non-zero arbitrary source and measures the resulting scattered field (caused by a tumor for example) at the surface. He models the scattering process with a linear scattering operator based on the wave equation. The scattering operator maps sources to scattered wave fields, whereas the adjoint scattering operator maps scattered wave fields to sources. By composing the scattering operator with its adjoint, he uses the power method to find the eigenfunction corresponding to the largest scattered signal. Novel in the approach is the ability to couple the power method with geometrical optics. This provides an analytical tool for computing the optimal sources that can then be implemented computationally in a very efficient way for both modeling and imaging the inversion. This work aims to provide a new method of imaging the female breast for use in diagnosing and treating of breast cancer. The technique is based on ultrasound waves, howver it uses much more information from these waves than is currently used. In particular, the shape of the waves that bounce off of a lesion or tumor in the breast is analyzed. The method is tailored to avoid artifacts that can appear in current imaging techniques. In addition, the method will be fast and feasible to implement. Because of the reliability and clarity of the images, this new imaging technique should significantly cut down on the number of unnecessary biopsies that are currently carried out in the United States each year. Because of the speed of the method, it can help to provide a quick diagnosis. The method also takes advantage of recently developed three dimensional imaging technology. Ultrasound is a tried and safe method of imaging; it involves no harmful radiation. The method is general enought that it could concievably have spin-offs into other modes of imaging (X-Ray, MRI, etc.). Finally, this new method of imaging should create opportunities for new and established companies to manufacture devices that take advantage of it.