Determination of the depth dependent Fourier spectra of catheter reflections for automatic catheter detection

Treatment of female breast carcinoma with high dose rate (HDR) brachytherapy allows dose concentration to the former tumor bed while sparing normal tissue. For this, catheters have to be implanted precisely in the treated region. Supervision of the implantation by 3-D ultrasound is a promising alternative to CT and stereotactic mammography if the catheters can be visualized intuitively. Analyzing the Fourier spectra of the catheter raw data signals has been suggested for catheter detection. Here it is investigated in how far a depth dependent analysis of the spectrum is a valuable approach to optimize catheter detection. Therefore, χ²-statistic is used to determine the similarity of catheter spectra of approximately equal deep positioned catheters and the difference of spectra of distant catheters, respectively. The investigations proofed the depth dependence of the Fourier spectra of a turkey breast phantom. Thus, in further research these results should be applied to catheter detection in female breast.