Preliminary study of modeling sagging breasts for support navigation in ultrasound guided biopsy

The main challenge in the biopsy procedure is to guarantee reproducibility of the needle’s tip position between biopsies. The general solution addressed to overcome this challenge is an image-based navigation system. While these are widely used for rigid tissue, applications for soft tissues are in the preliminary implementation stage. The paper presents the stages of a method for rigid registration of uncut sections and ultrasound implantation of the breast surface and the possibility of their visualization in a common coordinate system. Measurement of the quality of surface fit is based on the distance between the registered markers indicated on the breast surface by the user. The proposed methodology obtains the median Fiducial Registration Error to fit the fragile, flat, mutual surface areas and match markers in the Time of Flight image to the positions indicated in the tracker coordinate system of 12, 6.9, 5.8 and 15 mm respectively. A current challenge in breast biopsy is the changing position of the needle tip between biopsies.