Computer assisted biopsy of breast tumors

Abstract

In this paper we report our preliminary results of the development of a computer assisted system for breast biopsy. The system is based on tracked ultrasound images of the breast. A three dimensional ultrasound volume is constructed from a set of tracked B-scan images acquired with a calibrated probe. The system has been designed to assist a radiologist during breast biopsy, and also as a training system for radiology residents. A semiautomatic classification algorithm was implemented to assist the user with the annotation of the tumor on an ultrasound volume. We report the development of the system prototype, tested on a physical phantom of a breast with a tumor, made of polivinil alcohol.

Mammographic image analysis and computer assisted biopsy of breast tumors

“…(s x , s y ) are the corresponding scaling factors which convert from (row, column) to (m); p T i is the rigid transformation matrix that maps a pixel on the B-scan image to the reference frame attached to the ultrasound probe; t T p is the rigid transformation matrix that maps the reference frame of the ultrasound probe to the reference frame of the optical tracker [6].…”

“…The system was solved numerically using the Levenberg-Marquardt method. Once we have the values of the scaling factors, as well as the values of the transformation matrix p T i, together with the transformation matrix provided by the optical tracker t T p , we can map a pixel (u, v) on an ultrasound image to our reference volume using (1) [6]. In the next section our experimental setup for ultrasound calibration and system evaluation is described.…”

“…Two gaussian filtered images were produced with σ=1, σ=3 pixels, the corresponding gradient images were calculated as: GI=sqrt(Dx+Dy) (6) where Dx and Dy are the first derivatives in the horizontal and vertical direction.…”

Implementation of Polyvynil-Alcohol Mixed With Nano-Particles as a Near Representation of Biological Tissue: Ultrasonic and Photo- Thermal Study

“…Among the advantages of these techniques it is that one can get images free from diffuse NIR radiation, they are non-invasive and, the output signals can possess a large signal-to-noise ratio [2]. Furthermore, these techniques can be integrated to medical protocols on computer-assisted biopsy [3] and even to the so-called optical biopsy [4,5].…”