Development of Three Dimensional Image Analysis System for Computer Aided Diagnosis of Breast Cancer Using Ultrasonic Echography

This paper describes the computer aided diagnosis of breast cancer using three dimensional ultrasonic echography. The authors have already proposed the algorithm for automated breast tumor extraction from ultrasonic echographic images. 1,2,3 Three dimensional voxel data is constructed from a series of the cross sections is captured from video signals and probe position and orientation data which are simultaneously obtained by 3D space tracking system. In the algorithm the tumor is extracted by using the following concepts; voxel in tumor region is low echo level, each voxel is classified as one of “tumor”, “normal tissue”, or “boundary” by using fuzzy reasoning and membership function is calculated from outputs of 3D LoG filtering. In this paper we propose the improved algorithm with multiple filters thus we obtain over 90% successfulness for good agreement of computed contour with manual traced contour. It is important to judge the agreement of tumor contour by computer because various kinds of filters are iteratively applied the voxel data in the proposed algorithm. Therefore we try to judge the agreement of contour by fuzzy reasoning. The basic concepts for fuzzy reasoning are that voxel inside the tumor region is low echo level and the morphology of the tumor is reasonable. For over ninety percent of extracted tumor good agreements of computed judge with human judge are found. The results say that the proposed algorithm has a potential for computer aided diagnosis of breast cancer.