This paper presents a tumor detection system for fully digital mammography,
The processing scheme adopted in the proposed system focuses on the soluti
on of two problems. One is how to detect tumors as suspicious regions with
a very weak contrast to their background and another is how to extract feat
ures which characterize malignant turners. For the first problem, a unique
adaptive filter called the iris filter is proposed. It is very effective in
enhancing approximately rounded opacities no matter what their contrasts m
ight be. Clues for differentiation between malignant tumors and other tumor
s are believed to be mostly in their border areas. This paper proposes typi
cal parameters which reflect boundary characteristics. To confirm the syste
m performance for unknown samples, large scale experiments using 1212 CR im
ages were performed. The results showed that the sensitivity of the propose
d system was 90.5% and the average number of false positives per image was
found to be only 1.3. These results show the effectiveness of the proposed
system.