1. The CALMA project A CAD tool in breast radiography A.Ceccopieri, Padova 9-2-2000

2. Computer Assisted Library in MAmmography Screening mammography sensitivity (identified positives / true positives) 73% - 88% specificity (identified negatives / true negatives) 83% - 92% These merit figures INCREASE if diagnosis is performed by 2 independent radiologists

3. CALMA aims to: Build a DATABASE of mammograms in digital format Perform an automatic classification of parenchyma structures Detect the spiculated lesions Detect micro-calcification clusters

4. 900 patients 2900 images Glandular 58 % DN 5 % FA 37 % OUR DATABASE

5. DAQ: granularity: 85  m range:12 bit dimensions: ~2000x2600 pixels STORAGE 60 images/ CD (no compression) up to 240 CD HARDWARE

6. DAQ panel & database search Queries Full screen display Preview and images’ description

7. Automatic classification of breast parenchyma Left to right / top to bottom: - dense (DN) - irregularly nodular (IN) - micro-nodular (MN) - fiber-adipose (FA) - fiber-glandular (FG) - parvi-nodular (PN) -Glandular (IN+MN+FG+PN) Supervised FF-ANN Spatial frequencies analysis (FFT)

8. 512x512 pixels analysis ANN classification Feature extraction 2dim FFT GLANDULAR

9. RESULTS: TEXTURE ANALYSIS DENSE ADIPOSE GLANDULAR DENSE >95% 0% 0% ADIPOSE 16% 68±3% 16% GLANDULAR 4% 3% 93±1%

10. SPICULATED LESIONS Unroll spirals Spatial frequencies analysis(FFT) FF-ANN examples

11. MethodArea (cm2) spread (cm2) B (0-0)31 16 B (1-3)27 13 B (2-5)25 13 C neural36 12 C normalized36 18 C corona49 27 RESULTS @ sensitivity=90(±3)%:

12. Integration range 2-5

13. Spiculated lesions: CAD performances Red= radiologist Blue= CAD

14. RESULTS: SPICULATED LESIONS Sensitivity (per patient) 90±3% FALSE POSITIVES / IMAGE 1.4 AVERAGE ROI 25 cm 2 DATA REDUCTION ~ 10

15. Examples MICROCALCIFICATION CLUSTERS FF-ANN + Sanger learning rule PCA

16. Method Image Preprocessing (convolution filters) PCA through a NN trained with the Sanger rule Study of the first Principal Components Classification

17. Preprocessing 60x60 pixels windows selection convolution filters with dims: 5x5 7x7 9x9 Best results with a 7x7 filter with A=1\N 2  a ij <0 (a ij kernel element)

18. Results Sensitivity = 73 ± 2 % Specificity= 94 ± 2 % With micro- calcification clusters No Micro- calcification clusters

19. 2 3 1 Micro-calcification clusters: CAD Red= radiologist Blue= CAD

20. RESULTS: MICRO-CALCIFICATION CLUSTERS SENSITIVITY 73±2% SPECIFICITY 94±2%

21. FUTURE Software developement: 1- Local classification of parenchyma 2- Use parenchyma classification for lesions CAD 3- Use the asymmetry between the two sides to detect cancer. Increase the DATABASE “ON-LINE Validation”: Is CALMA a good (second) radiologist? Implementation of physician- friendly CAD workstations in the collaborating Hospitals