1. Volumetric Breast Density understandbreastdensity.or g

2. Composition of Breasts Breasts are comprised of fibroglandular and fatty tissue. Fibroglandular tissue includes nodes used for milk production, and ligaments. They appear white in mammograms. Images courtesy of Volpara Solutions Limited.

3. Breast Composition Categories The American College of Radiology created breast composition categories to describe mammographic density: a. The breasts are almost entirely fatty b. There are scattered areas of fibroglandular density c. The breasts are heterogeneously dense which may obscure small masses d. The breasts are extremely dense, which lowers the sensitivity of mammography

4. Measuring Breast Density Mammograms typically involve having two x-rays of each breast at different angles. Tomosynthesis is a 3D mammogram where multiple views of the breast are taken and reconstructed into a 3D view. BI-RADS is calculated by averaging the percentage of fibroglandular tissue, to determine which classification the woman is. Radiologists assess density by eye using the x-rays. Automated breast density software can also calculate this. Density cannot be assessed by examining the physical breast.

5. VolparaDensity Mammography Scorecard Images and volumetric assessments are courtesy of Volpara Solutions Limited. Volumetric data can be used to determine patient-specific dose and the pressure applied by the paddles

7. a. The breasts are almost entirely fatty 2.9% Volumetric Density

9. a. The breasts are almost entirely fatty 4.3% Volumetric Density

11. b. There are scattered areas of fibroglandular tissue 6.5% Volumetric Density

13. b. There are scattered areas of fibroglandular tissue 6.8% Volumetric Density

15. c. The breasts are heterogeneously dense which may obscure small masses 8.6% Volumetric Density

17. c. The breasts are heterogeneously dense which may obscure small masses 11.6% Volumetric Density

19. d. The breasts are extremely dense, which lowers the sensitivity of mammography 17.6% Volumetric Density

21. d. The breasts are extremely dense, which lowers the sensitivity of mammography 24.6% Volumetric Density

22. Mammograms for the same woman over 8 years

23. MRI shows breast composition in extremely dense breasts

24. Risk Associated with Breast Density It is difficult to identify cancers in dense tissue as the fibroglandular tissue appears white, the same as cancers, and can mask them. Studies have shown increased cancer risk for denser breasts – very dense breasts have a six times greater risk than very fatty breasts of getting cancer.