Volumetric
Breast Density
understandbreastdensity.org
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.
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
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.
VolparaDensity Mammography Scorecard
Volumetric data can be used
to determine patient-specific
dose and the pressure
applied by the paddles
Images and volumetric assessments are courtesy of Volpara Solutions Limited.
a. The breasts are almost entirely fatty
2.9% Volumetric Density
a. The breasts are almost entirely fatty
4.3% Volumetric Density
b. There are scattered areas of
fibroglandular tissue
6.5% Volumetric Density
b. There are scattered areas of
fibroglandular tissue
6.8% Volumetric Density
c. The breasts are heterogeneously
dense which may obscure small masses
8.6% Volumetric Density
c. The breasts are heterogeneously
dense which may obscure small masses
11.6% Volumetric Density
d. The breasts are extremely dense, which
lowers the sensitivity of mammography
17.6% Volumetric Density
d. The breasts are extremely dense, which
lowers the sensitivity of mammography
24.6% Volumetric Density
Mammograms for the same woman over 8 years
MRI shows breast composition in extremely
dense breasts
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.