Katja Pinker-Domenig MD, Presenter: Nothing to Disclose

Nicholas Mark Perry MD, Abstract Co-Author: Nothing to Disclose

Sue Elizabeth Milner BSC, Abstract Co-Author: Nothing to Disclose

Kefah Mokbel MD, Abstract Co-Author: Nothing to Disclose

Michael Weber, Abstract Co-Author: Nothing to Disclose

To compare automated quantitative breast density measurements with standard qualitative ACR BIRADS categorization, and to provide a range of equivalent values for each of the two methodologies.

An automated volumetric measurement system (Hologic, Quantra) was used to calculate breast density in 1600 women with an age range of 26-88 (mean 48 years) undergoing full-field digital mammography (FFDM). The system automatically estimated volume of fibroglandular tissue (cm3), volume of breast (cm3) and percentage of fibroglandular tissue (%). Two experienced breast radiologists separately and independently allocated one of the four standard BIRADS density categories (1- 0-24%; 2- 25-49%, 3- 50-74%, 4 >75%) to each of the 1600 mammograms. Descriptive statistics using the 25-75 % percentile were used to define the typical range of Quantra readings corresponding to the four BIRADS categories. Inter-observer agreement for the BIRADS classifications was calculated using Cohen’s kappa.

Density measurements ranged from 6% to 78% (mean 23.6%) using the automated system. Compared with the BIRADS categories, 25-75% percentile assessment demonstrated an interquartile range of percentage breast density of 11-15% for BIRADS 1, 14-23% for BIRADS 2, 21-33% for BIRADS 3 and 33-46% for BIRADS 4. There was good inter-observer agreement for the BIRADS classifications with a Cohen’s kappa of 0.8.

Quantitative density readings were consistently lower than qualitative assessment - often by about 50 %. Equivalent values were found with automated density readings of 0 – 13%, 14 – 23%, 24 – 33% and >34% respectively for each of the four BIRADS categories.

Quantitative measurements are quickly obtained, avoid subjective bias, and may be considered more suitable for communication of breast density to individual women.

Pinker-Domenig, K, Perry, N, Milner, S, Mokbel, K, Weber, M, Should Quantitative Measurements Be Used for Communication of Breast Density in Preference to Qualitative ACR BIRADS Classification.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12034114.html