Joseph Xavier Jeyanth MBBS,MMed, Presenter: Nothing to Disclose

Woo Kyung Moon, Abstract Co-Author: Nothing to Disclose

Won Hwa Kim MD, MS, Abstract Co-Author: Nothing to Disclose

Nariya Cho MD, Abstract Co-Author: Nothing to Disclose

Jung Min Chang MD, Abstract Co-Author: Nothing to Disclose

Hye Ryoung Koo MD, Abstract Co-Author: Nothing to Disclose

Volumetric breast density measured from breast MRI is more suitable for density analysis than mammographic density. However, measurement of volumetric percentage density (VPD) from MRI of the whole breast is time consuming and impractical to apply for large breast MRI databases. The purpose of this study was to determine whether VPDs measured from 3 representative slices of MRI correlates with the VPDs measured from the whole breast.

A total of 151 breast cancer patients who underwent bilateral breast MRI were included. Pre-contrast, T1 weighted, fat suppressed, sagittal images were used for VPD measurement. VPD of the contralateral normal breast was measured using MIPAV software (Version 5.3.3, NIH, USA). The borders of the breasts were outlined manually and fibro-glandular tissue was segmented from the fat tissue using Fuzzy C-Means algorithm. The number of slices ranged from 30 to 72 when measuring VPD from the whole breast. The 3 representative slices selected for density measurement were the middle (n), (n+15)th and (n-15)th slices. VPD was measured from the whole breast as well as from 3 representative slices for each patient and the results compared using t-test, intra-class correlation coefficient (ICC) and coefficient of variation (CV). The average time taken to measure each breast by each method was calculated.

Mean VPD measured from 3 representative slices was not significantly different from that measured from the whole breast (24.32% vs. 24.55%, P = .39; mean absolute difference = 2.72). The CV was 9.74%. VPDs measured between two methods showed excellent agreement (ICC = 0.96; CI = 0.95-0.97). Average time taken to measure VPD by 3 slice method was significantly lower than that by the whole breast measurement (2 vs. 10 min; P < .0001). The mean absolute difference in VPD between the two methods was not significantly different for fatty (<20% VPD) and dense (>40% VPD) breasts (2.37% vs. 2.62%; P = 0.67) however, CV was higher for fatty breasts (15.33% vs. 5.11% for dense breasts).

The 3 slice MRI VPD is in excellent agreement with the VPD measured from the whole breast MRI and is less time consuming.

The 3 slice method can be employed as a reliable, more practical and time saving method to measure VPD for large breast MRI databases.

Jeyanth, J, Moon, W, Kim, W, Cho, N, Chang, J, Koo, H, Quantification of Volumetric Breast Density Using MRI Data: Comparison between 3 Representative Slices Method and Whole Breast Density Measurement.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12043691.html