Consistency of breast density measured from the same women in four different MR scanners

Abstract

Purpose:To compare the breast volume (BV), fibroglandular tissue volume (FV), and percent density (PD) measured from breast MRI of the same women using four different MR scanners. Methods:The study was performed in 34 healthy Asian volunteers using two 1.5T (GE and Siemens) and two 3T (GE and Philips) MR scanners. The BV, FV, and PD were measured on nonfat-suppressed T1-weighted images using a comprehensive computer algorithm-based segmentation method. The scanner-to-scanner measurement difference, and the coefficient of variation (CV) among the four scanners were calculated. The measurement variation between two density morphological patterns presenting as the central type and the intermingled type was separately analyzed and compared. Results: All four scanners provided satisfactory image quality allowing for successful completion of the segmentation processes. The measured parameters between each pair of MR scanners were highly correlated, with R 2 ≥ 0.95 for BV, R 2 ≥ 0.99 for FV, and R 2 ≥ 0.97 for PD in all comparisons. The mean percent differences between each pair of scanners were 5.9%-7.8% for BV, 5.3%-6.5% for FV, 4.3%-7.3% for PD; with the overall CV of 5.8% for BV, 4.8% for FV, and 4.9% for PD. The variation of FV was smaller in the central type than in the intermingled type (p = 0.04). Conclusions:The results showed that the variation of FV and PD measured from four different MR scanners is around 5%, suggesting the parameters measured using different scanners can be used for a combined analysis in a multicenter study.

Breast Density Evaluation Using Spectral Mammography, Radiologist Reader Assessment, and Segmentation Techniques

“…Breast tomosynthesis (42), MRI (43, 44) and CT (35, 45, 46) can also be used for breast density measurement. The tomographic nature of these techniques reduces the anatomical background, which simplifies segmentation of fibroglandular and adipose tissues as compared with standard digital mammography.…”

Impact of positional difference on the measurement of breast density using MRI

“…The value of k was chosen based on our past experience analyzing many cases. 6,15,16,21,23,[25][26][27][28][29] For extremely fatty breasts, the number of clusters may need to be adjusted. However, for Asian women with relatively dense breasts, k = 6 (three for dense and three for fatty tissues) has worked very well.…”

“…Our group has devoted a substantial research effort to develop and refine a comprehensive 3D MR-based density method. 6,21,26 Potential sources of measurement variation that may arise from operators, 6 imaging sequences, 27 scanners, 28 and physiology 29 have been investigated.…”

“…A previous study 28 found that the variation of fibroglandular tissue volume (FV) and percent density (PD) measured from four different MR scanners was approximately 5%, suggesting that the parameters measured using different scanners could be used for a combined analysis in a multicenter study. For the correlation of PD between each pair of MR scanners, however, the variation was higher when the Siemens scanner was compared with other scanners manufactured by different vendors.…”

“…In that study, the arms/hands position for imaging using the Siemens scanner (hands-down, resting next to body) was different from the imaging done using GE and Philips scanners (hands-up, resting above the head); thus, it was postulated that the difference of arms/hands positions, hence the difference of breast positions, may partially account for the measurement variation. 28 Although in previous research 6 we investigated the impact of breast/body positioning on the measured density, only two subjects were studied.…”