Quantitative Measurements of Breast Density Using Magnetic Resonance Imaging: A Systematic Review and Meta-Analysis

Abstract

Breast density, a measure of dense fibroglandular tissue relative to non-dense fatty tissue, is confirmed as an independent risk factor of breast cancer. Although there has been an increasing interest in the quantitative assessment of breast density, no research has investigated the optimal technical approach of breast MRI in this aspect. Therefore, we performed a systematic review and meta-analysis to analyze the current studies on quantitative assessment of breast density using MRI and to determine the most appropriate technical/operational protocol. Databases (PubMed, EMBASE, ScienceDirect, and Web of Science) were searched systematically for eligible studies. Single arm meta-analysis was conducted to determine quantitative values of MRI in breast density assessments. Combined means with their 95% confidence interval (CI) were calculated using a fixed-effect model. In addition, subgroup meta-analyses were performed with stratification by breast density segmentation/measurement method. Furthermore, alternative groupings based on statistical similarities were identified via a cluster analysis employing study means and standard deviations in a Nearest Neighbor/Single Linkage. A total of 38 studies matched the inclusion criteria for this systematic review. Twenty-one of these studies were judged to be eligible for meta-analysis. The results indicated, generally, high levels of heterogeneity between study means within groups and high levels of heterogeneity between study variances within groups. The studies in two main clusters identified by the cluster analysis were also subjected to meta-analyses. The review confirmed high levels of heterogeneity within the breast density studies, considered to be due mainly to the applications of MR breast-imaging protocols and the use of breast density segmentation/measurement methods. Further research should be performed to determine the most appropriate protocol and method for quantifying breast density using MRI.

Quantitative Measurement of Breast Density Using Personalized 3D-Printed Breast Model for Magnetic Resonance Imaging

“…Previous studies have reported that the potential risk of breast cancer in women with dense breasts is three- to five-fold higher than in women with fatty breasts [ 5 , 6 , 7 ]. Recent developments in breast cancer screening have intensified the need for a standardized imaging protocol and/or measurement method for the evaluation of breast density predominantly for women at an elevated risk of developing breast cancer, such as those with high breast density [ 4 , 8 , 9 , 10 ]. A considerable amount of literature has been published on the assessment of breast density with several methods and algorithms proposed to segment and/or measure breast density using MRI datasets [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ].…”

“…Nevertheless, research has consistently shown that these methods/algorithms seem to have certain drawbacks, mostly due to the use of a semi-automatic approach or a high-level of dependency on user interaction. Likewise, numerous MR breast-imaging protocols have been applied to the screening and/or the assessment of breast density, ranging from contrast- to non-contrast-enhanced imaging with or without the implementation of fat-suppression techniques [ 3 , 4 , 8 , 9 , 10 , 20 , 21 , 22 , 23 , 24 , 25 ]. To date, there has been little consensus on the optimal MR breast-imaging protocol and measurement method for breast density screening and/or assessment, especially in the context of women with dense breast tissues.…”

“…The dynamic contrast-enhanced (DCE)-MRI technique has been widely used for the screening of women at high risk of breast cancer and has been included in standard clinical breast MRI protocols [ 4 , 8 ]. Despite its long clinical success, DCE-MRI has certain disadvantages, such as long scanning time, high cost, and potential harm caused by the contrast agent [ 4 , 26 ].…”

“…Non-fat-suppressed and fat-suppressed T1-weighted images are frequently used with either 2D spin echo (SE) or 3D gradient echo (GRE) in standard clinical breast MRI protocols [ 8 , 17 ]. Nevertheless, there is no consensus as to which of these sequences/techniques is the most efficient in this regard.…”

“…Nevertheless, there is no consensus as to which of these sequences/techniques is the most efficient in this regard. The American College of Radiology (ACR) has recommended that the fat-suppressed images with high spatial resolution be used in clinical breast MRI protocols as images acquired with this sequence can eliminate misregistration, which mainly occurs when a patient moves during the acquisition of pre- and post-contrast images [ 8 , 17 ]. However, this recommendation contrasts with that of the European Society of Breast Imaging (EUSOBI), which considers non-fat-suppressed sequences based on the acquisition of subtraction images more useful [ 17 , 33 ].…”