title: Quantitative 3D breast magnetic resonance imaging fibroglandular tissue analysis and correlation with qualitative assessments: a feasibility study.
abstract: BACKGROUND
  The amount of fibroglandular tissue (FGT) has been linked to breast cancer risk based on mammographic density studies. Currently, the qualitative assessment of FGT on mammogram (MG) and magnetic resonance imaging (MRI) is prone to intra and inter-observer variability. The purpose of this study is to develop an objective quantitative FGT measurement tool for breast MRI that could provide significant clinical value.
  
  
  METHODS
  An IRB approved study was performed. Sixty breast MRI cases with qualitative assessment of mammographic breast density and MRI FGT were randomly selected for quantitative analysis from routine breast MRIs performed at our institution from 1/2013 to 12/2014. Blinded to the qualitative data, whole breast and FGT contours were delineated on T1-weighted pre contrast sagittal images using an in-house, proprietary segmentation algorithm which combines the region-based active contours and a level set approach. FGT (%) was calculated by: [segmented volume of FGT (mm(3))/(segmented volume of whole breast (mm(3))] ×100. Statistical correlation analysis was performed between quantified FGT (%) on MRI and qualitative assessments of mammographic breast density and MRI FGT.
  
  
  RESULTS
  There was a significant positive correlation between quantitative MRI FGT assessment and qualitative MRI FGT (r=0.809, n=60, P<0.001) and mammographic density assessment (r=0.805, n=60, P<0.001). There was a significant correlation between qualitative MRI FGT assessment and mammographic density assessment (r=0.725, n=60, P<0.001). The four qualitative assessment categories of FGT correlated with the calculated mean quantitative FGT (%) of 4.61% (95% CI, 0-12.3%), 8.74% (7.3-10.2%), 18.1% (15.1-21.1%), 37.4% (29.5-45.3%).
  
  
  CONCLUSIONS
  Quantitative measures of FGT (%) were computed with data derived from breast MRI and correlated significantly with conventional qualitative assessments. This quantitative technique may prove to be a valuable tool in clinical use by providing computer generated standardized measurements with limited intra or inter-observer variability.
authors.affiliation: Department of Radiology, Columbia University Medical Center, New York, NY 10032, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Ha
authors.affiliation: Department of Radiology, Columbia University Medical Center, New York, NY 10032, USA.
authors.forename: Eralda
authors.initials: E
authors.lastname: Mema
authors.affiliation: Department of Radiology, Columbia University Medical Center, New York, NY 10032, USA.
authors.forename: Xiaotao
authors.initials: X
authors.lastname: Guo
authors.affiliation: Department of Radiology, Columbia University Medical Center, New York, NY 10032, USA.
authors.forename: Victoria
authors.initials: V
authors.lastname: Mango
authors.affiliation: Department of Radiology, Columbia University Medical Center, New York, NY 10032, USA.
authors.forename: Elise
authors.initials: E
authors.lastname: Desperito
authors.affiliation: Department of Radiology, Columbia University Medical Center, New York, NY 10032, USA.
authors.forename: Jason
authors.initials: J
authors.lastname: Ha
authors.affiliation: Department of Radiology, Columbia University Medical Center, New York, NY 10032, USA.
authors.forename: Ralph
authors.initials: R
authors.lastname: Wynn
authors.affiliation: Department of Radiology, Columbia University Medical Center, New York, NY 10032, USA.
authors.forename: Binsheng
authors.initials: B
authors.lastname: Zhao
keywords: Breast; fibroglandular tissue (FGT); qualitative assessments; quantitative