title: Accuracy of fully automated, quantitative, volumetric measurement of the amount of fibroglandular breast tissue using MRI: correlation with anthropomorphic breast phantoms.
abstract: To demonstrate the accuracy of fully automated, quantitative, volumetric measurement of the amount of fibroglandular breast tissue (FGT), using MRI, and to investigate the impact of different MRI sequences using anthropomorphic breast phantoms as the ground truth. In this study, 10 anthropomorphic breast phantoms that consisted of different known fractions of adipose and protein tissue, which closely resembled normal breast parenchyma, were developed. Anthropomorphic breast phantoms were imaged with a 1.5 T unit (Siemens, Avantofit) using an 18-channel breast coil. The sequence protocol consisted of an isotropic Dixon sequence (Di), an anisotropic Dixon sequence (Da), and T13D FLASH sequences with and without fat saturation (T1). Fully automated, quantitative, volumetric measurement of FGT for all anthropomorphic phantoms and sequences was performed and correlated with the amounts of fatty and protein components in the phantoms as the ground truth. Fully automated, quantitative, volumetric measurements of FGT with MRI for all sequences ranged from 5.86 to 61.05% (mean 33.36%). The isotropic Dixon sequence yielded the highest accuracy (median 0.51%-0.78%) and precision (median range 0.19%) compared with anisotropic Dixon (median 1.92%-2.09%; median range 0.55%) and T1-weighted sequences (median 2.54%-2.46%; median range 0.82%). All sequences yielded good correlation with the FGT content of the anthropomorphic phantoms. The best correlation of FGT measurements was identified for Dixon sequences (Di, R2= 0.999; Da, R2= 0.998) compared with conventional T1-weighted sequences (R2= 0.971). MRI yields accurate, fully automated, quantitative, volumetric measurements of FGT, an increasingly important and sensitive imaging biomarker for breast cancer risk. Compared with conventional T1sequences, Dixon-type sequences show the highest correlation and reproducibility for automated, quantitative, volumetric FGT measurements using anthropomorphic breast phantoms as the ground truth.
authors.affiliation: Medical University of Vienna, Department of Biomedical Imaging and Image-Guided Therapy, Division of Molecular and Gender Imaging, Vienna, Austria.
authors.forename: Georg J
authors.initials: GJ
authors.lastname: Wengert
authors.affiliation: Medical University of Vienna, Department of Biomedical Imaging and Image-Guided Therapy, Division of Molecular and Gender Imaging, Vienna, Austria.|Memorial Sloan-Kettering Cancer Center, Dept. of Radiology, New York, USA.
authors.forename: Katja
authors.identifier: http://orcid.org/0000-0002-2722-7331
authors.initials: K
authors.lastname: Pinker
authors.affiliation: Medical University of Vienna, Department of Biomedical Imaging and Image-Guided Therapy, Division of Molecular and Gender Imaging, Vienna, Austria.
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Helbich
authors.affiliation: Medical University of Vienna, Department of Biomedical Imaging and Image-Guided Therapy, Division of Molecular and Gender Imaging, Vienna, Austria.
authors.forename: Wolf-Dieter
authors.identifier: http://orcid.org/0000-0003-2197-5838
authors.initials: WD
authors.lastname: Vogl
authors.affiliation: University of Vienna, Department of Pharmaceutical Technology and Biopharmaceutics, Faculty of Life Science, Vienna, Austria.
authors.forename: Sylvia M
authors.initials: SM
authors.lastname: Spijker
authors.affiliation: Medical University of Vienna, Department of Biomedical Imaging and Image-Guided Therapy, Division of Molecular and Gender Imaging, Vienna, Austria.
authors.forename: Hubert
authors.initials: H
authors.lastname: Bickel
authors.affiliation: Medical University of Vienna, Department of Biomedical Imaging and Image-Guided Therapy, Division of Molecular and Gender Imaging, Vienna, Austria.
authors.forename: Stephan H
authors.initials: SH
authors.lastname: Polanec
authors.affiliation: Medical University of Vienna, Department of Biomedical Imaging and Image-Guided Therapy, Division of Molecular and Gender Imaging, Vienna, Austria.
authors.forename: Pascal A
authors.initials: PA
authors.lastname: Baltzer
mesh_terms: D001331:Automation; D001940:Breast / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D019047:Phantoms, Imaging
keywords: MRI; breast cancer; breast density; breast imaging; fibroglandular tissue; quantitative assessment; standard of reference