Inter- and intra-observer agreement of BI-RADS-based subjective visual estimation of amount of fibroglandular breast tissue with magnetic resonance imaging: comparison to automated quantitative assessment.
OBJECTIVE
To evaluate the inter-/intra-observer agreement of BI-RADS-based subjective visual estimation of the amount of fibroglandular tissue (FGT) with magnetic resonance imaging (MRI), and to investigate whether FGT assessment benefits from an automated, observer-independent, quantitative MRI measurement by comparing both approaches.


METHODS
Eighty women with no imaging abnormalities (BI-RADS 1 and 2) were included in this institutional review board (IRB)-approved prospective study. All women underwent un-enhanced breast MRI. Four radiologists independently assessed FGT with MRI by subjective visual estimation according to BI-RADS. Automated observer-independent quantitative measurement of FGT with MRI was performed using a previously described measurement system. Inter-/intra-observer agreements of qualitative and quantitative FGT measurements were assessed using Cohen's kappa (k).


RESULTS
Inexperienced readers achieved moderate inter-/intra-observer agreement and experienced readers a substantial inter- and perfect intra-observer agreement for subjective visual estimation of FGT. Practice and experience reduced observer-dependency. Automated observer-independent quantitative measurement of FGT was successfully performed and revealed only fair to moderate agreement (k = 0.209-0.497) with subjective visual estimations of FGT.


CONCLUSIONS
Subjective visual estimation of FGT with MRI shows moderate intra-/inter-observer agreement, which can be improved by practice and experience. Automated observer-independent quantitative measurements of FGT are necessary to allow a standardized risk evaluation.


CONCLUSIONS
• Subjective FGT estimation with MRI shows moderate intra-/inter-observer agreement in inexperienced readers. • Inter-observer agreement can be improved by practice and experience. • Automated observer-independent quantitative measurements can provide reliable and standardized assessment of FGT with MRI.
Department of Biomedical Imaging and Image-guided Therapy, Division of Molecular and Gender Imaging, Medical University of Vienna/ Vienna General Hospital, Waehringer Guertel 18-20, 1090, Vienna, Austria.
G J
GJ
Wengert
Department of Biomedical Imaging and Image-guided Therapy, Division of Molecular and Gender Imaging, Medical University of Vienna/ Vienna General Hospital, Waehringer Guertel 18-20, 1090, Vienna, Austria.
T H
TH
Helbich
Department of Biomedical Imaging and Image-guided Therapy, Division of Molecular and Gender Imaging, Medical University of Vienna/ Vienna General Hospital, Waehringer Guertel 18-20, 1090, Vienna, Austria.
R
R
Woitek
Department of Biomedical Imaging and Image-guided Therapy, Division of Molecular and Gender Imaging, Medical University of Vienna/ Vienna General Hospital, Waehringer Guertel 18-20, 1090, Vienna, Austria.
P
P
Kapetas
Department of Biomedical Imaging and Image-guided Therapy, Division of Molecular and Gender Imaging, Medical University of Vienna/ Vienna General Hospital, Waehringer Guertel 18-20, 1090, Vienna, Austria.
P
P
Clauser
Department of Biomedical Imaging and Image-guided Therapy, Division of Molecular and Gender Imaging, Medical University of Vienna/ Vienna General Hospital, Waehringer Guertel 18-20, 1090, Vienna, Austria.
P A
PA
Baltzer
Department of Biomedical Imaging and Image-guided Therapy, Computational Imaging Research Lab, Medical University of Vienna, Wien, Austria.
W-D
WD
Vogl
Department of Biomedical Imaging and Image-guided Therapy, Division of General and Pediatric Radiology, Medical University of Vienna, Wien, Austria.
M
M
Weber
Department of Scientific Computing in Medicine, State University of Florida, Tallahassee, FL, USA.
A
A
Meyer-Baese
Department of Biomedical Imaging and Image-guided Therapy, Division of Molecular and Gender Imaging, Medical University of Vienna/ Vienna General Hospital, Waehringer Guertel 18-20, 1090, Vienna, Austria. katja.pinker@meduniwien.ac.at.|Department of Scientific Computing in Medicine, State University of Florida, Tallahassee, FL, USA. katja.pinker@meduniwien.ac.at.|Department of Radiology, Molecular Imaging and Therapy Services, Memorial Sloan-Kettering Cancer Center, New York City, NY, USA. katja.pinker@meduniwien.ac.at.
Katja
http://orcid.org/0000-0002-2722-7331
K
Pinker
D000328:Adult; D000071060:Breast Density; D001943:Breast Neoplasms / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008875:Middle Aged; D015588:Observer Variation; D011446:Prospective Studies; D055815:Young Adult
Amount of fibroglandular tissue; Breast imaging; Inter-/intra-observer agreement; Magnetic resonance imaging; Quantitative assessment of breast density