Opportunistic Breast Density Assessment in Women Receiving Low-dose Chest Computed Tomography Screening.
Low-dose chest computed tomography (LDCT), increasingly being used for screening of lung cancer, may also be used to measure breast density, which is proven as a risk factor for breast cancer. In this study, we developed a segmentation method to measure quantitative breast density on CT images and correlated with magnetic resonance density.



Forty healthy women receiving both LDCT and breast magnetic resonance imaging (MRI) were studied. A semiautomatic method was applied to quantify the breast density on LDCT images. The intra- and interoperator reproducibility was evaluated. The volumetric density on MRI was obtained by using a well-established automatic template-based segmentation method. The breast volume (BV), fibroglandular tissue volume (FV), and percent breast density (PD) measured on LDCT and MRI were compared.



The measurements of BV, FV, and PD on LDCT images yield highly consistent results, with the intraclass correlation coefficient of 0.999 for BV, 0.977 for FV, and 0.966 for PD for intraoperator reproducibility, and intraclass correlation coefficient of 0.953 for BV, 0.974 for FV, and 0.973 for PD for interoperator reproducibility. The BV, FV, and PD measured on LDCT and MRI were well correlated (all r ≥ 0.90). Bland-Altman plots showed that a larger BV and FV were measured on LDCT than on MRI.



The preliminary results showed that quantitative breast density can be measured from LDCT, and that our segmentation method could yield a high reproducibility on the measured volume and PD. The results measured on LDCT and MRI were highly correlated. Our results showed that LDCT may provide valuable information about breast density for evaluating breast cancer risk.
Center for Functional Onco-Imaging, Department of Radiological Sciences, University of California, Irvine, No. 164, Irvine Hall, Irvine, CA 92697-5020; Department of Radiology, E-Da Hospital, I-Shou University, No. 1, E-Da Road, Kaohsiung, Taiwan. Electronic address: jeonhc@uci.edu.
Jeon-Hor
JH
Chen
Department of Radiology, Taichung Veterans General Hospital, Taichung, Taiwan; Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan.
Siwa
S
Chan
Department of Radiology, E-Da Hospital, I-Shou University, No. 1, E-Da Road, Kaohsiung, Taiwan.
Nan-Han
NH
Lu
Center for Functional Onco-Imaging, Department of Radiological Sciences, University of California, Irvine, No. 164, Irvine Hall, Irvine, CA 92697-5020.
Yifan
Y
Li
Department of Radiological Technology, China Medical University, Taichung, Taiwan.
Yu Chieh
YC
Tsai
Department of Radiological Technology, China Medical University, Taichung, Taiwan.
Po Yun
PY
Huang
Department of Radiological Technology, China Medical University, Taichung, Taiwan.
Chia-Ju
CJ
Chang
Center for Functional Onco-Imaging, Department of Radiological Sciences, University of California, Irvine, No. 164, Irvine Hall, Irvine, CA 92697-5020.
Min-Ying
MY
Su
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001940:Breast / Q000000981:diagnostic imaging; D000071060:Breast Density / Q000502:physiology*; D001943:Breast Neoplasms / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008327:Mammography / Q000379:methods*; D008875:Middle Aged; D011829:Radiation Dosage; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods*
breast density; low dose chest CT; magnetic resonance imaging