title: Digital Breast Tomosynthesis guided Near Infrared Spectroscopy: Volumetric estimates of fibroglandular fraction and breast density from tomosynthesis reconstructions.
abstract: A multimodality system combining a clinical prototype digital breast tomosynthesis with its imaging geometry modified to facilitate near-infrared spectroscopic imaging has been developed. The accuracy of parameters recovered from near-infrared spectroscopy is dependent on fibroglandular tissue content. Hence, in this study, volumetric estimates of fibroglandular tissue from tomosynthesis reconstructions were determined. A kernel-based fuzzy c-means algorithm was implemented to segment tomosynthesis reconstructed slices in order to estimate fibroglandular content and to provide anatomic priors for near-infrared spectroscopy. This algorithm was used to determine volumetric breast density (VBD), defined as the ratio of fibroglandular tissue volume to the total breast volume, expressed as percentage, from 62 tomosynthesis reconstructions of 34 study participants. For a subset of study participants who subsequently underwent mammography, VBD from mammography matched for subject, breast laterality and mammographic view was quantified using commercial software and statistically analyzed to determine if it differed from tomosynthesis. Summary statistics of the VBD from all study participants were compared with prior independent studies. The fibroglandular volume from tomosynthesis and mammography were not statistically different (p=0.211, paired t-test). After accounting for the compressed breast thickness, which were different between tomosynthesis and mammography, the VBD from tomosynthesis was correlated with (r=0.809,p<0.001), did not statistically differ from (p>0.99, paired t-test), and was linearly related to, the VBD from mammography. Summary statistics of the VBD from tomosynthesis were not statistically different from prior studies using high-resolution dedicated breast computed tomography. The observation of correlation and linear association in VBD between mammography and tomosynthesis suggests that breast density associated risk measures determined for mammography are translatable to tomosynthesis. Accounting for compressed breast thickness is important when it differs between the two modalities. The fibroglandular volume from tomosynthesis reconstructions is similar to mammography indicating suitability for use during near-infrared spectroscopy.
authors.affiliation: Department of Radiology, University of Massachusetts Medical School, Worcester, MA 01655, USA.
authors.forename: Srinivasan
authors.initials: S
authors.lastname: Vedantham
authors.affiliation: Department of Radiology, University of Massachusetts Medical School, Worcester, MA 01655, USA.
authors.forename: Linxi
authors.initials: L
authors.lastname: Shi
authors.affiliation: Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA.
authors.forename: Kelly E
authors.initials: KE
authors.lastname: Michaelsen
authors.affiliation: Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA.
authors.forename: Venkataramanan
authors.initials: V
authors.lastname: Krishnaswamy
authors.affiliation: Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA.
authors.forename: Brian W
authors.initials: BW
authors.lastname: Pogue
authors.affiliation: Department of Radiology, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03756, USA.
authors.forename: Steven P
authors.initials: SP
authors.lastname: Poplack
authors.affiliation: Department of Radiology, University of Massachusetts Medical School, Worcester, MA 01655, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Karellas
authors.affiliation: Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA; Department of Radiology, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03756, USA.
authors.forename: Keith D
authors.initials: KD
authors.lastname: Paulsen
keywords: Breast Density; Breast [A01.236]; Digital Breast Tomosynthesis; Mammography [E01.370.350.700.500]; Near-Infrared [E01.370.350.750]; Spectroscopy