title: Two-view versus single-view shear-wave elastography: comparison of observer performance in differentiating benign from malignant breast masses.
abstract: To determine whether two-view shear-wave elastography (SWE) improves the performance of radiologists in differentiating benign from malignant breast masses compared with single-view SWE.
  
  
  
  This prospective study was conducted with institutional review board approval, and written informed consent was obtained. B-mode ultrasonographic (US) and orthogonal SWE images were obtained for 219 breast masses (136 benign and 83 malignant; mean size, 14.8 mm) in 219 consecutive women (mean age, 47.9 years; range, 20-78 years). Five blinded radiologists independently assessed the likelihood of malignancy for three data sets: B-mode US alone, B-mode US and single-view SWE, and B-mode US and two-view SWE. Interobserver agreement regarding Breast Imaging Reporting and Data System (BI-RADS) category and the area under the receiver operating characteristic curve (AUC) of each data set were compared.
  
  
  
  Interobserver agreement was moderate (κ = 0.560 ± 0.015 [standard error of the mean]) for BI-RADS category assessment with B-mode US alone. When SWE was added to B-mode US, five readers showed substantial interobserver agreement (κ = 0.629 ± 0.017 for single-view SWE; κ = 0.651 ± 0.014 for two-view SWE). The mean AUC of B-mode US was 0.870 (range, 0.855-0.884). The AUC of B-mode US and two-view SWE (average, 0.928; range, 0.904-0.941) was higher than that of B-mode US and single-view SWE (average, 0.900; range, 0.890-0.920), with statistically significant differences for three readers (P ≤ .003).
  
  
  
  The performance of radiologists in differentiating benign from malignant breast masses was improved when B-mode US was combined with two-view SWE compared with that when B-mode US was combined with single-view SWE.
authors.affiliation: From the Department of Radiology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul 110-744, Korea (S.H.L., N.C., J.M.C., H.R.K., W.H.K., M.S.B., W.K.M.); Department of Radiology, Pusan National University Hospital, Pusan, Korea (J.Y.K.); and Department of Radiology, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul, Korea (A.Y.).
authors.forename: Su Hyun
authors.initials: SH
authors.lastname: Lee
authors.forename: Nariya
authors.initials: N
authors.lastname: Cho
authors.forename: Jung Min
authors.initials: JM
authors.lastname: Chang
authors.forename: Hye Ryoung
authors.initials: HR
authors.lastname: Koo
authors.forename: Jin You
authors.initials: JY
authors.lastname: Kim
authors.forename: Won Hwa
authors.initials: WH
authors.lastname: Kim
authors.forename: Min Sun
authors.initials: MS
authors.lastname: Bae
authors.forename: Ann
authors.initials: A
authors.lastname: Yi
authors.forename: Woo Kyung
authors.initials: WK
authors.lastname: Moon
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D003937:Diagnosis, Differential; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D008875:Middle Aged; D015588:Observer Variation; D011446:Prospective Studies; D016217:Ultrasonography, Mammary