title: Clinical application of qualitative assessment for breast masses in shear-wave elastography.
abstract: OBJECTIVE
  To evaluate the interobserver agreement and the diagnostic performance of various qualitative features in shear-wave elastography (SWE) for breast masses.
  
  
  METHODS
  A total of 153 breast lesions in 152 women who underwent B-mode ultrasound and SWE before biopsy were included. Qualitative analysis in SWE was performed using two different classifications: E values (Ecol; 6-point color score, Ehomo; homogeneity score and Esha; shape score) and a four-color pattern classification. Two radiologists reviewed five data sets: B-mode ultrasound, SWE, and combination of both for E values and four-color pattern. The BI-RADS categories were assessed B-mode and combined sets. Interobserver agreement was assessed using weighted κ statistics. Areas under the receiver operating characteristic curve (AUC), sensitivity, and specificity were analyzed.
  
  
  RESULTS
  Interobserver agreement was substantial for Ecol (κ=0.79), Ehomo (κ=0.77) and four-color pattern (κ=0.64), and moderate for Esha (κ=0.56). Better-performing qualitative features were Ecol and four-color pattern (AUCs, 0.932 and 0.925) compared with Ehomo and Esha (AUCs, 0.857 and 0.864; P<0.05). The diagnostic performance of B-mode ultrasound (AUC, 0.950) was not significantly different from combined sets with E value and with four color pattern (AUCs, 0.962 and 0.954). When all qualitative values were negative, leading to downgrade the BI-RADS category, the specificity increased significantly from 16.5% to 56.1% (E value) and 57.0% (four-color pattern) (P<0.001) without improvement in sensitivity.
  
  
  CONCLUSIONS
  The qualitative SWE features were highly reproducible and showed good diagnostic performance in suspicious breast masses. Adding qualitative SWE to B-mode ultrasound increased specificity in decision making for biopsy recommendation.
authors.affiliation: Department of Radiology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: Hye Mi
authors.initials: HM
authors.lastname: Gweon
authors.forename: Ji Hyun
authors.initials: JH
authors.lastname: Youk
authors.forename: Eun Ju
authors.initials: EJ
authors.lastname: Son
authors.forename: Jeong-Ah
authors.initials: JA
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D054459:Elasticity Imaging Techniques / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008875:Middle Aged; D015588:Observer Variation; D015995:Prevalence; D015203:Reproducibility of Results; D056910:Republic of Korea / Q000453:epidemiology; D012307:Risk Factors; D012680:Sensitivity and Specificity; D016217:Ultrasonography, Mammary / Q000706:statistics & numerical data*
keywords: BI-RADS; Breast masses; Breast ultrasound; Shear wave; Sonoelastography