title: Added value of shear-wave elastography for evaluation of breast masses detected with screening US imaging.
abstract: OBJECTIVE
  To evaluate the additional value of shear-wave elastography (SWE) to B-mode ultrasonography (US) and to determine an appropriate guideline for the combined assessment of screening US-detected breast masses.
  
  
  METHODS
  This study was conducted with institutional review board approval, and written informed consent was obtained. From March 2010 to February 2012, B-mode US and SWE were performed in 159 US-detected breast masses before biopsy. For each lesion, Breast Imaging Reporting and Data System (BI-RADS) category on B-mode US images and the maximum stiffness color and elasticity values on SWE images were assessed. A guideline for adding SWE data to B-mode US was developed with the retrospective cohort to improve diagnostic performance in sensitivity and specificity and was validated in a distinct prospective cohort of 207 women prior to biopsy.
  
  
  RESULTS
  Twenty-one of 159 masses in the development cohort and 12 of 207 breast masses in the validation cohort were malignant. In the development cohort, when BI-RADS category 4a masses showing a dark blue color or a maximum elasticity value of 30 kPa or less on SWE images were downgraded to category 3, specificity increased from 9.4% (13 of 138) to 59.4% (82 of 138) and 57.2% (79 of 138) (P < .001), respectively, without loss in sensitivity (100% [21 of 21]). In the validation cohort, specificity increased from 17.4% (34 of 195) to 62.1% (121 of 195) and 53.3% (104 of 195) (P < .001) respectively, without loss in sensitivity (91.7% [11 of 12]).
  
  
  CONCLUSIONS
  The addition of SWE to B-mode US improved diagnostic performance with increased specificity for screening US-detected breast masses. BI-RADS category 4a masses detected at US screening that showed a dark blue color or a maximum elasticity value of 30 kPa or less on SWE images can be safely followed up instead of performing biopsy.
authors: From the Department of Radiology, Seoul National University Hospital, Seoul National University College of Medicine, 28 Yongon-dong, Chongno-gu, Seoul 100-744, Korea.
authors: Su Hyun
authors: SH
authors: Lee
authors: Jung Min
authors: JM
authors: Chang
authors: Won Hwa
authors: WH
authors: Kim
authors: Min Sun
authors: MS
authors: Bae
authors: Mirinae
authors: M
authors: Seo
authors: Hye Ryoung
authors: HR
authors: Koo
authors: A Jung
authors: AJ
authors: Chu
authors: Hye Mi
authors: HM
authors: Gweon
authors: Nariya
authors: N
authors: Cho
authors: Woo Kyung
authors: WK
authors: Moon
mesh_terms: D000328:Adult; D000368:Aged; D001707:Biopsy, Needle; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D003937:Diagnosis, Differential; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008327:Mammography; D008875:Middle Aged; D060787:Neoplasm Grading; D017410:Practice Guidelines as Topic; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D016217:Ultrasonography, Mammary / Q000379:methods*