title: Differentiation of benign from malignant nonpalpable breast masses: a comparison of computer-assisted quantification and visual assessment of lesion stiffness with the use of sonographic elastography.
abstract: BACKGROUND
  Elastography has shown potential in differentiating benign from malignant breast tumors, but interobserver variability between experienced and inexperienced readers limits its wide usage.
  
  
  OBJECTIVE
  To compare the diagnostic performance of computer-assisted quantification and visual assessment of lesion stiffness with the use of sonographic elastography for the differentiation of benign from malignant nonpalpable breast masses.
  
  
  METHODS
  Sonographic elasticity images of 120 nonpalpable breast masses (70 benign and 50 malignant masses) were obtained in 120 women prior to performing a core biopsy. After subtraction of B-mode images from color elasticity images, the mean strain value of the lesion was computed. Elasticity images were also reviewed and were assigned a score on a five-point scale by two breast radiologists in consensus. Results were evaluated by using receiver operating characteristic (ROC) curve analysis.
  
  
  RESULTS
  The mean +/- standard deviation values of strain were 221+/-18 for malignant lesions and 175+/-21 for benign lesions (P<0.001). For the elasticity score, the mean score was 3.5+/-0.1 for the malignant masses and 2.0+/-0.9 for the benign masses (P<0.001). The overall Pearson's correlation coefficient between the strain values and elasticity score was 0.689 (P<0.001). The area under the ROC curve (A(z)) value was 0.878 for use of the computer-assisted quantification method and 0.850 for visual assessment by the radiologists. The difference was not statistically significant (P=0.198).
  
  
  CONCLUSIONS
  Computer-assisted quantification and visual assessment of lesion stiffness with the use of sonographic elasticity images had comparable diagnostic performance for the differentiation of nonpalpable breast masses.
authors.affiliation: Department of Radiology, Seoul Metropolitan Government Seoul National University Boramae Medical Center, Seoul, Korea.
authors.forename: Se Yeong
authors.initials: SY
authors.lastname: Chung
authors.forename: Woo Kyung
authors.initials: WK
authors.lastname: Moon
authors.forename: Ji Won
authors.initials: JW
authors.lastname: Choi
authors.forename: Nariya
authors.initials: N
authors.lastname: Cho
authors.forename: Mijung
authors.initials: M
authors.lastname: Jang
authors.forename: Kwang Gi
authors.initials: KG
authors.lastname: Kim
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; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008875:Middle Aged; D012372:ROC Curve; D012680:Sensitivity and Specificity; D013382:Subtraction Technique; D016217:Ultrasonography, Mammary / Q000379:methods*