title: Which supplementary imaging modality should be used for breast ultrasonography? Comparison of the diagnostic performance of elastography and computer-aided diagnosis.
abstract: OBJECTIVE
  The aim of this study was to evaluate and compare the diagnostic performance of grayscale ultrasonography (US), US elastography, and US computer-aided diagnosis (US-CAD) in the differential diagnosis of breast masses.
  
  
  METHODS
  A total of 193 breast masses in 175 consecutive women (mean age, 46.4 years) from June to August 2015 were included. US and elastography images were obtained and recorded. A US-CAD system was applied to the grayscale sonograms, which were automatically analyzed and visualized in order to generate a final assessment. The final assessments of breast masses were based on the American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) categories, while elasticity scores were assigned using a 5-point scoring system. The diagnostic performance of grayscale US, elastography, and US-CAD was calculated and compared.
  
  
  RESULTS
  Of the 193 breast masses, 120 (62.2%) were benign and 73 (37.8%) were malignant. Breast masses had significantly higher rates of malignancy in BI-RADS categories 4c and 5, elastography patterns 4 and 5, and when the US-CAD assessment was possibly malignant (all P<0.001). Elastography had higher specificity (40.8%, P=0.042) than grayscale US. US-CAD showed the highest specificity (67.5%), positive predictive value (PPV) (61.4%), accuracy (74.1%), and area under the curve (AUC) (0.762, all P<0.05) among the three diagnostic tools.
  
  
  CONCLUSIONS
  US-CAD had higher values for specificity, PPV, accuracy, and AUC than grayscale US or elastography. Computer-based analysis based on the morphologic features of US may be very useful in improving the diagnostic performance of breast US.
authors.affiliation: Department of Radiology, Severance Hospital and Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Si Eun
authors.identifier: 0000-0002-3225-5484
authors.initials: SE
authors.lastname: Lee
authors.affiliation: Department of Research Affairs, Biostatistics Collaboration Unit, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Ji Eun
authors.identifier: 0000-0001-7183-748X
authors.initials: JE
authors.lastname: Moon
authors.affiliation: Department of Research Affairs, Biostatistics Collaboration Unit, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Yun Ho
authors.identifier: 0000-0003-0841-7161
authors.initials: YH
authors.lastname: Rho
authors.affiliation: Department of Radiology, Severance Hospital and Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Eun-Kyung
authors.identifier: 0000-0002-3368-5013
authors.initials: EK
authors.lastname: Kim
authors.affiliation: Department of Radiology, Severance Hospital and Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jung Hyun
authors.identifier: 0000-0002-2100-3513
authors.initials: JH
authors.lastname: Yoon
keywords: BI-RADS; Breast; Diagnosis, computer-assisted; Elasticity imaging techniques; Ultrasonography