title: Correlation of Strain Elastography with Conventional Sonography and FNAC/Biopsy.
abstract: BACKGROUND
  Elastography is a new promising technique that can be especially helpful when used as an adjunct to conventional B-mode ultrasound in evaluating breast lesions.
  
  
  OBJECTIVE
  To evaluate the diagnostic performance of four interpretation criteria for elastography and to compare the diagnostic performance of sonoelastography with that of conventional sonography in characterising breast lesions as benign or malignant with FNAC/biopsy correlation.
  
  
  METHODS
  One hundred breast lesions were prospectively evaluated by ultrasound as well as by strain elastography followed by FNAC/ biopsy correlation. The criteria used were Elastography Score, Strain Ratio, Distance Ratio and Area Ratio. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value were calculated for each modality. The best cut-off point was calculated for each of the interpretation criteria using the MedCalc version 10.1 software. The diagnostic performance of the interpretation criteria was compared with that of conventional sonography by the area under the receiver operating characteristic curve using SPSS software.
  
  
  RESULTS
  The elastography score was found to have the best performance among the 4 criteria used with a sensitivity and specificity of 100% and 82.66%, respectively at the best cut-off point between 3 and 4. At a best cut-off point for conventional sonography between BI-RADS categories 4A and 4B, the sensitivity and specificity were found to be 96% and 92% respectively. The area under the curve value was slightly greater for conventional sonography (0.980) than for the elastography score (0.913) using receiver operating characteristic curve analysis.
  
  
  CONCLUSIONS
  While all interpretation criteria were able to differentiate benign and malignant lesions with statistical significance, the elastography score was found to be the most accurate. While conventional ultrasound remains the primary modality for the characterization of breast masses, elastography was found to have a role in low suspicion lesions (BI-RADS 3 and 4A) where it's greater specificity could justify avoiding unnecessary biopsy.
authors.affiliation: Senior Resident, Department of Radiodiagnosis, Goa Medical College , Goa, India .
authors.forename: Ramona
authors.initials: R
authors.lastname: Menezes
authors.affiliation: Associate Professor, Department of Radiodiagnosis, Goa Medical College , Goa, India .
authors.forename: Sanjay
authors.initials: S
authors.lastname: Sardessai
authors.affiliation: Associate Professor, Department of Radiodiagnosis, Goa Medical College , Goa, India .
authors.forename: Renny
authors.initials: R
authors.lastname: Furtado
authors.affiliation: Ex- Professor and Head, Department of Radiodiagnosis, Goa Medical College , Goa, India .
authors.forename: Mahesh
authors.initials: M
authors.lastname: Sardessai
keywords: BI- RADS; Breast lesions; Breast sonography; Criteria; Sonoelastography