title: Added value of Virtual Touch IQ shear wave elastography in the ultrasound assessment of breast lesions.
abstract: OBJECTIVE
  To determine the diagnostic performance of Acoustic Radiation Force Impulse (ARFI) Virtual Touch IQ shear wave elastography in the discrimination of benign and malignant breast lesions.
  
  
  METHODS
  Conventional B-mode and elasticity imaging were used to evaluate 110 breast lesions. Elastographic assessment of breast tissue abnormalities was done using a shear wave based technique, Virtual Touch IQ (VTIQ), implemented on a Siemens Acuson S3000 ultrasound machine. Tissue mechanical properties were interpreted as two-dimensional qualitative and quantitative colour maps displaying relative shear wave velocity. Wave speed measurements in m/s were possible at operator defined regions of interest. The pathologic diagnosis was established on samples obtained by ultrasound guided core biopsy or fine needle aspiration.
  
  
  RESULTS
  BIRADS based B-mode evaluation of the 48 benign and 62 malignant lesions achieved 92% sensitivity and 62.5% specificity. Subsequently performed VTIQ elastography relying on visual interpretation of the colour overlay displaying relative shear wave velocities managed similar standalone diagnostic performance with 92% sensitivity and 64.6% specificity. Lesion and surrounding tissue shear wave speed values were calculated and a significant difference was found between the benign and malignant populations (Mann-Whitney U test, p<0.0001). By selecting a lesion cut-off value of 3.31m/s we achieved 80.4% sensitivity and 73% specificity. Applying this threshold only to BIRADS 4a masses, we reached overall levels of 92% sensitivity and 72.9% specificity.
  
  
  CONCLUSIONS
  VTIQ qualitative and quantitative elastography has the potential to further characterise B-mode detected breast lesions, increasing specificity and reducing the number of unnecessary biopsies.
authors.affiliation: Radiology Department, Gustave Roussy, Villejuif, France.
authors.forename: Victor
authors.initials: V
authors.lastname: Ianculescu
authors.affiliation: Radiology Department, Gustave Roussy, Villejuif, France.
authors.forename: Laura Maria
authors.initials: LM
authors.lastname: Ciolovan
authors.affiliation: Department of Statistics, Gustave Roussy, Villejuif, France.
authors.forename: Ariane
authors.initials: A
authors.lastname: Dunant
authors.affiliation: Department of Biopathology, Gustave Roussy, Villejuif, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Vielh
authors.affiliation: Department of Surgery, Gustave Roussy, Villejuif, France.
authors.forename: Chafika
authors.initials: C
authors.lastname: Mazouni
authors.affiliation: Department of Oncology, Gustave Roussy, Villejuif, France.
authors.forename: Suzette
authors.initials: S
authors.lastname: Delaloge
authors.affiliation: Radiology Department, Gustave Roussy, Villejuif, France.
authors.forename: Clarisse
authors.initials: C
authors.lastname: Dromain
authors.affiliation: Department of Surgery, Bucharest Institute of Oncology, Bucharest, Romania.
authors.forename: Alexandru
authors.initials: A
authors.lastname: Blidaru
authors.affiliation: Radiology Department, Gustave Roussy, Villejuif, France; UMR 8081, IR4M, Paris-Sud University, 91405 Orsay, France. Electronic address: corinne.balleyguier@gustaveroussy.fr.
authors.forename: Corinne
authors.initials: C
authors.lastname: Balleyguier
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000000981:diagnostic imaging*; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods; D015588:Observer Variation; D010173:Palpation / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014110:Touch; D016217:Ultrasonography, Mammary / Q000379:methods*; D014584:User-Computer Interface
keywords: BIRADS 4a; Breast cancer; Elastography; Shear wave; Ultrasound; Virtual Touch IQ