title: Is Strain Elastography (IO-SE) Sufficient for Characterization of Liver Lesions before Surgical Resection--Or Is Contrast Enhanced Ultrasound (CEUS) Necessary?
abstract: OBJECTIVE
  To evaluate the diagnostic accuracy of IO-SE in comparison to IO-CEUS for the differentiation between malignant and benign liver lesions.
  
  
  METHODS
  In a retrospective diagnostic study IO-CEUS and SE examinations of 49 liver lesions were evaluated and compared to histopathological examinations. Ultrasound was performed using a multifrequency linear probe (6-9 MHz). The loops of CEUS were evaluated up to 5 min. The qualitative characterization of IO-SE was based on a color coding system (blue = hard, red = soft). Stiffness of all lesions was quantified by a specific scaling of 0-6 (0 = low, 6 = high) using 7 ROIs (2 central, 5 peripheral).
  
  
  RESULTS
  All malignant lesions displayed a characteristic portal venous washout and could be diagnosed correctly by IO-CEUS. 3/5 benign lesions could not be characterized properly either by IO-CEUS or IO-SE prior to resection. Thus for IO-CEUS sensitivity, specificity, positive and negative predictive value and accuracy were 100%, 40%, 94%, 100% and 94%. Lesion sizes were between 8 and 59 mm in diameter. Regarding the IO-SE, malignant lesions showed a marked variability. In qualitative analysis, 31 of the malignant lesions were blue colored denoting overall induration. Thirteen malignant lesions showed an inhomogenous color pattern with partial indurations. Two of the benign lesions also displayed overall induration. The other benign lesions showed an inhomogenous color mapping. Calculated sensitivity of the SE was 70.5%, specificity 60%, PPV 94%, NPV 18.75%, and accuracy 69%.
  
  
  CONCLUSIONS
  IO-CEUS is useful for localization and characterization of liver lesions prior to surgical resection whereas IO-SE provided correct characterization only for a limited number of lesions.
authors.affiliation: University Hospital Regensburg, Department of Radiology, Regensburg, Germany.
authors.forename: Ernst Michael
authors.initials: EM
authors.lastname: Jung
authors.affiliation: University Hospital Regensburg, Department of Radiology, Regensburg, Germany.
authors.forename: Natascha
authors.initials: N
authors.lastname: Platz Batista da Silva
authors.affiliation: Saarland University, Department of Materials Research, Saarbrücken, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Jung
authors.affiliation: University Hospital Regensburg, Department of Surgery, Regensburg, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Farkas
authors.affiliation: University Hospital Regensburg, Department of Radiology, Regensburg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Stroszczynski
authors.affiliation: University Hospital Regensburg, Department of Radiology, Regensburg, Germany.
authors.forename: Janine
authors.initials: J
authors.lastname: Rennert
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D003937:Diagnosis, Differential; D054459:Elasticity Imaging Techniques / Q000379:methods* / Q000592:standards; D005260:Female; D006801:Humans; D007089:Image Enhancement; D007432:Intraoperative Period; D008107:Liver Diseases / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D057234:Preoperative Period; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D047368:Tumor Burden
chemical_list: D003287:Contrast Media