title: Intrasurgical dignity assessment of hepatic tumors using semi-quantitative strain elastography and contrast-enhanced ultrasound for optimisation of liver tumor surgery.
abstract: OBJECTIVE
  To evaluate the efficacy of strain elastography (SE) using semi-quantitative measurement methods compared to constrast enhanced ultrasound during liver tumor surgery (Io-CEUS) for dignity assessment of focal liver lesions(FLL).
  
  
  METHODS
  Prospective data acquisition and retrospective analysis of US data of 100 patients (116 lesions) who underwent liver tumor surgery between 10/2010 and 03/2016. Retrospective reading of SE color patterns was performed establishing groups depending on dominant color (>50% blue = stiff, inhomogenous, >50% yellow/red/green = soft tissue). Semi-quantitative analysis was performed by Q-analysis based on a scale from 0 (soft) to 6 (stiff). 2 ROIs were placed centrally, 5 ROIs in the lesion's surrounding tissue. Io-CEUS was performed by bolus injection of 5-10 ml sulphurhexaflourid microbubbles evaluating wash-in- and -out- kinetics in arterial, portal venous and late phase. Histopathology after surgical resection served as goldstandard.
  
  
  RESULTS
  100 patients (m: 65, f: 35, mean age 60.5 years) with 116 liver lesions were included. Lesion's size ranged from 0.5 to 8.4 cm (mean 2.42 cm SD±1.44 cm). Postoperative histology showed 105 malignant and 11 benign lesions. Semi-quantitative analysis showed central indurations of >2.5 in 76/105 cases suggesting malignancy. 7 benign lesions displayed no central indurations correctly characterized benign by SE. ROC-analysis and Youden index showed a sensitivity of 72.4% and specificity of 63.6% assuming a cut-off of 2.5. Io-CEUS correctly characterized 103/105 as malignant. Sensitivity was 98%, specificity 72.7%.
  
  
  CONCLUSIONS
  Strain elastography is a valuable tool for non-invasive characterization of FLLs. Semi-quantitative intratumoral stiffness values of >2.5 suggested malignancy. However, sensitivity of Io-CEUS in detecting malignant lesions was higher compared to SE. In conclusion SE should be considered for routine use during intraoperative US in addition to Io-CEUS for optimization of curative liver surgery.
authors: Departement of Radiology, University Hospital Regensburg, Regensburg, Germany.
authors: N
authors: N
authors: Platz Batista da Silva
authors: Department of Cardiothoracic Surgery, University Hospital Regensburg, Regensburg, Germany.
authors: M
authors: M
authors: Schauer
authors: Department of Surgery, University Hospital Regensburg, Regensburg, Germany.
authors: M
authors: M
authors: Hornung
authors: Department of Surgery, University Hospital Regensburg, Regensburg, Germany.
authors: S
authors: S
authors: Lang
authors: Departement of Radiology, University Hospital Regensburg, Regensburg, Germany.
authors: L P
authors: LP
authors: Beyer
authors: Departement of Radiology, University Hospital Regensburg, Regensburg, Germany.
authors: I
authors: I
authors: Wiesinger
authors: Departement of Radiology, University Hospital Regensburg, Regensburg, Germany.
authors: C
authors: C
authors: Stroszczynski
authors: Departement of Radiology, University Hospital Regensburg, Regensburg, Germany.
authors: E M
authors: EM
authors: Jung
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media / Q000627:therapeutic use*; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012189:Retrospective Studies; D014463:Ultrasonography / Q000379:methods*
chemical_list: D003287:Contrast Media
keywords: CEUS; Ultrasound; elastography; strain elastography; surgery