title: The effect of steatosis on echogenicity of colorectal liver metastases on intraoperative ultrasonography.
abstract: OBJECTIVE
  To investigate the association of relative tumor echogenicity and hepatic steatosis in patients undergoing resection of colorectal liver metastases (CRLM).
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  The Johns Hopkins Hospital.
  
  
  METHODS
  A total of 126 patients undergoing liver surgery for CRLM from January 1, 1998, through December 31, 2008, in whom 191 lesions had complete intraoperative ultrasonography images for review and adequate linked pathological data available.
  
  
  METHODS
  The intraoperative ultrasonography images were reviewed and scored for echogenicity (hypoechoic, isoechoic, or hyperechoic). In addition, a histopathologic review of the nontumorous liver tissue was performed, and the extent of steatosis was scored and correlated with tumor echogenicity.
  
  
  RESULTS
  Of the patients undergoing surgery, 49 (38.8%) were found to have mild to severe steatosis. Of the 191 total CRLM visualized by intraoperative ultrasonography, 91 (47.6%) were found to be hypoechoic, 65 (34.0%) were isoechoic, and 35 (18.3%) were hyperechoic. In patients with steatosis, lesions were significantly more likely to be hypoechoic when compared with patients without steatosis (odds ratio, 4.17; 95% confidence interval, 1.87-8.47; P = .001). Echogenicity was independent of the cause of steatosis or response to chemotherapy.
  
  
  CONCLUSIONS
  The echogenicity of CRLM was significantly affected by the presence of liver steatosis, with decreased echogenicity and increased conspicuity of lesions despite overall poorer image quality. These findings might reinforce the usefulness of intraoperative ultrasonography in identifying additional CRLM in patients undergoing surgical therapy, even in those with fatty liver tissue.
authors.affiliation: Department of Surgery, The Johns Hopkins Hospital, The Johns Hopkins University School of Medicine, 600 N Wolfe Street, Baltimore, MD 21287, USA.
authors.forename: Mark G
authors.initials: MG
authors.lastname: van Vledder
authors.forename: Michael S
authors.initials: MS
authors.lastname: Torbenson
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Pawlik
authors.forename: Emad M
authors.initials: EM
authors.lastname: Boctor
authors.forename: Ulrike M
authors.initials: UM
authors.lastname: Hamper
authors.forename: Kelly
authors.initials: K
authors.lastname: Olino
authors.forename: Michael A
authors.initials: MA
authors.lastname: Choti
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000473:pathology*; D005234:Fatty Liver / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D016017:Odds Ratio; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D018084:Ultrasonography, Interventional