title: MR elastography of hepatocellular carcinoma: Correlation of tumor stiffness with histopathology features-Preliminary findings.
abstract: To determine if tumor stiffness by MR Elastography (MRE) is associated with hepatocellular carcinoma (HCC) pathologic features.
  
  
  
  A retrospective review was undertaken of all patients with pathologically confirmed HCC who underwent MRE prior to loco-regional therapy, surgical resection or transplant between 1/1/2007 to 12/31/2015. An independent observer measured tumor stiffness (kilopascals, kPa) by drawing regions of interest (ROI) covering the HCC and in the case of HCCs with non-enhancing/necrotic components, only the solid portion was included in the ROI. HCC tumor grade (WHO criteria), vascular invasion and tumor encapsulation were assessed from retrievable pathology specimens by an expert hepatobiliary pathologist. Tumor stiffness was compared by tumor grade, size, presence of capsule and vascular invasion using Student's t-test (or Exact Mann-Whitney test).
  
  
  
  21 patients were identified who had pathologically confirmed HCCs and tumor MRE data. 17 patients (81.0%) had underlying chronic liver disease. The mean±SD tumor size (cm) was 5.3±3.9cm. The mean±SD tumor stiffness was 5.9±1.4kPa. Tumors were graded as well differentiated (N=2), moderately differentiated (N=11) and poorly differentiated (N=8). There was a trend toward increased tumor stiffness in well/moderately differentiated HCCs (6.5±1.2kPa; N=13) compared to poorly differentiated HCCs (4.9±1.2kPa; N=8) (p<0.01). There was no significant correlation between tumor stiffness and liver stiffness or tumor size. There was no significant difference in tumor stiffness by presence or etiology of chronic liver disease, vascular invasion or tumor encapsulation.
  
  
  
  Preliminary data suggest that tumor stiffness by MRE may be able to differentiate HCC tumor grade.
authors.affiliation: Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN 55905, United States.
authors.forename: Scott M
authors.initials: SM
authors.lastname: Thompson
authors.affiliation: Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN 55905, United States.
authors.forename: Jin
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Laboratory Medicine and Pathology, Mayo Clinic, 200 1st St SW, Rochester, MN 55905, United States.
authors.forename: Vishal S
authors.initials: VS
authors.lastname: Chandan
authors.affiliation: Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN 55905, United States.
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Glaser
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Medicine, College of Medicine, Mayo Clinic, 200 1st St SW, Rochester, MN 55905, United States.
authors.forename: Lewis R
authors.initials: LR
authors.lastname: Roberts
authors.affiliation: Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN 55905, United States.
authors.forename: Richard L
authors.initials: RL
authors.lastname: Ehman
authors.affiliation: Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN 55905, United States. Electronic address: Venkatesh.Sudhakar@mayo.edu.
authors.forename: Sudhakar K
authors.initials: SK
authors.lastname: Venkatesh
mesh_terms: D000328:Adult; D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging* / Q000473:pathology; D054459:Elasticity Imaging Techniques; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D012189:Retrospective Studies
keywords: HCC; Hepatocellular carcinoma; MR elastography; MRE; Tumor grade