title: Ultrasound Shear Wave Elastography and Contrast Enhancement: Effective Biomarkers in Crohn's Disease Strictures.
abstract: Inflammation, fibrosis, and muscular hypertrophy lead to thickened bowel in Crohn's disease forming strictures. Ultrasound shear wave elastography (SWE) measures bowel wall stiffness. Contrast-enhanced ultrasound (CEUS) uniquely detects bowel wall inflammation. We aim to correlate SWE of ileal Crohn's disease in vivo to CEUS peak enhancement and pathology grades of inflammation, fibrosis, and muscular hypertrophy.
  
  
  
  In a prospective institutional review board-approved study, 105 consecutive ileal patients with Crohn's disease received ultrasound. At maximal bowel wall thickness (>4 mm), SWE and CEUS were performed. Fifteen patients had ileal resection within a mean time interval of 71.0 ± 66.9 days. Pathology scores for inflammation, fibrosis, and muscular hypertrophy were compared with SWE and CEUS measurements.
  
  
  
  Mean in vivo SWE velocity for patients with and without surgery was 2.8 ± 0.7 and 2.2 ± 0.8 m/s (P < 0.01), respectively. In all ileal specimens, chronic exceeded active inflammatory change (P < 0.001). There was an inverse relationship between CEUS peak enhancement and both fibrosis, r = -0.59, P = 0.02, and SWE velocity measurements, r = -0.61, P = 0.03. Strictured bowel specimens had more smooth muscle hypertrophy than fibrosis, P < 0.001. There was moderate correlation between SWE and muscular hypertrophy, r = 0.59, P = 0.02 and no significant relationship between SWE and fibrosis scores (P > 0.05).
  
  
  
  Stiffer bowel from smooth muscle hypertrophy increases SWE measurements. We report a novel relation of high SWE with muscle hypertrophy, and inverse relationship with CEUS peak enhancement; providing differentiation between active and chronic bowel wall inflammation to improve selection between medical therapy and surgery.
authors.affiliation: *Division of Gastroenterology, Department of Medicine, University of Calgary, Alberta, Canada; †Department of Pathology and Laboratory Medicine, University of Calgary, Alberta, Canada; ‡Department of Mathematics and Statistics, Information Technologies, University of Calgary, Alberta, Canada; and §Department of Diagnostic Imaging, University of Calgary, Alberta, Canada.
authors.forename: Cathy
authors.initials: C
authors.lastname: Lu
authors.forename: Xianyong
authors.initials: X
authors.lastname: Gui
authors.forename: Wenqian
authors.initials: W
authors.lastname: Chen
authors.forename: Tak
authors.initials: T
authors.lastname: Fung
authors.forename: Kerri
authors.initials: K
authors.lastname: Novak
authors.forename: Stephanie R
authors.initials: SR
authors.lastname: Wilson
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000032:analysis; D003251:Constriction, Pathologic / Q000000981:diagnostic imaging; D003287:Contrast Media; D003424:Crohn Disease / Q000000981:diagnostic imaging* / Q000473:pathology; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D007082:Ileum / Q000000981:diagnostic imaging / Q000473:pathology; D007422:Intestines / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies
chemical_list: D015415:Biomarkers; D003287:Contrast Media