title: Strain assessment in surgically resected inflammatory and neoplastic bowel lesions.
abstract: OBJECTIVE
  To investigate whether ultrasound-based strain imaging can discriminate between colorectal adenocarcinomas and stenotic Crohn's lesions in newly resected surgical specimens.
  
  
  METHODS
  Resected surgical specimens from 27 patients electively operated for colorectal tumors or stenotic lesions from Crohn's disease were prospectively examined with ultrasonography using a Hitachi HV 900 US scanner with real-time elastography (RTE). Three different methods were applied to assess tissue strain: A four-level categorical visual classification, a continuous visual analog scale (VAS, 0 - 100) and a strain ratio (SR) measurement between the lesion and surrounding reference tissue. The imaged sections were marked and subsequently examined by a pathologist. Results from RTE were evaluated according to diagnosis, degree of fibrosis, inflammatory parameters, tumor stage and grade.
  
  
  RESULTS
  16 sections from Crohn's lesions, 18 sections from adenocarcinomas and 4 sections from adenomas were examined. Both adenocarcinomas and Crohn's lesions were found to be harder than the surrounding tissue, but they could not be discriminated from each other by any of the strain imaging evaluation methods. All adenocarcinomas had significantly higher strain ratios than adenomas. The categorical classification differentiated poorly between Crohn's lesions, adenocarcinomas and adenomas. Categorical evaluation and VAS score showed fair interobserver agreement. SR measurements provided semi-quantitative strain data and added improved information about elasticity properties, despite substantial intra-observer variation.
  
  
  CONCLUSIONS
  Sonoelastography with SR measurements and visual evaluation of strain differences could not differentiate stenotic Crohn's lesions from adenocarcinomas in resected bowel specimens. A small number of adenomas were found to be significantly softer than adenocarcinomas using the same evaluation methods. The tumor stage or grade did not have a significant impact on the elastography results.
authors.affiliation: Institute of Medicine, University of Bergen.
authors.forename: R F
authors.initials: RF
authors.lastname: Havre
authors.affiliation: The Gade Institute, University of Bergen.
authors.forename: S
authors.initials: S
authors.lastname: Leh
authors.affiliation: National Centre for Ultrasound in Gastroenterology, Department of Medicine, Haukeland University Hospital, Institute of Medicine, Bergen.
authors.forename: O H
authors.initials: OH
authors.lastname: Gilja
authors.affiliation: Institute of Medicine, University of Bergen.
authors.forename: S
authors.initials: S
authors.lastname: Ødegaard
authors.affiliation: Department of Surgery, Haukeland University Hospital, Bergen.
authors.forename: J E
authors.initials: JE
authors.lastname: Waage
authors.affiliation: Institute of Surgery, University of Bergen.
authors.forename: G
authors.initials: G
authors.lastname: Baatrup
authors.affiliation: Institute of Medicine, University of Bergen.
authors.forename: L B
authors.initials: LB
authors.lastname: Nesje
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery*; D000236:Adenoma / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery*; D000465:Algorithms; D003106:Colon / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D015179:Colorectal Neoplasms / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery*; D003424:Crohn Disease / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery*; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005240:Feasibility Studies; D005355:Fibrosis / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D007415:Intestinal Obstruction / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery*; D011183:Postoperative Complications / Q000503:physiopathology*; D012016:Reference Values