title: Endorectal ultrasonography, strain elastography and MRI differentiation of rectal adenomas and adenocarcinomas.
abstract: OBJECTIVE
  Strain elastography is a method for recording tissue hardness. Strain in different areas may be compared using strain ratio (SR). The aims of this study were to validate a previously proposed SR cut-off value of 1.25 for differentiating adenocarcinomas from adenomas and to compare the performance of endorectal ultrasonography (ERUS), strain elastography and MRI in the same patients.
  
  
  METHODS
  A prospective evaluation of 120 consecutive patients with rectal neoplasia, using a predetermined elastography strain ratio cut-off value, was performed to differentiate adenomas from adenocarcinomas. ERUS and MRI were performed according to standard routine at Haukeland University Hospital, defining T0 as adenomas and T1-T4 as adenocarcinomas. Subsequent histopathology was used as the reference standard.
  
  
  RESULTS
  Histopathological evaluation revealed 21 adenomas and 99 adenocarcinomas. Sensitivity, specificity and accuracy (with 95% CI) were as follows: ERUS: 0.96 (0.90-0.99), 0.62 (0.40-0.80) and 0.90 (0.83-0.94); elastography SR: 0.96 (0.90-0.99), 0.86 (0.66-0.96) and 0.94 (0.88-0.97); and MRI: 0.99 (0.94-1.00), 0.07 (0.00-0.31) and 0.87 (0.80-0.93).
  
  
  CONCLUSIONS
  This study confirms that the elastography SR assessment accurately differentiates sessile adenomas from adenocarcinomas. SR assessment has a superior ability to differentiate adenomas and adenocarcinomas when compared with ERUS and MRI. MRI examination seems unable to recognize adenomas and should be interpreted with care when early-stage rectal neoplasia is suspected.
authors.affiliation: Department of Surgery, Haukeland University Hospital, Bergen, Norway.|Department of Clinical Medicine, University of Bergen, Bergen, Norway.
authors.forename: J E R
authors.initials: JE
authors.lastname: Waage
authors.affiliation: Department of Clinical Medicine, University of Bergen, Bergen, Norway.|Department of Pathology, Haukeland University Hospital, Bergen, Norway.
authors.forename: S
authors.initials: S
authors.lastname: Leh
authors.affiliation: Department of Radiology, Haukeland University Hospital, Bergen, Norway.
authors.forename: C
authors.initials: C
authors.lastname: Røsler
authors.affiliation: Department of Surgery, Haukeland University Hospital, Bergen, Norway.|Department of Clinical Medicine, University of Bergen, Bergen, Norway.
authors.forename: F
authors.initials: F
authors.lastname: Pfeffer
authors.affiliation: Academic Department of Surgery, Queen Elizabeth Hospital, Edgbaston, Birmingham, UK.
authors.forename: S P
authors.initials: SP
authors.lastname: Bach
authors.affiliation: Department of Clinical Medicine, University of Bergen, Bergen, Norway.|Department of Medicine, National Centre for Ultrasound in Gastroenterology, Haukeland University Hospital, Bergen, Norway.
authors.forename: R F
authors.initials: RF
authors.lastname: Havre
authors.affiliation: Department of Clinical Medicine, University of Bergen, Bergen, Norway.|Department of Radiology, Haukeland University Hospital, Bergen, Norway.
authors.forename: I S
authors.initials: IS
authors.lastname: Haldorsen
authors.affiliation: Department of Clinical Medicine, University of Bergen, Bergen, Norway.|Department of Medicine, National Centre for Ultrasound in Gastroenterology, Haukeland University Hospital, Bergen, Norway.
authors.forename: S
authors.initials: S
authors.lastname: Ødegaard
authors.affiliation: Department of Clinical Medicine, University of Bergen, Bergen, Norway.|Department of Surgery A, Odense University Hospital, Svendborg, Denmark.|Institute for Regional Health Science, University of Southern Denmark, Odense, Denmark.
authors.forename: G
authors.initials: G
authors.lastname: Baatrup
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis* / Q000473:pathology; D000236:Adenoma / Q000175:diagnosis* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D054459:Elasticity Imaging Techniques / Q000379:methods / Q000706:statistics & numerical data*; D019160:Endosonography / Q000379:methods / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012004:Rectal Neoplasms / Q000175:diagnosis* / Q000473:pathology; D012007:Rectum / Q000000981:diagnostic imaging; D012680:Sensitivity and Specificity
keywords: MRI; Rectum; adenocarcinoma; adenoma; endorectal ultrasound; strain elastography