title: MR enterography-histology comparison in resected pediatric small bowel Crohn disease strictures: can imaging predict fibrosis?
abstract: BACKGROUND
  Crohn disease is a chronic inflammatory condition that can lead to intestinal strictures. The presence of fibrosis within strictures alters optimal management but is not reliably detected by current imaging methods.
  
  
  OBJECTIVE
  To correlate the MRI features of surgically resected small-bowel strictures in pediatric Crohn disease with histological inflammation and fibrosis scoring.
  
  
  METHODS
  We included children with Crohn disease who had symptomatic small-bowel strictures requiring surgical resection and had preoperative MR enterography (MRE) within 3 months of surgery (n = 20). Two blinded radiologists reviewed MRE examinations to document stricture-related findings. A pediatric pathologist scored stricture histological specimens for fibrosis (0-4) and inflammation (0-4). MRE findings were correlated with histological data using Spearman correlation (ρ) and exact logistic regression analysis.
  
  
  RESULTS
  There was significant positive correlation between histological bowel wall fibrosis and inflammation in resected strictures (ρ = 0.55; P = 0.01). Confluent transmural histological fibrosis was associated with pre-stricture upstream small-bowel dilatation >3 cm at univariate (odds ratio [OR] = 51.7; 95% confidence interval [CI]: 7.6- > 999.9; P = 0.0002) and multivariate (OR = 43.4; 95% CI: 6.1- > 999.9; P = 0.0006, adjusted for age) analysis. The degree of bowel wall T2-weighted signal intensity failed to correlate with histological bowel wall fibrosis or inflammation (P-values >0.05). There were significant negative correlations between histological fibrosis score and patient age at resection (ρ = -0.48, P = 0.03), and time from diagnosis to surgery (ρ = -0.73, P = 0.0002).
  
  
  CONCLUSIONS
  Histological fibrosis and inflammation co-exist in symptomatic pediatric Crohn disease small-bowel strictures and are positively correlated. Pre-stenotic upstream small-bowel dilatation greater than 3 cm is significantly associated with confluent transmural fibrosis.
authors.affiliation: Department of Radiology, University of Michigan Health System, Ann Arbor, MI, USA.
authors.forename: Daniel T
authors.initials: DT
authors.lastname: Barkmeier
authors.affiliation: Division of Thoracoabdominal Imaging, Department of Radiology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH, 45229-3026, USA. Jonathan.Dillman@cchmc.org.
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Dillman
authors.affiliation: Department of Radiology, University of Michigan Health System, Ann Arbor, MI, USA.|Division of Abdominal Imaging, University of Michigan Health System, Ann Arbor, MI, USA.
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Al-Hawary
authors.affiliation: Department of Pathology, C.S. Mott Children's Hospital, University of Michigan Health System, Ann Arbor, MI, USA.
authors.forename: Amer
authors.initials: A
authors.lastname: Heider
authors.affiliation: Department of Radiology, University of Michigan Health System, Ann Arbor, MI, USA.|Division of Abdominal Imaging, University of Michigan Health System, Ann Arbor, MI, USA.
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Davenport
authors.affiliation: Department of Radiology, University of Michigan Health System, Ann Arbor, MI, USA.|Section of Pediatric Radiology C.S. Mott Children's Hospital, University of Michigan Health System, Ann Arbor, MI, USA.
authors.forename: Ethan A
authors.initials: EA
authors.lastname: Smith
authors.affiliation: Division of Pediatric Gastroenterology, Department of Pediatrics, C. S. Mott Children's Hospital, University of Michigan Health System, Ann Arbor, MI, USA.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Adler
mesh_terms: D000293:Adolescent; D003424:Crohn Disease / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D005260:Female; D005355:Fibrosis; D006801:Humans; D007415:Intestinal Obstruction / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D007421:Intestine, Small / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D011379:Prognosis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D016037:Single-Blind Method; D013223:Statistics as Topic
keywords: Children; Crohn disease; Histology; Inflammatory bowel disease; Magnetic resonance enterography; Stricture