title: Magnetic resonance evaluation for small bowel strictures in Crohn's disease: comparison with balloon enteroscopy.
abstract: BACKGROUND
  Magnetic resonance (MR) imaging is the recommended technique for detection of small bowel lesions in Crohn's disease. We aimed to evaluate the impact of stricture findings obtained by MR imaging on patient outcomes using balloon-assisted enteroscopy (BAE) as a reference.
  
  
  METHODS
  Two hundred Crohn's disease patients undergoing both MR enterocolonography and BAE were prospectively followed up for at least 1 year. The presence of strictures detected by MR enterocolonography was compared with endoscopic findings. Moreover, the relationship between MR findings and surgery was evaluated.
  
  
  RESULTS
  The accuracy of MR imaging for detection of small bowel strictures was defined by a sensitivity of 60.6% and a specificity of 93.4%. Major strictures (diameter less than 10 mm or with internal fistula), long strictures (length 10 mm or greater), and prestenotic dilatation were predictors of stricture detection by MR imaging (P = 0.001, 0.017, and 0.002 respectively). Surgery was performed in 31.6% of patients (18 of 57) in the MR-positive-BAE-positive stricture group and in 10.8% of patients (4 of 37) in the MR-negative-BAE-positive stricture group. Multiple regression analysis showed MR-positive-BAE-positive strictures were an independent risk factor for surgery (P = 0.002 at 6 months and P < 0.001 at 1 year). The surgery-free rate in the MR-negative-BAE-positive stricture group was significantly lower than that in nonstricture group at 1 year (P = 0.001).
  
  
  CONCLUSIONS
  The specificity of MR imaging for detection of small bowel strictures was clinically sufficient, and the MR procedure could detect critical strictures, which was a predictive factor for surgery. But MR-negative-BAE-positive strictures were also associated with an increased risk compared with no strictures after 1 year of follow-up.
authors.affiliation: Department of Gastroenterology and Hepatology, Internal Medicine, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.
authors.forename: Kento
authors.initials: K
authors.lastname: Takenaka
authors.affiliation: Department of Gastroenterology and Hepatology, Internal Medicine, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Ohtsuka
authors.affiliation: Department of Radiology, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Kitazume
authors.affiliation: Department of Gastroenterology and Hepatology, Internal Medicine, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.
authors.forename: Katsuyoshi
authors.initials: K
authors.lastname: Matsuoka
authors.affiliation: Department of Gastroenterology and Hepatology, Internal Medicine, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.
authors.forename: Toshimitsu
authors.initials: T
authors.lastname: Fujii
authors.affiliation: Department of Gastroenterology and Hepatology, Internal Medicine, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.
authors.forename: Masakazu
authors.initials: M
authors.lastname: Nagahori
authors.affiliation: Department of Gastroenterology and Hepatology, Internal Medicine, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.
authors.forename: Maiko
authors.initials: M
authors.lastname: Kimura
authors.affiliation: Department of Radiology, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Fujioka
authors.affiliation: Department of Gastroenterology and Hepatology, Internal Medicine, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Araki
authors.affiliation: Department of Gastroenterology and Hepatology, Internal Medicine, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan. mamoru.gast@tmd.ac.jp.
authors.forename: Mamoru
authors.initials: M
authors.lastname: Watanabe
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000071087:Balloon Enteroscopy; D003251:Constriction, Pathologic / Q000000981:diagnostic imaging / Q000209:etiology / Q000601:surgery; D003424:Crohn Disease / Q000150:complications / Q000000981:diagnostic imaging* / Q000601:surgery; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D007415:Intestinal Obstruction / Q000000981:diagnostic imaging* / Q000209:etiology / Q000601:surgery; D007421:Intestine, Small / Q000000981:diagnostic imaging / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012307:Risk Factors; D055815:Young Adult
keywords: Crohn’s disease; Magnetic resonance; Strictures