title: Active Crohn's disease and ulcerative colitis evaluated by low-field magnetic resonance imaging.
abstract: BACKGROUND
  Our aim was to evaluate low-field magnetic resonance imaging (MRI) in the assessment of disease extension and activity in inflammatory bowel disease.
  
  
  METHODS
  Nineteen patients with Crohn's disease (CD), 8 with ulcerative colitis (UC), and 5 healthy controls (HC) were examined using MRI (0.1 T) before and after intravenously administered gadodiamide and glucagon. MRI images were evaluated in a blinded fashion and compared with findings at endoscopy, double-contrast barium enema, small-bowel follow-through, and surgery.
  
  
  RESULTS
  Comparisons of diseased with both non-diseased bowel segments and segments from HC showed significant differences for both CD and UC with regard to signal intensity on T2-weighted (SI(T2)) images and post-contrast increment of signal intensity on T1-weighted images (%SI(T1). Agreements with regard to disease extension in CD between MRI and other examinations were 97%, underestimating the extension in two patients. For SI(T2) in CD a cut-off value of 1.0 showed a predictive value of a positive finding (PVpos) = 1.0 and a predictive value of a negative finding (PVneg) = 0.96. For %SI(T1) in CD a cut-off value of 15.0% showed values of PVpos = 0.95 and PVneg = 0.92. Agreements between MRI and conventional methods (disease extension) in UC was 87.5%. Extension was underestimated in two patients and overestimated in two patients as compared with barium enemas. Values of PVpos were 1.0 (SI(T2) >1.0) and 1.0 (%SI(T1) >15.0%), respectively, with corresponding values of PVneg being 0.94 and 0.94.
  
  
  CONCLUSIONS
  Low-field MRI seems a promising non-invasive, non-radiating method in the evaluation of inflammatory bowel disease.
authors.affiliation: Dept. of Medical Gastroenterology, Herlev Hospital, University of Copenhagen, Denmark.
authors.forename: S M
authors.initials: SM
authors.lastname: Madsen
authors.forename: H S
authors.initials: HS
authors.lastname: Thomsen
authors.forename: P
authors.initials: P
authors.lastname: Munkholm
authors.forename: S
authors.initials: S
authors.lastname: Dorph
authors.forename: P
authors.initials: P
authors.lastname: Schlichting
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003093:Colitis, Ulcerative / Q000453:epidemiology / Q000473:pathology*; D003106:Colon / Q000473:pathology; D003424:Crohn Disease / Q000453:epidemiology / Q000473:pathology*; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D007421:Intestine, Small / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D011237:Predictive Value of Tests; D012720:Severity of Illness Index