title: MR colonography with limited bowel preparation compared with optical colonoscopy in patients at increased risk for colorectal cancer.
abstract: OBJECTIVE
  To prospectively evaluate the diagnostic performance of magnetic resonance (MR) colonography by using limited bowel preparation in patients with polyps of 10 mm or larger in diameter in a population at increased risk for colorectal cancer, with optical colonoscopy as the reference standard.
  
  
  METHODS
  The institutional review boards of all three hospitals approved the study. All patients provided written informed consent. In this multicenter study, patients undergoing colonoscopy because of a personal or family history of colorectal cancer or adenomatous polyps were included. Two blinded observers independently evaluated T1- and T2-weighted MR colonographic images obtained with limited bowel preparation (bright-lumen fecal tagging) for the presence of polyps. The limited bowel preparation consisted of a low-fiber diet, with ingestion of lactulose and an oral gadolinium-based contrast agent (with all three major meals) starting 48 hours prior to imaging. Results were verified with colonoscopic outcomes. Patient sensitivity, patient specificity, polyp sensitivity, and interobserver agreement for lesions of 10 mm or larger were calculated for both observers individually and combined.
  
  
  RESULTS
  Two hundred patients (mean age, 58 years; 128 male patients) were included; 41 patients had coexistent symptoms. At colonoscopy, 12 patients had 22 polyps of 10 mm or larger. Per-patient sensitivity was 58% (seven of 12) for observer 1, 67% (eight of 12) for observer 2, and 75% (nine of 12) for both observers combined for polyps of 10 mm or larger. Per-patient specificity was 95% (178 of 188) for observer 1, 97% (183 of 188) for observer 2, and 93% (175 of 188) for both observers combined. Per-polyp sensitivity was 55% (12 of 22) for observer 1, 50% (11 of 22) for observer 2, and 77% (17 of 22) for both observers combined. Interobserver agreement was 93% for identification of patients with lesions of 10 mm or larger.
  
  
  CONCLUSIONS
  In patients at increased risk for colorectal cancer, specificity of MR colonography by using limited bowel preparation was high, but sensitivity was modest.
authors.affiliation: Department of Radiology, Academic Medical Center, PO Box 22660, 1100 DD Amsterdam, the Netherlands. j.florie@amc.uva.nl
authors.forename: Jasper
authors.initials: J
authors.lastname: Florie
authors.forename: Sebastiaan
authors.initials: S
authors.lastname: Jensch
authors.forename: Rutger A J
authors.initials: RA
authors.lastname: Nievelstein
authors.forename: Joep F
authors.initials: JF
authors.lastname: Bartelsman
authors.forename: Lubbertus C
authors.initials: LC
authors.lastname: Baak
authors.forename: Rogier E
authors.initials: RE
authors.lastname: van Gelder
authors.forename: Brigitte
authors.initials: B
authors.lastname: Haberkorn
authors.forename: Adrienne
authors.initials: A
authors.lastname: van Randen
authors.forename: Michiel M
authors.initials: MM
authors.lastname: van der Ham
authors.forename: Pleun
authors.initials: P
authors.lastname: Snel
authors.forename: Victor P M
authors.initials: VP
authors.lastname: van der Hulst
authors.forename: Patrick M M
authors.initials: PM
authors.lastname: Bossuyt
authors.forename: Jaap
authors.initials: J
authors.lastname: Stoker
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003111:Colonic Polyps / Q000175:diagnosis*; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care; D011446:Prospective Studies; D012680:Sensitivity and Specificity