Crohn's disease evaluated with magnetic resonance enteroclysis: diagnostic performance of experienced and inexperienced readers before and after training.

BACKGROUND: Magnetic resonance enteroclysis (MRE) is suggested to become the preferred radiological method in small-bowel Crohn's disease (CD). However, the performance of inexperienced readers may influence the diagnostic value of the method and has not been previously investigated. PURPOSE: To compare readings of MRE in small-bowel CD performed by experienced and inexperienced readers before and after training. MATERIAL AND METHODS: One experienced radiologist (observer 1) and two trainees (observers 2 and 3) reviewed 60 MRE examinations. A second reading was performed after training. Bowel wall thickness (BWT), ulcers (BWU), stenosis (BWS), fistulas (FIS), and abscesses (ABS) were evaluated. A reference standard based on clinical records was established. RESULTS: BWT in the terminal ileum was evaluated with high diagnostic performance (sensitivity: observer 1, 83%; observer 2, 72%; observer 3, 78%). Only BWU was diagnosed with a higher sensitivity by observer 1 (78% vs. 33% and 39%, respectively; P=0.02). False-positive findings for BWT in the jejunum (observer 2: 7; observer 3: 4) and fistulas and abscesses (observer 2: 11/5; observer 3: 5/4) were made by the trainees. Interobserver agreement in the jejunum was poor (observer 1/observer 2: kappa=0.23; observer 1/observer 3: kappa=-0.03) and in the ileum good (observer 1/observer 2: kappa=0.78; observer 1/observer 3: kappa=0.73). After training, evaluation of BWU (observer 2: 56%, P=0.22; observer 3: 44%, P=0.03), BWT (observer 2: 2; observer 3: 2), and interobserver agreement in the jejunum improved (observer 1/observer 2: kappa=0.66; observer 1/observer 3: kappa=0.66). However, the number of diagnosed fistulas and abscesses remained high. CONCLUSION: Before training, most findings of Crohn's disease in the terminal ileum were evaluated with high diagnostic performance by all readers. However, the inexperienced readers evaluated BWU with a low sensitivity and overestimated the number of FIS, number of ABS, and increased BWT in the jejunum. After training, evaluation by inexperienced readers of BWU and increased BWT in the jejunum improved.

Magnetic resonance enteroclysis in the diagnosis of small-intestinal Crohn's disease: diagnostic accuracy and inter- and intra-observer agreement.

PURPOSE: To evaluate the diagnostic accuracy and inter- and intra-observer agreement of magnetic resonance enteroclysis (MRE) in patients with or without Crohn's disease of the small intestine. MATERIAL AND METHODS: 60 consecutive patients with or without Crohn's disease examined with MRE were included. Two observers independently reviewed the MRE examinations, searching for 12 pathological signs. The reference standard was ileoscopy or surgery of the terminal ileum performed in 41 patients. RESULTS: Crohn's disease of the small intestine was found in 24 (40%) patients. MRE findings of increased intestinal wall thickness, intestinal wall enhancement, intestinal wall ulcer, and inflammatory activity of the terminal ileum showed high sensitivity, specificity, and positive and negative predictive values. Intestinal stenosis had sensitivities ranging from 43% to 100%, depending on the cut-off value. Inter- and intra-observer agreement was good or excellent for most pathological signs. However, observer agreement of intestinal wall edema was only fair and moderate. CONCLUSION: MRE evaluated Crohn's disease with a high diagnostic accuracy in the terminal ileum. Most MRE variables were evaluated with good or excellent observer agreement, indicating that the method was highly reproducible. Our study supports the notion that MRE is an appropriate method for diagnosing Crohn's disease.