Source: Gut  |  Posted 8 years ago

Gadolinium enhanced magnetic resonance imaging (MRI) with polyethylene glycol offers a sensitive and specific test to detect distal ileitis in children with Crohn's disease and to differentiate this from other inflammatory gastrointestinal conditions.

Researchers from the La Sapienza University of Rome, Italy, performed gadolinium enhanced MRI using polyethylene glycol as an oral contrast agent in 75 children with suspected Crohn's disease. Median age was 13.6 years and ranged from 8 to 17 years.

The children also underwent ileocolonoscopy with biopsy and were assessed using the Paediatric Crohn's Disease Activity Index (PCDAI).

Twenty-six patients had active Crohn's disease with distal ileitis. Eighteen showed active ulcerative colitis, while 11 showed spondyloarthropathy and indeterminate ileocolitis. Twenty children acted as controls.

In Crohn's disease patients, MRI showed marked ileal involvement with increased wall thickness and parietal contrast enhancement. MRI showed good concordance with endoscopy findings and histology results. MRI was negative in all controls and was also negative in 15 ulcerative colitis patients.

Three of the seven patients with backwash ileitis showed mild parietal contrast enhancement of the terminal ileum. Among spondyloarthropathy patients, Six had mucosal erosions and five had mild superficial ileitis. MRI was negative in four patients. Seven patients showed mild parietal contrast enhancement of the ileal wall. No patient with ulcerative colitis or spondyloarthropathy had increased thickness of the distal ileum wall.

The authors estimated that MRI had a sensitivity and specificity for endoscopy-documented erosive ileitis of 84% and 100% respectively. MRI correlated with endoscopy and histology in the entire population (r=0.94; r=0.95, respectively) and correlated with the PCDAI in patients with Crohn's disease (r=0.91).

They concluded that gadolinium enhanced MRI with polyethylene glycol offers a sensitive and specific test to detect distal ileitis in children with active Crohn's disease and to differentiate this from other inflammatory gastrointestinal diseases.

The test could offer a useful first-line diagnostic tool for children with suspected CD, the authors suggested. The correlation with ileal endoscopy results, histology and PCDAI may allow for use of this approach to monitor clinical course and treatment outcomes.