The team evaluated the sensitivity and specificity of MR imaging in assessing the activity of Crohn's disease.
The findings of the study were published in the December issue of the American Journal of Roentgenology.
A total of 30 symptomatic patients with Crohn's disease, but uncertain disease activity, were enrolled in the study. All were prospectively examined using MR imaging.
Of these patients, 29 were scored using the Crohn's disease activity index.
The subjects were given 600 ml of water orally and 1 mg of glucagon intramuscularly before imaging.
Breath-hold images were obtained using T2-weighted turbo spin-echo, T1-weighted fast low-angle shot, and fat-suppressed gadolinium-enhanced T1-weighted fast low-angle shot sequences.
Two radiologists, who were unaware of the patient's symptoms, clinical scoring, and other imaging tests, assessed the images.
The radiologists reached a consensus about the imaging findings (bowel wall thickening, bowel wall enhancement, and perienteric changes) and determined the absence or presence of active disease in each patient.
MR imaging findings were correlated with endoscopy and surgery.
|MR imaging for Crohn's (per patient basis):|
|American Journal of Roentgenology|
The researchers found that 23 patients had active disease and 7 patients had inactive disease.
Of a total of 168 bowel segments, 124 were examined with both MR imaging and endoscopy or surgery.
On a per patient basis, MR imaging was found to have an overall sensitivity of 91% and a specificity of 71% for active disease.
The Crohn's disease activity index had a sensitivity of 92% and a specificity of 28%.
On a per segment basis, MR imaging had a sensitivity of 59% and a specificity of 93%.
Bowel wall thickening of greater than 4 mm, bowel wall enhancement, and increased mesenteric vascularity were useful in identifying active disease.
It was additionally found that a layered enhancement pattern after the IV administration of gadolinium was highly specific for active inflammation.
Author D. M. Koh, of the Department of Radiology at the Chelsea and Westminster Hospital, London, concluded on behalf of the group, "MR imaging is useful in assessing the activity of Crohn's disease and may be helpful when clinical scoring is equivocal."