Simplified MRI index assesses Crohn's disease activity and severity

Last Updated: 2019-04-16

By Will Boggs MD

NEW YORK (Reuters Health) - A simplified four-item MRI-based index of activity (MARIAs) quickly assesses Crohn's disease (CD) activity and response to therapy, researchers from Spain report.

The original MARIA, developed in 2009, used wall thickening, neural contrast enhancement, presence of mural edema and mucosal ulcerations to predict the presence and severity of endoscopic lesions. While increasingly used as an objective measure of disease activity in patients with CD, its calculation can be cumbersome and time-consuming.

Dr. Ingrid Ordas and colleagues from Hospital Clinic of Barcelona and the University of Barcelona Faculty of Medicine sought to develop a simplified index that could more easily and quickly assess CD disease activity and response to therapy.

In the new MARIAs, based on data from 135 MRIs, they assigned one point each for wall thickness >3 mm, mural edema, and perienteric fat stranding, and two points for mucosal ulcerations.

MARIAs scores greater than one identified segments with active CD with 90% sensitivity, 81% specificity and 91% overall accuracy; scores of two or more detected severe lesions (ulcers) with 85% sensitivity, 92% specificity and 94% overall accuracy, the team reports in Gastroenterology, online April 3.

The MARIAs score showed 91% correlation with the original MARIA and 82% correlation with the Crohn's Disease Endoscopic Index of Severity (CDEIS).

The average time required for calculating the global MARIAs was 4.77 minutes, significantly less than the 17.14 minutes required to calculate the original MARIA, a significant difference.

In a prospective independent cohort of 37 patients with active CD who underwent MRI and endoscopy before and after a therapeutic intervention, the MARIAs decreased significantly after the intervention, and the change in global MARIAs showed 75% correlation with changes in global CDEIS.

"The use of MARIAs may help general implementation of objective assessment of CD activity based on a noninvasive examination," the authors conclude.

Dr. Carl A. J. Puylaert of the University of Amsterdam, in the Netherlands, who has studied MRI scoring systems in CD, told Reuters Health by email, "A more simple but equally accurate MARIA index is available, which definitely improves its usability. But it should first be externally validated, especially since the original MARIA has not performed as well in other datasets."

"The most interesting clinical role for the index would be therapeutic evaluation, i.e., the relative value before and after therapy is, I think, more valuable than its absolute value," he said. "The scores should not yet be used as a measure of overall disease activity, as the evaluation of transmural and extramural disease will not be optimal for a score which is developed against an endoscopic reference standard. It is more realistic to see it as a component of a full MRI assessment."

"I think the evaluation of ulcers and fat stranding still requires some training to achieve high reproducibility," Dr. Puylaert said. "It would be best if they publish a supplement with details on definitions and criteria with image examples."

Dr. Ordas did not respond to a request for comments.

SOURCE: https://bit.ly/2UicFi5

Gastroenterology 2019.