The Magnetic Resonance Index of Activity (MaRIA) can be used to determine the activity of Crohn's disease. The authors are from the Centro de Investigacio´n Biome´dica en Red de Enfermedades Hepa´ticas y Digestivas (CIBEREHD) in Barcelona, Spain.
Exam: magnetic resonance enterography
Segments (6): distal ileum, ascending colon, transverse colon, descending colon; sigmoid colon, rectum
Parameters:
(1) wall thickness in mm
(2) relative contrast enhancement (RCE)
(3) edema
(4) ulcers
RCE =
= ((wall signal intensity postgandolinium) - (wall signal intensity pregandolinium)) / (wall signal intensity pregandolinium) * 100 * ((standard deviation of noise pregandolinium) / (standard deviation for noise postgandolinium))
Parameter
Finding
Points
edema
absent
0
present
5
ulcers
absent
0
present
10
score for a segment =
= (1.5 * (wall thickness)) + (0.02 * (relative contrast enhancement)) + (points for edema) + (points for ulcer)
global score =
= SUM(scores for all 6 segments)
Interpretation:
• A segment score >= 11 indicates severe disease.
• A segment score >= 7 indicates active disease.
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