Segmental Magnetic Resonance Index of Activity (MaRIA) score calculator of ileocolonic Crohn’s disease activity (MRI)

Note to first time users: calculating the MaRIA score necessitates multiple, accurate measurements of bowel wall enhancement and signal intensity. If unfamiliar with the MaRIA score please go through the primary publications listed below, and make sure that measurements are carried out on the appropriate sequences. Note that the segmental MaRIA score is not the same as the simplified MARIA score (MARIAs) published in 2019. A calculator for the MARIAs can be found here, and should be used particularly of no intravenous contrast was used.

Notes

The formula

• The MaRIA score is calculated with the following formula:
  • MaRIA = 1.5 * wall thickness + 0.02 * RCE + 5 * edema + 10 * ulceration
• The relative contrast enhancement (RCE) equation:
  • RCE = [(WSI postgadolinium – WSI pregadolinium) / (WSI pregadolinium)] * 100 * (SD noise pregadolinium / SD noise postgadolinium)
    • WSI: wall signal intensity of the bowel wall measured on T1-weighted (e.g. VIBE sequences). Three pre- and postcontrast measurements should be performed, and the ROI should be placed to the same locations on both sequences.
    • SD noise: the average of three SD of the signal intensity measured outside(!) the body before and after gadolinium administration

Practical points

• The cutoff points of the MaRIA score are
  • moderate disease: ≥7
  • severe disease: ≥11
• It has been found that the MaRIA score correlates well with the Crohn’s Disease Endoscopic Index of Severity (CDEIS) score.
  • ^{Rimola J, Ordás I, Rodriguez S, García-Bosch O, Aceituno M, Llach J, Ayuso C, Ricart E, Panés J. Magnetic resonance imaging for evaluation of Crohn’s disease: validation of parameters of severity and quantitative index of activity. Inflamm Bowel Dis. 2011 Aug;17(8):1759-68. doi: 10.1002/ibd.21551. Epub 2010 Nov 8. PMID: 21744431.}

The global MaRIA index

• This calculator can be used to calculate the MaRIA score of a single bowel segment. If the Crohn’s disease activity must be assessed in the entire ileocolonic bowel then a global MaRIA index has to used. This is a tedious task, and requires calculating the segmental MaRIA score in the following six segments:
  • rectum
  • sigmoid
  • descending colon
  • transverse colon
  • ascending colon
  • ileum
• Afterwards the individual scores must be added to calculate the global MaRIA index. For this purpose you can use the calculator on this page to get the global MaRIA index by adding the score of all six segments.
• In the study referenced above the global MaRIA index showed significant correlation with CDEIS (r = 0.78, p < 0.001), Harvey–Bradshaw index (r = 0.56, p < 0.001) and c-reactive protein (CRP) (r = 0.53, p < 0.001).
• A recent review (open access) of MRI-based quantitative assessment techniques of Crohn’s disease activity also provides a good summary of the simplified and global MaRIA indices, and comparable scoring systems:
  • ^{Rozendorn N, Amitai MM, Eliakim RA, Kopylov U, Klang E. A review of magnetic resonance enterography-based indices for quantification of Crohn’s disease inflammation. Therap Adv Gastroenterol. 2018 Apr 13;11:1756284818765956. doi: 10.1177/1756284818765956. PMID: 29686731; PMCID: PMC5900818.}

Last updated: 2021-10-20