John Libbey Eurotext

Hépato-Gastro & Oncologie Digestive

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What is the value of diffusion-weighted MRI in inflammatory bowel diseases? Volume 23, issue 9, Novembre 2016

Figures

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  • Figure 2

Tables

Authors
1 Hôpital universitaire de Nancy,
service d’hépato-gastroentérologie,
1, Allée de Morvan, 54511 Vandoeuvre-lès-Nancy,
France
2 Hôpital universitaire de Nancy,
service de radiologie, 1, Allée de Morvan,
54511 Vandoeuvre-lès-Nancy, France
* Tirés à part

Diffusion-Weighted Magnetic Resonance Imaging (DW-MRI) has been applied recently in Inflammatory Bowel Diseases (IBD). This is a sequence capable of differentiating tissue based on the ease of extra cellular water molecules to diffuse into biological environments.

The interpretation of the sequence is double with a quantitative analysis that studies the hyperintensity of diffusion and a qualitative analysis that calculates the apparent diffusion coefficient (ADC). However, ADC measurements have no value in IBD to characterize hyperintense lesions due to the lack of standardization of technique, lack of universal value of ADC for a normal small bowel or colonic wall and very large standard deviations.

In Crohn's disease, magnetic resonance enterography is the gold standard to map the bowel damage, to seek extra-luminal complications and to detect post-surgical recurrence. The value of DW imaging is to detect with accuracy the mucosal inflammation and perianal fistulas. Its place remains undefined for the diagnosis of abscess, enteric fistulas and fibrosis. It can be used as an alternative to gadolinium-chelate enhanced dynamic MR sequence for patients with chronic renal impairment.

In ulcerative colitis, endoscopy stays the reference to define activity and severity of the disease. Magnetic resonance colonography without oral or rectal preparation and without fasting is an alternative. DW imaging is sensitive to assess inflammation and changes of colonic mucosa using Nancy score.

DW-MRI is a promising technique for which MRI scores are being developed to better assess inflammation and quantify IBD activity in a reproducible way. Further studies are still required to predict and to assess response to treatments. DW-MRI would monitor and optimize treatments to achieve mucosal healing.