MRI of the small bowel and colon in determining disease activity in patients with Crohn*s disease

Crohn*s disease (CD) is a transmural granulomatous inflammatory bowel disease
characterized by aphthous ulceration, cobblestoning, strictures and fistula
formation, which can affect any part of the gastrointestinal tract. However,
locations of predilection are the terminal ileum and colon. The disease
typically runs a chronic relapsing and remitting course and is associated with
prominent extra-intestinal manifestations and an increased incidence of
gastrointestinal cancer.
Grading of disease severity is important to be able to optimally determine
treatment strategy and response to treatment. In clinical practice, assessment
of activity can be performed by the Crohn*s Disease Activity Index (CDAI) or
the Harvey Bradshaw index, laboratory inflammation markers as C-reactive
protein, and/or endoscopy (scored in Crohn*s Disease Endoscopic Index of
Severity (CDEIS) and in case of ileal resection also scored in Rutgeerts*
score).
Ideally, an activity score should be objective, reproducible, quantifiable and
non-invasive. However, to none of the abovementioned methods all four criteria
are applicable; the CDAI or Harvey Bradshaw index is a clinical index that
incorporates subjective elements and therefore partly reflects patients*
perception of disease severity and laboratory findings can be unchanged in the
presence of altered disease activity. Endoscopy is an invasive procedure with a
burdensome bowel preparation. Moreover, none of the abovementioned methods
allows precise transmural and extra intestinal evaluation of disease.
Abdominal MR-imaging using luminal and intravenous contrast medium combines
transmural and extra-intestinal evaluation and can accurately show presence of
disease (e.g. stenosis, bowel wall thickening, abscess, fistula). Moreover, MRI
can discriminate between active and fibrotic disease as MRI studies undertaken
to determine Crohn*s disease activity in the small and large bowel have
indicated that a pathological increase in bowel wall enhancement after
intravenous contrast administration of Gadolinium is a useful discriminatory
sign of active disease.
Many studies have confirmed the role of MRI in the evaluation of CD, in the
detection of small bowel lesions and complications and the assessment of
disease activity. Available evidence indicates that MRI can be useful too for
the detection of activity and assessment of severity in colonic CD, but have
been investigated less extensively. Detection of extracolonic complications and
information regarding the whole abdominal cavity are the main strengths of this
technique and might obviate colonoscopy

The evaluation of MRI in Crohn*s disease is initially performed by
radiologists, which leaves room to variation in interpretation. An objective
method to grade disease activity would be important for patient management as
well for pharmaceutical studies. Therefore, the data acquired during this study
of consenting patients will also be used for the development and validation of
ICT tools to do so.

To study MRI of the small bowel and colon in determining disease activity in
patients with Crohn*s disease.

A prospective observational study that evaluates the accuracy of additional MRI
of the colon in patients with Crohn*s disease undergoing MRI of the small
bowel.

Patients will undergo an ileocolonoscopy, venapuncture and MRI scan as part of
their clinical follow-up. For this study, three additional sequences will be
made during the MRI scan, which causes 15 minutes of extra scan time. Also,
patients have to fill in a questionnaire, the Harvey Bradshaw index which will
take two minutes to complete.
No side-effects or risks have been reported on MR imaging, some patients may
experience claustrophobia.