Evaluation of dynamic MRI with T1-maps correlated with histopathology in patients with Crohn's Disease

Crohn*s disease (CD) is a transmural granulomatous inflammatory bowel disease,
characterized by remissions and exacerbations. Grading of severity of disease
is important to be able to optimally determine treatment strategy and response
to treatment. At present there is no satisfying gold standard for active
Crohn*s disease. Abdominal MR-imaging using luminal and intravenous contrast
medium combines transmural and extra-intestinal evaluation and can accurately
show presence of disease. Moreover, MRI can discriminate between active and
fibrotic disease as MRI studies undertaken to determine CD 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.
Hypothetically, calculation of the absolute T1-values in tissue before and
after intravenous injection of Gadolinium would provide objective measurements
of the Gadolinium-uptake. This so-called T1-mapping in abdominal MRI could
indeed be used to determine activity of disease in an objective, quantifiable,
reproducible manner and could be a valuable tool to the present imperfect
disease scores such as CDAI (Crohn*s Disease Activity Index) and CRP. Thereby,
conventional MRI has limitations in establishing remission or limited disease
activity, and dynamic MRI with T1-mapping and diffusion weighted imaging (DWI)
might be valuable to identify these entities. Our hypothesis is that
restriction of diffusion can be seen in inflamed tissue that could be an aid in
diagnosing disease activity.

To determine the correlation between enhancement curves at DCE-MRI with T1-map
and DWI and the level of histopathological activity.

Prospective observational study. Patients will undergo a venapuncture and MRI
scan as part of clinical routine before surgery. For this study, a dynamic
sequence (DCE-MRI) with T1-map and DWI sequence will be made during the MRI
scan; therefore the scanning time will be prolonged for 15 minutes. Total
scanning time will be 50 minutes. Also, patients have to fill in 1
questionnaire, the CDAI (duration less than 5 minutes). ). For anatomical
reference, the resected bowel will also be scanned in the MRI. The inclusion
period of the study will be 2 years.

Patients will undergo MRI scan as part of their clinical pre-operative
assessment. For this study, an additional dynamic sequence with T1-mapping
sequence and DWI sequence will be made during the MRI scan and patients have to
fill in 1 questionnaire, the CDAI. The MRI scan will last 50 minutes, including
15 minutes additional scanning for research purposes. No side-effects or risks
have been reported on MR imaging provided that contra-indications are taken
into account. Some patients may experience claustrophobia.