Mapping of T1-values and Gadolinium-concentrations in MRI as indicator of disease activity in luminal Crohn's disease: A feasibility study.

Purpose To determine the feasibility of T1-mapping and calculation of Gadolinium-values in luminal Crohn's Disease (CD). Materials and Methods Nine patients with active CD were included. For each patient disease activity was determined, based on endoscopic and histopathological results. The Crohn's Disease Endoscopic Index of Severity (CDEIS), the Harvey-Bradshaw index (HBI) and C-reactive protein (CRP) were also determined as reference standards. T1-measurements were performed before and after intravenous administration of Gadodiamide in 14 slices in a single breath-hold using the Look-Locker (LL) sequence in combination with a segmented three-dimensional Turbo Field Echo sequence. A Region of Interest (ROI) was drawn around inflamed bowel loops and the mean Gadolinium-concentration within the ROI was calculated. Gadolinium-concentrations were compared between patients with mild and marked disease, as determined by the reference standards. Results Mean Gadolinium-concentrations were higher in bowel loops of patients with more active disease, as defined by endoscopic and histopathological examination, CRP, and HBI. Conclusion By using a breath-hold LL sequence in the bowel quantitative assessment of contrast agent concentration is possible, thus permitting objective evaluation of physiological changes in actively inflamed tissue in an area that suffers from motion problems. J. Magn. Reson. Imaging 2009;29:488-493. © 2009 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]