Combination of MR Cell Size Imaging and Magnetization Transfer Imaging to Predict Intestinal Disease Progression in Crohn’s Disease

Motivation: Intestinal fibrosis assessment by simultaneously characterizing mesenchymal cells and extracellular collagen may help predict disease progression in patients with Crohn's disease (CD). Goal(s): To evaluate the efficacy of time-dependent diffusion MRI (TD-dMRI) in characterizing cellular properties, and combine it with magnetization transfer (MT)-MRI to depict intestinal fibrosis and predict disease progression. Approach: 124 CD patients (31 received surgery) were prospectively enrolled and underwent TD-dMRI to map fibrotic microstructures and MT-MRI to quantify collagen levels. 93 nonsurgical patients were followed up. Results: TD-dMRI-derived cell diameter (d) was highly correlated with myofibroblasts/fibroblasts-area-ratio (r=0.58; P<0.001). d was significant risk factor for disease progression (HR: 1.2; P=0.001). Impact: TD-dMRI-derived d effectively characterizes fibrosis-associated cellular microstructures in patients with CD, and combined with normalized MT ratio enables a comprehensive assessment of intestinal fibrosis and thus accurate prediction of disease progression.