Comparison of a New Magnetic Resonance Imaging Protocol and Magnetic Resonance Follow-Through in Patients with Inflammatory Bowel Disease—A Prospective Pilot Study

Objective: Inflammatory bowel disease (IBD) is a chronic disease, consisting of two main subgroups: Crohn’s disease (CD) and ulcerative colitis (UC). Imaging is an essential component in the treatment of IBD and is used repeatedly to determine activity and severity of inflammatory lesions. The aim of our study was to prospectively obtain pilot data on the accuracy of magnetic resonance imaging with no oral contrast (MRI-NOC) and magnetic resonance follow-through (MRFT) using endoscopy as the reference standard. Materials and Methods: Patients diagnosed with CD and UC referred to magnetic resonance imaging (MRI) were included in this study population. For the evaluation, the bowel was divided into 9 segments. Two radiologists, blinded to clinical findings, evaluated bowel wall thickness, diffusion weighted imaging and mural hyperenhancement. Results: 14 patients (9 males and 5 females;median age 41;range 20 - 62) underwent both type of MRI examinations;9 had CD and 5 had UC. The overall sensitivity for small bowel was zero for both MRI protocols, as neither identified any lesions, whereas in colon the sensitivity ranged from 7% to 29% in MRI-NOC and 14% - 29% in MRFT. Specificity and accuracy in MRI-NOC ranged from 78% to 98% and 74% - 93%, respectively, in small bowel, and from 90% to 96% and 77% - 82%, respectively, in colon. Specificity and accuracy in MRFT ranged from 83% to 100% and 79% - 95%, respectively, in small bowel, while it ranged from 93% to 97% and 81% - 85%, respectively, in colon. Conclusion: The location of lesions in the colon combined with the lack of oral contrast in the colon renders MRFT and MRI-NOC functionally identical.

MRI of the Bladder in Patients Suspected of Bladder Tumors

Objective: To prospectively evaluate the use of MRI for the detecting of bladder tumors and the T- stage using T2W, T1W and diffusion-weighted images (DWI). Material and methods: Twenty-eight consecutive patients (21 men, 7 women;age range, 20 - 82 years;mean age, 62.8 years) suspected of bladder tumors underwent MRI, flexible cystoscopy and transurethral resection (TURB). The presence of bladder tumor was confirmed by histopathology in 21 patients;18 patients had pTa, one pT1 and two pT2. The images were reviewed by two uroradiologists. They assigned the presence of a bladder tumor and whether the tumor was non-muscle invasive (Ta and T1) or muscle- invasive (T2, T3 or T4). Results: Compared to the histopathological results, the accuracy for identifying a bladder tumor was 60.7% and 53.7% for reviewer A and B, respectively. The sensitivity and specificity were 66.7%/61.9% and 57.1%/42.9%. Positive predictive values were 82.6%/ 76.5%. The overall staging was correct in 47.6%/52.5%, but improved on stage-by-stage up to 50%/66.7%. The agreement between the reviewers was moderate in the detecting, staging and location of the tumor (Kappa = 0.47 - 0.57). Conclusion: A simple MRI using no contrast media, but DWI, cannot replace flexible cystoscopy in the detection of new or recurrent bladder tumors.