Imaging of Strictures in Crohn's Disease.

Crohn's disease (CD) is a chronic inflammation of the digestive tract, and it frequently affects young patients. It can involve any intestinal segment, even though it frequently affects the distal ileum. Up to 80% of patients with CD present with inflammatory behavior, and 5% to 28% develop stricturing disease. Based on the predominant mechanism causing them, strictures can be categorized as inflammatory, fibrotic, or mixed. Determining the relative amounts of inflammation and fibrosis in a stricture can influence treatment decisions. Imaging is an extremely useful tool in patients with small bowel stricturing CD to confirm the diagnosis and to evaluate disease characteristics, usually using CT or MRI. The aim of this paper is to describe how imaging can evaluate a patient with small bowel CD stricture.

CT and MRI Evaluations in Crohn's Complications: A Guide for the Radiologist.

Inflammatory bowel diseases (IBD) are a group of chronic inflammatory intestinal conditions with unknown etiology. Crohn's disease (CD) and ulcerative colitis (UC) are the two main types of IBD and they have some interchangeable and some different clinical and pathological characteristics. When diagnosis is performed for the first time, the majority of CD patients have a predominant inflammatory condition. As the disease progresses most patients experience the development of complications, such as abscesses, fistulas, perforation, strictures, and others. Both computed tomography (CT) and Magnetic Resonance Imaging (MRI) allow great view of the whole length of the intestinal tract together with the eventual extra-and intra-intestinal complications. MR enterography (MRE) and CT enterography (CTE), performed after oral administrations of contrast medium, have similar diagnostic accuracy for the diagnosis of CD and its complications. Even though CT is still the most familiar diagnostic technique used for studying CD worldwide, MRE have several important benefits that are leading to rapid increase in its employment in the last years. In particular, MRE allows a superior soft tissue contrast resolution compared to CT, offering a better visualization of bowel wall and its inflammatory and fibrotic characteristics. Moreover, Pelvic Magnetic Resonance is the principal technique in patients with perianal disease due to its ability of providing precise and fine detail images of the sphincter complex, which are crucial for evaluating pelvic disease. In this paper we describe common and uncommon complications in patients with CD, and explain how to identify their findings in CT and MR exams.

A review of Magnetic Resonance Enterography classification and quantitative evaluation of active disease in patients with Crohn's disease.

Crohn's disease (CD) is a chronic inflammation of the gastro-intestinal system in which episodes of clinical worsening alternate with episodes of clinical regression. Monitoring of disease is mandatory to evaluate the efficacy of therapy and it is usually performed using a combination of clinical symptoms, laboratory tests, endoscopy and radiological exams, such as MR enterography or CT enterography. MR enterography should be preferred to CT enterography because of the absence of ionizing radiation, a very high soft tissue contrast, and a lower incidence of adverse events. In 2003, Maglinte introduced a radiological classification to identify patients in different stages of disease (active inflammatory, fibrostenotic and fistulising/perforating subtypes), based on following parameters: oedema, ulcers, stenosis, mural thickening, stratified contrast enhancement, engorged vasa recta, fistulae/abscess and mesenteric inflammation. In general, medical therapy is efficient in reducing inflammation while fibrotic disease and fistulising subtypes usually require surgery. Moreover, in patients with active CD it is important to quantify disease activity in order to adequately plan therapy and to monitor drug effects, by using some MR enterography indexes such as MaRIA score, Clermont index, and others. In this review we describe how to apply Maglinte's classification in MR enterography exams and how to quantify active disease.