title: Magnetic resonance enterography for the evaluation of the deep small intestine in Crohn's disease.
abstract: For the control of Crohn's disease (CD) a thorough assessment of the small intestine is essential; several modalities may be utilized, with cross-sectional imaging being important. Magnetic resonance (MR) enterography, i.e., MRE is recommended as a modality with the highest accuracy for CD lesions. MRE and MR enteroclysis are the two methods performed following distension of the small intestine. MRE has sensitivity and specificity comparable to computed tomography enterography (CTE); although images obtained using MRE are less clear compared with CTE, MRE does not expose the patient to radiation and is superior for soft-tissue contrast. Furthermore, it can assess not only static but also dynamic and functional imaging and reveals signs of CD, such as abscess, comb sign, fat edema, fistula, lymph node enhancement, less motility, mucosal lesions, stricture, and wall enhancement. Several indices of inflammatory changes and intestinal damage have been proposed for objective evaluation. Recently, diffusion-weighted imaging has been proposed, which does not need bowel preparation and contrast enhancement. Comprehension of the characteristics of MRE and other modalities is important for better management of CD.
authors.affiliation: Department of Gastroenterology and Hepatology, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Ohtsuka
authors.affiliation: Department of Gastroenterology and Hepatology, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Kento
authors.initials: K
authors.lastname: Takenaka
authors.affiliation: Department of Radiology, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Kitazume
authors.affiliation: Department of Gastroenterology and Hepatology, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Toshimitsu
authors.initials: T
authors.lastname: Fujii
authors.affiliation: Department of Gastroenterology and Hepatology, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Katsuyoshi
authors.initials: K
authors.lastname: Matsuoka
authors.affiliation: Department of Gastroenterology and Hepatology, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Maiko
authors.initials: M
authors.lastname: Kimura
authors.affiliation: Department of Gastroenterology and Hepatology, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Nagaishi
authors.affiliation: Department of Gastroenterology and Hepatology, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Mamoru
authors.initials: M
authors.lastname: Watanabe
keywords: Balloon-assisted enteroscopy; Capsule endoscopy; Computed tomography enterography; Diffusion magnetic resonance imaging; Magnetic resonance enterography