title: Feasibility of MRI in experimentally induced inflammatory small bowel disease: a pilot study in a porcine model.
abstract: The purpose of this study was to compare the macroscopic and microscopic findings of experimentally induced inflammatory lesions in jejunum and ileum with magnetic resonance imaging (MRI) findings. Inflammatory small bowel lesions were experimentally induced in six pigs. Bowel segments in jejunum and ileum were isolated, and a solution with trinitrobenzenesulfonic acid and ethanol (TNBS-EtOH) was installed. MRI of the small bowel was performed 7 days after surgery. Before the MRI examination, a 6% mannitol solution was installed through a nasogastric tube. The MRI protocol consisted of single-shot turbo spin echo T2 sequences, steady state free precession (BFFE) sequences, and a 3D T1 gradient echo sequence with fat saturation and intravenous contrast. The following image findings were evaluated: increased bowel wall thickness (BWT), increased bowel wall enhancement (BWE), and bowel stenosis. After the MRI examination, the animals were sacrificed. The small bowel was removed and examined macroscopically and microscopically. Inflammatory lesions developed in jejunum and ileum in all animals. The lesions were visible macroscopically and microscopically. The microscopic findings consisted of variable degrees of inflammation, ulcer formation, and fibrosis. In jejunum the inflammatory lesions were not diagnosed with MRI, except in one pig with a bowel necrosis probably caused by an intramural injection or leakage of the TNBS-EtOH solution. In ileum the bowel wall thickness was increased and the inflammatory lesions were diagnosed with MRI. In conclusion, the inflammatory lesions were visible macroscopically and microscopically. Lesions in ileum had increased BWT and were possible to image with MRI. Lesions in jejunum had normal BWT and were not diagnosed with MRI, except in one pig with increased BWT probably caused by complications to the installation of TNBS-EtOH.
authors.affiliation: Department of Radiology, Akershus University Hospital, Sykehusveien 25, 1478 Lørenskog, Norway. anne.negard@medisin.uio.no
authors.forename: Anne
authors.initials: A
authors.lastname: Negaard
authors.forename: Else Marit
authors.initials: EM
authors.lastname: Loberg
authors.forename: Paal Aksel
authors.initials: PA
authors.lastname: Naess
authors.forename: Morten
authors.initials: M
authors.lastname: Eriksen
authors.forename: Nils-Einar
authors.initials: NE
authors.lastname: Klow
mesh_terms: D000818:Animals; D005240:Feasibility Studies; D007082:Ileum / Q000473:pathology*; D015212:Inflammatory Bowel Diseases / Q000175:diagnosis* / Q000473:pathology; D007583:Jejunum / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D013552:Swine