Open AccessIn Vivo19F MR Imaging Cell Tracking of Inflammatory Macrophages and Site-specific Development of Colitis-associated Dysplasia
Author(s) -
Soo Hyun Shin,
Deepak K. Kadayakkara,
Jeff W.M. Bulte
Publication year - 2017
Publication title -
radiology
Language(s) - English
Resource type - Journals
eISSN - 1527-1315
pISSN - 0033-8419
DOI - 10.1148/radiol.2016152387
Subject(s) - medicine , colitis , in vivo , azoxymethane , dysplasia , ex vivo , ulcerative colitis , inflammatory bowel disease , descending colon , magnetic resonance imaging , pathology , ascending colon , inflammation , gastroenterology , colorectal cancer , radiology , rectum , cancer , biology , microbiology and biotechnology , disease
Purpose To investigate whether the magnitude of in vivo fluorine 19 ( 19 F) magnetic resonance (MR) imaging signal is associated with subsequent development of colitis-associated dysplasia after in situ fluorination of inflammatory macrophages in a mouse model of inflammatory bowel disease (IBD). Materials and Methods Experiments were approved by the institutional animal care and use committee. Mice in the experimental group (n = 10) were administered azoxymethane and dextran sulfate sodium to induce colitis-associated dysplasia. Five mice were in the noninduced control group. Animals were injected with a commercially available perfluorocarbon and were examined in vivo with an 11.7-T MR imager for up to 110 days. Colons were then harvested followed by high-spatial-resolution ex vivo MR imaging. Multiple colon segments with or without 19 F signal were histologically graded and were correlated with 19 F signal intensity by using a Spearman correlation test. The signal intensity in mice with colitis-associated dysplasia was compared with that in control mice with a two-tailed Mann-Whitney U test. Results Patchy distributions of 19 F signal intensity in the colon wall were seen on in vivo and ex vivo images, representing chronic inflammation as shown by immunohistochemistry. Histologic scores of inflammation and site-specific development of colitis-associated dysplasia in the descending colon showed good correlation with normalized 19 F signal intensity (r = 0.88, P = .033 for the ascending colon; r = 0.82, P = .006 for the descending colon). A significantly (P = .002) higher normalized 19 F signal-to-noise ratio was found at sites that developed dysplasia (mean, 0.58 ± 0.09 [standard deviation]) as compared with sites that did not (mean, 0.17 ± 0.22). Conclusion 19 F MR imaging cell tracking of macrophages can be used to assess local inflammation in a mouse model of IBD. The resulting local 19 F signal intensity, representing the magnitude of inflammation, has a positive correlation with the development of colitis-associated dysplasia. © RSNA, 2016 Online supplemental material is available for this article.