Table of Contents
International Journal of Molecular Imaging
Volume 2015, Article ID 507909, 8 pages
http://dx.doi.org/10.1155/2015/507909
Research Article

Nanoparticle Enhanced MRI Scanning to Detect Cellular Inflammation in Experimental Chronic Renal Allograft Rejection

1Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh EH16 4TJ, UK
2MRC Centre for Inflammation Research, The University of Edinburgh, Edinburgh EH16 4TJ, UK
3Clinical Research Imaging Centre, University of Edinburgh, Edinburgh EH16 4TJ, UK
4Edinburgh Preclinical Imaging, University/BHF Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh EH16 4TJ, UK
5The Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh EH16 4TJ, UK

Received 7 December 2014; Revised 12 March 2015; Accepted 12 March 2015

Academic Editor: Adriaan A. Lammertsma

Copyright © 2015 S. R. Alam et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Objectives. We investigated whether ultrasmall paramagnetic particles of iron oxide- (USPIO-) enhanced magnetic resonance imaging (MRI) can detect experimental chronic allograft damage in a murine renal allograft model. Materials and Methods. Two cohorts of mice underwent renal transplantation with either a syngeneic isograft or allograft kidney. MRI scanning was performed prior to and 48 hours after USPIO infusion using -weighted protocols. values were calculated to indicate the degree of USPIO uptake. Native kidneys and skeletal muscle were imaged as reference tissues and renal explants analysed by histology and electron microscopy. Results. values in the allograft group were higher compared to the isograft group when indexed to native kidney (median 1.24 (interquartile range: 1.12 to 1.36) versus 0.96 (0.92 to 1.04), ). values were also higher in the allograft transplant when indexed to skeletal muscle (6.24 (5.63 to 13.51)) compared to native kidney (2.91 (1.11 to 6.46) ). Increased signal in kidney allograft was associated with macrophage and iron staining on histology. USPIO were identified within tissue resident macrophages on electron microscopy. Conclusion. USPIO-enhanced MRI identifies macrophage.