In Vivo Assessment of the Number of Iron-Labeled Cells Using T2 Quantification

Jean-Christophe Brisset^1,2, Virginie Desestret^1,2, Sebastien Marcellino^1,3, Emilie Devillard^1,4, Fabien Chauveau^1,2, Florence Lagarde^1,3, Serge Nataf^1,4, Norbert Nighoghossian^1,2, Yves Berthezene^1,2, Marlene Wiart^1,2

The purpose of our study was to test the hypothesis that T2 quantification could be used in vivo to estimate the number of iron-labeled cells into the brain. Macrophages were incubated in the presence of Ferumoxtran-10 or anionic nanoparticles AMNP and stereotaxically injected in the striatum of mice. MRI was performed at 7T using multi-slice multi-echo imaging for T2 quantification. There was an overall fair agreement between the number of injected cells and the number of cells estimated from T2 measurements. Further studies are needed to assess the potential of this approach to estimate small number of cells.