In Vivo Quantification of Particle Based & Gene Based MRI Reporters in the Rodent Brain

Janaki Raman Rangarajan¹, Greetje Vande Velde², Caroline Guglielmetti³, Ruth Vreys³, Marleen Verhoye³, Tom Dresselaers², Annemie Van Der Linden³, Uwe Himmelreich², Frederik Maes¹

Iron-oxide based particles or MRI reporter genes (e.g. ferritin) can be used for labeling and visualization of endogenous stem cells in the rodent brain. While the quantification of hypo-intense contrast induced by these MRI reporters using parametric T2-maps is often constrained by their low resolution and are sensitive to B1 inhomogeneity, we have developed an image analysis pipeline for regional quantification from 3D T2*-weighted MRI. We demonstrate its potential for in vivo assessment of both iron-oxide particle based and gene based MRI reporters, which creates new opportunities for large scale in vivo imaging studies, including longitudinal follow-up within the same animal.