Semi-Quantification of LipoCEST CA in vivo. Application to Molecular Imaging of ανβ3 Integrins Expressed During Angiogenesis Using Targeted LipoCEST CA in a Tumor Mouse Brain Model

Julien Flament¹, Franoise Geffroy¹, Christelle Mdina², Caroline Robic², Philippe Robert², Marc Port², Gilles Bloch¹, Denis Le Bihan¹, Franck Lethimonnier¹

LipoCEST are promising contrast agents for molecular imaging which can be functionalized to target specific biomarkers. Although in vivo detection is complicated by to endogenous MT effects, several studies have already shown feasibility. Still, quantification remains very challenging. Here, we used a 4-pools model which takes into account both endogenous and exogenous MTRasym effects as well as field inhomogeneities in order to establish in vivo quantitative maps. This model was evaluated in a tumor mouse brain model with a functionalized RGD-lipoCEST which targets α _ν β ₃ integrins expressed during tumor angiogenesis.