In vivo PET/MRI Imaging of the Chorioallantoic Membrane

The Hen's Egg Test Chorioallantoic-Membrane (HET-CAM) of fertilized chick eggs represents a unique model for biomedical research. With its steadily increasing use, non-invasive in ovo imaging for longitudinal direct quantification of the biodistribution of compounds or monitoring of surrogate markers has been introduced. The full range of imaging methods have been applied to the HET-CAM model. From the current perspective, Magnetic Resonance Imaging (MRI), providing detailed anatomical and functional data, and Positron Emission Tomography (PET), providing excellent sensitivity, must be considered the most promising candidates for HET-CAM imaging. Especially by combining both techniques, the required sensitivity and anatomical localization of the signal source renders feasible. In the following a review of recent applications of MRI and PET for in ovo imaging with a special focus on techniques for imaging xenotransplanted tumors on the CAM will be provided.