Fig. 4
From: Immune cell labelling and tracking: implications for adoptive cell transfer therapies
Cell tracking using MRI with contrast agents and 19F labels. Therapeutic cells (e.g. dendritic cells or stem cells) are labeled using contrast agents (Gd or SPIO), or a 19F label. Conversely, typical anatomical MRI utilizes the 1H from H2O in tissues. Labeled cells are transferred to the patient by localized transfers, including intradermal or intranodal injections; the patient is then imaged to determine cell localization. Gd and SPIO (superparamagnetic iron oxide) labels typically require “before” and “after” images for localization (white arrows), resulting in a final hyperintense or hypointense spot signal, respectively. With a 19F label, imaging can be carried out in a longitudinal manner for 19F (specifically the labeled cells) and 1H (anatomy) without a “before” image. Furthermore, the total 19F signal can be calculated from the in vivo data, providing tracking information for both the localization and number of cells. Such quantitative, unambiguous cell tracking is not possible using standard imaging techniques in conjunction with metal-based contrast agents (Srinivas et al. 2010)