Figure 2.

a) Schematic illustration of chelator-based radiolabeling of IONPs with 89Zr using DFO as a chelator. Reproduced with permission from Ref. [22]. Copyright 2014, Nature Publishing Group. b) Schematic illustration of the chelator-free synthesis of *As (or 69Ge)-SPIONs. TEM images of SPIONs c) before and d) after transferring them into hydrophilic solutions. e) In vivo lymph node PET imaging with *As-SPION and T2-MRI with SPIONs. Reproduced with permission from Ref. [20]. Copyright 2013, Wiley-VCH.