Manganese in PET imaging: Opportunities and challenges

Several radionuclides of the transition metal manganese are known and accessible. Three of them, ⁵¹ Mn, ^52m Mn, and ^52g Mn, are positron emitters that are potentially interesting for positron emission tomography (PET) applications and, thus, have caught the interest of the radiochemical/radiopharmaceutical and nuclear medicine communities. This mini-review provides an overview of the production routes and physical properties of these radionuclides. For medical imaging, the focus is on the longer-living ^52g Mn and its application for the radiolabelling of molecules and other entities exhibiting long biological half-lives, the imaging of manganese-dependent biological processes, and the development of bimodal PET/magnetic resonance imaging (MRI) probes in combination with paramagnetic ^nat Mn as a contrast agent.